This circuit uses a feedback integrator. We found it in Ferranti's transistor manual from 1974. Transistors are general-purpose types at the time.
Indicated for activation by microcontrollers, this circuit was found in the Radio Electronics...
November 2016 - The new OLED modulator for displays with 2 x 16 format can be obtained from Mouser...
This interesting circuit for the RDA8851 allows you to obtain two volumes with a simple touch. The...