Thanks for this very useful video! I was able to clone the project and eliminate the photo sensors on a Liftmaster commercial roll-up door operator. Here are a few helpful notes I'd like to share: 1) There are different versions of the 555 timer board out there. The one I found was cheap, came from China, and had the Vcc and Output pins reversed. 2) A really good source for a connector is a CD drive audio cable from back in the days where there was a separate audio signal from the drive to the computer's audio card or MoBo. These connectors had positions for 4 conductors. Shift one connector over a slot, and grind off the extra connector housing with a disk sander or Dremel tool. 3) Without the diode, you'd not be able to connect the output and the Vcc lines together. There is a necessary resistor on the Receiver board that helps make this work. Connect those lines without a diode, and your 555 will get really HOT. 4) Timing - No substitute for some type of scope to see what is going on. Again, my board was different. The jumper on the board controls the output frequency range. Mine ended up on a different set of pins. The GDO will probably tolerate wide timing variations, but if you want to get close so long-term success is more assured, look at the waveform you're trying to copy. Mine ended up being 2.7mS High, with low pulses of 0.7mS (294Hz) 5) To the guy who is satisfied with the totally in-elegant solution of mounting the photosensors on the wall pointed at each other - you've just demonstrated the difference between engineers and much of the rest of the world. You're sending a message to all who witness your solution. They'll say nothing, and leave with a definite impression. Do it this way, and they'll be asking how you did it, and admiring your ingenuity!

I did it for an ancient Genie Blue Max. I cut the 6 pin connector into one 3 pinner and one 2 pinner. I used the 3 pinner to tie into the timing board per your instructions, and I used the 2 pinner to tie into the STB connection on the box. I had to turn the upper pot about 3 turns ccw, and voila, IT WORKS!!! YAY!! THANKS!!!

I did this on my garage door, and it worked perfectly . Thanks for the tip.

This works perfect! I just did this to my brand new chamberlain and it works flawless. I got 2 boards and 100 diodes on eBay for about $9!

Water damaged the sensors of our circa 1990s Raynor garage door system. Sensors are no longer available and there are no competitor models that are compatible. The N555 adjustable circuit to the rescue - with one minor tweak. The base frequency 1-50Hz with the jumper in the 1st position is too low. Place the jumper in position 2 the 50 - 1KHz and slowly CCW turn the pot until the LED on the N555 board lights, as described in the video. The 'No Sensor LED' on the garage door opener goes out and the opener responds to wireless and wired key presses. Many thanks for putting up this video.

Exactly what I was looking for...thank you!

Very good video! Thank you for explaining how this works!

Thank you, this is exactly what I needed. I did it the cheap way, I built the equivalent circuit to the Arduino board and used fixed resistors because I didn’t have 10k pots, and it works perfectly. Thanks again for the great video!

brilliant! worked perfect on my motorlift ml850. thumbs up! thanks

Thank you for this video.

Tremendo. Gracias! Amazon tiene este modulo por menos de $8.

genius!! thank you so much

Love it, thanks!

Awesome.

Great video for an opener for free and didn’t want to buy sensors and couldn’t really mount them on the rails so this worked perfect. It wouldn’t work at disaffected but I kept cranking backwards and it finally lit up and worked

Thanks for the info

Hello, very cool setup! I actually am trying to do something harder maybe. I found a really nice seco-larm photoeye set that mounts into single gang box in the drywall either side of garage. Looks very cool and is fully adjustable. I connected 12v to each receiver and transmitter. White common and green normally closed to opener motor contacts. I can hear the photoeye tripping so it is working. But the signal from the eyes must not be what the opener wants. It keep flashing 4led at me as if there no connection. Must be this pulse issue. Do I throw these away or is there hope of getting them to work? I even tried an inline 10k resistor which in hiensight reveals my lack or real knowledge. seco-larm e-932-d33tbq eye Liftmaster 1/2 hp 41Ac050-2

I did not get a 3-pin connector for the Vcc/Gnd/Output in my order? Do you know where i can get that so i can connect everything up?

THANK YOU !!!!!!!

excellent

Hello is there anyway to bypass RPM sensor in garage doors thanks

Do you weld it together

So, according to your previous video, the voltage is low for 500uS and high for 6mS for a total period of 6.5mS. That equates to about 154 Hz. Is this correct? The opener circuit must be pulling the power line to +6V through a resistor. The 555 circuit shorts it every 6 mS for 500uS. The 555 module itself is powered by the same power, but its filtered by the diode and the internal caps on the 555 board. Thanks for a great video!

Great video and information. Thank you Does the pulse generator board come with the 3-pin connector for the Vcc/Gnd/Output?

Can this be used to for the travel distance to be increased to around 16ft? My opener has a timer or something that stops the door at 10ft. Even after removing the travel adjustment contacts.

I have a craftman 1/2 HP opener part no. 41AC150-1M that has 4 connection points. 2 for the contact switch and 2 for the sensor wires. Will this system in your video work on that motor? if yes then how do I need to connect it? if no then do you know of any other bypass system?

Doesn't connecting the output of the 555 timer to the + on the opener run voltage down and to the chip on the timer which can damage the chip?

are there any specifications on the diode and will an led work?

Led is solid after turning out a few turns but opener still won't go down

Why didn't you just mount the sensors facing each other out of the walking path????? You did this the hard way since you actually demonstrated how to get around it at the beginning of your video!

you forget to tell where to put the jumper on the board ?

wow, you did this the very hard way. I simply remounted the sensors at the high point on the track, still facing each other. took about 10 minutes and the sensors are out of my life.

Save yourself 15 minutes, read this: Step 1: Move the jumper one-level up to the 2nd set of pins. Step 2: Rotate both blue flat-head screws clockwise until you hear a small click. Step 3: Connect GND pin to 2nd screw on garage door opener. Step 4: Connect OUT pin to 3rd screw on garage door opener. Step 5: Rotate the blue flat-head screw that's farther from the jumper counter-clockwise until an LED on the board turns on. Note, you do not need a diode.

anyone have a name or a link for the 3 pin connector. tried google search with no luck.

Wow, this seems like a ton of work (not to mention a few $$) to eliminate the safety. Why not just take the two sensors and electrical tape them together so they think the beam isn't being broken, and zip tie them to the top of the control unit and wire them up? I have mine installed as they should be, but they are a PITA ever time you bump them. I'm gonna be trying the "tape together" method as soon as the weather warms up...

This is great, but there's a MUCH simpler method: Take an 8" strip of metal or wood, drill 2 holes in it and mount both sensor devices on it nose-to-nose using their own fasteners, and zip-tie that up behind the opener on the ceiling.

I think this is awesome that you have figured this out. HOWEVER !!!! And garage door opener that does NOT meet the safety standards of today's standards can not be worked on by a garage door service company. Lets say that the person was trying to sell their home that has this cheat on it. They will have to replace the opener or install a pair of the OEM safety eye's !!! You can buy a set of the safety eyes on the internet for a very cheap price and keep it SAFE !!! Again this is great that you have cracked the code. BUT !!! Very UN-safe and will eventually have to be Fixed the right way !!!

sigh- just mount sensor units high- slide both units to top of track

HAAHA supereasy. What a joke