This interesting circuit for the RDA8851 allows you to obtain two volumes with a simple touch. The circuit is from an Electronics Now from December 1988. Note the amplifier voltages.
August 2017 - STMicroelectronics' new T850 switches with triacs up to 8 A can be obtained from...
This circuit is from the 1990 Motorola Linear Databook. The circuit can be applied to other...
Found in documentation from the 90s, this circuit makes use of components from the time....