Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

> Did you post this on your website?

Yes: http://formicapeak.com/~jimc/miscellaneous.html#4Aug2021 


> Our sensors have red LED to indicate their state.  LED on steady = normal
> operation, ready to go.  Blinking = blockage in the optical path signal
> (usually leaves that blow in).  The one not working has a dark LED, so I'm
> not sure if the sensor has died or the wiring is the fault, or ??

WD's have a green LED.  It's on if the path is clear, dark otherwise.
Our malfunctioning opener was 'glitchy'.  No visible disturbance to
the LED's, but missing pulses were clearly detectible with the 'scope,
and also, of course, by the opener itself.

We're quite happy now.  The other three openers are still working properly,
and have not been 'adjusted'.

-- Jim

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Meade Dillon via Mercedes]

Did you post this on your website?  I've got one garage door sensor that
has been on the fritz for a couple years, but we only use the wall mounted
button on that side of the garage so we just hold down the button and force
it closed.

Our sensors have red LED to indicate their state.  LED on steady = normal
operation, ready to go.  Blinking = blockage in the optical path signal
(usually leaves that blow in).  The one not working has a dark LED, so I'm
not sure if the sensor has died or the wiring is the fault, or ??
-
Max
Charleston SC


On Sat, Aug 28, 2021 at 3:47 PM Jim Cathey via Mercedes <
mercedes@okiebenz.com> wrote:

> It's been over a week, and the door has worked flawlessly.
> Numerous little 555 boards are available for sale online,
> anybody sick of malfunctioning mandated nanny-state sensors
> can do this fairly easily.  I suspect that all openers use the
> same system, though I have no proof of that.
>
> -- Jim
>
>
> ___
> http://www.okiebenz.com
>
> To search list archives http://www.okiebenz.com/archive/
>
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
>
>
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

> Hmm. Good. I just have to learn electronics now.

Not really.  Just follow the directions!

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Rick Knoble via Mercedes]

Hmm. Good. I just have to learn electronics now.


Rick

From: mercedes@okiebenz.com
Sent: August 28, 2021 2:47 PM
To: mercedes@okiebenz.com
Reply-to: mercedes@okiebenz.com
Cc: jim.cathey...@gmail.com
Subject: Re: [MBZ] OT: Garage door mayhem

It's been over a week, and the door has worked flawlessly.
Numerous little 555 boards are available for sale online,
anybody sick of malfunctioning mandated nanny-state sensors
can do this fairly easily.  I suspect that all openers use the
same system, though I have no proof of that.

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

It's been over a week, and the door has worked flawlessly.
Numerous little 555 boards are available for sale online,
anybody sick of malfunctioning mandated nanny-state sensors
can do this fairly easily.  I suspect that all openers use the
same system, though I have no proof of that.

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

> Did you think of trying to put a hood over the emitter or the sensor

First thing I tried.

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Meade Dillon via Mercedes]

Did you think of trying to put a hood over the emitter or the sensor, such
that they would be shielded as if nighttime (but still be able to see each
other)?  I have an old SLR film camera that started producing terrible pix,
my father figured out it had a light leak, found and plugged that light
leak, and restored it to perfect picture taking operation again.  This saga
reminds me of that problem / solution.
-
Max
Charleston SC


On Thu, Aug 19, 2021 at 4:42 PM Jim Cathey via Mercedes <
mercedes@okiebenz.com> wrote:

> Wednesday, August 4, 2021 <>I decided I had a bit of time to look into our
> always-irritating Wayne Dalton garage door opener, which usually refuses to
> go down in the day. It seems to correlate with light and/or heat, and you
> have to bounce it down, sometimes inches at a time, with the remote. Very
> irritating! [If you just hold down the wall switch you can force it to
> close while ignoring the malfunctioning door safety sensor. Good to know.]
> We've already replaced the door sensor components once, not that long ago.
> Now it's doing it again.
> I got out the oscilloscope and looked at the signals. There are two, 10
> VDC with a several-volt slow square wave (Fluke says 42 Hz) riding on it on
> the emitter side, and a negative-going pulse train on the sensor side. (The
> emitter supply is probably just dirty DC, with no intentional signal at
> all.) The aiming seems correct, as when I flexed the mount on the sensor
> side it dropped out about equally on both directions. The sensor pulse
> train is about a 10 VDC resting signal, with a 220 µs drop to zero, and
> another 200 µs slow rise. The period is about 6.5 ms, and measures (Fluke)
> at 151 Hz. (Another opener measures around 170 Hz.) With two pulses on the
> screen (negative trigger) I could see that the second pulse wasn't always
> there when the door was open to the daylight. With the door down it was
> always there. The system is clearly quite sensitive to missing pulses, it
> doesn't have to be missing very long for it to trip.
>
> So, flange up a timer-based pulse train to eliminate the wretched 'safety'
> switch? The prior opener didn't have one, just the back-pressure safety
> switch, and I never felt the least bit unsafe. We don't have crushable
> babies crawling around the garage door while we're driving in and out, and
> I suspect that the car itself is a greater threat to whatever than the door
> is.
>
> I think a 555 timer could do the job. IIRC that's a 555, two resistors and
> a capacitor for the timing components, and two diodes to ensure a steady
> power supply from the door opener. Maybe one more resistor to ensure that
> the 555 output doesn't draw too much current. Do I have any 555's left in
> the junkbox? [Maybe, but I didn't want to conduct a heavy search. I ordered
> a pack of 12 new ones through Amazon, I went for TI rather than no-name
> Chinese. Probably cost 2–3× as much, but they're still cheap.]
>
> Thursday, August 19, 2021 <>
> The 555 timers I ordered came, I flanged up an old-school point-to-point
> knot of a circuit, using the classic astable form from the datasheet. I
> used a 150 kΩ timing resistor (RA), a 6.8 kΩ discharge resistor (RB), and a
> 0.1 µF timing capacitor. I left no 555 pins unconnected, there's a
> decoupling capacitor on VREF, and RESET is tied inactive.
> I had mis-read the wiring on the opener earlier, getting the pushbutton
> wiring mixed with the sensor wiring. The emitter and sensor hook to the
> same two wires, marked Common and OBS on the side of the opener. Because
> power and signal share a pin, I used an inline diode and a 100 µF filter
> capacitor to isolate the output pin of the 555 from the power. (When the
> [short] low-going pulse of the 555 grounds the OBS pin on the opener, the
> filter capacitor keeps the 555 timer powered, and the diode keeps the
> filter capacitor from discharging back through the output.)
>
> So, to summarize this is a 100% standard astable oscillator, right out of
> the data sheet, but with a diode/capacitor filter-isolater in the power
> feed line, and the output tied to the power feed. The component tolerances
> were not great, but I was using junkbox parts. The signal is slower than
> the door sensor's, at around a 10 ms cycle rather than the target 6.5 ms,
> but the opener doesn't seem to care. I didn't have to tweak the values
> after the first build, I just installed it as-is. We'll see if it has
> problems later, but initial results are positive.
>
> Basically a 2-wire circuit blob that hooks to Common and OBS, in place of
> the wiring to the door sensor modules.
>
>
> -- Jim
>
> ___
> http://www.okiebenz.com
>
> To search list archives http://www.okiebenz.com/archive/
>
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
>
>
___
http://www.okiebenz.com

To search list archives http://

Re: [MBZ] OT: Garage door mayhem

[dan penoff.com via Mercedes]

That’s what I tried but I don’t recall if it worked or not.

I would get sunlight falling on one of the photo devices late in the afternoon 
in the fall and spring. The door would start to move down, then reverse and do 
the “blinky light” thing to let you know it had reversed. You could try it 
multiple times and it would eventually work.

It happened so infrequently I never really worried about it - I was always 
reminded when it occurred and would make a mental note to check it out. Then I 
wouldn’t be able to repeat it.

-D

> On Aug 20, 2021, at 11:32 AM, Curt Raymond via Mercedes 
>  wrote:
> 
> I was wondering if a tube on each end (sensor and emitter) would help to 
> remove outside influences, make them more directional and less prone to 
> outside interference.Our garage door opener is old enough (Craftsman even) 
> that it doesn't have 'em...
> 
> -Curt
> 
>On Friday, August 20, 2021, 11:28:57 AM EDT, Rick Knoble via Mercedes 
>  wrote:  
> 
> I was surprised to see that the input signal is pulsed. I would think the 
> photo eye would be a simple set of contacts, and you could merely jump them 
> out.
> 
> I have seen sunlight play weird tricks on long range photo eyes at work. A 
> few days a year the sunlight would affect them. Installed some form of sun 
> block and the problems are gone.
> 
> 
> Rick
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 
> 
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Allan Streib via Mercedes]

When I was a kid (maybe 10 or so?) and back when Radio Shack sold electronic 
project kits, I built an "electric eye" alarm kit. The light beam was from an 
incandescent bulb behind a lens, both it and the detector (I think it was a 
photoresistor) were mounted in tubes about 3 inches long or so, the purpose 
being to shield the detector from extraneous light. It would work across a span 
of 6' or so.

What I remember about that kit was that the instructions were pretty good, and 
it did actually work when I was done, but they didn't really explain the 
electronic principles. So I didn't learn much beyond organizing/identifying 
parts, following instructions, and soldering.

Allan


On Fri, Aug 20, 2021, at 11:32 AM, Curt Raymond via Mercedes wrote:
> I was wondering if a tube on each end (sensor and emitter) would help to 
> remove outside influences, make them more directional and less prone to 
> outside interference.Our garage door opener is old enough (Craftsman even) 
> that it doesn't have 'em...
> 
> -Curt
> 
> On Friday, August 20, 2021, 11:28:57 AM EDT, Rick Knoble via Mercedes 
>  wrote:  
>  
> I was surprised to see that the input signal is pulsed. I would think the 
> photo eye would be a simple set of contacts, and you could merely jump them 
> out.
> 
> I have seen sunlight play weird tricks on long range photo eyes at work. A 
> few days a year the sunlight would affect them. Installed some form of sun 
> block and the problems are gone.
> 
> 
> Rick
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 
>   
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 
> 
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

> I was wondering if a tube on each end (sensor and emitter) would help to 
> remove outside influences,

Tried that last time, didn't help.  Wife got disgusted, called door repairman 
while
I was at work.  Spent plenty of money and had the sensors replaced.  Lasted a
year or two, then started the same BS again.

> I was surprised to see that the input signal is pulsed. I would think the 
> photo eye would be a simple set of contacts, and you could merely jump them 
> out.

That's exactly why it's not done that way.  Also, with this system you only 
need two
wires, both sides of the door are hooked to the same two wires.  Multiplexed.  
Saves
wire and simplifies installation.

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Curt Raymond via Mercedes]

 I was wondering if a tube on each end (sensor and emitter) would help to 
remove outside influences, make them more directional and less prone to outside 
interference.Our garage door opener is old enough (Craftsman even) that it 
doesn't have 'em...

-Curt

On Friday, August 20, 2021, 11:28:57 AM EDT, Rick Knoble via Mercedes 
 wrote:  
 
 I was surprised to see that the input signal is pulsed. I would think the 
photo eye would be a simple set of contacts, and you could merely jump them out.

I have seen sunlight play weird tricks on long range photo eyes at work. A few 
days a year the sunlight would affect them. Installed some form of sun block 
and the problems are gone.


Rick
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

  
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Rick Knoble via Mercedes]

I was surprised to see that the input signal is pulsed. I would think the photo 
eye would be a simple set of contacts, and you could merely jump them out.

I have seen sunlight play weird tricks on long range photo eyes at work. A few 
days a year the sunlight would affect them. Installed some form of sun block 
and the problems are gone.


Rick
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

> You may want to replace the capacitors in the power supply for the motor 
> head, I'm finding all sorts of issues cured by clean DC.  Easy to check with 
> an oscilloscope, if there is significant AC on the filter cap for the circuit 
> boards it's gonna act strange.

We have four of these openers, only one of them (the most used) has these 
problems.
Your advice certainly applied to our 70's-vintage RadarRange, which we use 
daily.

I think the photo switch 'safety' is basically stupid.  Similar to the AFD 
circuit breakers
that are now standard for _all_ circuits.  I hate them.  What happens when you 
switch
on or off a light?  A small arc in the switch.  Which the breakers detect, and 
then plunge
the entire room into darkness.  Take a good idea, execute it past the point of 
utility
into ridiculousness, and then nail it in place with legislation.  You can 
probably find
many other parallels, if you try.

-- Jim


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Curt Raymond via Mercedes]

 I closed ours on a snowmobile once...
-Curt

On Friday, August 20, 2021, 09:16:33 AM EDT, dan penoff.com via Mercedes 
 wrote:  
 
 No worse than the time I tried shutting the garage door with the tailgate of 
my wagon still open.

Ouch.

-D

> On Aug 20, 2021, at 9:07 AM, Mitch Haley via Mercedes  
> wrote:
> 
> The light sensors are mostly useless if you set the downforce properly. I 
> back off on it until the door won't close reliably, then turn it up until it 
> does.
> 
> Funny story: my bosses' husband bought a new Tahoe last winter. Two days 
> later the kids couldn't get the door to shut, the pressure sensor kept 
> opening it back up. Hey dad, enjoy the first scratches in your new truck, you 
> left the bumper in the way of the garage door.
> 
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

  
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[dan penoff.com via Mercedes]

No worse than the time I tried shutting the garage door with the tailgate of my 
wagon still open.

Ouch.

-D

> On Aug 20, 2021, at 9:07 AM, Mitch Haley via Mercedes  
> wrote:
> 
> The light sensors are mostly useless if you set the downforce properly. I 
> back off on it until the door won't close reliably, then turn it up until it 
> does.
> 
> Funny story: my bosses' husband bought a new Tahoe last winter. Two days 
> later the kids couldn't get the door to shut, the pressure sensor kept 
> opening it back up. Hey dad, enjoy the first scratches in your new truck, you 
> left the bumper in the way of the garage door.
> 
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Mitch Haley via Mercedes]

The light sensors are mostly useless if you set the downforce properly. 
I back off on it until the door won't close reliably, then turn it up 
until it does.


Funny story: my bosses' husband bought a new Tahoe last winter. Two days 
later the kids couldn't get the door to shut, the pressure sensor kept 
opening it back up. Hey dad, enjoy the first scratches in your new 
truck, you left the bumper in the way of the garage door.


___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[dan penoff.com via Mercedes]

I had issues in a previous home at certain times of the day/year where one 
sensor would get sunlight into it and get wonky. Once I established the cause I 
just ignored it, as it didn’t happen that often. I would just have to remind 
myself as it only happened a couple times a year - sort of like Stonehenge.

-D

> On Aug 20, 2021, at 12:40 AM, fmiser via Mercedes  
> wrote:
> 
>>> fmiser wrote:
>>> 
>>> Wow.  I think I would have taken the two sensors, mounted them
>>> 5 cm apart maybe wrapped in duct tape, probably next to the
>>> opener control board.  Always dark, always close, always
>>> "safe"!
> 
>> Allan wrote:
>> 
>> Almost exactly how they are set up in my garage. No duct tape
>> though.
> 
> Jim was having what appeared to be light pollution problems, so I
> figure drastically reducing the opportunity for light to get in
> there would improve the chances of it keeping on working.
> 
> I actually set up my sensors, but I had some short people running
> around.  But so far I'm not aware of a single situation where it
> has prevented harm.  It has, however, triggered many times when
> there was no danger.
> 
> ___
> http://www.okiebenz.com
> 
> To search list archives http://www.okiebenz.com/archive/
> 
> To Unsubscribe or change delivery options go to:
> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
> 

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[fmiser via Mercedes]

> > fmiser wrote:
> >
> > Wow.  I think I would have taken the two sensors, mounted them
> > 5 cm apart maybe wrapped in duct tape, probably next to the
> > opener control board.  Always dark, always close, always
> > "safe"!

> Allan wrote:
> 
> Almost exactly how they are set up in my garage. No duct tape
> though.

Jim was having what appeared to be light pollution problems, so I
figure drastically reducing the opportunity for light to get in
there would improve the chances of it keeping on working.

I actually set up my sensors, but I had some short people running
around.  But so far I'm not aware of a single situation where it
has prevented harm.  It has, however, triggered many times when
there was no danger.

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Allan Streib via Mercedes]

On Thu, Aug 19, 2021, at 11:24 PM, fmiser via Mercedes wrote:

> Wow.  I think I would have taken the two sensors, mounted them 5
> cm apart maybe wrapped in duct tape, probably next to the opener
> control board.  Always dark, always close, always "safe"!

Almost exactly how they are set up in my garage. No duct tape though.

Allan
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[fmiser via Mercedes]

> Jim wrote:

> I decided I had a bit of time to look into our always-irritating
> Wayne Dalton garage door opener, which usually refuses to go
> down in the day. It seems to correlate with light and/or heat


> ... With the door down it was always there. The system is
> clearly quite sensitive to missing pulses, it doesn't have to be
> missing very long for it to trip.
> 
> So, flange up a timer-based pulse train to eliminate the
> wretched 'safety' switch?

Wow.  I think I would have taken the two sensors, mounted them 5
cm apart maybe wrapped in duct tape, probably next to the opener
control board.  Always dark, always close, always "safe"!

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Curt Raymond via Mercedes]

 Neat.
I've missed you posting stuff like this. I don't understand all of it but I'm 
interested in reading it...
-Curt

On Thursday, August 19, 2021, 04:42:03 PM EDT, Jim Cathey via Mercedes 
 wrote:  
 
 Wednesday, August 4, 2021 <>I decided I had a bit of time to look into our 
always-irritating Wayne Dalton garage door opener, which usually refuses to go 
down in the day. It seems to correlate with light and/or heat, and you have to 
bounce it down, sometimes inches at a time, with the remote. Very irritating! 
[If you just hold down the wall switch you can force it to close while ignoring 
the malfunctioning door safety sensor. Good to know.] We've already replaced 
the door sensor components once, not that long ago. Now it's doing it again.
I got out the oscilloscope and looked at the signals. There are two, 10 VDC 
with a several-volt slow square wave (Fluke says 42 Hz) riding on it on the 
emitter side, and a negative-going pulse train on the sensor side. (The emitter 
supply is probably just dirty DC, with no intentional signal at all.) The 
aiming seems correct, as when I flexed the mount on the sensor side it dropped 
out about equally on both directions. The sensor pulse train is about a 10 VDC 
resting signal, with a 220 µs drop to zero, and another 200 µs slow rise. The 
period is about 6.5 ms, and measures (Fluke) at 151 Hz. (Another opener 
measures around 170 Hz.) With two pulses on the screen (negative trigger) I 
could see that the second pulse wasn't always there when the door was open to 
the daylight. With the door down it was always there. The system is clearly 
quite sensitive to missing pulses, it doesn't have to be missing very long for 
it to trip.

So, flange up a timer-based pulse train to eliminate the wretched 'safety' 
switch? The prior opener didn't have one, just the back-pressure safety switch, 
and I never felt the least bit unsafe. We don't have crushable babies crawling 
around the garage door while we're driving in and out, and I suspect that the 
car itself is a greater threat to whatever than the door is.

I think a 555 timer could do the job. IIRC that's a 555, two resistors and a 
capacitor for the timing components, and two diodes to ensure a steady power 
supply from the door opener. Maybe one more resistor to ensure that the 555 
output doesn't draw too much current. Do I have any 555's left in the junkbox? 
[Maybe, but I didn't want to conduct a heavy search. I ordered a pack of 12 new 
ones through Amazon, I went for TI rather than no-name Chinese. Probably cost 
2–3× as much, but they're still cheap.]

Thursday, August 19, 2021 <>
The 555 timers I ordered came, I flanged up an old-school point-to-point knot 
of a circuit, using the classic astable form from the datasheet. I used a 150 
kΩ timing resistor (RA), a 6.8 kΩ discharge resistor (RB), and a 0.1 µF timing 
capacitor. I left no 555 pins unconnected, there's a decoupling capacitor on 
VREF, and RESET is tied inactive.
I had mis-read the wiring on the opener earlier, getting the pushbutton wiring 
mixed with the sensor wiring. The emitter and sensor hook to the same two 
wires, marked Common and OBS on the side of the opener. Because power and 
signal share a pin, I used an inline diode and a 100 µF filter capacitor to 
isolate the output pin of the 555 from the power. (When the [short] low-going 
pulse of the 555 grounds the OBS pin on the opener, the filter capacitor keeps 
the 555 timer powered, and the diode keeps the filter capacitor from 
discharging back through the output.)

So, to summarize this is a 100% standard astable oscillator, right out of the 
data sheet, but with a diode/capacitor filter-isolater in the power feed line, 
and the output tied to the power feed. The component tolerances were not great, 
but I was using junkbox parts. The signal is slower than the door sensor's, at 
around a 10 ms cycle rather than the target 6.5 ms, but the opener doesn't seem 
to care. I didn't have to tweak the values after the first build, I just 
installed it as-is. We'll see if it has problems later, but initial results are 
positive.

Basically a 2-wire circuit blob that hooks to Common and OBS, in place of the 
wiring to the door sensor modules.


-- Jim

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

  
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

Re: [MBZ] OT: Garage door mayhem

[Peter Frederick via Mercedes]

You may want to replace the capcitors in the power supply for the motor head, 
I'm finding all sorts of issues cured by clean DC.  Easy to check with an 
oscilloscope, if there is significant AC on the filter cap for the circuit 
boards it's gonna act strange.
___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com

[MBZ] OT: Garage door mayhem

[Jim Cathey via Mercedes]

Wednesday, August 4, 2021 <>I decided I had a bit of time to look into our 
always-irritating Wayne Dalton garage door opener, which usually refuses to go 
down in the day. It seems to correlate with light and/or heat, and you have to 
bounce it down, sometimes inches at a time, with the remote. Very irritating! 
[If you just hold down the wall switch you can force it to close while ignoring 
the malfunctioning door safety sensor. Good to know.] We've already replaced 
the door sensor components once, not that long ago. Now it's doing it again.
I got out the oscilloscope and looked at the signals. There are two, 10 VDC 
with a several-volt slow square wave (Fluke says 42 Hz) riding on it on the 
emitter side, and a negative-going pulse train on the sensor side. (The emitter 
supply is probably just dirty DC, with no intentional signal at all.) The 
aiming seems correct, as when I flexed the mount on the sensor side it dropped 
out about equally on both directions. The sensor pulse train is about a 10 VDC 
resting signal, with a 220 µs drop to zero, and another 200 µs slow rise. The 
period is about 6.5 ms, and measures (Fluke) at 151 Hz. (Another opener 
measures around 170 Hz.) With two pulses on the screen (negative trigger) I 
could see that the second pulse wasn't always there when the door was open to 
the daylight. With the door down it was always there. The system is clearly 
quite sensitive to missing pulses, it doesn't have to be missing very long for 
it to trip.

So, flange up a timer-based pulse train to eliminate the wretched 'safety' 
switch? The prior opener didn't have one, just the back-pressure safety switch, 
and I never felt the least bit unsafe. We don't have crushable babies crawling 
around the garage door while we're driving in and out, and I suspect that the 
car itself is a greater threat to whatever than the door is.

I think a 555 timer could do the job. IIRC that's a 555, two resistors and a 
capacitor for the timing components, and two diodes to ensure a steady power 
supply from the door opener. Maybe one more resistor to ensure that the 555 
output doesn't draw too much current. Do I have any 555's left in the junkbox? 
[Maybe, but I didn't want to conduct a heavy search. I ordered a pack of 12 new 
ones through Amazon, I went for TI rather than no-name Chinese. Probably cost 
2–3× as much, but they're still cheap.]

Thursday, August 19, 2021 <>
The 555 timers I ordered came, I flanged up an old-school point-to-point knot 
of a circuit, using the classic astable form from the datasheet. I used a 150 
kΩ timing resistor (RA), a 6.8 kΩ discharge resistor (RB), and a 0.1 µF timing 
capacitor. I left no 555 pins unconnected, there's a decoupling capacitor on 
VREF, and RESET is tied inactive.
I had mis-read the wiring on the opener earlier, getting the pushbutton wiring 
mixed with the sensor wiring. The emitter and sensor hook to the same two 
wires, marked Common and OBS on the side of the opener. Because power and 
signal share a pin, I used an inline diode and a 100 µF filter capacitor to 
isolate the output pin of the 555 from the power. (When the [short] low-going 
pulse of the 555 grounds the OBS pin on the opener, the filter capacitor keeps 
the 555 timer powered, and the diode keeps the filter capacitor from 
discharging back through the output.)

So, to summarize this is a 100% standard astable oscillator, right out of the 
data sheet, but with a diode/capacitor filter-isolater in the power feed line, 
and the output tied to the power feed. The component tolerances were not great, 
but I was using junkbox parts. The signal is slower than the door sensor's, at 
around a 10 ms cycle rather than the target 6.5 ms, but the opener doesn't seem 
to care. I didn't have to tweak the values after the first build, I just 
installed it as-is. We'll see if it has problems later, but initial results are 
positive.

Basically a 2-wire circuit blob that hooks to Common and OBS, in place of the 
wiring to the door sensor modules.


-- Jim

___
http://www.okiebenz.com

To search list archives http://www.okiebenz.com/archive/

To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com