sci.electronics.repair@googlegroups.com

Google Groups

"Ron D." <Ron.Dozier@gmail.com>: Jul 30 09:32PM -0700 Audio load: http://www.mcmelectronics.com/product/28-048 (No mention of tolerance)   Done.   Scopes have a lot of errors. A DVM may work, but pay attention to frequency response. If you stick to a sine wave you won't need a TRMS meter.   Next problem, you need to know the resistor value accurately.   I don't think you want or need want 0.001% accuracy.

Phil Allison <pallison49@gmail.com>: Jul 31 02:14AM -0700 Ron D. wrote:   > Audio load: http://www.mcmelectronics.com/product/28-048 > (No mention of tolerance)     ** I use the same resistors for all amplifier bench testing.   Submerged in water, they can handle 1000W each.   Using a pair and a simple switching scheme gives 4, 8 and 16 ohms.   > Scopes have a lot of errors.   ** That's a a bit harsh. Many analogue scopes manage 2% accuracy for time and amplitude & modern DSOs have on-screen displays of the same parameters with better than 1% accuracy.   > A DVM may work, but pay attention to frequency response.     ** Most can be trusted to about 1kHz on sine waves.     .... Phil

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Jul 31 08:17PM +1000 On 31/07/2015 2:32 PM, Ron D. wrote:   > Scopes have a lot of errors. A DVM may work, but pay attention to > frequency response. If you stick to a sine wave you won't need a > TRMS meter.   **Digital 'scopes often have true RMS display capability, with excellent accuracy.     > Next problem, you need to know the resistor value accurately.   > I don't think you want or need want 0.001% accuracy.   **Far and away the biggest source of inaccuracy lies with line Voltage regulation. Or lack of it. I would certainly not panic about resistor accuracy nor 'scope accuracy, when faced with typical line Voltage swings. Naturally, most professionals use a variable auto transformer (aka: Variac™) and a line Voltage monitor.     -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

"pfjw@aol.com" <pfjw@aol.com>: Jul 31 07:00AM -0700 On Monday, July 27, 2015 at 6:09:33 PM UTC-4, Ralph Mowery wrote:   > You can probably go at least 5 and maybe 10 times the power on the load > resistor if you put it in some water or oil. Many times that if you have > liquid nitrogen.   NO!!!!   Most metallic conductors are Zero-Resistance at cryogenic temperatures. So, a wire-wound resistor may drop off to near-zero in liquid nitrogen.

"Ralph Mowery" <rmowery28146@earthlink.net>: Jul 31 11:05AM -0400 <pfjw@aol.com> wrote in message news:ab86ef38-7eac-4270-93f0-017fbea84a34@googlegroups.com...   > NO!!!!   > Most metallic conductors are Zero-Resistance at cryogenic temperatures. > So, a wire-wound resistor may drop off to near-zero in liquid nitrogen.   The liquid nitrogen was mainly a joke to the extreme of cooling. However if enough power is being used, the resistor its self would be heated to a more normal temperture and would be way above the temperature of the nitrogen. This woudl bring the resistance back up.

MJC <gravity@mjcoon.plus.com>: Jul 31 04:42PM +0100 In article <ab86ef38-7eac-4270-93f0-017fbea84a34@googlegroups.com>, pfjw@aol.com says...   > Most metallic conductors are Zero-Resistance at cryogenic temperatures. > So, a wire-wound resistor may drop off to near-zero in liquid nitrogen.   If only superconductors for liquid N2 temperatures (77K, -196C) were so common! Even at liquid He (4.22K, -270C) only a minority of metals make the transition.   My Kaye and Laby says: "At low temperatures the effects of impurities etc become increasingly important and these largely determine the value of the residual resistance to which many metals decrease at low temperature."   Mike.

M Philbrook <jamie_ka1lpa@charter.net>: Jul 30 02:41PM -0400 In article <d821f37c-370c-4030-b5b9-557793c313bc@googlegroups.com>, pyroartist.dw@gmail.com says...   > > > Dean   > > Do you do TIG/MIG welding in this garage?   > No. I don't own a TIG/MIG welder.   You need a non inductive load on the same circuit, along with a capacitor across it..   Your motor windings are getting killed by the drop out of the TRIAC at each phase angle. You need to suppress it somehow so that both the HV pulse that shouldn't be there and lack of lower Z at the base of the sine wave, for the motor and cap of the motor to properly operate..   These are cheap motors and they run warm to start with, minimum copper and coating on the wire is used.   Try getting your hands on a motor run capacitor, somewhere around 3..5uf at the proper rated voltage and put that across the load side of your SSR.   ALso, putting a non-inductive load on the output helps, too... If you can get a low wattage incandescient bulb that would be fine or maybe a 5 watt R at around 400 ohms or so across the SSR load, along with the run cap.   Also, I suspect when you connect these components, you'll also hear a slight difference of motor noise, which indicates this issue..   SSR switches don't always have a proper snubber in them, so you may also want to use a 100R and .1 Cap in series around the SSR, back to the soure so that the load will cycle back to the line on spikes.   Have a good day Jamie

avagadro7@gmail.com: Jul 30 04:48PM -0700 diode the relay   use the resistor   use 2 Tyco/Bosch mechanical relays with diodes for relays and inputs

avagadro7@gmail.com: Jul 30 04:51PM -0700 On Wednesday, July 29, 2015 at 1:27:35 PM UTC-4, Pat wrote: > eventually open. Unfortunately, I can't think of any way to explain > why that would happen.   > Pat   the thermometer rapidly operates relay on and off circuitry passing something of this to the fans who are confused square one without dioding separating the systems unbalanced properties.

avagadro7@gmail.com: Jul 30 05:01PM -0700 AC relay with a triac-output optoisolator, with a smallish capacitor shunting > the input terminals (1 uF?), there ought to be no drive-side problems.   ///////////   they're mating   http://goo.gl/Dj00S9

