Post by thread:[EE:] Power Supplies

I'm getting pretty sick of my LM317 adjustable power supply I cobbled together when I first started with PICS, and am getting the urge for something a bit more substantial (read "more than 100mA output. I don't have much $ to blow on a fancy lab bench supply, and I really only need +5,+12 volts. What do most of you guys use as a basic power supply for cheap? -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

What you can do is upgrade the LM317 design for a more substantial one using an LM338, adjustable with 5A capability. I have built 100's (yes 100's) of units using this device for student bench supplies and have had less than a dozen returned with blown regulators. At full current and max Vin to Vout differential you will need a substantial heatsink. Good luck. PS: Check out the NatSemi WWW site fo more app data. Nino Benci. Robert B. wrote: {Quote hidden}> I'm getting pretty sick of my LM317 adjustable power supply I cobbled > together when I first started with PICS, and am getting the urge for > something a bit more substantial (read "more than 100mA output. I don't > have much $ to blow on a fancy lab bench supply, and I really only need > +5,+12 volts. What do most of you guys use as a basic power supply for > cheap? > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- ------------------------------------------------------ | Antonio (Nino) L. Benci | | Professional Officer, Electronic Services | | School of Physics & Materials Engineering | | Monash University | | email: spam_OUTelectronic.servicesTakeThisOuTspme.monash.edu.au | | T: 61 3 9905 3649. F: 61 3 9905 3637 | ------------------------------------------------------ -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Couldnt you use an old computer power supply, as far as I know the outputs are 5v and 12v. ----- Original Message ----- From: "Robert B." <.....piclistKILLspam@spam@NERDULATOR.NET> To: <PICLISTKILLspamMITVMA.MIT.EDU> Sent: Wednesday, April 21, 2004 8:48 PM Subject: [EE:] Power Supplies {Quote hidden}> I'm getting pretty sick of my LM317 adjustable power supply I cobbled > together when I first started with PICS, and am getting the urge for > something a bit more substantial (read "more than 100mA output. I don't > have much $ to blow on a fancy lab bench supply, and I really only need > +5,+12 volts. What do most of you guys use as a basic power supply for > cheap? > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

On Wednesday, Apr 21, 2004, at 21:29 US/Pacific, Robert B. wrote: >>> I don't have much $ to blow on a fancy lab bench supply Just how much do you have to spend? For between $50 and $100 you can get a pretty nice bench supply, with meters. I've found my bench supply to be unexpectedly useful; having voltage and current meters is like having an extra two DMMs that are always connected, and can keep you somewhat out of trouble. (see that little pic circuit start to draw an amp of current? Something's wrong!) Also charges batteries, runs hot wire cutters, shows motor run characteristcs, tests LEDs, and zaps NiCds.. www.bgmicro.com/prodinfo.asp?prodid=PWR1166 http://www.elexp.com/tst_3003.htm http://www.elexp.com/tst_1802.htm BillW -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Most of the bench supplies I've seen have been well over $100. $50 I would definitely go for. For now I dug out an old atx power supply as someone suggested and converted it to a $0.00 net +5/+12 supply. I think I might have cut off the - wires on accident, but oh well. It doesn't have a fan so it will probably melt someday and burn down my house.... all for saving a measley $50. Such is life. {Original Message removed}

On Wednesday, Apr 21, 2004, at 23:54 US/Pacific, Robert B. wrote: > $50 I would definitely go for. > http://www.elexp.com/tst_1802.htm is $58 (plus postage/etc. sigh.) You have some leeway in your lm317 design. Should be good for at least 500mA with a heatsink. I'm starting to be a fan of wall warts of assorted types. They can usually be plucked out of the trash. Some aren't regulated at all, but others deliver the same sort of convenient voltages as a PC supply in a much nicer package... BillW -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> I'm getting pretty sick of my LM317 adjustable power supply I cobbled > together when I first started with PICS, and am getting the urge for > something a bit more substantial (read "more than 100mA output. I don't > have much $ to blow on a fancy lab bench supply, and I really only need > +5,+12 volts. What do most of you guys use as a basic power supply for > cheap? I've done the same for the longest time, but finally settled and bought a cheap bench power supply: www.bgmicro.com/prodinfo.asp?sid=0410497685185185659563113&prodid=PWR 1166&page=3&cri=power+supply&stype=3&time_out=19:33 or http://makeashorterlink.com/?B17025918 It's a great little supply, and has done all I've needed it to do. Thanks, TTYL ---------------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

