switch S1 to the wall as shown in Figure 1. Attach the 90
degree angle bracket to the garage door with a couple of
screws so that when the garage door is closed, the roller
arm on switch S1 is also closed.
Make sure the bracket can move freely. Also, attach
the transmitter black box to the garage wall with Velcro™
The TWS-434A transmitter chip and the RWS-434
receiver chip cost less than $10 each. Certainly, some
piece of mind is worth that. NV
December 2013 41
■ FIGURE 4. ■ FIGURE 3.