David Lesher <wb8foz@panix.com>: Jul 31 02:55AM > The motor still spins easily. There is no DC continuity from the power p= >lug but I beleive this is normal for induction motors? Perhaps the overheat= > sensor has opened permenently.   You got it. As they age the bearing dry and they pull more current. Eventually they open the Microtemp protecter within....   -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433

Phil Allison <pallison49@gmail.com>: Jul 30 08:25PM -0700 David Lesher wrote:   > > sensor has opened permenently.   > You got it. As they age the bearing dry and they pull more current. > Eventually they open the Microtemp protecter within....   ** "The motor still spins easily" contradicts that idea.   Seen a few cheap Chinese fans with tight/stuck bearings - takes a fair bit of solvent to get them spinning again.   The OP has no so far bothered to open a fan a check the motor wiring for continuity.   ... Phil

"Ron D." <Ron.Dozier@gmail.com>: Jul 30 09:42PM -0700 Deane:   What relay are you using? What is the the motor?   Some SSR bricks designed for this purpose have 3-32 V for an input and no series resistor is required. A heat sink with the appropriate thermal grease is. They have to be triac or back to back SCR's.   Some offer to switch at zero current. It should be random.   Some require series resistors.   Some SSR's are triacs, dual SCR's, SCR's (won;t work) or MOSFETS (won;t work).

kenny.sourcing@gmail.com: Jul 30 10:55PM -0700 On Tuesday, July 28, 2015 at 10:06:47 AM UTC+8, Deane Williams wrote: > Does anyone know of a reason why I can't run an induction motor from a SS relay? What is killing the fans? I have taken two apart and there is no smoke smell, no visible damage and if there is a capacitor it tests OK. > Thanks for any ideas. I am going to switch over to a mechanical relay.   > Dean   If you need the thermal fuse, please feel free to contact xx.liu@setfuse.com. We are thermal fuse, MOV and thermal protected MOV manufacturer in China.   Any question, please do not hesitate to inform us.   Best Regards Leo

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

sci.electronics.repair@googlegroups.com

Google Groups

"Ian Field" <gangprobing.alien@ntlworld.com>: Jul 29 06:36PM +0100 "Dave Platt" <dplatt@coop.radagast.org> wrote in message news:fuil8c-cpd.ln1@coop.radagast.org...   > Could it be that the charging circuit is a buck regulator? The feed > from the wall wart could be "higher voltage, lower current", which > would result in lower losses the wire.   There is an SMD inductor on the PCB, so that's very likely.   But I was a bit surprised that they step down from as much as 25V.   If the battery runs flat, I can't plug the charger in and carry on shaving. IMO: if they'd used a charging voltage closer to that of the cell, it would have been trivial to make the shaver capable of operating while charging.

"Ian Field" <gangprobing.alien@ntlworld.com>: Jul 30 05:38PM +0100 "Dave Platt" <dplatt@coop.radagast.org> wrote in message news:fuil8c-cpd.ln1@coop.radagast.org...   > Could it be that the charging circuit is a buck regulator? The feed > from the wall wart could be "higher voltage, lower current", which > would result in lower losses the wire.   As luck would have it I found the service manual, but the schematic is a jumble with no component values.   So far I've done a first draft of re drawing the schematic, so now I can recognise most of the circuit blocks, but it needs more tidying before I can follow how it actually works.   My best guess is, its a distant relative of the hysteretic buck with a synchronous rectifier, but it needs more study to figure it out.

Pat <pat@nospam.us>: Jul 29 01:27PM -0400 On Wed, 29 Jul 2015 08:12:51 -0700 (PDT), Deane Williams   >> John :-#)#   > The motor still spins easily. There is no DC continuity from the power plug but I beleive this is normal for induction motors? Perhaps the overheat sensor has opened permenently. Home Depot gave me a replacement so I will try it again. These fans typically last for many years when plugged directly into a wall socket. This is a real mystery to me. Perhaps SS relays generate some large spikes on their output? I should check it with a scope. >Thanks for the comments.   You have an interesting problem. I hope you figure it out. I have never used SS relays, but I can't image they cause spikes and other anomolies that would kill a simple AC motor. Is the relay rated for inductive loads?   By the way, I have a similar fan I purchased years ago. I just measured its DC resistance and found it to be about 18 ohms on its high setting. Clearly, that number is no indication of its impedance at 60 Hz while in operation, but it definitely conducts DC. My best guess is something is causing the motor windings to overheat and eventually open. Unfortunately, I can't think of any way to explain why that would happen.   Pat

MJC <gravity@mjcoon.plus.com>: Jul 29 07:32PM +0100 In article <qf2irahhpfft1l1vnhbef69q2k01erc0qi@4ax.com>, pat@nospam.us says... > never used SS relays, but I can't image they cause spikes and other > anomolies that would kill a simple AC motor. Is the relay rated for > inductive loads?   I can't be bothered to study SSRs so I just speculate... Could it be that the ones you use just deliver one polarity of AC instead of both, like a rectifier? Resulting in a DC component which the fans do not like...   Mike.

