We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency given by the components according to the formula next to the diagram.
This circuit was obtained from a Popular Electronics of 1994. The magazine no longer exists in its...
This circuit is from Motorola documentation on 1976 power devices. SCRs are powered according to...
This latching alarm using SCR was found in a Popular Electronics from 1992. The circuit triggers a...