Instructables

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

nedfunnell5 years ago
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.
ReCreate (author)  nedfunnell5 years ago
a resistor? By current do you mean the amps or watts of volts?
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.
ReCreate (author)  nedfunnell5 years ago
yes i do know what it means...its just that some times people refer to current as voltage...yeah i know
I really think that you ought to take some time and read up. 50VDC can kill.
ReCreate (author)  nedfunnell5 years ago
No...its actually 60 Volts DC and 30 volts AC
Well how about rectifying the AC output then? It would help to know what this thing is... L
ReCreate (author)  lemonie5 years ago
how?
Diode(s) L
ReCreate (author)  lemonie5 years ago
yes i know that diodes can be used to turn AC into DC I meant to ask why would it help to know what the thing is? Also my power source is DC not AC
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?
ReCreate (author)  tudgeanator5 years ago
Well i don't know. I must have made a mistake, its DC
k i understand
ReCreate (author)  tudgeanator5 years ago
Ok then
ReCreate (author)  ReCreate5 years ago
ERR...i mean why?
ReCreate (author)  nedfunnell5 years ago
About 1 amp or so
lemonie5 years ago
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
ReCreate (author)  lemonie5 years ago
umm...what? Rephrase that
What exactly have you got? It might help us to give you good answer :L
ReCreate (author)  lemonie5 years ago
what do you mean? whats the input voltage? or what does the output need to be?
What is the device that's providing you with 50V output, and what's the device you want to run at 30V? L
ReCreate (author)  lemonie5 years ago
ermm...its quite hard to explain why do you want to know where the electricity is coming from and going to?
If we know what you're dealing with we might be able to give you a better answer. L
ReCreate (author)  lemonie5 years ago
how about i tell you how much capacity the source can handle?
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
ReCreate (author)  lemonie5 years ago
I will look back and laugh... slow charge a 12 lead acid batt-use an inverter-charge your cellphone EKK...yes i know i freaked out
I've given up trying to find out what this is, but thanks for the replies. L
ReCreate (author)  lemonie5 years ago
Who cares what the source is! Its no ones problem if the source is electricity from planet mars or if it is a rotting away apple outside! All you should care to know is the voltage which is 50Volts AC! But tell me,Why do you want to know what the power source is? Why does that matter ?
. 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.
ReCreate (author)  NachoMahma5 years ago
And so what?
The ring signal?
Screw you.
. 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.
ReCreate (author)  NachoMahma5 years ago
Really,i have been shocked by 400V capacitors,Outlets,inverters And pretty much everything else that you can think of,And guess what Im not dead
The ring signal?
Yes i AM aware of the ring signal,I'll cross that bridge when we get there And besides I am not going to have this hooked up all day long!
And yes,SCREW YOU! SHOO FLY SHOO!
Your not my guardian angel,Really you(should) do not care if i kill myself with electricity...
Turkin ReCreate5 years ago
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.
ReCreate (author)  Turkin5 years ago
Oh no,Here we go again
> 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.
~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
ReCreate (author)  lemonie5 years ago
im not sucking an amp from the phone line,nor do i plan to But why is that so relevant? Huh? Are you just trying to pop my buble or what?
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
ReCreate (author)  lemonie5 years ago
well don't,seriously.
Admit it - It is the phone line isn't it? L
ReCreate (author)  lemonie5 years ago
OH MY GOSH,IM GONNA USE THE PHONE LIKE TO TRICKLE CHARGE MY CELL PHONE BATTERY! OH MY GOSH ITS THE END OF THE WORLD THE FBI WILL BE LOOKING FOR ME BECAUSE I JUST CHARGED MY CELLPHONE BATTERY WITH THE PHONE LINE TO TAKE A PICTURE EKK...So what?
ReCreate (author)  ReCreate5 years ago
Just in case,Im not braking the "be nice" policy Its just like a joke...yeah what i said
frollard5 years ago
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?!
ReCreate (author)  frollard5 years ago
hmm... light bulbs ingenius! because...the device accepts 35 volts and under...don't ask
Thats just what I mean - I dont care what it is, just why use a 50v supply for a 30v item?
ReCreate (author)  frollard5 years ago
because the minimal output voltage is 50 volts!
PKTraceur5 years ago
Resistors... i mean, really, like a few thousand ohms... -PKT
ReCreate (author)  PKTraceur5 years ago
hmm...where can i get em?
RadioShack, online, they're a really common comodity.
ReCreate (author)  PKTraceur5 years ago
oh no...15 dollars for a few leds...YOU GOTTA BE KIDDING!
ReCreate (author)  PKTraceur5 years ago
i have 100 ohm resistors...so i wire them all in series to equal a thousand ohms
The correct amount isnt a thousand ohms, you'd need a voltage/resistor/ohm calculator to find it.
ReCreate (author)  PKTraceur5 years ago
several thousands ohms?