Pat <pat@nospam.us>: Jul 29 02:40PM -0400 On Wed, 29 Jul 2015 19:32:06 +0100, MJC <gravity@mjcoon.plus.com> wrote:   >like a rectifier? Resulting in a DC component which the fans do not >like...   >Mike.   That's an interesting thought. Even if most SSRs handle full AC, maybe this particular one is faulty and only passes one polarity. That would certainly make the fan motor unhappy.   Pat

all2001@spambog.com (Wolfgang Allinger): Jul 29 02:38PM -0300 On 29 Jul 15 at group /sci/electronics/repair in article qf2irahhpfft1l1vnhbef69q2k01erc0qi@4ax.com >guess is something is causing the motor windings to overheat and >eventually open. Unfortunately, I can't think of any way to explain >why that would happen.   I think but don`t know! If the SSR is bad (or not designed for inductive load) it may have different half wave signals, so a DC current may flow thru the motor and heats the coil (too much). A light bulb didn`t show any defects, because it converts all current to heat and a little light :)   Just my 2 cent.   I will recommand a true mechanical relay for this job.     Saludos (an alle Vernünftigen, Rest sh. sig) Wolfgang   -- Wolfgang Allinger, anerkannter Trollallergiker :) reply Adresse gesetzt! Ich diskutiere zukünftig weniger mit Idioten, denn sie ziehen mich auf ihr Niveau herunter und schlagen mich dort mit ihrer Erfahrung! :p (lt. alter usenet Weisheit) iPod, iPhone, iPad, iTunes, iRak, iDiot

John Robertson <spam@flippers.com>: Jul 29 12:49PM -0700 On 07/29/2015 11:40 AM, Pat wrote: > maybe this particular one is faulty and only passes one polarity. That > would certainly make the fan motor unhappy.   > Pat   The motor would run at half speed at best.   The motor won't overheat though unless it stalls/is jammed and can't self cool.   It is more likely that the motors are just of a cheap quality construction (for example are the UL or CSA rated?) and fail far too easily. A SS AC modular relay is simply a high current TRIAC and these are used on many fans around the world - what do you think a motor speed control is?   A moments research pulled up this PDF:   http://www.omron.com/ecb/products/pdf/precautions_ssr.pdf   (quote)   The following will demonstrate the process to determine the effective ratings of non-motor control rated Solid State Relays for use in motor control applications: Example question: "Can I use a standard Solid State Relay (which is not included in the Crydom Motion Control Brochure and therefore without HP or KW Motor rating) to control the start/stop of a motor?" The answer: Yes, you need only to consider the motor nominal current value (FLA), inrush current value (LRA), motor power factor (typically 0.1 to 0.9) to select the appropriate turn-on switching type (zero-crossing or random) and possible need for SSR transient protection to select an appropriate Solid State Relay.   (end quote)   John :-#(#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

whit3rd <whit3rd@gmail.com>: Jul 29 04:36PM -0700 On Monday, July 27, 2015 at 7:06:47 PM UTC-7, Deane Williams wrote: > I set up a thermostat in my garage that comes on at 80 degrees F. and sends a 6 VDC battery voltage to control a 120 VAC solid state relay which powers up the vent fan. The fans always quit within 2 months to a year with no obvious defects.,,, there is no smoke smell, no visible damage and if there is a capacitor it tests OK.   Three possibilities: your thermostat could be chattering (sending a bouncy-switch signal to the SSR) and that is causing rectification. Your SSR could be a zero-crossing type, which is exactly the most stressful motor-start situation (and an inexpensive motor might take a magnetization at turn-off, then saturate at turn-on, and melt its fusible protector). Third, the SSR might be susceptible to some other signal than your thermostat (RF or maybe even input/output feedback oscillation).   If you use an AC relay, it cannot operate fast enough to rectify; if you feed that AC relay with a triac-output optoisolator, with a smallish capacitor shunting the input terminals (1 uF?), there ought to be no drive-side problems.

"ScottWW" <spamtrap@dcorp.com>: Jul 30 08:50AM -0400 >there is a capacitor it tests OK. >Thanks for any ideas. I am going to switch over to a mechanical relay.   >Dean   Some induction motors will have a thermal fuse incorporated onto the main winding. In the absense of a thermal fuse, this is my amateur speculation: The switching of the SSR creates voltage spikes. Normally these are easily absorbed by the induction motor. With enough time and heat, the lacquer insulation on the motor windings gets brittle, thermal cycling compromises its ability to insulate, then the voltage spikes begin jumping across high potential areas (between winding ends or where wire leads are tied to windings). If there is a capacitor involved, the arc is that much more spectacular, and the motor's demise quicker. Scott

john_a_s2004@hotmail.com: Jul 30 04:18AM -0700 Hi,   I've just fixed one of these 60W power supplies. This has triple output (+5V, +15V, -15V). Fault was -15V output gave -1V and +15V output gave +6V, LED not lit.   First saw that C37 (-15V smoothing capacitor) was bulged, replaced with 450uF 35V low ESR. This caused -15V output to become -6V, +15V still only +6V. Started to look at primary, unsoldered mains input capacitor (C5, 150uF 400V), measured at 60uF so replaced - no change.   Looked around for any other suspects, unsoldered C8 (47uF 50V) and found it was nearly shorted. Replaced and all outputs now OK, LED lit. Tested up to 1A load, very little voltage drop.   I think C8 might be in the starter circuit but I don't have a schematic.   Regards, John

Jeff Liebermann <jeffl@cruzio.com>: Jul 29 03:26PM -0700 On Wed, 29 Jul 2015 08:24:13 -0400, "J.B. Wood"   >Thanks, for the detailed info, Jeff. I wouldn't have guessed how to >make new rubber retainers/bumpers. Folks who restore pinballs and >jukeboxes probably know this stuff. Sincerely,   Also check with antique auto restorers. It's not very difficult. I've done it many times with good success. There are plenty of instructions available on the web. For example: <https://www.google.com/#q=how+to+mold+rubber+parts> <https://www.youtube.com/results?search_query=mold+rubber+parts> <https://sugru.com> <http://versimold.com> <http://www.freemansupply.com/video.htm> <https://www.youtube.com/watch?v=JD-NP0DwLEE> <http://tag.wonderhowto.com/cast-rubber-parts/> and so on. Plenty more including kits and presses. If you need something flexible, definitely look into Sugru.   Incidentally, plaster of paris and FixAll molds are my favorites, but you can also make formed molds from just about anything than hardens, such as silicon rubber. You can also machine or gouge a mold from wood, metal, plastic, whatever.   Good luck. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

brian.street.102@gmail.com: Jul 29 03:02PM -0700 On Wednesday, December 5, 2007 at 6:48:44 AM UTC-8, Arfa Daily wrote: > supply.   > If you need more help with schematics etc, contact me off group.   > Arfa   Arfa: Could I impose on you to provide a copy of the AWR1-1W Series 2? I know the 5v is missing (Cannot find it anywhere) but I also do not find a 5v regulator either. Same no display and a burst of sound when the unit is unplugged.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

sci.electronics.repair@googlegroups.com

Google Groups

avagadro7@gmail.com: Jul 28 04:35PM -0700 > http://www.bcae1.com/relays.htm   https://goo.gl/TCo6MH

