These 7400 ic testors i biult in 2 sections to make biulding them easyer , just add a push button and plug the 7400 ic into the socket and push the button to test, leds will alternate to indicate that the first section is working ok . to test the other section just plug the 7400 ic into the socket in the other circiut to teast the 2nd half of it , note the simplicity of the 2 section 7400 ic testor .
by Steven (received via e-mail)
by Steven (received via e-mail)