sci.electronics.repair@googlegroups.com

Google Groups

Micky <NONONOmisc07@bigfoot.com>: Nov 13 12:48AM -0500 I need a DC power supply, bigger than what I've got. Any reason why I can't connect two automobile battery chargers in parallel to suply the same vehicle?   Let's say one puts out 13.8 volts and the other 14.2. Is the first one really going to be a load on the second?   What happens if they are both connected to a discharged lead acid battery that's now putting out 4 or 8 volts**? Won't that lower the voltage of the 14.2 charger to where it's not backcharging the 13.8 charger? And won't the battery charge at rate of the sum of the two chargers, 2 (or 10) amps and 10 amps?   **Or if they are both connected to motor scooter whose starter motor is engaged.     A separate question: The charger I'm using now has 2 amp and 10 amp settings. It was on 2 amps, to charge a sealed burglar alarm style lead acid gel battery, used in place of a motorcycle battery in a motorscooter I'm working on. When I pressed the starter button to electrically crank the engine, the ammeter on the charger went immediately all the way to the right, 10 amps or more. But it was not enough to crank the engine. It made an effort, a little noise, and stopped immediately.   Given the way chargers are usually wire, will setting the charger on 10 amps provide more starting power than setting it on 2 amps? I would have assumed the answer was yes, but the ammeter went to 10 amps even in the 2 amp setting.     And before anyone brings it up, I've been testing the kick starter too, and the ignition and fuel systems. I'm making mulitples tests, in order to test all the systems. Before I recommend spending money on a battery and a couple other parts.

gregz <zekor@comcast.net>: Nov 13 07:45AM > too, and the ignition and fuel systems. I'm making mulitples tests, > in order to test all the systems. Before I recommend spending money > on a battery and a couple other parts.   Your talking chargers, an we have to assume things. I'm assuming anything, so I have no idea, depends. I blew out my Harbor Freight charger, don't know if it was something I did.   Start out slow charging the battery first before anything using one charger and see if it cranks.   I can't see the chargers or schematics. It could be regulated chargers with a 2 amp setting being lower voltage connected to ammeter. It's possible to connect two supplies in parallel under certain conditions and depends on circuit design.   Greg

Paintedcow@unlisted.moc: Nov 13 03:41AM -0600 On Fri, 13 Nov 2015 00:48:52 -0500, Micky <NONONOmisc07@bigfoot.com> wrote:   >I need a DC power supply, bigger than what I've got. Any reason why I >can't connect two automobile battery chargers in parallel to suply the >same vehicle?   I've used two battery chargers at the same time on cars many times. Never had a problem. Of course I'm talking about two small chargers. Like a 6 AMP and a 10 AMP. I would not connect two 30 or 50 Amp chargers together. I'm just charging at a rate of 16 AMPS, which charges the battery faster than the individual chargers. Since you can buy a 30 or 50 A charger, 16 A is still minimal compared to the bigger chargers.   Just sharing my experience, not guaranteeing you can do it safely. But like i said, I've never had any problems doing it.