Deane Williams <pyroartist.dw@gmail.com>: Jul 29 08:12AM -0700 > motor isn't overheating.   > Does the fan still spin? Is there continuity in the winding?   > John :-#)#   The motor still spins easily. There is no DC continuity from the power plug but I beleive this is normal for induction motors? Perhaps the overheat sensor has opened permenently. Home Depot gave me a replacement so I will try it again. These fans typically last for many years when plugged directly into a wall socket. This is a real mystery to me. Perhaps SS relays generate some large spikes on their output? I should check it with a scope. Thanks for the comments.

Deane Williams <pyroartist.dw@gmail.com>: Jul 29 08:13AM -0700 On Tuesday, July 28, 2015 at 3:15:20 AM UTC-4, N_Cook wrote: > > Thanks for any ideas. I am going to switch over to a mechanical relay.   > > Dean   > Do you do TIG/MIG welding in this garage?   No. I don't own a TIG/MIG welder.

Deane Williams <pyroartist.dw@gmail.com>: Jul 29 08:14AM -0700 > http://www.bcae1.com/relays.htm   Thanks for the detailed treatise on mechanical relays. But I am using a solid state relay (SSR).

"J.B. Wood" <arl_123234@hotmail.com>: Jul 29 08:24AM -0400 On 07/27/2015 02:51 PM, Jeff Liebermann wrote: > contact surfaces with vaseline so that you can take it apart. Fill > the mold with your favorite rubber compound (I used hard automotive > RTV) to clone the part. Clean up the flashing with an Xacto knife.   Thanks, for the detailed info, Jeff. I wouldn't have guessed how to make new rubber retainers/bumpers. Folks who restore pinballs and jukeboxes probably know this stuff. Sincerely, -- J. B. Wood e-mail: arl_123234@hotmail.com

N_Cook <diverse@tcp.co.uk>: Jul 29 09:03AM +0100 PMH1000 schematic is very similar, 2 zener drop per ch, 2 SMPS ICs the same etc I didn't bother checking the pots function as 4 pots would not fail in the same manner - wrong. Logo B in a triangle, blue body, marked 05 C5 02 on the underside. Very iffy resistance at both ends of the track. Used here as simple variable resistors,wiper tied to min gain end , max gain at zero ohms position. 5K Log track, mid track 300R, but last mm or so jumps from roughly 100R to 0R, similar the other end. Last 3/4mm or so very irregular resistance Took apart and cleared out the grease, same patchy response on reassembly. I don't think its wear as all pots the same at both ends (min gain end does not matter here in use as imperceptible). Perhaps the grease reacts with the track surface , scraping back the track surface , seems to make the situation worse. Same patchiness on the part of the track not swept by the wiper. Main problem was perhaps SMPS going into protect, or "digital amps" goung into protect ,as unusually amp was used outdoors in sunshine or failure of a PA-Prea insert switch if one channel failed

Jeff Liebermann <jeffl@cruzio.com>: Jul 28 06:44PM -0700 >> cooling (something more than mere heat sinks and fans, IOW).   >> Many thanks.   >2) only if you know the current carrying capacity of their winding wire   Nope. A fuse works by heating the wire high enough to where the wire oxidizes and turns into an metallic oxide which then crumbles. If you can extract the heat from the wire to maintain a temperature below this point, the fuse will last indefinitely. Dumping the load resistor into a bucket of water does this quite nicely. To do this, the wire is in intimate contact with a refractory ceramic which then transfers the heat to a metal case and finally to the water. No air gaps allowed.   You can demonstrate the principle with a common coffee cup heating coil: <http://www.ebay.com/itm/171376872247> If you bypass the internal thermostat and run it in open air, it will blow up rather quickly. However, if you immerse it in water, the water will conduct most of the heat away, thus preventing the heater wire from fusing.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

"Ralph Mowery" <rmowery28146@earthlink.net>: Jul 28 11:11PM -0400 "Phil Allison" <pallison49@gmail.com> wrote in message news:0c799d3c-9477-4076-b521-a6a8a6bd7410@googlegroups.com...   >> or other odd ball waveforms   > ** An audio amplifier reproducing a square wave will not pass harmonics > much above 50kHz top the load - so you are wrong again.   Do try and keep up. This is about the output of the amplifier. It does not mater what the amp is going to pass.   From a quick test with a couple of wire wound resistors an audio frequency square wave was producing a spike on the leading and trailing edges of the ww resistor. It did not do that with a carbon resistor.

Phil Allison <pallison49@gmail.com>: Jul 28 09:39PM -0700 Ralph Mowery wrote:   > > much above 50kHz top the load - so you are wrong again.   > Do try and keep up. This is about the output of the amplifier. It does not > mater what the amp is going to pass.   ** Huh ????   Since amplifiers cannot pass the harmonic frequencies, they will NOT appear at the output.     > From a quick test with a couple of wire wound resistors an audio frequency > square wave was producing a spike on the leading and trailing edges of the > ww resistor.   ** An "audio frequency square wave" must have its harmonics filtered out above the audio band.   However, what you have is a *WIDE BAND* square wave with its fundamental at an audio frequency.   I understand your test and a similar one to compare low value WW resistors for such inductance. Normally you see overshoot and ringing at frequencies in the low MHz range on the scope - using a 100kHz square wave.       ... Phil           ... Phil     It did not do that with a carbon resistor.

