High Gain JFET Audio Amplifier

This is a simple high gain JFET audio amplifier circuit. This circuit need very low power but it provides high gain amplifying function. It also called “JFET µ amp”. Here is the circuit : The lower drain current is, the more gain is obtained because µ of a JFET increases as drain current decreases. However it will sacrifice input dynamic range […]

Read more

Ultrasonic Proximity Detector

This is ultrasonic proximity detector circuit. This circuit consist of micropower opamp and a pair of matched piezo-ceramic tranducers. It uses a 9V battery as power supply. This circuit uses the radar principle, when the objects or people is nearby it will reflect the transmitter’s steady tone back to the reciever. Here is the circuit : First circuit is a […]

Read more
1 2 3 4 5 30