General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs that are not common components today. Note the timing components that may change.
This circuit enables the bilateral command of triacs with the use of low current switches. The...
The figure shows a way to apply gain control to the LM3600 OTA. The circuit is from a Radio...
This configuration was found in a 1990s documentation. Modern operational amplifiers can be used...