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I am performing an experiment for school investigating the magnetic force of a solenoid. While doing this experiment I realized that I needed to connect the solenoid to the DC output of the power supply instead of the AC.
I am perplexed since for current induction, fluxtuations in the magnetic field are needed. I thought this would be the same "the other way round", i.e. using a fluxtuating current to create a magnetic field.
To be fair, you don't actually need continuous DC current, but you do need a waveform that is always in the positive (or always in the negative) voltage range. An AC source with a simple half-wave or full-wave rectifier (4 diode) will work fine without the need for a transformer or DC converter. It is still DC, it's just unregulated. Note that a half wave rectifier will only let you use half of the energy, with the same voltage but a 50% duty cycle pulse train. It might cause issues, depending what you are doing.
The important part is that the waveform does not go say from 0V to 12V to 0v to -12v etc... With AC, every time the voltage is positive the field will go in one direction, and in reverse when negative, so overall it is approximately cancelled.
To produce a steady magnetic field by a current in a coil you need a direct current. If you use an ac current the magnetic field would change with time and change direction every half period of the ac current.
