This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the 80's, using a component of the era. Transistors are general purpose types.
September 2017 - Semtech's proximity sensors SX9310 with Specific Absorption Rate (SAR) can be...
This circuit uses two sensors that are placed at the intersection of a miniature railroad, causing the LED...
This is a traditional complementary-output transistor amplifier sourcing 2 to 4 watts to a 4 ohm...