Is there something i can put into a circuit that will will make DC irregular

[willserrell]

Hey Guys,

I am new to the forum and just got into bending and have been really enjoying it so far! I did search the forum for the above question but couldn't find any answers so was looking for some friendly faces on here to help out. I have a cassette deck that I am currently bending and i'm looking to put something between the motor and the batteries that basically makes the power intermittent (or if it the same idea could be applied to the playhead in someway). The effect that i am trying to achieve or have in mind is that the tape plays back irregularly and maybe stops and starts occasionally. It would be great if there was something that could do this without the need of me turning a pot or flicking switches etc.

I've also been looking at bias oscillator transformers, could this produce the desired effect?

Thanks in advance!