CurSns4 – Amplifiers: Difference: Isolation.

RE: CurSns4 – Amplifiers: Difference: Isolation.

peterjcs23 — Mon, 23 Mar 2015 09:50:55 GMT

On another blog someone suggested a really good range of components for current shunt monitoring. These things are high side monitors and have a common mode capability between 20V and 60V.

http://diodes.com/catalog/current_output_79/

...Peter

RE: CurSns4 – Amplifiers: Difference: Isolation.

jw0752 — Fri, 13 Mar 2015 21:23:51 GMT

Thank you for the continuing tutorials.

John

RE: CurSns4 – Amplifiers: Difference: Isolation.

DAB — Fri, 13 Mar 2015 19:31:22 GMT

Good post.

It is easy to forget the many uses for the differential capability of the Op Amp.

Thanks for the reminder.

DAB

RE: CurSns4 – Amplifiers: Difference: Isolation.

michaelkellett — Fri, 13 Mar 2015 14:34:39 GMT

The problem with isolation amplifiers is the high cost, both of the amplifier itself and the isolated power supply required. The amp specs are often poor in some respects.

For high side current measurements it is a good idea to consider alternatives as well - like current sensors or hall effect sensors.

And for some applications a few extra resistors can massively increase the amplifier's common mode range (at the expense of noise and common mode rejection) - see amps like: AD8479 (600V, and pretty good general specs) or the older INA117 (200V). (£5.05 and £7.15 each (1 off Farnell) compared with £4.33 for the ACPLC790 which also needs an isolated power supply).

RE: CurSns4 – Amplifiers: Difference: Isolation.

clem57 — Fri, 13 Mar 2015 13:16:16 GMT

Excellent tutorial [mention:fb1238db64d142ca970213a1c696a43d:e9ed411860ed4f2ba0265705b8793d05]. Each time I think you nailed a topic, you find another good one. Keep it up. I especially like the references at the end.

Thanks,

Clem