On Thu, Apr 22, 2004 at 12:03:52AM -0700, Mike nicholas wrote: > Couldnt you use an old computer power supply, as far as I know the outputs > are 5v and 12v. A couple of caveats though. The primary one is that a substantial load is required in order to get the supply into regulation. Tie (and heatsink) a 25W 8 ohm power resistor across the +5 supply line. That should force enough current to stabilize the supply. The other is that if it's a current ATX supply you'll have to figure out how to switch it to get it to work. See the MB actually controls powering up and down the supply, not the switch on the panel. Ideally you want to get one that has an on/off switch on the supply itself. BAJ -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Try going to a hamfest and picking up a good used three-output lab supply with meters and current limiting. I picked one up for $5. Sometimes you can get some real bargains on used stuff. With the summer season upon us in the US, there's a hamfest (electronics flea market) almost every weekend within driving distance. Who knows what else you can pick up. You can check the ARRL website for a hamfest in your area. Rick http://www.arrl.org/hamfests.html "Robert B." wrote: > I'm getting pretty sick of my LM317 adjustable power supply I cobbled > together when I first started with PICS, and am getting the urge for > something a bit more substantial (read "more than 100mA output. I don't > have much $ to blow on a fancy lab bench supply, and I really only need > +5,+12 volts. What do most of you guys use as a basic power supply for > cheap? > > - -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> A couple of caveats though. The primary one is that a substantial load is > required in order to get the supply into regulation. Tie (and heatsink) a 25W > 8 ohm power resistor across the +5 supply line. That should force enough > current to stabilize the supply. > Right idea, wrong value. 8 ohms on a 5 volt rail will only pass 600mA, about 3 watts. Generaly PC power supplies need about 30% of the rated load on the lowest output voltage to produce regulation. The one I have here is rated for 18 amps on the 5V rail so you would need about a 1 Ohm reistor (or slightly less) to force it into regulation. Newer ATX supplies need the draw on the the 3.3 volt rail. 0.5 to 1 ohm should suffice here. > The other is that if it's a current ATX supply you'll have to figure out > how to switch it to get it to work. See the MB actually controls powering > up and down the supply, not the switch on the panel. Ideally you want to get > one that has an on/off switch on the supply itself. > > BAJ ATX is easy enough to power up. There should be one green wire, short it to any black (ground) wire and the supply should power up just fine. (mine does :o) -Denny -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

