Pop open kitchen cupboard doors with solenoid

Solenoids aren't very good where you want a force that is constant over a distance.

I suggest a motor. You can set the gearing of the motor so that a spring will return it if you remove the power. That is how most of the door-release motorised "solenoids" on cars are arranged.

You will need a timer with a solenoid or motor so that they are not left energised continually.

As you will need a timer, it's really not much more work to have a servo-motor operate when the person is sensed, and then return after a fixed time. A servo motor would let you adjust how much the door opens, and at what speed. A solenoid or motor could be a bit harsh and noisy.

The door handles on my car are flush and come out when the car is unlocked. They use simple dc motors to push the handle out. The mechanism is arranged so that when the motor returns to the retracted position, the handle can stay out with only a spring pushing it closed, so that trapping someone's hand isn't an issue.

You will need to measure the force to open the door.. You could use one of the scales designed to check your luggage is OK to go on an aircraft.

Dont forget, in a power failure, you won' be able to get in to your cupboard unless you have a back up power source - another level of complexity.

augustinetez said:

Dont forget, in a power failure, you won' be able to get in to your cupboard unless you have a back up power source - another level of complexity.

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I don't think that is a major problem. Cupboard doors are probably just held shut with a spring and it's easy enough to get something around the edge to pull the door, or use a suction cup.

I had an idea for this in the middle of the night:-

If you got a small concentric-pole type solenoid magnet and a "cup" or "pot" style screw fixed magnet with exactly the same outer diameter, the solenoid would just act like a piece of iron when off and the magnet would pull to it.

Power the solenoid with the correct polarity (so the poles repel the magnet) and it would pop the door open.

No moving parts!

You could add a brass shim or rubber pad to space the two apart if the holding pull was too strong.


Examples of the styles of items, though these are much larger than I'd think to be practical - probably 12 to possibly 20mm would be nearer appropriate?

Here's a commercial option https://www.blum.com/au/en/products/motion-technologies/servo-drive/overview/