How can I control electromagnet current based on proximity?

[Mazero]

I'm looking for some examples/ideas on how to control the current to an electromagnet based on the height something is levitating above it.

Schematics would be nice, but even any ideas/sensor recommendations would be appreciated.
or any similar application, I've seen something does using an IR emitter/detector but that wouldn't be the best application for this.

Thanks,

 

[rayjohn01]

Why Not?

You are going to have to measure the height somehow and light is a good and relatively simple way to do that and it in no way disturbs the action
it does not Have to be IR.
Ray

 

[ravenprp]

One possible solution for controlling the current to an electromagnet based on the height of an object levitating above it could be to use a proximity sensor. This type of sensor can detect the distance between the sensor and an object, and can be programmed to trigger a specific action based on the distance measured.

One idea could be to use an ultrasonic proximity sensor, which emits high frequency sound waves and measures the time it takes for the waves to bounce back to the sensor. The closer the object is to the sensor, the shorter the time it takes for the waves to bounce back, and vice versa.

Based on the distance measured, the sensor can be programmed to control the current to the electromagnet. For example, when the object is at a certain distance, it can trigger the circuit to increase the current to the electromagnet, causing it to become stronger and levitate the object. As the object moves closer or further away, the current can be adjusted accordingly to maintain the desired levitation height.

Another possible solution could be to use a capacitive proximity sensor, which senses changes in capacitance between the sensor and an object. This type of sensor can be very precise and can detect even small changes in distance.

In terms of schematics, it would depend on the specific components and sensors being used. However, a basic circuit could involve an Arduino or other microcontroller to read the sensor data and control the current to the electromagnet through a transistor or relay.

Some sensor recommendations for this application could include the HC-SR04 ultrasonic distance sensor or the Adafruit Capacitive Touch Sensor Breakout - MPR121. These are just a few examples and there are many other options available.

Overall, the key is to choose a sensor that can accurately measure the distance between the object and the electromagnet, and then program the sensor to trigger the appropriate action based on the distance measured. I hope this helps and gives you some ideas to explore for your project. Good luck!