How would I go about measuring the in-rush current on a DC feed of 30V. I have built a current limiting circuit which should limit current to 8mA and I need to how that the in-rush current does not exceed 10mA for 100ms.
Currently I use a relay to switch the feed on and off, however this bounces so I am going to replace this with a mercury wetted 0 bounce relay is this the correct thing to do?
Most sites I have seen discussing in-rush current seem to use a current probe but they are measuring Amps if not 100s of amps on motor feeds not a few milli amps are there current probes which can measure the mA range accurately enough for me.
Currenly I am using a shunt resistor in lieu of the current probe and notice that I appear to exceed the in-rush just from powering the current limiter without a load although only for the firt 12uS. Is this likely to be noise from the relay or the response of the transistors limiting the current, I am using a Transistor VBE referenced current source circuit from AOE, is there anything I can do to remove this initial spike or do I need to allow that there will always be this inital rush.
Any good web sites with this sort of info would also be appreciated
Many Thanks for any help
Paul.