Under this name, Radioelectronics magazine published in the January 1974 issue a light exposure meter for photographers. The circuit used general-purpose transistors and a FET, with an LDR sensor.
This small transmitter sends signals to the 7 MHz band, but can be modified to operate at other...
We found this circuit in a publication of 1990. With the changes it can be mounted easily today....
This circuit is from a 1992 publication and is based on CMOS technology. The circuit is powered by a 6 V...