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
This may seem like a stupid question, but are you sure your switch is on the live wire of the mains, and not the neutral?
Just a thought???
Just a thought???
Dosnt it sound more like he is seeing the voltage of the psu caps?? Else he would measure the same voltage all the time if it was the 0 wire he had the switch on??
Magura🙂
Magura🙂
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
Wow. I've never been censored before. I'll have to bring this up at the next UN poliy meeting.
For those scratching their heads, the four letter word I used is common North American vernacular pertaining to the excretion of liquid from one's engorged bladder.
Kofi
For those scratching their heads, the four letter word I used is common North American vernacular pertaining to the excretion of liquid from one's engorged bladder.
Kofi
Me thinks Magura has a point - check your voltages - things may be rotten in Denmark!
Were you really born on Friday?
Steve
Were you really born on Friday?
Steve
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
If its DC comming in from the neutral vire, you can kill it by adding a feed through capacitor.
Magura🙂
Magura🙂
As Magura said, this needs a schematic also to show exactly where you measure. What kind of meter do you use? VTVM, multimeter, what scale/mode setting?
Jan Didden
Jan Didden
Did you check for phase and neutral reversal at the wall outlet? It's not as uncommon as you might think.
However you do seem to have a potentially serious problem, so take great care, and if you are in doubt when measuring something, keep one hand in your back pocket for safety.
However you do seem to have a potentially serious problem, so take great care, and if you are in doubt when measuring something, keep one hand in your back pocket for safety.
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
Kofi Annan said:
Moving to Denmark will solve your problem if its voltage on neutral of the mains outlet. We have nice and relatively clean AC here 🙂
It may be easier to solve the problem with less drastical means though 😉
Magura🙂
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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