Tunnel diode delay (CB21431E)

With two cascading tunnel diodes, this circuit found in a 196 General Electric documentation provides capacitor-dependent delays.

| Clique na imagem para ampliar |

Going Astern Alert (CB4774E)
We found this circuit in a Popular Electronics of the 90s. The circuit still uses light bulbs, but...
Window comparator with lamps (CB5077E)
Instead of LED bulbs, LEDs with a series 470 ohm 1k resistor can be used in this 80's circuit....
Touch Switch (CB24695E)
This simple circuit can use any general-purpose transistor. The power supply must be isolated. The circuit...