We found this mains-powered switch circuit in Electronics Now magazine from July 1994. It could be used in a table lamp or touch control.
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...