high power lead needs to power or trigger an electromagnet.

[emcelhannon]

Hi,

I'm trying to wire a circuit that will use the high voltage lead from an old crt to power an electromagnet. I'm getting no reaction from my coil...lots of juice, no magnetic field.   Is it an AC thing? I thought the hp leads on crts were dc.  Just in case I took a high voltage diode from a microwave and fit it in, but it made no difference. What are my options? 

Many thanks for your replies.

Ernie

[John Cuthber]

The magnetic field from a coil is governed by the current through it. A CRT supply  certainly won't deliver much current. You would probably do better with a torch battery.

[swansont]

An AC current will give an oscillating field, and the current will be smaller because of the increased impedance from the inductance.

You can increase the field by increasing the number of turns in the coil, as long as you aren't power limited.

[emcelhannon]

Thanks guys. What about powering a relay? I need the electromagnet to come on the moment the high voltage lead makes its spark.

[John Cuthber]

Relays are slow.

 

What are you trying to do?

[emcelhannon]

I want to keep it swinging with a little juice to the repelling electromagnet below it. I'll have an opposing pole facing down on the pendulum.  The current from the high voltage lead isn't enough. I tried a neon sign transformer too. 

 

[emcelhannon]

On ‎12‎/‎27‎/‎2017 at 8:20 AM, John Cuthber said:

Relays are slow.

 

What are you trying to do?

My true goal is to make my son idolize me as mad scientist in the basement.  It's an oddly compelling and enduring motivation.

What about a mosfet.

I want to power a pendulum with a magnet on the tip. The push will be a base electromagnet that triggers on when the pendulum reaches near equilibrium position. The high voltage lead will be connected to the pendulum. The switch will be the close proximity to ground which will be centered beneath.

My goal is to create a nice arc at equilibrium position which will send power to the electromagnet. I thought it would be easy. The hv was suppose to actually power the electromagnet, but it's all volts and no amps, sort of. It's just hv  art. Any help you can give me would be greatly appreciated.

Many, many thanks,

Ernie

 

[emcelhannon]

come on , guys

[Andrius319]

How is it going?

It is already 3 months late, but will try giving some vague hints.

First, you can find plenty of similar works by googling 'electromagnetic pendulum'. If you have signal generator you can amplify it with bridge or if heating might be a problem switching type amplifier.

Second, you must make sure you produce correct signal you amplify. It either have match resonant pendulum freaquency or detect pendulum position with sensor.

Also, starting might be problematic,  since for good initial motion it requeres aligment missmatch.

Here is one of the weboage which might turn usefull

http://www.instructables.com/id/Magnetic-Pendulum/