Maker Pro
Maker Pro

Constant current (or voltage) source WITHOUT semiconductors?

NuLED

Jan 7, 2012
294
Joined
Jan 7, 2012
Messages
294
Hello - Is there a way to provide constant current (or voltage) without using ICs or even transistors?

I would expect a lot of energy lost through heat, from analog current and voltage division (or maybe not?) but what about the feedback system to maintain the constant level?

Thanks.
 

Bluejets

Oct 5, 2014
6,988
Joined
Oct 5, 2014
Messages
6,988
Look at the older DC generator systems on automotive charging circuits.
 

Ratch

Mar 10, 2013
1,099
Joined
Mar 10, 2013
Messages
1,099
Hello - Is there a way to provide constant current (or voltage) without using ICs or even transistors?

I would expect a lot of energy lost through heat, from analog current and voltage division (or maybe not?) but what about the feedback system to maintain the constant level?

Thanks.
Sure, it is easy to do. Suppose you want to build a 10 ma constant current DC current source. Find a 100 volt DC supply. Then insert a 10k resistor in series with the voltage.source. Now you have a 10 ma current source that will use 100 volts to assure that 10 ma exists. If that is not enough, then higher voltages and resistances can be used.

Ratch
 

BobK

Jan 5, 2010
7,682
Joined
Jan 5, 2010
Messages
7,682
A battery makes a pretty good constant voltage source.

Bob
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
you could also build a circuit with valves!
 
Top