Step 5: Test it!

After you had built your power supply, test it with your multimeter to make sure they are no solder bridges.

After you tested it, put it in a plastic box or something to protect you from shocks.
But do not operate the power supply like I did, it is very dangerous because of the mains voltage on the transformer, you or somebody will get badly shocked!

My power supply has 11.73v output, not too bad, I don't need it to be exactly 12v...
N3v3rm0r34 years ago
How much current can that power supply give? I need 800mA....
brady9114 years ago
so do you connect the GND connection to the negative lead? i know this sounds like a stupid question maybe...
 Like magic, an LED appears!

Can you tell me how and where it was added? I noticed a (limiting?) resistor, too.

Maybe add it to the schematic, please.

Also, I am using your project as a guide to modify a circuit I put together to convert the 18VAC output from my home's Bell Transformer so as to power a LARGE 12VDC Bell (ARCHER 275-498 - Old RS Bell) that worked great off my car battery, but not so much off the 18VAC Bell Transformer through a diode package from RS. 

I thought the capacitors and regulator might help - hence my interest. 

BTW, if I am on the wrong track and need something entirely different, let me know that, too please!

Thank you
ir_syed4 years ago
Hello.i want ask 3 i want to vary voltage 12v ??should i use a variable resistor to control it??and where suppose i should put the variable resistor in the circuit???...anyone can help me...plezz
codex6535 years ago
is that 12v ac or dc?? i'm looking to make an 12v ac power supply from a battery to power some of my projects as the mains seem to be quite too high! :)
Plasmana (author)  codex6535 years ago
It is DC output.