In the figure we have a stereo decoder from the 70's with pilot lamp for signal indication. The circuit employs a component of the time, which is uncommon today.
The transistor of this constant current source may be the BC548 or equivalent. Resistor R2 may be...
The LMV321 is a low voltage operational amplifier from ON Semiconductor. The following diagram,...
Two FETs connected as shown in the figure behave similarly to a light diode whose characteristics are the...