Matt circuit

This circuit uses an NE555 timer IC, some LEDs, a couple of piezo buzzers and a few other components to produce audio-visual effects as per your requirement. The timer NE555 and its equivalents are widely used for all sorts of audio and visual indications, such as door alarms. But the sound produced by these circuits may not be always pleasant to hear, or the light produced may not be visually appealing. With this circuit you can get different audio-visual effects. Here we use LEDs for visual indication and buzzers for audible alarms as they require relatively low current to operate. By simply connecting some resistors and capacitors to NE555 we can obtain some interesting visual and audible effects as described here. Circuit and working Fig. 1 shows the circuit of the versatile audio-visual alarm which is built around timer NE555 (IC1), LEDs, buzzers and some resistors and capacitors. Resistors R1 and R2 and capacitor C1 determine the frequency of the LEDs’ blinking. The frequency is ...