This circuit demonstrates a simple universal voltage doubler using the popular timer IC NE555 timer IC. The timer is configured in astable mode to generate a switching signal of about 3kHz. This signal drives a complementary transistor pair consisting of BD139 NPN transistor and BD140 PNP transistor, which alternately switch the charge-pump stage.
The voltage doubling action is achieved using electrolytic capacitors and fast Schottky diodes such as 1N5819 Schottky diode. During each switching cycle, the capacitors charge and transfer energy through the diodes, producing nearly twice the input voltage at the output.
The circuit works with different input supplies, making it versatile for many DIY applications. For example, a 6V input can produce around 12V, 9V can give about 17V, and 12V can generate nearly 23V, depending on the load conditions. This project helps beginners understand timer-based switching, transistor driving, and simple DC–DC voltage boosting techniques.
