simple current alternator

[blipblipblur]

heya

i have what i think might be a simple question for you guys.

if i wanted to build a device that takes electricity from a uk mains power supply and change its power and rate of alternation with the ability to respond to led sensors what would i need to do.

what it is im needing is for a flow to an electromagnet to change direction constantly from this device.

many thanks

 

[MikeMl]

I think you need a 240 Vac to XXX Vdc power supply. Use an H-Bridge, similar to what would be used to change direction of a DC motor, to drive the electromagnet. The H-Bridge will allow you to control the magnitude and the direction of the current through the electromagnet. XXX depends on the resistance, inductance, and how fast you need to establish the current in the coil.

 

[blipblipblur]

dose that work if i want to use a sensor to alter the speed/magnitude? and what if i wanted 3 separate magnets?

 

[MikeMl]

dose that work if i want to use a sensor to alter the speed/magnitude?

Sure, H-Bridges are usually modulated by a pulse-width controller where the controller responds to a sensor of some type...

...and what if i wanted 3 separate magnets?

Is the current the same through the three magnets, or do you need independent control of the three?

If independent control, with three sensors, you are effectively building three identical controllers....

 

[blipblipblur]

Sure, H-Bridges are usually modulated by a pulse-width controller where the controller responds to a sensor of some type...


Is the current the same through the three magnets, or do you need independent control of the three?

If independent control, with three sensors, you are effectively building three identical controllers....

dose that mean id need 3 separate psu's? and im not sure if il be needing them to pulse individually at the moment as im still in experimenting states.

 

[MikeMl]

Just one PSU. What are coil ratings?

 

[blipblipblur]

coil ratings?

 

[MikeMl]

coil ratings?

You have been talking about three electromagnets. What is the Inductance & Resistance of the electromagnet coil? How much current through the coil does it take to produce the magnetic attraction you need?

What are you trying to do with the coil(S)? The fact that you want to reverse the current through the coils suggests that you want it to interact with a permanent magnet?

 

[blipblipblur]

im just experimenting so i have no specifics when it comes to strength and size atm, the item that is going to be pulled and pushed with the electromagnets hopefully will be a ball of tiny magnets all with the same polarity.