Comments on: Voltage regulator http://apowersupply.com/voltage-regulator-circuit-152.html Mon, 30 Aug 2010 14:53:37 +0000 hourly 1 http://wordpress.org/?v=3.0 By: ece http://apowersupply.com/voltage-regulator-circuit-152.html/comment-page-1/#comment-1518 ece Fri, 23 Apr 2010 15:27:12 +0000 http://apowersupply.com/?p=152#comment-1518 Can I get me half my homework Can I get me half my homework

]]> By: miloman http://apowersupply.com/voltage-regulator-circuit-152.html/comment-page-1/#comment-1490 miloman Sun, 11 Apr 2010 21:19:27 +0000 http://apowersupply.com/?p=152#comment-1490 well here I am again back where I started 3yrs ago,,I have no formal education in electronics and at my age of 54 have NO desire "physically" to sit in any classroom atmosphere,,however after 27yr contract plumbing career ended from an accident, I found myself ingulfed with time and a sudden intrest in electronics. I built the "JL Naudin" 30KV powersupply fromscratch learning as I went how to read capps and resistor values because I wanted a variable power supply to test ideas of mine and everytime I tried to adjust voltage down on a project using a pot the pot of course would burn from the current, So I wound what later I found out to be availabe,,my own verzion of rheostat using nicrhome wire from a stripped out heating blanket wound on a cpvc pipe and the core of a alkaline battery for a wiper,,,crude but it worked . Still have it, still works but then I found the Naudin PS and built it. I have used it for sometime until the other day when I was testing a froze 12 V fuel pump and not knowing it had froze, I hooked it up and immediately smelt smoke from my supply,,,so upon exam I found I had burned up the 5K pot used to adjust the 2n3055, I replaced it and started it up again and hooked up an auto brakelight bulb after cking with my multimeter that it operated,,,BURNED up that NEW pot! through further exam I found my LM7812 had also decessed and was allowing all the 60V through to the variable circuit so puzzeled I reexamined the schematics, then went to my data on the 78xx's and found that the in Voltage was way to high for this regulator,,,but it had worked for 3 years and had never shown signs of over voltage. How could this schematic have the req of a 75VA2x24V 1.56A transformer and use the 78XX seris regulation ? I haven't replaced the regulator yet because I thinnn I know what went wrong,,,I never FOUND a transformer in my area with those specs but I did manage to salvage one trans from an old magnovox stereo tv combo cabnet that put out 70V on the multimeter as to the 1.56A I had nor have no idea what amps this transformer puts out but under a resistive load she sure HUMMMS WELL! MY questIon is; before silicone, what was the circuit used to reduce voltage with discrete parts off the shelf,,, kirchoffs? Voltage dividers?? I would like to be able to say I know how to do this with parts instaed of Regulators, variac's,or rheostat's. Any help out there for a old sore bone would really make me happy! Thanks Ed well here I am again back where I started 3yrs ago,,I have no formal education in electronics and at my age of 54 have NO desire “physically” to sit in any classroom atmosphere,,however after 27yr contract plumbing career ended from an accident, I found myself ingulfed with time and a sudden intrest in electronics. I built the “JL Naudin” 30KV powersupply fromscratch learning as I went how to read capps and resistor values because I wanted a variable power supply to test ideas of mine and everytime I tried to adjust voltage down on a project using a pot the pot of course would burn from the current, So I wound what later I found out to be availabe,,my own verzion of rheostat using nicrhome wire from a stripped out heating blanket wound on a cpvc pipe and the core of a alkaline battery for a wiper,,,crude but it worked . Still have it, still works but then I found the Naudin PS and built it. I have used it for sometime until the other day when I was testing a froze 12 V fuel pump and not knowing it had froze, I hooked it up and immediately smelt smoke from my supply,,,so upon exam I found I had burned up the 5K pot used to adjust the 2n3055,
I replaced it and started it up again and hooked up an auto brakelight bulb after cking with my multimeter that it operated,,,BURNED up that NEW pot! through further exam I found my LM7812 had also decessed and was allowing all the 60V through to the variable circuit so puzzeled I reexamined the schematics, then went to my data on the 78xx’s and found that the in Voltage was way to high for this regulator,,,but it had worked for 3 years and had never shown signs of over voltage.
How could this schematic have the req of a 75VA2x24V 1.56A transformer and use the 78XX seris regulation ? I haven’t replaced the regulator yet because I thinnn I know what went wrong,,,I never FOUND a transformer in my area with those specs but I did manage to salvage one trans from an old magnovox stereo tv combo cabnet that put out 70V on the multimeter as to the 1.56A I had nor have no idea what amps this transformer puts out but under a resistive load she sure HUMMMS WELL!
MY questIon is; before silicone, what was the circuit used to reduce voltage with discrete parts off the shelf,,, kirchoffs? Voltage dividers?? I would like to be able to say I know how to do this with parts instaed of Regulators, variac’s,or rheostat’s.

Any help out there for a old sore bone would really make me happy! Thanks Ed

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