This receiver, called Peace, was manufactured in the 1960s in Japan and was powered by a 9 V battery. The radio for medium waves had an earphone and good sensitivity.
The sensor for this alarm is an LDR and it consists of an oscillator that goes into action when...
This circuit tests quartz crystals of frequencies between 100 kHz and 10 MHz. The circuit is from...
We found this FM transmitter circuit with the 2N2218 transistor in a documentation from the 90s....