We found this circuit in a 1996 publication. The circuit uses components that are still common. The timing depends on C1, which can be changed, and the triac can be of any type.
This circuit shows how it is possible to control 9 loads with only 6 Triacs using the matrix...
This passive circuit was found in a 1980s documentation. The circuit serves to indicate the...
Placed in the vicinity of a telegraphic transmitter (CW), this circuit produces an audible signal on...