Please check my simple circuit for errors

[ceefna]

Thanks Bountyhunter for your explaination, The only reason I fitted a completly seperate atx power supply was to power these meters so it looks like I will have to squeeze another 12V supply in there. Is there any other way I could utilise the ATX supply to run both meters?

Ceefna

 

[bountyhunter]

Thanks Bountyhunter for your explaination, The only reason I fitted a completly seperate atx power supply was to power these meters so it looks like I will have to squeeze another 12V supply in there. Is there any other way I could utilise the ATX supply to run both meters?

Ceefna

Exactly what voltage/current requirements do the meters have to run on?

 

[Mr RB]

Damn I hate those stupid meters. I had some of those mongrel things in the '80's. I didn't know anybody still sold them, most of the electronics suppliers here have the common ground digital panel meters now.

By far the easiest way to run them is just use a 9v battery for each display. They only draw a few mA so the batteries should last hundreds of anodising sessions.

Alternatively, ditch the digital current meter and just use a nice 10A or 20A analog meter. You don't need an exact current display, it's more important to see the basic current value, AND if it drops etc when anodising is complete. The analog meter is so much better for that.

And for the one digital voltmeter, well you can use a 9v battery, or get a tiny DC supply from a little wallwart etc.

You know there would be nothing wrong with an analog voltmeter too...

 

[ceefna]

Hello guys, the meters are rated at 9-12v AC or DC and 75mA. Think the 9v battery will be the easiest just didn't want to fit more switches. Could I use a 12v to 12v dc convertor? would like to power them from the ATX. Chinese rubbish!!!!

 

[bountyhunter]

You know there would be nothing wrong with an analog voltmeter too...

+1, make life simple.

 

[mneary]

The ATX power supply's 0V line is grounded. Since the voltmeter cannot share the same ground with the measured power, you probably can't use the ATX power supply for the voltmeter either. Aside from batteries or an analog meter, the best way would be to get a separate wall wart (9 to 12V) for each of them.