Are There Ready-Made Amplifier Modules for 50A 50mV Current Shunts?

4 replies · 3K views · last reply
Jdo300
Messages
548
Reaction score
5
Hello All,

I'm designing a test setup that requires the use of a 50A 50mV current shunt to take measurements for a circuit which produces pulsed DC currents up to about 100 kHz or so (highest frequency component anyway). I would like to use this shunt here, but also amplify the signal 10x or 100x before feeding it into an oscilloscope.

I have been searching around online but was wondering if anyone knows of any nifty amplifier modules that are made for use with shunts? I know I could find a shunt IC and roll my own circuit but if there is already a ready-made solution out there, that would be a very good time-saver.

Thanks,
Jason O
 

Discussion

This sort of thing used to be common in labs under the name bench amp or lab amp or similar.
Mine still works well after all these years. It has a low frequency point of 1Hz.

Old fashioned broadband (milli/micro) voltmeters and telecommunications field testing kit often had output terminals as well as input so you could use as an amp.

You would need to trawl the second hand/surplus outlets to find one.
 
Attachments
  • Vintage Levell advertisement for A.C. Amplifiers types TA401, TA601 and TA605, showing a small transistor amplifier box with cable and a larger TA605 bench amplifier with rotary gain switch marked OFF, 20, 30, 40, 50, 60 dB and INPUT and OUTPUT terminals.
    benchamp.jpg
    34.9 KB · Views: 581
Last edited:
I don't think it would be hard to make a very suitable amplifier with an off the shelf OP amp chip. Are you after a particularly good noise performance?
 
This sounds like something similar to what is called the transmitter for thermocouples. Probably not a direct fit but it would be a place to start.
 
50mV and 100kHz is nothing special. Make a so-called "instrumentation amplifier" from three op amps.

Fun: for power meters, one company got a patent to use a copper resistor in the ratio that defines the gain of an op amp. This resistor was coupled thermally with the shunt, so it compensated the temperature drift. Public meanwhile.