# Raising the current to a circuit without switches

Discussion in 'General Electronics Discussion' started by StrawberryBro, Mar 20, 2013.

1. ### StrawberryBro

1
0
Mar 15, 2013
Hi , I am new to electronics and was conducting an experiment, I'm learning, I pose the following case:

Suppose we have a normal circuit, where an LED is powered by a source of 1V, we do not know the polarity of the source, and we want to raise the supply current of 1V to 20V without using switches and without removing the source of 1V .

What could be done?, This is a diagram I did, on the left there is the circuit without modification, and to the right, is a reference about how it should be.

Thanks

2. ### BobK

7,682
1,688
Jan 5, 2010
As a theoretical question: Yes, put a bridge rectifier on both of the voltage sources and connect together the two + outputs and two - outputs. You can now plug in either or both voltage sources with either polarity. The larger one wins.

However, if you really are dealing with 1V (which will not drive any LED I know of) then it won't work very well, since the two diodes will drop more than 1V than that across the bridge.

Bob

3. ### davennModerator

13,833
1,950
Sep 5, 2009
And why would you want to put 20V across a couple of LED's ??
their life span is going to be measured in milliseconds

what is it that you are really trying to achieve ?
time for all the information

Dave

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,496
2,837
Jan 21, 2010
And 20V is voltage, not current.