This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
This circuit trips when a negative pulse is applied to its input or when the voltage drops below a...
August 2017 - The new N-channel MOSFETs from Vishay's TrenchFET Gen IV family can now be purchased from...
The frequency of the produced sound depends on the capacitor. With capacitors of known values, you can...