"pfjw@aol.com" <pfjw@aol.com>: Nov 13 04:01AM -0800 On Friday, November 13, 2015 at 12:49:07 AM UTC-5, Micky wrote: > I need a DC power supply, bigger than what I've got. Any reason why I > can't connect two automobile battery chargers in parallel to suply the > same vehicle?   YIKES!   A few things about lead-acid batteries:   a) They do not like to be charged beyond about 10% of their AH rating. That is not to suggest that more amps will destroy them - but that some care is needed during the charging process.   b) Charging amps, AH ratings and the actual operation of the battery are, at best, first cousins - related but not directly. For instance, even a high-rated gel-type battery is generally not suitable for motorcycle operation as its chemistry is generally not suitable to provide the very fast discharge (very high amperage) needed to turn the starter motor at sufficient speed to start the engine. Conversely, a much lower *rated* battery may be perfectly fine for the purpose as its chemistry is designed for a very high amperage discharge for the few seconds necessary.   c) That your charger jumped to 10A is not a surprise, most such chargers are 'smart' inasmuch as they recognize the draw of the battery and react accordingly. But 10A is not hardly enough to turn the average small starter motor under load. For instance, a marine-grade Group 24 battery (most common group of that type) is rated at a mere 80 AH, but is capable of 800 CCA (cold-cranking amps) for a few seconds to start a big diesel boat engine, for example. Your little cycle-starter may need 50+CCA or more to operate properly.   d) A motor could care less how many amps are available to it, as long as they are in excess of its draw at a given load. If you want to test the starter, us a regular car battery. If you want to use an outboard device to test, get a Starter/Charger unit. These devices either have a rapid-discharge battery on board or a series of capacitors boosting the output the few seconds needed to start.   e) Ganging up chargers is generally not a good idea unless they are identical in behavior and type. It is generally not a good idea to use these things beyond their design parameters - at least, you would void any warranties. At worst, you would pick the only two chargers that if paralleled would go the way of Chernobyl.   Peter Wieck Melrose Park, PA

philo <philo@privacy.net>: Nov 13 06:50AM -0600 On 11/12/2015 11:48 PM, Micky wrote:   > too, and the ignition and fuel systems. I'm making mulitples tests, > in order to test all the systems. Before I recommend spending money > on a battery and a couple other parts.   The open circuit voltage of a charger means next to nothing.     The only problem I can see is that most chargers today are automatic and need to sense battery voltage before they turn on.     If the battery voltage is too low, the charger will not even turn on so a non-automatic charger would need to be used to get the current flowing.     If the battery is /extremely/ low I've seen situations at work where we'd have to put the battery on a variable charger and crank the voltage quite high in order to get the charging process started...then after a very short time switch the battery over to a conventional charge.     (As you probably know by now I was in the industrial battery business)     At any rate I don't recommend putting two chargers in parallel but on the other hand I don't see that it would hurt anything just as long as you disconnected one once the battery got close to 80% charged.     NOTE: To avoid a spark and explosion do not disconnect while under power

Micky <NONONOmisc07@bigfoot.com>: Nov 13 08:25AM -0500 >50 A charger, 16 A is still minimal compared to the bigger chargers.   >Just sharing my experience, not guaranteeing you can do it safely. But >like i said, I've never had any problems doing it.   Good enough. Thanks. (Though I've written down your email address and my estate will be suing you if this proves fatal.)

Micky <NONONOmisc07@bigfoot.com>: Nov 13 08:54AM -0500 >need to sense battery voltage before they turn on.   >If the battery voltage is too low, the charger will not even turn on so >a non-automatic charger would need to be used to get the current flowing.   Not even an override switch? That seems like a bad idea.   For example, the battery I started with, which I have only for testing things, had a voltage of 0.1 or 0.2 volts, but I can usually charge it to 11 volts or more. Actually I'm not sure the battery will help here since it's sooo bad. But I'm stuck in the mold of my car, where the oldest crummiest battery I ever had would still, when jumped from another car, take a charge in about 5 minutes and spit it back to the starter motor when the jumper cables were too thin to directly start the car.   Somewhere I think I have an old motorcycle battery I also saved for testing, but I haven't found it. >quite high in order to get the charging process started...then after a >very short time switch the battery over to a conventional charge.   >(As you probably know by now I was in the industrial battery business)   Yes. I'm sure you know what you're talking about.   >At any rate I don't recommend putting two chargers in parallel but on >the other hand I don't see that it would hurt anything just as long as >you disconnected one once the battery got close to 80% charged.   Okay. Once the scooter starts running, it has its own alternator/rectifier.   I'm told on a scooter forum that there are scooters that run on AC current mostly and that they will start without a battery, but that those that are DC won't. (or perhaps it's enough if they have a charger connected.)   For the AC current scooters, seems to me, they should make AC batteries. Isn't AC Delco a big maker of AC batteries?

philo <philo@privacy.net>: Nov 13 08:38AM -0600 On 11/13/2015 07:54 AM, Micky wrote: > another car, take a charge in about 5 minutes and spit it back to the > starter motor when the jumper cables were too thin to directly start > the car.     If the battery was brought down to a very low voltage but charged within a few days, it should recover (if it was OK to begin with)     However if a battery is left to sit "dead" for a very long time...once stage 3 sulfation (permanent crystallization) has set in...there is zero chance of it being recovered.

