This step of two transistors has a high input impedance due to the use of FET. We can use BF245 for this function and the bipolar can be BC548. The circuit is from an 1975 American documentation.
This circuit causes the relay to be energized when the input voltage exceeds the voltage value of...
The maximum frequency of this circuit is 500 kHz. We found it in a documentation for radio...
The mains cables work as antennas. We can take advantage of them with this circuit that consists of a...