This circuit from Popular Electronics powers a small speaker. The transistor can be of general use and the capacitors can be altered to change the sound generated.
Line voltage compensation (CB8816E) This circuit for the alternating current line (AC line) was...
September 2017 - IXYS Class X2 to 700 MOSFETs can now be purchased from Mouser Electronics....
Depending on the value of C1, this oscillator can produce signals of up to 1 MHz. For a capacitor of 10...