500 mW amplifier using the 741 (CB6991E)

This circuit was found in 80's Popular Electronics. Transistors are commonly used. The potentiometer R5 adjusts the gain.

| Clique na imagem para ampliar |

Positive Comparator (CB24963E)
The circuit with a common operational amplifier uses a zener as a reference. The circuit is from...
Automotive stethoscope (CB8953E)
This circuit was found in a 90’s Popular Electronics. The circuit is used to analyze noise in...
Three Phase Protection (CB4342E)
This 1989 circuit activates a protection relay if one or two phases are missing from a three-phase...