This circuit causes an LED to flash at a frequency determined by the capacitor. The circuit is powered by only 3 V and can be used for signaling.
This circuit allows the use of an electret microphone with a 1.5 V source. We found it in the...
This is one of the many versions we have of this alarm on our website. It was found in an English...
The circuit shown in the figure was found in a 1974 publication. The field effect transistor may...