This circuit was suggested by General Electric in 1970 documentation. It makes use of a photo-SCR or LASCR, an uncommon component today.
The gain is given by R1 and R2. The circuit is from the 1993 Motorola Linear Interface ICs. The...
This circuit has a fairly common configuration consisting of a counter phase oscillator. The power...
This circuit with Norton operation is from an article in Radio Electronics magazine. The gain is...