This power supply has a resolution of 10 pA in the current range from -100 to +100 nA. The circuit is from a 90s Electronic Design operating with voltages from -4 to +3.5 V.
We found this circuit in the On Semiconductor thyristor manual. He makes use of a triac and a PUT....
This 80's circuit uses a light-sensitive SCR or LASCR and a one-sided silicon switch SUS, uncommon...
Using an RCA CA3018 as a base, this circuit has a sensitivity of 2 Mohms per volt. The circuit is from a...