This is a total newbie question, but...
Today I was rewiring my Gainclone (aka "Ghettclone"-- worst wiring job EVER) when I thought I had blown a crappy Radio Shack switch and it was failing OPEN!
After futher review (and the purchase of a few more switches) I found that the cause is apparently NOT the switch. When I have the switch on, the voltage across the rectifier diodes is about 17.5 (about what it should be), when I turn the switch OFF, the voltage drops BUT DOES NOT GO AWAY!
I have measured the voltage across the rectifiers at anywhere from 2 volts to 10 volts.
I know that this may seem an idealistic newbie vewpoint, but I thought OFF meant OFF! When I unplug the power completely, the voltage drops to zero.
Is it possible that I have not properly grounded the power supply (I'm testing this) or that I there's a cold joint on the wiring for the neutral / return for the AC?
Maybe I'll just take up knitting, like Mrs. Annan.
Please help!
Kofi
Today I was rewiring my Gainclone (aka "Ghettclone"-- worst wiring job EVER) when I thought I had blown a crappy Radio Shack switch and it was failing OPEN!
After futher review (and the purchase of a few more switches) I found that the cause is apparently NOT the switch. When I have the switch on, the voltage across the rectifier diodes is about 17.5 (about what it should be), when I turn the switch OFF, the voltage drops BUT DOES NOT GO AWAY!
I have measured the voltage across the rectifiers at anywhere from 2 volts to 10 volts.
I know that this may seem an idealistic newbie vewpoint, but I thought OFF meant OFF! When I unplug the power completely, the voltage drops to zero.
Is it possible that I have not properly grounded the power supply (I'm testing this) or that I there's a cold joint on the wiring for the neutral / return for the AC?
Maybe I'll just take up knitting, like Mrs. Annan.
Please help!
Kofi
Actually, the answer is no to both questions.
The switch is connected to the live wire and there are no ps caps attached yet. By the way, there are no stupid responses-- only stupid questions, like mine.
After I re-grounded (is this a word?) the power supply, the voltage on the rectifier diodes with the switch OFF is steady at about 2.5 volts. Not enough to kill (probably), but enough to **** me off.
Any other thoughts? I would happily engage in Santaria if I thought it would go away as a result.
Kofi
The switch is connected to the live wire and there are no ps caps attached yet. By the way, there are no stupid responses-- only stupid questions, like mine.
After I re-grounded (is this a word?) the power supply, the voltage on the rectifier diodes with the switch OFF is steady at about 2.5 volts. Not enough to kill (probably), but enough to **** me off.
Any other thoughts? I would happily engage in Santaria if I thought it would go away as a result.
Kofi
I guess you're talking about measuring the voltage between the neutral plug and the earth ground plug on the AC receptacle?
If so, there's nothing with the ps unplugged, but about 25V AC with the ps plugged in and aobut 47V AC with it plugged in and switched on. No ps caps here and no amp circuit connected-- just the grounded power supply and some moron who put it all together.
Kofi
If so, there's nothing with the ps unplugged, but about 25V AC with the ps plugged in and aobut 47V AC with it plugged in and switched on. No ps caps here and no amp circuit connected-- just the grounded power supply and some moron who put it all together.
Kofi
Just a hunch... unplug everything and check voltage between hot and ground, and then, neutral and ground at the wall. I'm new to this forum so there is usually some safety concerns when working on the "mains" (as the Brits are fond of saying). So be careful, say a Novina and wear a helmet!
It would not be uncommon to see what is termed a "back feed" where neutral (that should be -0- VAC) is really some other number that is not zero.
Let us know what happens.
It would not be uncommon to see what is termed a "back feed" where neutral (that should be -0- VAC) is really some other number that is not zero.
Let us know what happens.
Just tried it and there is nary a volt to measure between neutral and ground at the wall.
I'll post a schematic tomorrow morning. If you have any other ideas, please let me know.
I have a feeling that this really is coming in from the neutral wire, as you suggested. If it is, then nothing I can do about it, I guess.
What about a DPDT switch with both the hot and neutral attached? Would this provide some added safety? It is worth it?
Kofi
I'll post a schematic tomorrow morning. If you have any other ideas, please let me know.
I have a feeling that this really is coming in from the neutral wire, as you suggested. If it is, then nothing I can do about it, I guess.
What about a DPDT switch with both the hot and neutral attached? Would this provide some added safety? It is worth it?
Kofi
The power supply schematic I'm using comes from Thorsten's site (I think its actually Fedde's?) here.
I'm thinking it must be the neutral wire that's carrying some voltage (about 2V).
I'm using the stellar Radio Shack $9.99 multimeter ($7.99 with Battery Club membership) at the "2V" (lowest) scale and it shows, coincidentally, 2 volts. I measured the current at lowest sensitivity and its too low to measure.
Again, do you think a DPDT switch would do the trick if the neutral wire is actually carrying the current? I have never used a DPDT before, but I'm thinking it has three terminals-- one for the live AC, one for the neutral and one for the "out" to the fuse. Theoretically, wouldn't the off position turn cut the live and the neutral off? Should I rewire my house? Should I move to Denmark?
Kofi
I'm thinking it must be the neutral wire that's carrying some voltage (about 2V).
I'm using the stellar Radio Shack $9.99 multimeter ($7.99 with Battery Club membership) at the "2V" (lowest) scale and it shows, coincidentally, 2 volts. I measured the current at lowest sensitivity and its too low to measure.
Again, do you think a DPDT switch would do the trick if the neutral wire is actually carrying the current? I have never used a DPDT before, but I'm thinking it has three terminals-- one for the live AC, one for the neutral and one for the "out" to the fuse. Theoretically, wouldn't the off position turn cut the live and the neutral off? Should I rewire my house? Should I move to Denmark?
Kofi
I think that you want a DPST switch. Double pole, single throw. That's what I bought for my GC. Don't ask me why, but that's what I read on http://www.decdun.fsnet.co.uk/gainclone.html. Seemed like a good idea.. whether you live in Denmark (where, evidently, nobody has ever wired a light switch backwards) or Racine, USA, Planet Earth.
I would also consider that your GC project might take second fiddle to a little thing I like to call "brokering world peace".
I would also consider that your GC project might take second fiddle to a little thing I like to call "brokering world peace".
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