Micoamperes detector

Discussion in 'The Projects Forum' started by badrove, Apr 7, 2008.

  1. badrove

    Thread Starter Member

    Mar 18, 2008
    Hello every body,

    I need to detect a low value of current in a circuit(1.5uA to 50 uA) and i have to use just transitor(s), resistances and capacity(ies).

    About resistance, i think that i have to choose some high values to detect these current values(10 Mega, 1 Meg or...).

    can you help me please to define this scheme.

    thank you.

  2. DC_Kid

    AAC Fanatic!

    Feb 25, 2008
    the skie's the limit if you can use as many transistors as you want. where exactly is this small current you trying to "detect".

    i perhaps would use a very low precision resistor (1% or .5% .05ohm) in series with this small current, then using the transistors you have build a diff op-amp with large gain to sense the small voltage drop across that resistor. however, using discrete transistors to build a usable high gain diff op-amp may prove to be cumbersome and futile.....