"Ian Field" <gangprobing.alien@ntlworld.com>: Jul 28 07:20PM +0100 Recently my Philips coolshave started not giving many shaves per charge - as luck would have it, I'd just salvaged a pack of 1000mAh Ni-Cd cells (Ni-Mh that I have bags of won't do) from some scrap equipment.   Since it was apart anyway, the connections from the charging plug were more easily accesible than the holes in the charger plug, so I grabbed the DMM - 25VDC charger for a single 1.2V cell.   Would anyone care to offer comments on the likely rationale of that?   Thanks.

John Robertson <spam@flippers.com>: Jul 28 02:05PM -0700 On 07/28/2015 11:20 AM, Ian Field wrote: > the DMM - 25VDC charger for a single 1.2V cell.   > Would anyone care to offer comments on the likely rationale of that?   > Thanks.   Might be the unloaded voltage.   High voltage but very low current might be good for keeping the whiskers from building up inside the cells. not that I know for sure, simply a guess.   What is the voltage when you plug it into the battery pack?   John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

"Ian Field" <gangprobing.alien@ntlworld.com>: Jul 28 10:12PM +0100 "John Robertson" <spam@flippers.com> wrote in message news:AtmdnY6DsZ6LcirInZ2dnUU7-IOdnZ2d@giganews.com... > from building up inside the cells. not that I know for sure, simply a > guess.   > What is the voltage when you plug it into the battery pack?   As I explained - it was easier to get at the connections while the shaver was open and taking a reading from the terminals inside.   The charger was plugged into the shaver when I measured it.

John Robertson <spam@flippers.com>: Jul 28 02:49PM -0700 On 07/28/2015 2:12 PM, Ian Field wrote:   > As I explained - it was easier to get at the connections while the > shaver was open and taking a reading from the terminals inside.   > The charger was plugged into the shaver when I measured it.   No better idea other than it would appear that the ni-cad battery is open, otherwise it would load that down and possibly get rather warm if there is any current available.   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

dplatt@coop.radagast.org (Dave Platt): Jul 28 05:22PM -0700 In article <UeStx.44972$3n4.31287@fx35.am4>,   >As I explained - it was easier to get at the connections while the shaver >was open and taking a reading from the terminals inside.   >The charger was plugged into the shaver when I measured it.   Could it be that the charging circuit is a buck regulator? The feed from the wall wart could be "higher voltage, lower current", which would result in lower losses the wire.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

sci.electronics.repair@googlegroups.com

Google Groups

N_Cook <diverse@tcp.co.uk>: Jul 28 10:52AM +0100 +/-15V on the "level" opamps, and 48V and 5V for digital. Looks as though I'll have to trace out the schematic around one of these pots and opamps to see what could be common to all the channels, requiring removing all the hardware to get to the other side of the pcb.

N_Cook <diverse@tcp.co.uk>: Jul 28 11:35AM +0100 I've just realised I've not seen a Level Set LED light on any channel with any input. No such LEDs on the 2800 schematic. Try and find the common voltage to the transistors or whatever buffer to those on each channel, before removing all the hardware.

N_Cook <diverse@tcp.co.uk>: Jul 28 12:41PM +0100 Getting somewhere now. To save desoldering a shielding plate I'd been probing the stereo channels. Problem is with 1 to 4 channels only, so removed shield. +/-15V ok on those opamps. LED supplies are off the -15V line, one zener per channel, giving nominal voltage of about -8.4V, varying a bit on each channel. Just pins 2 and 3 of each of the 4 off level double-opamp ICs show that same negative voltage on each channel, the B opamp of each is normal. Still a mystery what the problem in common is to cause that to each channel, but zeroing in.

N_Cook <diverse@tcp.co.uk>: Jul 28 03:13PM +0100 There are 2 simple -8.4V zener drop supplies per channel. One of those -8.4V is connected to pin 2input and the other to pin 3 output of the opamp, what is that about? Still no wiser what the interchannel coupling problem is either

Deane Williams <pyroartist.dw@gmail.com>: Jul 27 07:06PM -0700 I set up a thermostat in my garage that comes on at 80 degrees F. and sends a 6 VDC battery voltage to control a 120 VAC solid state relay which powers up the vent fan. The fans always quit within 2 months to a year with no obvious defects. These are inexpensive 20 inch box fans with induction motors. I have tried several brands and styles of fans. The latest was a Home Depot unit that only lasted 2 months. Does anyone know of a reason why I can't run an induction motor from a SS relay? What is killing the fans? I have taken two apart and there is no smoke smell, no visible damage and if there is a capacitor it tests OK. Thanks for any ideas. I am going to switch over to a mechanical relay.   Dean

John Robertson <spam@flippers.com>: Jul 27 11:32PM -0700 On 07/27/2015 7:06 PM, Deane Williams wrote: > Does anyone know of a reason why I can't run an induction motor from a SS relay? What is killing the fans? I have taken two apart and there is no smoke smell, no visible damage and if there is a capacitor it tests OK. > Thanks for any ideas. I am going to switch over to a mechanical relay.   > Dean   Have you had any other fans of the same make/model running on just 115VAC to see if they run any longer? They could be just cheap fans whose oil dries up.   Hard to see where a SS AC Relay could hurt an induction motor if the motor isn't overheating.   Does the fan still spin? Is there continuity in the winding?   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

N_Cook <diverse@tcp.co.uk>: Jul 28 08:15AM +0100 On 28/07/2015 03:06, Deane Williams wrote: > Does anyone know of a reason why I can't run an induction motor from a SS relay? What is killing the fans? I have taken two apart and there is no smoke smell, no visible damage and if there is a capacitor it tests OK. > Thanks for any ideas. I am going to switch over to a mechanical relay.   > Dean   Do you do TIG/MIG welding in this garage?

