Found in Motorola's 1967 documentation this circuit can use any general-purpose transistor. The signal should be applied to a good amplifier. The noise diode can be replaced with a common one.
We found this circuit in the La Radio per Tutti magazine in Italy in 1926. The coil can be made...
This simple circuit uses a common phototransistor as a sensor, turning on an LED when it receives the...
This is one of many timer settings with the 555 found on this site. This is the traditional...