Non Inverting Amplifier (CB6437E)

This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any operational amplifier.

Simple Symmetric Power Supply (CB11921E)
This symmetrical or dual source without regulation is indicated for the feeding of experimental projects...
Relaxation Oscillator with common Transistors (CB10211E)
We can say that this circuit is equivalent to a unijunction transistor in the relaxation...
Shadow Activated Motor (CB15459E)
The passage of an object in front of the LDR, producing a shadow or even turning off the ambient...