BUILD THE GARAGE
By Brian Beard
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Automatic garage door openers can be a real blessing. I know, I feel that way
every time I drive home in the rain. As convenient as they are, they are also a
potential danger. Everyone — at one time or another — has gotten distracted
and failed to close the garage door. An open garage door is an invitation for
thieves and vandals. And don’t forget the mischief birds, cats, raccoons, and
other animals can cause in your garage. So, I decided it was time to build a
circuit that would close my garage door when it was unintentionally left open.
My goal was to design an automatic closer circuit that
was simple and reliable. Because it is a safety device
intended to compensate for my forgetfulness, I didn’t want
to power it with batteries that I would have to remember
to change in the first place. If the closer could be powered
by the garage door opener itself, that would be ideal. I
have a Genie radio-controlled automatic garage door
operator. Like every automatic garage door operator, it
also has a local normally-open pushbutton to open and
close the door.
■ FIGURE 1. Voltage and current
available on the PUSH BUTTON
output of my Genie garage door
operator as a function of load