Is there any simple circuit to lower dc voltage?

(which is about 50v) by at least 20 volts(so it reached the thirties or twenties in voltage) And NO it NOT the phone line Keep it as simple as possible

53 answers
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Mar 14, 2009. 4:26 PMlemonie says:
Is this coming off a transformer? Are there any other taps on it? Loathed as I am to say "rewind", it is an option... L
Mar 14, 2009. 5:34 PMlemonie says:
What exactly have you got? It might help us to give you good answer :L
Mar 15, 2009. 4:52 AMlemonie says:
What is the device that's providing you with 50V output, and what's the device you want to run at 30V? L
Mar 15, 2009. 12:55 PMlemonie says:
If we know what you're dealing with we might be able to give you a better answer. L
Mar 17, 2009. 4:05 PMlemonie says:
Admit it - It is the phone line isn't it? L
Mar 16, 2009. 12:25 AMlemonie says:
It's the phone isn't it? You want to tap the phone line for power? Forget it, it's not going to work. L
Mar 18, 2009. 12:23 AMlemonie says:
I've given up trying to find out what this is, but thanks for the replies. L
Mar 19, 2009. 12:35 PMNachoMahma says:
. If you're trying to steal power from the phone system, you're clueless.
. POTS uses -48VDC. Then there's the ring signal that you have to take into consideration.
. As L points out, the telco can tell.
Mar 20, 2009. 2:04 AMNachoMahma says:
. ROFLMAO . > And so what? . At times, there is potentially lethal voltage on the lines. Even if it doesn't kill you, it will make you hurt yourself getting away from it . > The ring signal? . Yes, the ring signal. . > Screw you. . Thanks for the offer, but I'm straight. And I'm guessing that you're underage, anyway.
Mar 23, 2009. 3:25 AMTurkin says:
I can't believe how much of a child you are being here. People tried to help you, and you responded with the online equivalent of kicking and screaming while rolling on the floor. Now even when some people still offer advice you come back and throw more trash around. If you can't take the advice go find a book and attempt to read it, if you are able.
Mar 21, 2009. 4:09 AMNachoMahma says:
> i have been shocked by 400V capacitors ... Im not dead
. I've been shocked by tens of thousands of volts and I'm still here. I've also been put into cardiac arrest by just a few volts. You obviously don't understand how electricity works.
.
> And NO it NOT the phone line
> Yes i AM aware of the ring signal, I'll cross that bridge...
. OK, you're a liar. I'll have to remember that.
.
> SCREW YOU!
. Unwanted sexual advances is harassment. I am not interested. That's two.
.
> Really you(should) do not care if i kill myself with electricity...
. I'm there. Feel free to consider the warnings to be meant for others and ignore them.
Mar 19, 2009. 11:21 AMlemonie says:
~6 days, 38 comments - are you any closer to getting the answer you wanted? You do want to tap the phone system don't you? Trying to suck an amp out of it will cause problems.

L
Mar 19, 2009. 11:53 AMlemonie says:
Mar 14, 2009. 7:40 PM you replied to nedfunnell's question with "About 1 amp or so". If you overload the phone system and the company trace the fault back to your house (as well they might) your bubble will be popped.
Trying to save you some hassle man...

L
Mar 14, 2009. 9:06 PMfrollard says:
It's been said below. What is your source, and what is your application? I assume 50v DC? 30 volt drop at 1 amp is (30x1) 30 Watts. Thats more than any basic resistor would be happy to do. Various lightbulbs might do the trick Calculate the resistance you need, then measure the resistance of the bulb :D Lastly - why on earth would you run something 20 volts off of a 50 volt source?!
Mar 15, 2009. 1:06 AMfrollard says:
Thats just what I mean - I dont care what it is, just why use a 50v supply for a 30v item?
Mar 14, 2009. 6:34 PMPKTraceur says:
Resistors... i mean, really, like a few thousand ohms... -PKT
Mar 14, 2009. 8:10 PMPKTraceur says:
The correct amount isnt a thousand ohms, you'd need a voltage/resistor/ohm calculator to find it.
Mar 14, 2009. 8:10 PMPKTraceur says:
RadioShack, online, they're a really common comodity.
Mar 14, 2009. 3:05 PMnedfunnell says:
How much current? You typically want a voltage regulator. 50V is more than most voltage regulators can handle and 30v is still atypically high, but there are higher voltage ones I'm sure. If your load is permament and has a constant current, you could just use a resistor.
Mar 14, 2009. 5:19 PMnedfunnell says:
Honestly, if you don't know that, you probably ought to do a couple weeks of reading before trying to build anything. Current is amps, voltage is volts, power is watts, and resistance is ohms.
Mar 14, 2009. 7:06 PMnedfunnell says:
I really think that you ought to take some time and read up. 50VDC can kill.
Mar 15, 2009. 12:58 PMlemonie says:
Well how about rectifying the AC output then? It would help to know what this thing is... L
Mar 15, 2009. 4:15 PMlemonie says:
Diode(s) L
Jun 14, 2009. 10:41 AMtudgeanator says:
Quote-All you should care to know is the voltage which is 50Volts AC! Y are you so useless at getting your facts straight? Is it AC or DC?
Jun 15, 2009. 3:15 AMtudgeanator says:
k i understand

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