Large Scale Central

Name of an electronic part?

Electronics
#1

I’m looking for the name of a part that changes polarity coming in so it it always the same going out. Mainly so a battery could be hoked up in any polarity and not smoke electronics. I know it exists just can’t remember the name.

If anyone knows of any or how to make them mine would need to handle at least 18v and over 4 amps. I’m a bit of a novice at this so please keep the explanations simple :slight_smile:

And, while on this topic, is it diodes that stop positive voltage from going one way? What size or number would I need for the same application above?

Thanks,
Terry

#2

You are thinking of a full wave bridge. Might also be called a bridge rectifier. They can be made from 4 diodes, or purchased as an assembled part in various current ratings. Their primary use is to convert AC to DC, but can also be used in DC applications. DC input would go on the “AC” terminals. Regardless of which AC terminal is connected to +, the DC Output is always + or - as marked on the part.

#3

Jon is correct.
Bear in mind that each silicone diode drops .7 of a volt so a bridge rectifier will drop 1.4 volts. That is fine if voltage is not critical.
If you are using just DC voltage a single diode should be all that is necessary. As the voltage will only go one way it does not matter what polarity is of the DC supply leads. One way it will work. The other way it will not work.
If voltage drop is a problem you can use Schottky diodes which only drop .2 volt.

#4

Thanks!