I have obtained a military vibrating-reed frequency meter that I would like to turn into an educational display unit, with a knob that adjusts the frequency from 380 to 420 Hertz, giving the user the ability to hear the frequency on a loudspeaker as well as see it in the frequency meter.
However, my experience is only with digital circuits like 74 logic, some BJT audio circuits, etc... have never generated AC myself before. How should I generate a 26 volt 400Hz signal?
I was thinking something like... Microntroller to generate a variable sine wave, which I would feed to an audio amplifier. One channel of the audio amplifier would go to a speaker and the other would go to a step-up transformer and then to the meter. Would that work?