Amplitude discriminator
A discriminator is an electronic device that converts an analog input signal to a standardized digital output pulse when the input signal amplitude exceeds a specified voltage threshold. Such discriminators are often used to filter pulses with amplitudes below a specified reference level.
The scale is scattered with seeds that birds enjoy. Every so often, a bird comes to feed. This is an electronic scale and its output voltage is directly proportional to the bird's weight. The scale's sensitivity is 0.01 V/g (i.e., we have a simple conversion factor: 10 g = 0.1 V). By using a voltage discriminator, it is possible to count only those birds whose mass exceeds a certain predetermined value. In other words, only birds with a mass greater than the threshold set on the comparator's reference input are counted.