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IR beam garage door circuit

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staffshawn

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Hi everyone. I can't believe I'm new to this forum. It's awsome.

Does anyone have an idea on how to defeat the IR safety beam on a garage door opener (temporarily of course)? The IR transmitter and receiver are wired in parallel at the opener unit and are connected to what appears to be power and ground.

Simply connecting the two connections together on the opener unit won't do it.

Thanks!!!

Shawn
 
HarveyH42 said:
Prevent you from closing the door on your car or kids...
Sounds good, our cat (he was deaf) had the panel lift door close on his head. He survived without any injury as it had an over current detection.

In order to by pass the beam I can think of 2 possibilities.

1. disable the receiver. You would need to know how it works in order to decide how to do this.

2. insert an IR transmitter in front of the receiver so it continues to receive a signal even though the real beam is broken.
 
Usually the receiver is interlocked with the actuating motor circuit (main board). Find the wires from the receiver unit to the main board, and depending on how it was wired, either bridge the wires where it's connected in the main board, or leave it open.
(Usually you will have to bridge it out. Wire break and failsafe wiring requires a permanently closed loop).
 
figured it out (maybe)

A little late coming back, but thanks for the pointers. I dug into this a bit more on the transmitter/receiver side. Circuit details if you're interested: It appears the transmitter, utilizing a common IR LED, is driven by a transistor driver on the low side (NPN) which is driven by the output of an oscillator involving the LM2903 comparator. The oscillator is made so that the output consists of about 20 short pulses of 5 ms each that occur every 100 ms or so. I didn't read the exact timing. See attached diagram.

The receiver utilizes the Siemens part SFH 506 which is a IR receiver with signal conditioning circuitry built in to remove dc, apply AGC, etc.... See the TSOP17 from Vishay - a cross. It's output follows the pulses, but removes the short pulses. That drives a transistor driver that acc. to the circuit, if powered with 24 directly (as most garage openers do) would sink 750 ma. Plus no evidence of the data would appear at the opener unit, so I concluded the source contained a series resistance of about 60-100 ohms. When the driver was activated by the receiver IC, the supply voltage is dragged down, producing data at the opener unit.

I also noticed the "gnd" side of the receiver IC is floated, clamped to the supply voltage by a 5 V zener, so the receiver IC is supplied with 5V no matter the input voltage.

By the way, the driver transistor on the transmitter was blown. I though for sure it was the Siemens part. Happy to find it was a lot simpler part to find.

thanks for readin',
Shawn
 

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  • Manatec garage door opener circuit.JPG
    Manatec garage door opener circuit.JPG
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sorry i have a question i need to connect the ir beams to the opener itself i need to know the connection points thank you
 
sorry i have a question i need to connect the ir beams to the opener itself i need to know the connection points thank
you

hi Henry,
This post is 2 years old.:)

I would suggest you start a new thread.

Use the forum SEARCH for Gargage Doors there is a lot of information.
 
Last edited:
Hi everyone. I can't believe I'm new to this forum. It's awsome.

Does anyone have an idea on how to defeat the IR safety beam on a garage door opener (temporarily of course)? The IR transmitter and receiver are wired in parallel at the opener unit and are connected to what appears to be power and ground.

Simply connecting the two connections together on the opener unit won't do it.

Thanks!!!

Shawn
I don't know but I would like to know where to buy one?
 
it will be a good simple Idea to use simple cheap circuit
just an oscillator in radio freq range say 88 MHz in your car activated by user
and remains active till a delay circuit operates on the other side
which is the garage of course that has a delay time enough to operate the automatic door motor
and a passer - two way switch will be on the opposite turn
which will turn off the door
for circuit diagram
please touch in
industry_smith@yahoo.com
 
I too need to do this. I just bought an old Chamberlain opener (used), to raise and lower some stairs to a storage area. I was going to use a motor and winch with limit switches, but the limit switches in the opener would work well for this. But the lack of any beam system is keeping the unit from working. The really old openers had schematics, but not the later ones.
 
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