We found this Vox in a 1969 Motorola documentation. Transistors support modern equivalents and the SCR can be a TIC106. The reset is done by a push button.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit activates a relay by activating one of a series of optical sensors that can be...
We found this circuit in a 1996 publication. Equivalent components can be tried, especially in the...