{Quote hidden}>-----Original Message----- >From: Byron A Jeff [.....byronKILLspam.....CC.GATECH.EDU] >Sent: 22 April 2004 16:43 >To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU >Subject: Re: [EE:] Power Supplies > > >On Thu, Apr 22, 2004 at 12:03:52AM -0700, Mike nicholas wrote: >> Couldnt you use an old computer power supply, as far as I know the >> outputs are 5v and 12v. > >A couple of caveats though. The primary one is that a >substantial load is required in order to get the supply into >regulation. Tie (and heatsink) a 25W 8 ohm power resistor >across the +5 supply line. That should force enough current to >stabilize the supply. > >The other is that if it's a current ATX supply you'll have to >figure out how to switch it to get it to work. See the MB >actually controls powering up and down the supply, not the >switch on the panel. Ideally you want to get one that has an >on/off switch on the supply itself. > >BAJ The last bit is easy, you simply ground the green wire going to the main connector to switch the supply on. Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= Any questions about Bookham's E-Mail service should be directed to postmasterspam_OUTbookham.com. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I always build 'em, usually in desperation when the old one quits. The last one I built I put in a canned 5V open frame power supply, rated maybe 5 amps, and a 0-24V supply built up out of a 24V 2 amp transformer, a PIC, a FET chopper arranged into a regulator. The output is metered with a DC digital voltmeter, and slew controls run the voltage up and down. The slew controls just adjust the digital setpoint of the PIC regulator. It is not very sophisticated but it has served well for a while. I have one half built that will do +70VDC, but haven;t needed it bad enough to finish it yet. I have a high current version at home that started out life as a battery charger. Makes a nice cheap chassis. -- Lawrence Lile Herbert Graf <@spam@mailinglist2KILLspamFARCITE.NET> Sent by: pic microcontroller discussion list <KILLspamPICLISTKILLspamMITVMA.MIT.EDU> 04/22/2004 09:52 AM Please respond to pic microcontroller discussion list To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU cc: Subject: Re: [EE:] Power Supplies > I'm getting pretty sick of my LM317 adjustable power supply I cobbled > together when I first started with PICS, and am getting the urge for > something a bit more substantial (read "more than 100mA output. I don't > have much $ to blow on a fancy lab bench supply, and I really only need > +5,+12 volts. What do most of you guys use as a basic power supply for > cheap? I've done the same for the longest time, but finally settled and bought a cheap bench power supply: www.bgmicro.com/prodinfo.asp?sid=0410497685185185659563113&prodid=PWR 1166&page=3&cri=power+supply&stype=3&time_out=19:33 or http://makeashorterlink.com/?B17025918 It's a great little supply, and has done all I've needed it to do. Thanks, TTYL ---------------------------------- Herbert's PIC Stuff: http://repatch.dyndns.org:8383/pic_stuff/ -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Ah yes, you must have meters! Once I was working on a CB, and hit the transmit button, and noticed the output power was suddenly 15 watts. 5 Watts is all that is legal, and it had just measured 5 watts a few minutes before. Puzzled, I looked over at my DC power supply, and noted that the meter on the front was pegged at over 50 volts! Luckily I reached for the big switch with my right arm, which shielded my face from the explosion that came out of the CB radio about 5 seconds later. Pass transistor failed shorted, you know. -- Lawrence Lile Senior Project Engineer Toastmaster, Inc. Division of Salton, Inc. 573-446-5661 voice 573-446-5676 fax William Chops Westfield <spamBeGonewestfwspamBeGoneMAC.COM> Sent by: pic microcontroller discussion list <TakeThisOuTPICLISTEraseMEspam_OUTMITVMA.MIT.EDU> 04/22/2004 01:44 AM Please respond to pic microcontroller discussion list To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU cc: Subject: Re: [EE:] Power Supplies On Wednesday, Apr 21, 2004, at 21:29 US/Pacific, Robert B. wrote: >>> I don't have much $ to blow on a fancy lab bench supply Just how much do you have to spend? For between $50 and $100 you can get a pretty nice bench supply, with meters. I've found my bench supply to be unexpectedly useful; having voltage and current meters is like having an extra two DMMs that are always connected, and can keep you somewhat out of trouble. (see that little pic circuit start to draw an amp of current? Something's wrong!) Also charges batteries, runs hot wire cutters, shows motor run characteristcs, tests LEDs, and zaps NiCds.. www.bgmicro.com/prodinfo.asp?prodid=PWR1166 http://www.elexp.com/tst_3003.htm http://www.elexp.com/tst_1802.htm BillW -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

This is how I built mine. http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM David Bearrow At 10:42 AM 4/22/04, you wrote: {Quote hidden}>On Thu, Apr 22, 2004 at 12:03:52AM -0700, Mike nicholas wrote: > > Couldnt you use an old computer power supply, as far as I know the outputs > > are 5v and 12v. > >A couple of caveats though. The primary one is that a substantial load is >required in order to get the supply into regulation. Tie (and heatsink) a 25W >8 ohm power resistor across the +5 supply line. That should force enough >current to stabilize the supply. > >The other is that if it's a current ATX supply you'll have to figure out >how to switch it to get it to work. See the MB actually controls powering >up and down the supply, not the switch on the panel. Ideally you want to get >one that has an on/off switch on the supply itself. > >BAJ > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Spend the $58 and get a current-limited supply. That feature alone is worth it. I've saved many buggy boards by having the current limit trip and not destroy a board while I figure out what's wrong. The wall-warts I totally agree with. I have a bin of them from misc wherever - trash, flea markets, household electronic junk friends are tossing, etc., and I use them all the time for one-offs I give to clients. You do have to watch the voltages out, but most circuits I wind up making are 7805 @ < 200mA and its hard to go wrong. J William Chops Westfield wrote: {Quote hidden}> On Wednesday, Apr 21, 2004, at 23:54 US/Pacific, Robert B. wrote: > >> $50 I would definitely go for. >> > > http://www.elexp.com/tst_1802.htm is $58 (plus postage/etc. sigh.) > > You have some leeway in your lm317 design. Should be good for at least > 500mA with a heatsink. > > I'm starting to be a fan of wall warts of assorted types. They can > usually be plucked out of the trash. Some aren't regulated at all, but > others deliver the same sort of convenient voltages as a PC supply in a > much nicer package... > > BillW > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> Awe! But I really love the smell of melted silicon in the morning. If > all I had to look forward to after a long bout of soldering was the > click of a current limiting power supply, I might just drop the hobby > all together. :-D You can always set the limit high and troubleshoot by observing the smoke source if that's your personal style ... Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservmitvma.mit.edu with SET PICList DIGEST in the body

