I am dealing with this problem that I am not completely sure about and any mistep would let to something ufixable so I am asking somebody better versed in these kind of things and I hope somebody would have the patience to answer my question in detail.

As the title suggest I need to drive an electromagnet using audio amplifier and I am trying not to destroy it.

The amplifier has Hammond Manufacturing 125DSE audio trasformator (http://www.digikey.com/product-detail/en/125DSE/125DSE-ND/454501) and has 4 / 8 / 16 ohm outputs. The speaker curently attached to it is 60W, 8ohm.

I would like to use this (http://www.ebay.com/itm/12V-DC-22-LB-10kg-Electric-Lifting-Magnet-Electromagnet-Solenoid-Lift-Holding-/360519627296?hash=item53f0a4f220) electromagnet with following specifications:

  • Input Voltage: 12V DC
  • Current: 0.42A
  • Power Consumption: 5W
  • Diameter: Approx. 30 mm
  • Center Diameter: Approx. 12 mm
  • Wire Length: Approx. 23 cm

I know that electromagnet on itself is behaving differently than electroagnet in speaker but Im not sure about anything else. Could you reccomend an electromagnet that would work and would not overheat after few hours?

Thank you very much in advance for any kind of answer.

(also sorry for my english, Im not a native speaker)


Thank you for the answers. For clarification:

The electro magnet I mentioned is just an example, the real question is, what magnet that would work would you recommend?

What I am trying to achieve is to control intesity of the electro magnet with input from sound (guitar, effects and so on). It does not have to be particulary strong but it would be better. I wont be lifting anything just controling the field.


closed as off-topic by Fizz, Null, PeterJ, Dave Tweed Oct 15 '15 at 1:56

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  • \$\begingroup\$ What is the electromagnet supposed to be affecting? Is it really supposed to vibrate along with the audio like a speaker? \$\endgroup\$ – pjc50 Oct 14 '15 at 13:41
  • \$\begingroup\$ As I said in the post (I hope I said it well enough, sorry if not), just control the intensity of the electromagentic field so for example if I made the signal more powerful (lets say with added distortion pedal on effect chain) it would have more strength or if I put a tremolo effect, it would quickly change from weak to strong back and forth. \$\endgroup\$ – Zebra Oct 14 '15 at 14:53
  • \$\begingroup\$ I'm confused about what you are trying to do. But the magnet will have both resistance (R) (~ 28 ohms) and inductance (L). (unknown) and this will limit the time response to L/R \$\endgroup\$ – George Herold Oct 14 '15 at 14:56
  • \$\begingroup\$ Hi, sorry, Im not really sure how to be more clear. Basically, if I take out the electromagnet from the speaker, thats exactly what I want. I just dont know how to choose an electromagnet that would have enough strenght so it could exctually move small objects, wouldnt overheat and wouldnt destroy the amp when connected. \$\endgroup\$ – Zebra Oct 14 '15 at 15:01

Nothing should get hurt by you trying to drive the magnet from the audio amp. If you do, switch the output to 16 Ω, since that is a better match for your magnet than 8 Ω.

However, it's not clear what you are trying to accomplish with this magnet, and therefore whether it will work. This magnet is apparently meant for lifting things, so it is probably meant to be run from DC. Low frequency AC may work well enough, but the magnet pull force will be reduced as the frequency goes up.

Basically, a audio amplifier is not the appropriate power source for this magnet. A DC power supply is what you really want.


The spec for the electromagnet is DC. The spec for the output transformer is limited below 100 Hz. You are probably wasting your time unless you want to drive the electromagnet with AC. However, driving it at 100 Hz will probably cause excessive heating up due to eddy current losses in the electromagnet (it's an AC thing).


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