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Author Topic: Reverse engineering the electrics/electronics for an awning motor  (Read 3636 times)
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Stockholm
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Hi!

I have an awning (sun blind, marquis, ...) motor that is supposed to be controlled by a radio remote control. However, the remote control is gone and buying a new one costs me about 60 euros. Also, I don't have the need for a remote control, a simple switch for up and down is enough. It would be cheaper to make and also a lot more fun to do!!

I managed to open the electronics controlling the AC motor. (I believe it's an AC motor at least, it runs at a typical speed for an awning motor and it has not cought fire yet!) There are 3 cables for the motor; 1 phase and 2 neutrals/ground depending if the motor shall rotate clockwise or counterclockwise. Please take a look at the image.  There are two relays controlling which neutral conductor to use. There is also a transformator to 18 v which is for the electronics for the radio receiver and also controlling the relay coils.

So I have managed to bypass the relays so I know that the motor works and can rotate in both directions. My next step is to get some current through the relay coils, but I have no idea how this circuit works (encircled in yellow). It is not important to know how it works, but to find out where 18v and ground is. The four soldered points at lower centre of the rear view are supposed to be the output of 18 v but I have not managed to measure any voltage at all. Any ideas?
How about ground, where is it?
Also, if you understand how the circuit for the relay coils work, please tell me. I have no idea how this circuit knows which relay to use.

Any other comments or ideas on how to incorporate a simple switch to this is welcome!

Regards,
Hans


* elen.JPG (1445.45 KB, 2000x1246 - viewed 105 times.)
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Why not remove the receiver and take the pins high/low that the receiver was controlling?
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CrossRoads, do you mean that I should apply voltage to the pins of the relays?
The problem is that I cannot understand from where to take it. When I wrote my previous post I thought that the blue thingie is a converter from 230 V~ to 18 V= (DC), but I don't think so anymore. I read about rectifiers and diode bridges on wikipedia and on the reverse side of the blue transformator there are 4 diodes in square (diode bridge). So if I make a semi-wild guess, should there be +9 V (DC) at the lower horizontal line directly following the diode bridge (on the rear side), and -9 V at the parallell line?
I wish I could measure that with my voltmeter, but I won't do it easily since the circuit won't be closed because the remote control is missing.

But still I am wondering how this circuit "knows" which relay to use. Any ideas?


Yesterday, while taking a bath, I also came up with another solution. That would be to skip the relays totally by replacing the power cord with another power cord with 4 cables (phase, ground, neutral x 2) and put the switch directly on the power cord. The purpose of the switch is then just to "choose" which of the motor-connected neutral connector to use. If I press "up" the current will flow in neutral connector A, and "down" in neutral connector B, phase and ground will be common to these. Any thoughts on that?
I think it's a simple solution but I am wondering about the safety aspect.
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If you look over on the left, there are 2 resistors labelled 222 that connect to what look like 2 transistors, and 2 diodes.
More than likely the diodes are across the relay coils, and connect to one transistor lead each.
Two transistor leads are in common.
More than likely, the pin that remains on each at the other end of the resistors is the control pin.
Measure them in the inactive state - if "high", you likely need to pull them low. if "low", you likely need to drive them high.
The relays are marked 24V, so be careful probing to measure voltages when the circuit is powered.

If you can read any marking on the transistors that would help.
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You don't even need the control board; you just need a DPDT switch.

See attached image, but please use due diligence in confirming that this would be an appropriate wiring. I'm basing this advice on how you've described the motor and what I can see from the board.


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Thanks, I thought about that idea (see my reply #2), and as you say I think that is the easiest. And as a bonus I will get 2 relays that I may reuse in other projects. Now I just need to get the appropriate materials to continue.

How about earthing?
The motor chassi will be connected to earth. Do I also need to consider that for the switch (ofcourse placed in some box) since it will be placed outdoors and therefore exposed to such conditions?

Understanding how the circuit works would be fun, but too complicated for me.
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You only need a SPDT. if you look at the picture.
Why not visit the shop and play with a remote. Capture the signal with a arduino and dumping it to a sd card. This is all very well documented.
Then you can program a standard remote to work. If you have a programmable remote you can use a free button from that remote. That will be far cheaper than placing a box in your garden with a relays.
And you won't feel ripped off.
Best regards
Jantje
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