Using a dual 555 CMOS this very useful circuit on the bench was found in the July 1998 Electronics Now magazine. The circuit is battery powered.
This circuit can be used for several purposes such as pulse counter, pass counter, roulette, etc....
This amplifier was obtained from the CA3140 datasheet, an operational amplifier with JFET at the...
Analog Devices suggests this circuit in documentation from the 1990s. The circuit is for 75-ohm...