When I took out the tunnel that the dogs would stand on and terrorize the neighborhood, I put in a new vignette 
and wanted the passenger trains to stop there. As it is, the placement works well in that the beer train coming from the opposite direction will now stop at the brewery.
I wanted the trains to slow, then stop and wait, then slowly pull out and I wanted to do it using existing electronic parts without 555 timing chips for the various āeventsā.
I had three 2.7 volt supercaps and three unused 4PDT, 5 amp, 6 volt relays, as well as the usual fare. The idea is to charge up the supercaps then let them discharge into the relays for the various events. Once the supercaps discharge, the relays open and they begin their recharge cycle for the next train that approaches. The caps are rated at 2.7 volts (8.1 volts for three in series) and because the relays are really only subject to the discharge cycle, and activate through a diode loosing 0.7 volt, they never really see 8 volts.
The momentary reed switch activates the three relays and they reopen, one-by-one as hysteresis holds them open. Therefore, when assessing your relays, it is not a matter of what voltage they activate at, but rather at what voltage hysteresis lets then reopen. You want the relay that requires the MOST voltage to be the slow relay, the relay with the mid voltage to be the stop relay and the relay with the lowest voltage to be the go relay. You then adjust the timing as desired by using resistors on the relays to reduce the available voltage to them, and this reduces the time they stay closed. Because I want them to stop as long as feisible, no resistor is used on the stop relay. Note that the values used are very small. The LEDs let you see the relay timing.
As each of the slow and stop relays reopen, their windings are taken out of the circuit so the capacitorās energy is not wasted through them when they are no longer engaged. If the resistor for the Acceleration relay is too big and this relay cuts out before the stop relay normally would, it will also reopen the stop relay and you need to decrease this resistorās value.
