I have a computer AT power supply mounted to bottom of desk. From that, I use to power my computer speakers, and a TS-100 soldering iron. I use a step-up voltage booster on the soldering iron to deliver 24 volts, for the purpose of making the heat-up time faster.
I turn the solder iron on, and my computer speakers get a FART sound through them. It's a low frequency buzz. I figure this was due to some type of severe drop in voltage through a pulse, but I do not know enough about electronics to know what to do. My first thoughts was to put a capacitor near the power input to the step-up power supply that drives the DC soldering iron. I think I need a power filter or coil, but I do not know what I am doing. Attached is a picture from my oscilloscope, that shows the 12v power supply noise. Can anyone advise, please?