Decreasing voltage (newbie question)

[Ben]

I have a 5 Volt CC, 1 A power source but I need a 3.7 V one.
Since I couldn't find the proper power source in any place I hope somebody
can tell me how to set the voltage to 3.7, preferably in an easy way, since
where I'm living (Dominican Republic) is not easy to get electronic parts.

Thanks in advance,
Ben

 

[Joerg]

Hello Ben,

I have a 5 Volt CC, 1 A power source but I need a 3.7 V one.
Since I couldn't find the proper power source in any place I hope somebody
can tell me how to set the voltage to 3.7, preferably in an easy way, since
where I'm living (Dominican Republic) is not easy to get electronic parts.

A normal voltage regulator cannot really live with that small
differential of 1.3V, you'd need a low dropout regulator (LDO). That may
be difficult to buy over there. If the voltage does not have to be
precise you could use two diodes in series with the 5V pin. Something
big like 3A diodes. The usual 1N4007 is too weak for 1A.

But be aware that with two diodes in series the voltage will not be
precise. You could connect a resistor to ground to load the 3.7V side a
bit, to avoid excessive voltage under no load.

Sometimes you can also adjust the output voltage inside the supply. But
then it may dissipate more heat so you can't load it with the full 1A
for too long. If it is a switch mode supply or you don't know how it
works I wouldn't do that though. If there is a ham radio operator in
your area you could ask, they often know this stuff pretty well.

Regards, Joerg