Pulse generator with delay 555 (CB8922E)

We found this circuit in a Hands On Electronics from the 90s. The delay is given by the formulas next to the diagram.

Magic Spring (CB13041E)
Here is an interesting circuit to be used in physics demonstrations involving energy...
Phase Rotation Damped Oscillator (CB12363E)
This circuit, obtained from a 1978 publication, generates damped signals and can be used in...
Photoelectric Sensor with Opposite Cells 741 (CB14645E)
We found this circuit in a manual of optoelectronics from Texas Instruments. In it photodiodes or...