This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
The integrated circuit of this instrument is not common today. Equivalent operational can be...
This circuit was found in a Radio Electronics Constructor, English magazine from April 1976; The...
The accuracy of this simple circuit depends on the accuracy of the input circuit resistors. Any...