Free circuit diagrams 4U

TV Transmitter circuit diagram (VHF)

Published on 2012-01-22 01:29:00

Most of people ask TV transmitters.So Today I'm going to give you a very useful circuit diagram.By using this circuit you can send your signals 75m to 100m.This circuit diagram is not my own circuit one of my friends gave me this.I suppose you guys also can send your own circuit diagrams for us.Then we can publish them through our website.Here They have used common transistor BC 108 If you are unable to find this transistor you can use equal transistors like BC337, 2N2222, BC546.Note# To make L

Burglar alarm

Published on 2012-01-02 11:25:00

This is a very useful circuit diagram because these days there are lots of crimes in every where.So I suppose this would be an answer for your matter.Here I have used common Transistor BC107.After fixing this circuit switch on s1 and adjust R2 until the horn makes sound.Then switch off the s1 .Now if some one broke the thin wire the horn will make a sound.You can cover your garden with this circuitNote# Build this circuit on a PCB#Don't supply more than 12V# Use very thin wire to get good resul

Basic Sound Generator Circuit Diagram

Published on 2011-10-18 00:17:00

This is so important circuit for the persons who came to this field recently.Here I have used common IC NE555.According to the pules (Frequency) of the IC We can generate the sound.You can change the speed of the sound by adjusting R2.This circuit operates with 5V.# Note# Don't give over 5V# Build this circuit on a PCB# Don't give the much heat to the IC NE555