This old circuit, from the 80's, uses an integrated circuit that is uncommon today. The circuit is intended for loads controlled by triac and the resistors depend on the desired control.
In the figure we have an anti-ring or debouncer circuit with 555. The duration of the pulse is...
One of the application circuits we gave with the 4013 in this circuit bank was a bistable switch...
This analog volt-ammeter was found in an Electronics World of 1968. It makes use of a 0-1 mA...