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"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.

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