[quote user="BigAl 956"]
Hi, welcome to the hobby.
Your question is confusing because it does not reflect the purpose of a dwarf signal wich is commonly found in yards where clearances prohibit the use of full height signals.
First of all, the Dwarf signal is red or green. Are you proposing to replace the red bulb with yellow?
Second, Not sure of the operational reason to have this signal perform the way you want.
So here is how you activate a signal. You wire in insulated tracks to all 4 sidings. Tie all the insulated outer rail tracks to a SPDT relay. (Make sure the relay is seperately powered from the track or the relay will not work when the tracks are unpowered.) Connect the poles of the relay to the red/yellow and green bulbs on the signal. What you will end up with is the wheels of the engin or cars acting like a switch to conduc current to activate a relay that can switch power between two positions.
There are numerouse wiring circuits on line to do this.
First of all, Yes!. Second, recall Big Jim on Taxi saying whhhhhaaaaat dooooos aaaa yeeellooooow liiiight meeeean?
So thank you for the information on the SPDT relay. I honestly, wasn't aware of their existence! I'll give them a read.
