This switch or band selector for receivers was found in a Popular Electronics from the 1990s. The circuit uses a PIN diode.
In this 1974 circuit, the Triac fires when the neon lamp reaches its ionization voltage of around 85...
The circuit shown in the figure is suggested by National Semiconductor and is based on an...
The 7401 is a different member of the TTL family, as it consists of four NAND ports, but with the...