This high gain circuit is from 1969 General Electric documentation. The transistors are of the time, but equivalent types can be tested.
I found this circuit in an English magazine from July 1982. The circuit is still viable because all...
August 2017 - Mouser Electronics is in stock with the PGA460 and PGA460 Q1 ultrasonic processors...
We found this circuit in a Philips documentation from 1965. The circuit uses a common LDR sensor...