SOLAR BUG - 2 If a digital voltmeter is connected across...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
CIRCUIT IDEAS ELECTRONICS FOR YOU • APRIL 2005 67 WWW.EFYMAG.COM SANI THEO H ide this solar-powered circuit suitably and see the reaction of your friends to the chirpy sound produced by it every few min- utes. In all probability, it will coax them to find out where the sound is coming from. The circuit runs off a miniature so- lar power panel, which can be taken out from an old calculator such as Citi- zen CT-500. A panel giving 1.5V to ± D. SOMNATH SOLAR BUG 2.5V is required. Note that the circuit can work properly from a panel as small as 3 cm
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2 . If a digital voltmeter is connected across capacitor C2, a slow build-up of voltage can be observed when the panel is exposed to light. Transistors T1 and T2 form a relaxation oscillator. When C1 charges to 0.6V, transistor T1 conducts and the charge built up in C2 is discharged through the piezobuzzer to produce a short beep. While testing the circuit, the value of resistor R1 can be reduced to, say, 1 kilo-ohm. Use a good-quality buzzer to ensure that the sound produced is loud enough. z...
View Full Document

This document was uploaded on 01/12/2011.

Ask a homework question - tutors are online