Motorised Screen Help Needed  

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Rallyingace
(@rallyingace)
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Joined: 2 months ago
Posts: 2
2020-02-23 8:12 pm  

Hi all

completely new to the forum & looking for help please

I’m also a complete beginner & novice when it comes to the complexities of electronics & programming.

I need to motorise a screen that’s attached to an Audi Screen mechanism, the mechanism has a 12v Motor & two limit switches, I need to figure out the best way to motorise the screen to open when the 12v ignition feed of the vehicle is switched on & then close when the ignition is switched off, I’d also like to put a switch inline to close the screen when required when the ignition is on.

 

I was looking at using a combination of relays to achieve this but then I had a thought as to whether I could use a H-Bridge & an Arduino?

what would be my best route to take please?

If I take the route of the relays what would my wiring diagram look like please?

& if I used the H-Bridge & the Arduino what would the programming be?

as much help as possible would be greatly appreciated 

 

kind regards

Darren


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casey
(@casey)
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Joined: 10 months ago
Posts: 363
2020-02-25 12:41 am  

Nobody has replied so I decided to give it a quick untested response.
You could do it with an Arduino, h-bridge and some code but maybe it can be done with three relays?
The circuit below is untested at this stage. The little boxes marked C and B are the limit switches.
Perhaps later when I have some spare time I will wire up an example to test it,  in the meantime don't assume it will work as is as it is just off the top of my head.

Right mouse click and choose open link to new window for enlarged version.

limitCircuit

 

This post was modified 1 month ago 2 times by casey

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casey
(@casey)
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Joined: 10 months ago
Posts: 363
2020-02-25 5:26 am  

Here is how I imagine the circuit would work.  I have redrawn it.

A limit switch is turned OFF when pushed by the bar otherwise it is turned ON.

limitSwitches

 


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Rallyingace
(@rallyingace)
New Member
Joined: 2 months ago
Posts: 2
2020-02-27 5:17 pm  

@casey

Hi Casey

I can’t thank you enough for the diagrams, could I ask just one more thing please, could you possibly number the relay pin outs for me please?

I’d like to give you a drink for doing that! If I could have your PayPal details I’ll transfer you a drink!


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casey
(@casey)
Reputable Member
Joined: 10 months ago
Posts: 363
2020-02-27 7:35 pm  

The diagrams are only a suggestion as I haven't actually tested the circuit nor can I tell you where the wire to the ignition would go as I don't have the circuitry of the Audi.  It is important that you understand how a circuit works that is why there are four images to show how I imagine it would work.

Without knowing what relay you might use I have no idea what pin numbers they might have used.  You might google for the relay connection details to find out which two pins connect to the coil and which ones connect to the switches.  I work out unknown connections using a electric meter or if the relay case is clear you might be able to see the connections.

You would also need to place a diode between the coil connections with reverse polarity from the power supply to protect against huge voltage spikes.  With regards to the motors are they already part of the screen? The motors may well need a capacitor between their coils to protect against current spikes.

I am only a self taught from books on electronics most of which I taught myself back in the 80's I have no formal qualifications.  Since then I haven't done much electronics only some programming.  I responded because no one else had although apparently there are some highly qualified electronic experts on the forum.  For me it looked like an interesting piece of wiring logic to solve and I had hoped some forum expert would have checked it out.

 


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