Content for BC109


NPN Silicon Planar Epitaxial Transistors. Suitable for applications requiring low noise and good hFE linearity, eg. audio pre-amplifiers, and instrumentation

Mini serial console with three different serial ports

“This is my “poor man’s HID” that I want in my projects to enter data and display messages. Story It is a simple serial console that can be used for data display and data input. It can handle three …

4 Microphones Mixer Preamplifier

“Some time ago I was asked to solve the following problem: a small choir plays a number of four fixed microphones. The audio signals from these four microphones had to be amplified, mixed and the resulting signal had to be …