This circuit was published in the July 1993 issue of Electronics Now magazine. It uses a sensor from the time and triggers a buzzer with a Sonalert-type oscillator.
This phase shift oscillator generates sinusoidal signals in the audio range. Frequency depends on...
We obtained this circuit in an English publication in 1983. Equivalent operational amplifiers can...
The figure shows how to implement an amplifier with gain 10 using the operational amplifier LM41....