The AT422 has a built in feature of two "coins to start" settings, plus two "time per coin" settings. For example, a location could program the vacuum feature for $.75 for 4 minutes and another...
Microcontroller Based Circuitry Accumulates 1 to 15 Coins - 1 Second to 17 Minutes per coin Multiple Time Delay Selection Dual Control: No Interfacing Totalizer and Timer ...
