This analog instrument circuit was found in a 1990s William Sheets. The components are common and are only suitable for cars with mechanical switching (platinum).
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...