Audio Circuits

19 + 19W Stereo Bridge Amplifier Circuit Using LA4440

Stereo Amplifier Board

Shown below is the one section of the stereo amplifier using LA4440. Parts Required: Capacitor: C1 – 10uF,16V C2 – 220uF,16V C3 – 2A222J C4 – 220uF,16V C5 – 220uF,16v C6 – 220uF,16V C7 – 220uF,16V C8 – 2A104J C9 – 2A104J C10 – 2200uF,25v Resistors R1 – 100E R2 …

Read More »

Power failure and resumption alarm cum indicator circuit using 555 timer ic

Power Failure And Resumption Alarm Cum Indicator Circuit Project Kit

Power Failure And Resumption Alarm Cum Indicator Circuit Project from KJMIndia This is a very simple circuit built using only few components to detect ac mains power failure and its resumption. The heart of the circuit is the most popular timer Ic 555 which is wired as monostable multivibrator. Bty, …

Read More »

Burglar Alarm Using NPN(BC548)And PNP(SK100) Transistor

The burglar alarm circuit shown here sounds an alarm when the wire loop is broken.The system is implemented by installing a sensing loop, which is basically a thin copper wire. This way, the loop is both invisible and brittle enough to break easily and initiate the alarm mechanism.At the time …

Read More »


Parts Required: Capacitors C1 – 0.02uF ceramic disc C2 – 1000uF, 12V or 25V Resistors (All 1/4Watts) R1 – 100K R2 – 2.2K R3 – 47E Transistors T1 – BC547 (NPN) T2 – S8550 (PNP) Loudspeaker – 8 ohms Battery – 9V This is a simple audio alarm which operates from …

Read More »