Transistor astable construction project (presentation and PCB design)

A mini project involving the soldering together of a simple transistor based astable multivibrator causing two LEDs to flash alternatively. Students can investigate the effects of changing capacitance values.

The circuit is designed for BC548 and BC108 transistors. I have used the circuit to allow students to develop their soldering skills and then to investigate the operation of the circuit. It can could also be used as the basis of other projects which require flashing LEDs.

A PCB design is provided in the powerpoint. A Circuit Wizard file can be also be forwarded by emailing

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  • NPNAstable.pdf
  • NPNAstable.pptx

About this resource


Created: Jun 23, 2018

Whole lesson

pdf, 1 MB



pptx, 910 KB


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