We found this circuit in 1967 General Electric documentation. SCRs can be replaced by current equivalents. The circuit is for 110V power grid.
In the figure we have the typical circuit of a Baxandall tone control applied to an operational...
August 2017 - Microchip's new ATtiny1617 8-bit AVR microcontrollers running at 20 MHz and 16 kB...
This Signetics circuit uses a double 555 (556) to generate tone bursts at frequencies determined by...