Integrator with bias compensation (CB20991E)

This circuit was found in a Popular Electronics from the 90's. It can be implemented with equivalent operational amplifiers.

Locked alarm (CB22472E)
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...
Triac Power Switch (CB11918E)
This circuit is used for incandescent lamps and other resistive loads up to 3A using the TIC206. This...
Stepper Motor Controller (CB4674E)
This circuit is from 1995 documentation, but can be easily assembled today, as the components used are...