Hi Im attempting to build a push button start system for my car and I plan on using a decade counter and a single button to trigger the counter and I need help with how I should design it to take into account a few details of this type of circuit that a normal 4017 decade counter wont do on its own. The way it needs to work is as follows:
1. Press Button once and release, circuit goes from OFF to ACC which is first position.
2. Press Button and release again, circuit keeps ACC on and turns on IGN which is second position
3. Press Button and HOLD for start, IGN (position 2) must stay on and the start fuction should only function while the button is held on.
4. After Button is released from start position, ACC and IGN both are active.
5. Press Button and release and circuit resets to off position.
I figured using a circuit similar to the LED sequencer with the 555 timer to debounce the switch would work as the basis of the circuit. Tying the different outputs together and isolating them with diodes would help seperate the funtions of the different positions of the counter and would solve the issue of the counter not being able to count up and retain certain positions together (such as IGN and ACC staying on together after pressing the button twice"i hope this isnt confusing") As far as triggering relays I figured I could use a set of transitors to trigger relays for each individual circuit. My main concern though is how to momentarily trigger the START circuit and then go to the next position after it is released since I do not want the STARTER to have to be pressed on and then have to be pressed off again. Im hoping this problem is easily solved with an additional circuit or posibbley just an extra component.
1. Press Button once and release, circuit goes from OFF to ACC which is first position.
2. Press Button and release again, circuit keeps ACC on and turns on IGN which is second position
3. Press Button and HOLD for start, IGN (position 2) must stay on and the start fuction should only function while the button is held on.
4. After Button is released from start position, ACC and IGN both are active.
5. Press Button and release and circuit resets to off position.
I figured using a circuit similar to the LED sequencer with the 555 timer to debounce the switch would work as the basis of the circuit. Tying the different outputs together and isolating them with diodes would help seperate the funtions of the different positions of the counter and would solve the issue of the counter not being able to count up and retain certain positions together (such as IGN and ACC staying on together after pressing the button twice"i hope this isnt confusing") As far as triggering relays I figured I could use a set of transitors to trigger relays for each individual circuit. My main concern though is how to momentarily trigger the START circuit and then go to the next position after it is released since I do not want the STARTER to have to be pressed on and then have to be pressed off again. Im hoping this problem is easily solved with an additional circuit or posibbley just an extra component.