Incidently, I did this with an amplifier which was in my car... Kept on blowing fuses so I replaced the fuse with a piece of copper wire to see where the smoke comes from.... Replaced some mosfets and now everything is working perfectly again :) -----Original Message----- From: pic microcontroller discussion list [RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU] On Behalf Of Peter L. Peres You can always set the limit high and troubleshoot by observing the smoke source if that's your personal style ... Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservspam_OUTKILLspammitvma.mit.edu with SET PICList DIGEST in the body

we had a proto board that halfway through building developed a short, part had to be out that day of course. After 3 people looked at it for half an hour we were still no closer to finding it. Wound up pulling the valuablle chips and connecting a 12V SLA battery across 5V and gnd, found the fault, a tantalum cap and failed got a few choice holes burnt into the desk (i'm not joking these are serious holes) and blew a 5v regulator (understandablly I think, I really should have removed that too). A note to all who try this method AIM AWAY FROM FACE. Seriously that ammount of energy and things go pop with a bang. {Original Message removed}

> we had a proto board that halfway through building developed a short, part > had to be out that day of course. After 3 people looked at it for half an > hour we were still no closer to finding it. Wound up pulling the valuablle > chips and connecting a 12V SLA battery across 5V and gnd, found the fault, a > tantalum cap and failed Electronics lessons to learn the hard way. 103. ***NEVER*** use tantalum capacitors in other than low energy high impedance circuits if the voltage may exceed the capacitors rating for any period of time. Here the word "any" assumes the normal meaning. eg a 1 uS pulse is included in the period "any of the time". A power supply rail is never a low energy high impedance circuit. 104. *** NEVER *** listen to people trying to assure you that rule 103 is bunkum. 105 Tantalum capacitors belong to the common class of electronic components which contain crisis detectors. These allow them to detect when the worst possible time to fail will be and to act accordingly. __________________ Tantalum capacitors are great fun. I have seen one, in sequence: - smell terrible - emit smoke - emit a jet of flame - shriek loudly - explode - short the power supply rail. Solid aluminium capacitors (NOT common Al electrolytics) are much more boring. Apart from having about the same capacitance for size as Tantalum caps, they lack all the interesting features. YMMV but only in terms of what combination and sequence of events will happen to you. RM -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body

> > Electronics lessons to learn the hard way. > > > > 103. ***NEVER*** use tantalum capacitors in other than low energy high > > impedance circuits if the voltage may exceed the capacitors rating for any > > period of time. Here the word "any" assumes the normal meaning. eg a 1 uS > > pulse is included in the period "any of the time". > > > > A power supply rail is never a low energy high impedance circuit. > > > > 104. *** NEVER *** listen to people trying to assure you that > > rule 103 is > > bunkum. > > > > 105 Tantalum capacitors belong to the common class of electronic > > components which contain crisis detectors. These allow them to detect when > > the worst possible time to fail will be and to act accordingly. > > Comment on this from my friend Ken who has extensive manufacturing experience. {Quote hidden}> From: "Ken Mardle" > Russell, > > Yes agree entirely. > > I have long held suspicions that tantalum capacitors were invented by the > munitions industry and/or are manufacturing fallouts from companies > manufacturing electrically activated fuses. They should make excellent > detonators. > > Have used tens of thousands of solid-Al (Philips 128-series) across power > rails in industrial products over the last 15 years and NEVER had one > instance of failure (except one customer who tried to dry out a board in a > microwave). > > Regards, > > Ken Mardle -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu

>> 103. ***NEVER*** use tantalum capacitors in other than low energy high >> impedance circuits if the voltage may exceed the capacitors rating for any >> period of time. Here the word "any" assumes the normal meaning. eg a 1 uS >> pulse is included in the period "any of the time". >> >> A power supply rail is never a low energy high impedance circuit. > I was just following the spec sheet for the $160 A/D chip I figure if they > feel they can charge $160 for a chip they know a bit more about stuff than > little old me lol. > > All the rest of my power supply caps were electrolytic or ceramic. I suspect that your results speak for themselves. People who make $160 ICs probably also use laboratory grade supplies for testing and tend to assume that you do too. Unless they specify the purity of the supply that feeds the tantalum capacitor you have a grey area. Tantalums often fail when applied voltage is SLIGHTLY above rated voltage. If there is enough energy available in the line they are connected to (and power supply lines usually qualify nicely for this) then they will make a very hard short circuit, sometimes but not always preceded by smell, smoke, flame and explosion. This is a very predictable feature of Tantalum capacitors but they still seem to often be specified in this sort of application. If you can GUARANTEE that the supply to them will NEVER exceed their specification then they are a very nice capacitor - low impedance & compact. Excellent filter capacitors. But even better over-voltage crowbars :-). Solid Aluminium capacitors (not electrolytic) (available from Philips and others) have similar performance but lack the bad features. Russell McMahon -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu

