Power Supply Question

Hello, I’ like to know if converting AC to DC (with diodes bridge and capacitors) in addition to voltage, the output amperage increases, too

For example.
I have a 15 Volt 500mA transformer and after the diodes and capacitors I get around 21 Volt ... but the amperage remains 500mA or it encreases proportionally too?

Regards

No. What you're seeing is that the 15V faceplate spec of the transformer is the AC voltage output of the transformer, and the peak voltage of that 15V AC sine wave is 1.41 (square root of 2) times its average voltage. The rectifiers, unloaded into an output capacitor, give you the 21.2V output, but if you start to draw current off of that output capacitor, then that DC voltage will also go down.

In no case will the output current rating change, regardless of what you do to the 15V AC output of your transformer. That's essentially a power rating of the transformer that takes various losses into account.

If anything the current would go down.  There are some formulas to determine things,  the actual voltages and currents will change depending on how you convert,  half wave,  full wave,  capacitor input,  inductor input,  etc.

But as pointed out,  it's really a power issue.  Best case is the load gets close to the power delivered by the transformer.

http://www.sowter.co.uk/rectifier-transformer-calculation.php

Cheers

Ian

Thank you to all!

You want "more voltage" AND more current?

You want the free lunch with that?

To avoid violating the Universe's NO Free Lunch rule, the current ability must go DOWN.

You might suspect "1.414", but it is actually worse. 1.6 to 1.8 depending.

Unless you can custom-design just-right transformers, "2" is an easy and safe bet. Your 500mA AC PT should not be asked for more than 250mA DC. Maybe 300mA, but sag may be bad.

If you actually plan a 500mA DC current, you need to shop for near 1A AC rating. A 800mA part may work, barely.