Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using common LDRs as sensors. Transistors can be modern PNP equivalents.
This booster for listening to signals in the range from medium waves to 30 MHz was found in a 1998...
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
Using a 7400 we have a short-wave transmitter from 4 to 9 MHz, shown in the figure. The coil...