Alex: You are new to the forum and may not have seen the relay modules that are much less expensive. Since you're no stranger to eBay, try the following number in the search box:
183776948137
Make these your starting point. The relays are rated for 10 amps; perfect for running O-gauge model trains. They will certainly work to fuel your crossing signals.
They do take a bit longer to arrive since they come from overseas. But you can find US sellers on eBay as well with the price a little higher.