avagadro7@gmail.com: Jul 28 04:47AM -0700 http://www.bcae1.com/relays.htm

Jeff Liebermann <jeffl@cruzio.com>: Jul 27 09:58AM -0700 On Mon, 27 Jul 2015 12:50:31 +0000 (UTC), Cursitor Doom >> which Newark and Digikey do not seem to carry.   >Is that inductiveness seriously likely to be a problem at audio >frequencies?   Disclaimer: I am not an audiophile or expert on audio equipment beyond a few occasional repairs and some long past work at a recording studio and several radio stations.   Well, that depends on what you're trying to accomplish with the dummy load. If it's performance tests for a data sheet with calibrated equipment, then yes, every divergence from exactly 8+j0 is important. However, if you're using the load to simulate a real loudspeaker to test for ringing, oscillations, crossover distortion, resonant peaks, and such, then there's no way a purely resistive load is even close to a real world loudspeaker impedance: <https://www.google.com/search?tbm=isch&q=loudspeaker+impedance>   Let's do some measuring and math. Digging through my junk box, I find a dummy load that I think was used to test power supplies: <http://www.11junk.com/jeffl/pics/drivel/slides/dummy-load-inductance.html> That's 2ea 2.5 ohm and 2ea 5.9 ohm inductive RH type resistors in series for a total of 16.8 ohms. Measured inductance of 16 uHy at 1KHz yields: Xl = 2*Pi*f*L = 2 * 3.14 * 1000 * 16*10^-6 = 0.1 ohms So, this load looks like: 16.8+j0.1 Good enough. However, if you were making measurements up to 100 KHz, where the load would look like: 16.8+j10 methinks a non-resistive load might be useful.   Considering that your original question was about testing a used amplifier to see "what it was capable of", y'er right. You can do that nicely without using overpriced non-inductive terminators. When you actually build your load, you might want to do the above measurement and calculations.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Jul 28 07:32AM +1000 On 27/07/2015 10:50 PM, Cursitor Doom wrote: >> which Newark and Digikey do not seem to carry.   > Is that inductiveness seriously likely to be a problem at audio > frequencies?   **No.   -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Cursitor Doom <curd@notformail.com>: Jul 27 09:32PM Thank you, gentlemen.   So we're all agreed:   1. there's no problem using wire-wounds for a load provided the power output measurement is carried out with sine waves from a suitable external generator.   2. Even low rated power resistors can be used for the load provided their case temperatures are kept low by some effective means of external cooling (something more than mere heat sinks and fans, IOW).   Many thanks.

"Ralph Mowery" <rmowery28146@earthlink.net>: Jul 27 06:09PM -0400 "Cursitor Doom" <curd@notformail.com> wrote in message news:mp681u$8ul$2@dont-email.me...   > 2. Even low rated power resistors can be used for the load provided their > case temperatures are kept low by some effective means of external > cooling (something more than mere heat sinks and fans, IOW).   That is the way I see it.   You can probably go at least 5 and maybe 10 times the power on the load resistor if you put it in some water or oil. Many times that if you have liquid nitrogen.

MJC <gravity@mjcoon.plus.com>: Jul 27 11:31PM +0100 In article <mp681u$8ul$2@dont-email.me>, curd@notformail.com says... > 2. Even low rated power resistors can be used for the load provided their > case temperatures are kept low by some effective means of external > cooling (something more than mere heat sinks and fans, IOW).   To an extent. Seems to me that the winding temperature will rise because the insulation between case and wire will not have infinite heat conduction. At some power level the lifetime must start to shorten...   Mike.

Phil Allison <pallison49@gmail.com>: Jul 27 08:08PM -0700 Cursitor Doom wrote:   > > which Newark and Digikey do not seem to carry.   > Is that inductiveness seriously likely to be a problem at audio > frequencies?     ** Not in the slightest.   Liebermann is blowing it out his arse, as usual.     .... Phil

Phil Allison <pallison49@gmail.com>: Jul 27 08:14PM -0700 Ralph Mowery wrote:     > Used a 100 MHz scope, function generator and Fluke 87 meter.   > From low audio up to 20,000 Hz and a sine wave with the 10 ohm WW there did > not appear to be any noticable difference.   ** And this is a sufficient test for the purpose.     > When I switched to a square wave   ** Which has harmonics into the medium and HF bands.     > I noticed a large spike on the leading and trailing edges, especially as I > went higher up in frequency.   ** All due to the harmonics way above audio range.     > From this rough test, I would say that if using sine waves you could get a > close to true test, but if music   ** Music signals stop at 20kHz.     > or other odd ball waveforms     ** An audio amplifier reproducing a square wave will not pass harmonics much above 50kHz top the load - so you are wrong again.     .... Phil

N_Cook <diverse@tcp.co.uk>: Jul 28 08:19AM +0100 On 27/07/2015 22:32, Cursitor Doom wrote: > case temperatures are kept low by some effective means of external > cooling (something more than mere heat sinks and fans, IOW).   > Many thanks.   2) only if you know the current carrying capacity of their winding wire

Phil Allison <pallison49@gmail.com>: Jul 28 02:19AM -0700 N_Cook wrote:     > 2) only if you know the current carrying capacity of their winding wire     ** Huh ??   Wot a classic Kookism.       .... Phil

Phil Allison <pallison49@gmail.com>: Jul 27 09:06PM -0700 N_Cook wrote:   > In my sort of electronics world, for torroidal transformers an NTC > thermistor would be included to avoid down-rating RCD or uprating MCB. > What would they do in the electrical world, anything like NTC thermistors?     ** MCBs come with various rating for the tripping time, known as B, C and D curve.   The C curve is the one usually chosen for motor start applications, it allows a current of up to 10 times the nominal rating to pass for about 5 seconds.   The problem is not the same as with large transformers ( ie core saturation due to DC component ) but simply that the motor is stalled when power is first applied and takes time to spin up.       ... Phil

avagadro7@gmail.com: Jul 27 03:14PM -0700 on the whole, computer video has a brain sorting the input to the output holding info on various standards rather than a group of bipods 'agreeing' on a 'standard'   TV has no brain. !!!! Eureka !   but the rig needs coupling and cable to start.   I assume the hookup and directions answers are found in brand forums as Dell Forums Inspirion.