Tony Hwang <dragon40@shaw.ca>: Nov 13 08:41AM -0700 Micky wrote: > too, and the ignition and fuel systems. I'm making mulitples tests, > in order to test all the systems. Before I recommend spending money > on a battery and a couple other parts.   Just amazing!!!!

jurb6006@gmail.com: Nov 12 10:22PM -0800 How the hell do you deal with that plastic coating stuff n the wood ? Looks to me that the wood shrinks and then you can't get the chassis out. Of course I guess they want it that way so it does not rattle, but this is going too far. We are talking the width here. Leave some damn clearance.   Today I had to simply cut some of that shit off and it is noticable, I figure to paint it black as the rest of it is not in the greatest condition cosmetically anyway. But it simply would not come apart with screwdriver nor hook. I did not try the hammer and handgrenade method, but I was tempted.   Another amp, I did not cut this off, but I had to peel it. The edge of the chassis pushed the shit out and then there was no way except to get down to the plane. Then it came out. I guess I could glue it back down but then the volume of the glue would make it even tighter.   Maybe I should grind down the bare wood a bit ? Or maybe I should grind down the chassis pans.   I am trying not to break shit, that is not what I get paid for bu it seems to be easier said than done. And all this applies to amp heads, not just combos. And these big old tube ones, damn.   But these are nice amps and people like them. Plus, no matter what I would rather see them than most of the new class D shit.   And then, I had one, a tube amp but with some solid state (so it wasn't from 19fucking15) that had no bleeders on the main filters at like 500 volts, and absolutely no way to bleed them that was apparent before removing the board. Who the designs this shit ? People who can't do real audio or anything really useful ? For want of a 68K resistor. How the hell did they get that past the UL ?   Rant over, please do add. Any advice on these made to stay put cases and cabinets would be appreciated. I am really thinking of groinging stuff down at this point because if we get involved with it and it comes back, it comes back to me. Unless I quit.   Oh yeah, I got a chance to go work for RSQ. Their stuff it really a blast too, I just met with a rep last week. I do not know where this is going but I can tell you this - it is less heavy lifting and my back is tired.

Phil Allison <pallison49@gmail.com>: Nov 12 11:04PM -0800 jurb......     > Another amp, I did not cut this off, but I had to peel it. The edge of the chassis pushed the shit out and then there was no way except to get down to the plane. Then it came out. I guess I could glue it back down but then the volume of the glue would make it even tighter.   > Maybe I should grind down the bare wood a bit ? Or maybe I should grind down the chassis pans.   > I am trying not to break shit, that is not what I get paid for bu it seems to be easier said than done. And all this applies to amp heads, not just combos. And these big old tube ones, damn.   ** I do know what you mean !!   The vinyl material binds and jams the chassis cos the glue job was bad   OR   the chassis ends move outwards when the side bolts are done up, particularly with the aluminium chassis used in many Fender SS models - and takes the foil shielding with it.   OR   the chassis was fitted before the vinyl glue dried and becomes glued itself   OR   the front, edge of chassis catches on the aluminium shield plate stapled to the inside of the cabinet - as with older tube Fenders and Marshalls.   IME chassis beating and cabinet repairs & mods are part of the joys of fixing guitar amps.     ... Phil

