Dual Tracking Power Supply from Single Output Isolated Power Supply

[hteo]

Hi. I have an Agilent E3615A single output isolated power supply rated for 35V at 1.7A. It has the +ve and -ve terminals together with a mains earth terminal. Instead of getting a dual output tracking power supply for dual polarity use such as with opamps, would it be possible to connect the +ve terminal of the E3615A to the positive power rail, the -ve terminal to the negative power rail and connect the mains earth to the ground?

Would this configuration even work? Of course, the circuit will not be isolated anymore and one would have to be careful where one connects the ground leads when probing with a scope to avoid shorts. If it does work, are there any drawbacks?

Thanks.

[madires]

Since the output is isolated you won't close a circuit loop by connecting your OPamp to -ve and earth or +ve and earth. You may test that by measuring the voltage between the earth terminal and the -ve/+ve terminals.

[DaveW]

Hi. I have an Agilent E3615A single output isolated power supply rated for 35V at 1.7A. It has the +ve and -ve terminals together with a mains earth terminal. Instead of getting a dual output tracking power supply for dual polarity use such as with opamps, would it be possible to connect the +ve terminal of the E3615A to the positive power rail, the -ve terminal to the negative power rail and connect the mains earth to the ground?

Would this configuration even work? Of course, the circuit will not be isolated anymore and one would have to be careful where one connects the ground leads when probing with a scope to avoid shorts. If it does work, are there any drawbacks?

Thanks.

For low current use like simple op-amp circuits, have a look at rail splitting circuits (or virtual grounds), like these http://vsagar.com/2011/12/02/what-is-a-virtual-ground-discussion-on-virtual-ground-circuits/.
You use a potential divider to find the half way voltage and then use an op-amp to buffer this. If you set your power supply to say 30V, this gives you +-15V, with the ground being generated by the rail splitter

[Stephen Hill]

DaveW,

The article you linked to is a copy of one written by Warren Young: http://tangentsoft.net/elec/vgrounds.html

[Stephen Hill]

Infact, that whole site smells of copied content. I checked a random sample of articles and the contents were all copies from other websites. Shame on the website owner!