On Sunday, Apr 25, 2004, at 16:16 US/Pacific, Russell McMahon wrote: >>> 103. ***NEVER*** use tantalum capacitors in other than low energy >>> high impedance circuits if the voltage may exceed the capacitors >>> rating for any period of time. Here the word "any" assumes the >>> normal meaning. eg a 1 uS pulse is included in the period "any of >>> the time". >>> >>> A power supply rail is never a low energy high impedance circuit. But Mommy... EVERYBODY does it! (Hmm. Can you tell the difference between Solid Al and Solid Ta SMT caps just by looking at them?) BillW -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu

I was using a 35V 2.2uf cap from +5 to gnd running after a 7805 powered from a +12 SLA. The 7805 has whatever caps the manufacturer recomends across input and output (an electrolytic and ceramic). After we found that short and replaced it, its been working fine for several tens of hours now (its test equipment (acceleromiter) so it dosent get much use). Its running on a 16 bit A/D chip and there are another 2 caps on the chips 2.5 volt ref lines. Crrently it looks like we are getting around 0 counts of noise from the chip and 6 from the feeder circutry which is pretty good for 2 bigass veroboard boards with a 20mhz pic nearby isnt it? (Frst A/D project ;->) Would the solid Al caps be good to use for bypass caps? Is there some nice page that talks about the different kinds of caps in something like a "caps for dummies" style with examples of use perhaps? {Original Message removed}

Jake Anderson wrote: <...> > Is there some nice page that talks about the different kinds of caps in > something like a "caps for dummies" style with examples of use perhaps? > Capacitors on bypassing. http://www.glencoe.com/ps/ee/williamson/bypass.html#introduction Picking Capacitors. http://www.capacitors.com/picking_capacitors/pickcap.htm -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu

>Spend the $58 and get a current-limited supply. That feature alone is >worth it. I've saved many buggy boards by having the current limit trip >and not destroy a board while I figure out what's wrong. Agreed. Especially when the object you power up is someone else's. First realisation of this came when the 8086 was the "new chip on the block" and the local distributor had just received his demo kit. he did not have time to build it, and I wanted to play with it, so was allowed use of it over Christmas if I built it. When powered on the supply went into current limit. A quick check showed no solder splashes or anything else untoward. A quick probe around with a meter with a lot of digits showed that one of the ceramic bypass capacitors was shorted. I found it by measuring across each one, and looking for the lowest voltage. Another experience was the absolute opposite of this. A new computer had arrived, and was left running a memory test to soak test for a bit. Next thing I got a panic call from the customer that it was on fire. again one of the ceramic bypass capacitors on the memory board had gone short circuit, and the 300 amp 5V supply just kept on going, as the Eveready advert says. The result was a sizable hole burnt into the circuit board, that required some work to patch it up - we could not send it back as it had been purchased as a minimum memory configuration and then we had fully populated the board ourselves, but it was one of the original components that died. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

ya know I'm thining i should stay away from these caps completley ;-> -----Original Message----- From: pic microcontroller discussion list [EraseMEPICLISTEraseMEMITVMA.MIT.EDU]On Behalf Of Alan B. Pearce Sent: Monday, April 26, 2004 9:29 PM To: @spam@PICLIST@spam@spam_OUTMITVMA.MIT.EDU Subject: Re: [EE:] Power Supplies <Snip> Another experience was the absolute opposite of this. A new computer had arrived, and was left running a memory test to soak test for a bit. Next thing I got a panic call from the customer that it was on fire. again one of the ceramic bypass capacitors on the memory board had gone short circuit, and the 300 amp 5V supply just kept on going, as the Eveready advert says. The result was a sizable hole burnt into the circuit board, that required some work to patch it up - we could not send it back as it had been purchased as a minimum memory configuration and then we had fully populated the board ourselves, but it was one of the original components that died. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads