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Ken - the solution I have actually devised (rather than postulated, as in the post you quoted) uses a similar approach to yours, in that it triggers the power supply to the remote's circuitry (with one of the remote's switches 'on' all the time), rather than closing one of the switches, but instead of switching the battery in and out, I'm using power supplied by the bike, so there's no battery to go flat. The remote will only power up for half a second when the high beam switches in, which isn't that frequent in my experience.
Sounds good. It is always nice when some gadgetry works, isn't it?
I liked your idea of wiring up a garage remote control so much that I am doing it to my bike.
I am an electrician by trade, (not an electronics technician). As the remote controls have either a 6 volt or 9 volt battery, it does make it difficult to use any of the bikes existing switch gear to operate, as it may burn out the electronics in the remote control.

1. Remove the battery from the remote control.
2. On the remote control, set up the open door button so it is on all the time. (I did this by taking the circuit board out of the case and fitting a plastic screw cap over the button so that when the case is reassembled the plastic cap holds the button on all the time. It can also be done by putting a wide rubber band around the remote control and placing a small item on top of the button and under the rubber band. This saves dismantelling the remote control.)
3. Find a suitable location for the remote control. (I am putting mine under the seat, small remote controls may fit inside the head light shell or under the fuel tank.)
4. Run two wires from your new switch location into the remote control and use these to control the connection for the battery. (Depending on the type of garage remote control, this may be the most difficult part of the whole task. I have an old remote control which is about the size of a cigarette pack, which makes the job easy. Those with newer and smaller remote controls may have more difficultly doing this task.)
5. Purchase a neat 'momentary on switch' and place it at your desired location. (I have to make up a small bracket to mount the switch, but it will be neatly located between the speedo and handle bars, adjacent the clutch cable.)

I believe this to be the easiest way to install a garage remote control on your bike. It will sure beat fumbling around in your jacket pocket to open the garage door. (I have not completed the job yet, as I need to purchase a switch.)

Hope this will help,
Ken
I got the switch and it all works well.
Thanks for the idea guys. I am very happy with the outcome.
Ken
Readers Digest version

View attachment 107373

War and Peace version

The original post on this thread, by @bostewart, piqued my curiosity on this issue – one I’ve pondered in the past. The stumbling block with the way the headlight flasher circuit is arranged has been to find a way to trigger a momentary pulse from a continuous voltage, given that the headlight flasher and high beam setting use one and the same circuit.

I did some searching for a momentary action relay, thinking I may be able to purchase such a device. I came across a very useful site called the12volt.com which has circuit diagrams for a multitude of relay applications, including exactly what I was looking for.

The continuous-to-momentary circuit simply adds a capacitor and resistor, in parallel, to the negative lead of the relay’s trigger circuit (solenoid).

When voltage is applied to the relay solenoid, the solenoid triggers until the capacitor reaches a critical state of charge (voltage) where the voltage difference across the trigger terminals (and hence current) is insufficient to hold the relay’s solenoid in place, whereupon the solenoid drops out. This status will be retained until the supply voltage is removed, whereupon leakage via the resistor depletes the capacitor’s charge, making the relay ready to act upon another trigger voltage. The bigger the capacitor, the longer the momentary pulse. The values in the example circuit,1000uF and 10k Ohms, promised about half a second momentary action, so that’s what I used.

The next issue was to tap power for the remote from the bike, rather than embed a remote with a battery that will eventually fail. Recalling a bit of high school physics, I figured a resistor of appropriate value in series with the remote, on the positive lead, would do the trick (a voltage divider circuit). Given that the current draw is constant when the remote is activated, nothing more sophisticated is required.

The first step was to determine the voltage of the remote’s battery supply – two CR2016 buttons in series, nominally 6V the pair, but measured at 6.65V. The current drawn when a button was depressed measured 0.012A. This is the current that needs to be supplied by the bike when the relay is closed.

R = V/I so the resistance of the remote’s circuitry (load resistance) is:

Load resistance = 6.65/0.012 = 550 Ohms

The voltage measured at the high beam bulb with the engine running is 13.6V. This is where I would draw power to activate the relay and the remote, either from activating the flasher or switching to high beam.

Using the formula above, the total resistance of the relay circuit needed to deliver the required 6.65V and hence 0.012A current through the remote should be:

Total resistance = V/I = 13.6/0.012 = 1133 Ohms.

So the series resistor value in the power supply line can be calculated as:

Series R = Total R – Load R = 1133-550 = 583 Ohms

Checking the electronic parts catalogue, the closest resistors to this value are 560 and 620 Ohms. Choosing the higher value will produce a slightly lower voltage at the remote – a safer option than the alternative of going slightly higher. Actual total resistance will therefore be:

Actual total R = 620+550 = 1170 Ohms

Actual voltage at the remote will then be:

Load R / Total R x Supply Voltage = 550/1170 x 13.6 = 6.4V

This is lower than two new CR2016 batteries but still higher than their nominal 6V.

Construction notes:
  • I chose to bridge one of the remote’s micro-switches rather than mechanically hold one button depressed; as in @kgdavo Ken’s solution, the power supply is switched, not the button micro-switch terminals.
  • The voltage divider resistor was fitted inside the remote case, soldered to the battery holder’s positive tab, the other end to a red lead, and sheathed in heat-shrink.
  • The leads were passed out the side of the case after cutting a couple grooves in the joining face of one half.
  • The leads for the resistor of the momentary-action circuit were wrapped around the capacitor’s wires to support the latter and then leads soldered on before sheathing in heat-shrink. Once tested with the relay on my bench 12V battery, I covered the capacitor/resistor assembly with some woven sheathing I happened to have, secured with hot glue at the rear then at the leads to protect and to guard against mechanical fatigue.
  • Note that electrolytic capacitors are polarity sensitive – a stripe along the body indicates the negative lead.
  • The high beam bulb is the lower of the two on the LC (obviously…) with the positive lead being white and the negative (ground) being brown.
  • I used a diode protected relay to guard against flyback spikes when voltage is removed from the relay solenoid. If unavailable, add a protection diode as shown in the linked web site.
    Note that power in for the relay (+ve) is terminal 2, earth side is terminal 1.
  • The remote and the relay were zip-tied to the horizontal wiring loom so that they didn’t rattle around.
It works, and I can now open the door of the PanzerHöhle as I approach with just a flash of high beam. Mission accomplished at a cost of A$8.55 plus a remote and some terminal connectors and hook-up wire.

This solution is translatable to any bike, subject to room to mount the relay, remote and capacitor/resistor assembly. Do your own measurements and calculations though as your remote’s parameters are likely to differ.
I am very impressed. The thing that had me most concerned was the momenty relay, but you sorted that out. Well done
Ken
 

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Discussion Starter #42
Just to round this to a close (at least on my end) I had forgotten that my new garage door openers come with a phone app. Since my phone sits in a cradle on the bars, and since i have a 4 minute slow ride thru the 'hood to my crib, it dawned on me it's easier to open an app and hit "OPEN" for the garage door than to go thru a lot of wiring.
 

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🤦‍♂️

Glad you asked the question, though. It prompted me to solve a long-standing desire of mine, and now I reckon it’s my best ever farkle. 😄
 

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I've got a Hex Ezcan with open channels. Wondering how I could leverage that....
So, between all of the different ideas here, including your post wondering about using the EzCAN, I ended up wiring a remote into my Roadster today using a 'hybrid' approach:

I used a Hex EzCAN spare light channel, plus a constant to momentary relay circuit as per Panzermann, but instead of a bridged remote switch and switched power, I retained the battery to power the garage remote and used the momentary circuit as an external switch for the remote.

Basically, I used a spare auxiliary lighting channel on the EzCAN, set up to be 0% except on high beam, and used a relay, resistor and capacitor the same as Panzermann, making the power output from the EzCAN effectively momentary. The garage remote is a 3 button type, but on opening it up, there happened to be a spare position for a 4th microswitch. I simply soldered a couple of wires to the PCB where the 4th switch position is, and ran these to the secondary side of the relay to use as a switch. I cut a small slot in the side of the remote to run the wires through, applied cable ties, heatshrink and tape as needed, and plugged it into the EzCAN under the seat.
After pairing the 4th switch position to my garage door opener, it all works perfectly, and being plugged into the EzCAN means it's completely plug and play with easy access to change the remote battery if needed.

A small but noteworthy point is that due to the capacitor remaining at least partly energised until it 'bleeds down', there is a roughly 7 second delay between possible activations of the circuit. So flashing the lights within 7 seconds does nothing, except extend the time before the circuit can be used again by another 7 seconds. Not a problem though - my door takes 11 seconds to cycle anyway. It just means I can't reverse the door immediately following an accidental activation.
 
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