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Topic: Electronics help for a simple project (Read 267 times) previous topic - next topic

Jackamus

I an not an electronics engineer and I am looking for someone who can help me design a simple piece of electronics with some low level programming. I understand that using Arduino would be an obvious route to go.

Attached is an algorithm I created detailing the operation of an electric door closer using a 24v battery operated DC motor. The motor has a reduction gear box from 3000 to 4 rpm. This provides sufficient torque to close to door if only slightly open.
More information available if needed.

PaulS

What hardware do you need designed? To do what?

How do you intend to sense "resistance" in the closer? How will you control the motor current? Within what limits? Current is pulled, not pushed. If the power supply can't keep up with the demand, the motor will stall. If the power supply can supply 2K Amps, the motor wiring certainly can't support the motor trying to pull that much current.
The art of getting good answers lies in asking good questions.

blimpyway

If the door is balanced and motor slow, any resistance increases torque and it should be detected as an increase in motor's current.

There-s still the discussion of opening the door. Not sure how well it works manually - by pulling the door against motor's gears and back-emf. So  opening  might need also motor assistance, which means both opening and closing sequences have to be covered in code.

What voltage/amperage does your motor has? Important too - what is its maximum, stall current?

As someone pointed out on the original thread, motion (or proximity) sensors on both sides of the door would be a wise choice.

blimpyway

I would also consider using a normal hydraulic arm door closer and use motor+spool+rope pull for opening the door.

This way you have a device certified not to harm anyone if anything ( mechanics/electrics/program/power) goes wrong and a functional normal door in case it does.

So the entire program logic would be reversed, focused on when to open and when to let the door close itself.

cedarlakeinstruments

You mean something like this? http://www.power-access.com/Model-2300-door-opener.html
Electronics and firmware/software design and assistance. No project too small

Jackamus

Hi Guys,
The problem is that you only have half of the story. I have already researched the mechanics and the door closer has a built-in mechanical clutch that allows the door to be free all the time except when programmed to close. There is no way that the door closer can harm anyone anymore than a normal hydraulic one.

It is not necessary for me now to go into any further detail as I think I have now found someone who can design the electronics.

I am most grateful to all who have offered advice and asked questions about my project.

It was a good move for me to try out this forum to seek a solution and now I'm pretty sure I have one.


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