Garage Door Safety Sensors

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You meant to say 'unlimited moxie' yes? :) I agree that would heat things up a bit.

There is a 'constant moxie controller' powering the transmitter. In US5465033 it is set up to limit at 62.5 milli moxies.

'Works great!

--Winston

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We were discussing the infrared transmitter/receiver pair that prevents the garage door from closing if an object is placed so as to interrupt the beam.

--Winston

In my lingo "limited moxie" means limited strength means current limited ;-)

The LM317 is set up as a current source.

Further observance shows that a supply greater than 8.2V (current limited) is needed to see the modulation (note the 8.2V zener (D1, SK8V2). ...Jim Thompson

In American controllers there is _also_ a requirement for motor torque sensing (due to hitting an object... set it high enough to eliminate nuisance obstruction by leftists :-) ...Jim Thompson

Hang a fishing practice weight (rubber plumb bob looking thing) on monofilament fishing line from the ceiling so it lines up with the center of the windshield (mirror mount is a nice target).

Careful- I think there are at least two kinds of 2-wire sensors. One seems to run on high voltage and one on ~6V.

Replacement parts refer to those with red and those with green LEDs being incompatible.

Best regards, Spehro Pefhany

Yup, you nailed it!

That is possible, but it would not be as good, IMHO. More complex and it would mean that the millisecond pulses are generated inside the receiver so an internal failure after the demodulator could cause a false "no obstruction" signal. Easy enough to test if someone had the bits- just use independent current-limited* supplies for each half.

Yup, only two connections to the box and no combination of reversed, shorted, broken or damaged sensors can plausibly cause a false positive (or cause any damage or even much stress to the bits thanks to the current-limited supply and diodes).

• I'd build a little unbypassed current/voltage-limited supply rather than use a bench supply neat- there's always(?) a largish e-cap across the output terminals in the latter, and that could kill the receiver even if the supply limits the steady-state current. A resistor and

Best regards, Spehro Pefhany

Which is an unreliable method so I doubt its used very much. I've never seen it used on garage doors.

It's on every "made for USA" automatic garage door opener since 1993....

For my purposes it looks like the Genie unit is best... old style... no smarts (aka crap uP to screw things up :-)

Simple analog deciphering. ...Jim Thompson

You live under a rock ?:-) ...Jim Thompson

My solution was a ping pong ball suspended fro the roof. If it hit the windshield, she's a little closer than she prefers to be.

No batteries, no wiring.

RL

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Well, yes there is.

Only if you really cut your wheel hard. The most obvious obstruction will be from frontists or rearests.

:)

--Winston

It is mandated and popular, here in Silicon Gulch, CA.

--Winston

Or a tennis ball. A bright yellow one.

You haven't looked at very many, at least in the last 20 years.

Have you been tested for Alzheimer's? It's a contact closure, when the beam of the electric eye (or the pressure strip at the bottom of the door) gets triggered, it tells the door to open.

How could someone who, at his own admission, already knows everything there is to know, not know such a simple thing?

Really, Jim. Have your wife drive you to the doctor.

Good Luck! Rich

I guess it must be another case where a representative from a manufacturer got a product cast in the law.

Why are you Europeons so obstinate? We have multiple safeties here that include light beams AND torque sensors AND OFTEN door edge switches.

Apparently Europeons don't have any head-up-butt sensors, because there would be no one to see it ;-) ...Jim Thompson