This timer was found in Japanese documentation from the 1960s. The transistor can be replaced by an equivalent and the relay must be of the sensitive type with voltage according to the power supply.
This circuit for old photo enlargers was found in a 1970s RCA manual. The components are from the...
This CMOS oscillator circuit generates signals up to a few megahertz, depending on the capacitor value....
This circuit was found in a 1977 Radio Handbook. The ports used are CMOS like 4001 and the...