This 100 second timer was found in the September 1992 issue of Radio Electronics magazine. The circuit has two timing ranges and time adjustment at R6.
This high-gain circuit uses junction FETs (JFETs) and must be powered by somewhat high voltages. The...
This circuit counts 1 per second, displaying the value in binary. The circuit is TTL and must be...
Critical components of this project are the Geiger tube and the 300V battery. The battery can be...