"J.B. Wood" <arl_123234@hotmail.com>: Jul 27 02:17PM -0400 Hello, all. After 20+ years of home storage, I finally fired up the subject slide projector (Kodak's top-of-the-line in its day) which I purchased new way back when. The projector functioned but I have a cosmetic problem to solve. The rubber (?) retaining rings that secure the two wood-grained inserts to the side panels of the projector have broken in several spots due to dry rot. Anyone have any suggestions? The parts list for this projector shows only the side panels (which I presume includes the retainers and inserts). But then there's the problem of spare parts...Thanks for your time and comment. Sincerely, -- J. B. Wood e-mail: arl_123234@hotmail.com

Jeff Liebermann <jeffl@cruzio.com>: Jul 27 11:51AM -0700 On Mon, 27 Jul 2015 14:17:09 -0400, "J.B. Wood" >The parts list for this projector shows only the side panels (which I >presume includes the retainers and inserts). But then there's the >problem of spare parts...Thanks for your time and comment. Sincerely,   Don't toss the old parts. Glue or scotch tape the pieces together. Fill any gaps with some kind of putty. Using the old part as a pattern, make a two part mold using plaster of paris. Smear the contact surfaces with vaseline so that you can take it apart. Fill the mold with your favorite rubber compound (I used hard automotive RTV) to clone the part. Clean up the flashing with an Xacto knife.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

sci.electronics.repair@googlegroups.com

Google Groups

"Gareth Magennis" <sound.service@btconnect.com>: Jul 26 07:50PM +0100 "Gareth Magennis" wrote in message news:TP7tx.48715$m04.7988@fx43.am4...       "Cursitor Doom" wrote in message news:mp2lbl$9no$2@dont-email.me...   Hi all,   I have an Audiolab 8000 amplifier I picked up at a boot sale and would like to establish what it's capable of, since subjectively the power output seems a bit on the low side when driving recommended speaker loads. Anyway, ideally I'd like to use an 8 ohm 100W power resistor as a dummy load for each channel and then measure the p-p voltage output across it on a scope with the amp turned right up. Trouble is, I don't have such a resistor and was wondering if there's any suitable substitute? I recall someone somewhere using a car headlamp bulb but I doubt they come as 8 ohm units so some sort of elaborate series/parallel combo of lamps would be necessary to get that value. Has anyone a better idea? cheers, CD.         Here's another idea: Get a reel of this - http://uk.farnell.com/pro-power/ecw0-80/wire-0-8mm-copper-enamelled-125m/dp/1230984   By my calculations it will have a resistance of 4.25 ohms. (117m of the 125m length gets you 4 ohms) Although it is only rated at 0.8A, I reckon you could extend that massively by unravelling it all and laying it in a large container of water. You could even have a flow of water through the container to keep the temperature down.   It would be interesting to find out what power rating this could actually tolerate.   Or is this a really stupid idea?! (For some reason this amuses me)       Gareth.               Just to extend that idea a little further:   You could probably put a wood former into the chuck of an electric drill, and quickly and easily make a long coil using this enamelled copper wire. You could then partition the coil into several smaller ones without cutting the wire, and suspend them vertically in a container of water.   Quick back of a fag packet calculations: Suppose you made a long coil 10cm diameter. You would then suspend 0.5m lengths vertically in the container, so the windings are spaced 5mm apart on average. This gives 100 turns at 31.4cm per turn giving 31.4 meters of wire per coil.   So you would need 4 of these series coils from the 117m of wire required to get a 4 ohm load.     Now, how many Watts could this contraption handle?       Gareth.

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Jul 27 06:56AM +1000 On 26/07/2015 10:55 PM, Cursitor Doom wrote: > ohm units so some sort of elaborate series/parallel combo of lamps would > be necessary to get that value. Has anyone a better idea? > cheers, CD.   **Lamps are a really bad idea. Don't do it. Incandescent lamps exhibit a HIGHLY variable resistance, depending on how much current is flowing.   Just buy four of these of these:   http://www.newark.com/vishay-dale/rh0504r000fe02/wirewound-resistor-4-ohm-50w-1/dp/41K9167   Dump them in a bucket of water, or bolt them to a chunk of aluminium and place a small fan on the aluminium.   -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Phil Allison <pallison49@gmail.com>: Jul 26 04:43PM -0700 Cursitor Doom wrote:   > load for each channel and then measure the p-p voltage output across it > on a scope with the amp turned right up. Trouble is, I don't have such a > resistor and was wondering if there's any suitable substitute?     ** 10 watt rated resistors will handle 100 watts if submerged in a container of water.     .... Phil

jurb6006@gmail.com: Jul 26 06:54PM -0700 >"Just buy four of these of these:   >http://www.newark.com/vishay-dale/rh0504r000fe02/wirewound-resistor-4-ohm-50w-1>/dp/41K9167 "   Why do those Vishays look so much like Dales ?

