This simple optical alarm circuit was found in the 1991 Electronics Experimenter Handbook. The circuit uses a lamp as the emitter but can use LEDs.
The quadrature oscillator is another type of phase shift oscillator, where each of the three...
The power supply shown in the figure provides output voltages in the range of 1.2 to 25 V with...
The frequency ranges that this receiver can tune in depend only on the coils. For medium waves L1...