Dose any one know how it works like do yyou need the detection unit to make it work?
It is possible to control the crossing signal manually through the use of a switch such as a toggle or slider or whatever. But, on a larger layout, that can be a real pain, running over to activate the switch, then waiting for the train to pass the crossing before you can turn off the switch.
The automated way to activate the crossing signal is to install some time of detection system such as an occupancy detector, light sensor, etc.
Hope that helps. Others may elaborate more.
Rich
You need a detection circuit such as the Grade Crossing Pro from Logic Rail Technologies and a Tortoise slow-motion switch motor.
Although not technically a wig-wag signal, these crossing signals can be operated manually with a switch and do not require a Tortoise.
http://www.walthers.com/exec/productinfo/189-5934
Also, if you set up crossing signals without gates, you won’t need to use Tortoises to control the flashing lights, just an occupancy detection system.
Rich