Here is a paste from my blog. This circuit made with common components will activate the gas station up to every 8 minutes
The following is a repeat cycle timer for accessories activated by momentary pushbutton operation. MTH Sinclair gas station,firehouse,car wash,Mels diner,and lionel PW arrival board are some. The unused NO contacts of the relay are put in parallel with the pushbutton circuit of the accessory. Power is always applied to the black wires (AC in). The timer circuit (green wire- ) goes through a set of NC contacts on the relay. After the set time the relay energizes. The timer circuit is then broken and the relay closes,renewing the cycle. A 1000uf 35 volt capacitor across the relay coil (IN PROPER POLARITY) stores energy and hold the relay open momentarily allowing enough time to reset the timer and give sufficient pushbutton duration to start the accessory. So if hooked to one of the accessories mentioned such as the gas station and the timer was set at say 5 minutes it would cycle every 5 minutes just as if you were there pushing the button.
 |
 |
This and More circuits using the Mars timer his here and is a bit more legible
