This light meter circuit was found in 80's Radio Electronics. The circuit uses a milliammeter as an indicator and the sensor is a common LDR. The power supply must be symmetrical.
Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be...
We found this configuration in a 1975 publication. It can be implemented easily, as it uses only...
The high number of transistors on this radio for the medium wave range is an indication of its...