Re: How to use Liftmaster garage door IR safety sensors for other uses?

[eeewoz50@xxxxxxxxx]

On Monday, June 25, 2012 at 5:37:06 PM UTC-4, Bob F wrote:
> I picked up a couple pairs of these Liftmaster 41A5034 garage door safety=
=20
> sensors, which I thought I might be able to use for other sensing on my h=
omebrew=20
> home control system. Does anyone know what voltage/current the sender nee=
ds, and=20
> what connections the 2 wire detector needs and how it signals. They both =
have=20
> white 2 conductor wire with a black line on one of the conductors.

The way that the sensors work might be this:  The transmit module power lea=
ds and the sensor power leads are connected in parallel.  The transmit modu=
le pulses on at a fixed rate. The detector module shorts out the power lead=
s whenever it detects a light pulse from the LED module.  The control unit =
watches for pulses on the power leads.  No pulses means the light path is b=
locked.