Found in Philips' 1967 documentation, this circuit makes use of period components. The SCR can be of any type, depending on the power of the controlled load.
This dual balanced modulator configuration was obtained in a 1980s telecommunications...
To excite a higher power load, such as a 40mA lamp, we have the circuit in the figure. For this...
We found this circuit in old documentation from National Semiconductor. The circuit makes use of a...