Up to 3 minutes timer (CB21429E)

We found this circuit in a 1967 General Electric SCR manual. The time is set to R1 and depends on C1 which must be a low-leak capacitor.

| Clique na imagem para ampliar |

Sampling and holding (CB9188E)
Using components from the era, this 90's EDN circuit is used in analog to digital conversion...
Car adapter (CB7252E)
Found in an American publication from the 90s, this circuit allows the supply of 3, 6 and 9 V...
Light Controlled Monostable (CB21018E)
We found this circuit in an old Popular Electronics. The circuit is experimental, driving an LED...