N_Cook <diverse@tcp.co.uk>: Nov 13 08:21AM > And then, I had one, a tube amp but with some solid state (so it wasn't from 19fucking15) that had no bleeders on the main filters at like 500 volts, and absolutely no way to bleed them that was apparent before removing the board. Who the designs this shit ? People who can't do real audio or anything really useful ? For want of a 68K resistor. How the hell did they get that past the UL ?   > Rant over, please do add. Any advice on these made to stay put cases and cabinets would be appreciated. I am really thinking of groinging stuff down at this point because if we get involved with it and it comes back, it comes back to me. Unless I quit.   > Oh yeah, I got a chance to go work for RSQ. Their stuff it really a blast too, I just met with a rep last week. I do not know where this is going but I can tell you this - it is less heavy lifting and my back is tired.   Sash-cramps , with the active faces reversed, plus a couple of thin steel measuring rules are your friends

jurb6006@gmail.com: Nov 13 01:00AM -0800 >"IME chassis beating and cabinet repairs & mods are part of the >joys of fixing guitar amps. "   You got talent in the sarcasm biz son.   Hmmm, you might be older, so if you are over 55 then :   You got talent in the sarcasm biz pops.   Seriously, I have every reason to believe that all this shit comes back to me eventually if I live long enough. So why not make it easy on myself ? Grind a little off the edges, round off the corners. If it doesn't go in easy then, use a fucking hammer and chisel.   Too bad you can't do that with speaker baffles. POUND the son a bitches out. Well now, pull the grill cloth off and grind down the wood a few mms, then restretch it tight as possible. Not rattling does not depend on being tight, it depends on being rigid.   And now, how the hell do you get Mackie mixers apart. And Behringer, no parts, fuck you. In a way they shouldn't be allowed to do it but it would be wrong to stop them. better to make them apprise the customer of the rest of the terms of the warrauntee as follows :   "...at our discretion, repair or replace ... manufacturing defects..."   But what they left out is that it is very possible that this $8,000 thing you bought has to be replaced in three years. They could make it like that but the market would not bear it.   "Whatever the market will bear".

jurb6006@gmail.com: Nov 13 01:09AM -0800 >"Sash-cramps , with the active faces reversed, plus a couple of thin >steel measuring rules are your friends "   Thanks for that, it gives me ideas. I almost got into that today but I know the stuff to do that is not available. Might be there, but not available. Actually not exactly that, but things like that.   PUTTY KNIVES !   Gonna gets me some putty knives. I give it a try. Whaddeyegottoolose ?

Mike Tomlinson <mike@jasper.org.uk>: Nov 13 03:52AM En el artículo <n1q6ij$5r7$1@dont-email.me>, N_Cook <diverse@tcp.co.uk> escribió:   >it used to be on Google as ><http://groups.google.co.uk/groups?selm=47khvl%24o1i%40alpha.aladdin.co.uk&outpu >t=gplain>   That message ID is actually <47khvl$o1i@alpha.aladdin.co.uk>. Did you type it in manually from a screengrab, or did you cut and paste it?   I haven't been able to find it. The article lookup at al.howardknight.net is usually reliable but that can't find it either. I'm wondering if you made a typo when entering it manually.   -- (\_/) (='.'=) Bunny says: Windows 10? Nein danke! (")_(")

N_Cook <diverse@tcp.co.uk>: Nov 13 07:43AM On 13/11/2015 03:52, Mike Tomlinson wrote:   > I haven't been able to find it. The article lookup at > al.howardknight.net is usually reliable but that can't find it either. > I'm wondering if you made a typo when entering it manually.   Copied and pasted in 2001 and every now and then over the years, clicked on, and it brought up the original message, text as per Mark Zenier finding. Until just recently, when it no longer returned anything.

junebug1701 <junebug1701@gmail.com>: Nov 12 10:05PM -0800 > Does anyone know anything about this?   > WBR > Sonnich   I recently fixed one of these for a friend at work. His daughter had let the battery run completely down on her 7" Galaxy Tab. He kept trying to charge it using a phone charger cable, and of course that did nothing. When I finally got him to bring the original cable and charger, it still did nothing. Then I found a Youtube video showing how to pry the thing apart. I disconnected the battery, and reconnected it after waiting a few minutes. Put it back together, and then it started charging. It took around 6 hours for it to completely charge, and after that it worked fine.

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.