Applications for this circuit include hearing aid, stethoscope, etc. Transistors are general purpose and powered by a single 1.5 V battery.
Found in a 90s Popular Electronics, this circuit is interspersed between the filter and the...
This circuit is from an 80's documentation. The integrated circuit is from the time and the...
This circuit was found in a 80s American documentation. The zener diodes determine the points of...