Common negative for more than 1 power supply?

[dfarning]

I am making a mock up of my electroplating bench to test my tank layout before I build a permanent bench and am wondering about the power busses.

I currently have 2 power supplies going, a 10A CC and a 25A CC. Is it possible for both power supplies to share a common negative bus and each have their own positive bus? or am I nuts? If it would work it would be really flexible without being too confusing.

The buses will look something like this.


ps 2 + ---------------------------------------------------------

ps 1 + ---------------------------------------------------------

comm - --------------------------------------------------------

| tank1 |rinse1a| tank2 |rinse2a| tank3 |rinse3a| tank4 |rinse4a|
| tank1 |rinse1a| tank2 |rinse2a| tank3 |rinse3a| tank4 |rinse4a|
| tank1 |rinse1b| tank2 |rinse2b| tank3 |rinse3b| tank4 |rinse4b|
| tank1 |rinse1b| tank2 |rinse2b| tank3 |rinse3b| tank4 |rinse4b|


Each tank is 17.5 gallons followed by 2 X 5 gallon rinse tanks.

Thanks
Dave

[jrow]

Re: Common negative for more than 1 power supply?

dfarning,

Yes electrically you can tie them together, BUT I don't know what the feed back from one power supply thru the other would do to the power supply that is off!

Try this: get an [OFF/ON /OFF] switch. Attach the comman from one of your power supplies to the OFF contact and the other comman from your other power supply to the other OFF contact. The ON would be attached to your comman buss. This will allow you to switch between either power supply and share the same comman. Radio Shack should have the switch.

Make sure you size the wire and the switch properly.

John

[sswee]

Re: Common negative for more than 1 power supply?

jrow's switch suggestion is sometimes called a 3-way switch. I'm with him on the feedback possibility.
SS

[dfarning]

Re: Common negative for more than 1 power supply?

Thanks guys,

The three way switch is a good idea. Well, enough ideas. I guess it is time to get out a couple of multi-meters, some scrape, and a fire extingisher and run some tests.

Dave