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Jul 27 12:26PM +1000 >> "Just buy four of these of these:   >> http://www.newark.com/vishay-dale/rh0504r000fe02/wirewound-resistor-4-ohm-50w-1>/dp/41K9167 "   > Why do those Vishays look so much like Dales ?   **Success breeds imitation. That's my take. You probably should ask Vishay (who owns Dale). It would seem that Dale originated the aluminium clad resistor (I may be wrong though) and others have copied the design. Engineers don't have to worry about supply, since there are several suppliers of essentially identical parts.   -- Trevor Wilson www.rageaudio.com.au   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Jeff Liebermann <jeffl@cruzio.com>: Jul 26 08:18PM -0700 On Mon, 27 Jul 2015 06:56:53 +1000, Trevor Wilson   >Just buy four of these of these: >http://www.newark.com/vishay-dale/rh0504r000fe02/wirewound-resistor-4-ohm-50w-1/dp/41K9167   The RH variety is inductive. For non-inductive, you want the NH series, which Newark and Digikey do not seem to carry. Mouser has it at: <http://www.mouser.com/Search/Refine.aspx?Keyword=NH0504R000FE02> for twice the price.   >Dump them in a bucket of water, or bolt them to a chunk of aluminium and >place a small fan on the aluminium.   An aluminum heat sink will keep my coffee warm. All the water does is raise the humidity in the lab and create a huge mess when I tip over the bucket. I'll take the aluminum heat sink, but without the fan, which makes too much noise.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Cursitor Doom <curd@notformail.com>: Jul 27 12:50PM On Sun, 26 Jul 2015 20:18:28 -0700, Jeff Liebermann wrote:   > The RH variety is inductive. For non-inductive, you want the NH series, > which Newark and Digikey do not seem to carry.   Is that inductiveness seriously likely to be a problem at audio frequencies?

"Ralph Mowery" <rmowery28146@earthlink.net>: Jul 27 12:21PM -0400 "Cursitor Doom" <curd@notformail.com> wrote in message news:mp59en$khn$3@dont-email.me... >> which Newark and Digikey do not seem to carry.   > Is that inductiveness seriously likely to be a problem at audio > frequencies?   I just did a quick check with a 10 ohm 60 watt wire wound resistor and a couple of other low value resistors. Used a 100 MHz scope, function generator and Fluke 87 meter.   From low audio up to 20,000 Hz and a sine wave with the 10 ohm WW there did not appear to be any noticable difference. When I switched to a square wave I noticed a large spike on the leading and trailing edges, especially as I went higher up in frequency. I did not see the spike with the resistor removed from the test leads.   From this rough test, I would say that if using sine waves you could get a close to true test, but if music or other odd ball waveforms then you would want the noninductive types.

N_Cook <diverse@tcp.co.uk>: Jul 27 11:52AM +0100 PA and PREA work separately and as normal but low output at normal signal input and control levels. I don't think I've come across this situation before. The ground or common to all the "level set" pots on all the channels is missing presumably. You can only get normal throughput with the pots set in range 95% to 100% of each of their tracks, jumping from very low to max in a couple of mm of movement and all such pots would not have failed at the same time. So inside we go.

N_Cook <diverse@tcp.co.uk>: Jul 27 03:52PM +0100 Made 2007 Although the pmp1000 uses 4580 opamps like the 1280, not the same in the prea area. The wipers of the level pots there are at ground, "low" and "high" via Rs/Cs to opamp inputs. The 1000 has stereo pots, the pairs of low-side, wipers or high-side are not connected together, but similarly close connected to opamp inputs. Without a SM this will be a pain. Next thing is check +/-rails for the opamps.

N_Cook <diverse@tcp.co.uk>: Jul 27 02:07PM +0100 Luckily I'm not directly involved with the installation of these, its subcontractor's problem , just interested bystander, in what would be done in the electrical world to cure this problem. A batch of local houses as part ofa marine flood protection scheme have had sumps and pumps installed,one per house, about 2KW motors surprisingly. One of the residents tested one setup , with buckets of water to trigger the pump. It cut out at the mini "consumer unit" installed utility side of the normal consumer unit. All the others are likely to do the same. I assume it is large inductor , current inrush problem, like the notorious spin-cycle of washing machines. Inductive unbalancing the RCD or short duration over-current of the MCB. In my sort of electronics world, for torroidal transformers an NTC thermistor would be included to avoid down-rating RCD or uprating MCB. What would they do in the electrical world, anything like NTC thermistors?

M Philbrook <jamie_ka1lpa@charter.net>: Jul 26 01:36PM -0400 In article <eca56518-7629-4947-b234-d9e3ea2c7e28@googlegroups.com>, petereasthope@gmail.com says...   > Can anyone explain how a computer serial port is disabled and enabled? Many Web pages cover the software topics but I've found nothing explaining how a BIOS disables a port. Is is done by clearing any interrupt assignment to the port? Is the power to the UART shut off? Other ways? Probably more than one technique has been used but not a large number.   > Can anyone cite a Web page which answers this?   > Thanks, ... Peter E.   if Bios has control of it, it simply flips a bit in a device manager chip on the board..   From that point, the OS does not see that serial port. Which also means, there is no IRQ assigned to it or port addresses etc.. in otherwords, no resources assigned to it.   USB serial ports are a different story..   Jamie

Peter Easthope <petereasthope@gmail.com>: Jul 26 11:09AM -0700 On Sunday, July 26, 2015 at 10:32:05 AM UTC-7, M Philbrook wrote: > if Bios has control of it, it simply flips a bit > in a device manager chip on the board.   OK, that would be in evidence when the Bios interface allows disabling.   > From that point, the OS does not see that serial port.   There must be a customary way for the OS to read the state of the bit. Otherwise communication software would have to allow for obscure hardware variations. Can software flip the bit? Ie. can a port can be enabled and disabled when the system is running?   > USB serial ports are a different story.   Fortunately I'm only interested in RS-232 style serial ports, for now at least.   Thanks! ... Peter E.

Johann Klammer <klammerj@NOSPAM.a1.net>: Jul 27 03:04PM +0200 On 07/26/2015 08:09 PM, Peter Easthope wrote: > to allow for obscure hardware variations. Can software > flip the bit? Ie. can a port can be enabled and disabled > when the system is running?   Depends what you mean by software. The ancient vt1211 superi/o chip does its configuration via port writes. You may need to be in kernel context to be allowed to do that(or ioperm()). You may have to browse datasheets, to find out if others are similar or if there's a de-facto standard. Having a look at intels LPC bus specs may be necessary, too. (they're available online)

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.