Rongge

This diy sound activated lights circuit turns a lamp ON for a short duration when the dog barks (or a relatively strong sound) giving an impression that the occupants have been alerted. The condenser microphone fitted in a place to monitor sound and generates AC signals, which pass through DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 along with transistor T2 amplifies the sound signals and provides current pulses from the collector of T2. When sound is produced in front of the condenser mic, triac1 (BT136) fires, activates lights and the bulb (B1) glows for about two minutes.  Sound Activated Lights Circuit Diagram Assemble the sound activated lights circuit on a general purpose PCB (circuit board) and enclose in a plastic cabinet. Power to the sound activated switch circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circui...

This is a Relay activated by Sound Circuit Diagram . Generally a circuit has a basic function, but according to our needs can modify or add to a circuit making it more complex. This circuit is a relay activated by sound, which can be used in an alarm system, home automation, robot and even in an Arduino. Undoubtedly this control by sound can be very useful, an example is a light activated by the sound of a knock on the door or a round of applause. The light turns off automatically after a few seconds. An alternative is to use protection against theft - if someone wants to open the door or break something light illuminates, indicating that someone is home. The circuit can work with any voltage 5-12 Vdc, it depends on the voltage of the relay coil. Relay activated by Sound Circuit Diagram

Compact circuit, Can be wired in parallel to existing switches This device allows one or more lamps to illuminate at sunset and turn off at dawn.Q1 and Q2 form a trigger device for the SCR, providing short pulses at 100Hz frequency. Pulse duration is set by R2 and C1.When the light hits R1, the photo resistor assumes a very low resistance value, almost shorting C1 and preventing circuit operation. When R1 is in the dark, its resistance value becomes very high thus enabling circuit operation.   Circuit Diagram: Dark Activated 220 volt AC Lamp Circuit Diagram Parts: R1 = LDR R2 = 100K R3 = 200K R4 = 470R R5 = 12KR6 = 1KR7 = 470R C1 = 10nF-63V D1 = TIC106D D2 = 1N4007D3 = 1N4007D4 = 1N4007 D5 = 1N4007 Q1 = BD327 Q2 = BD337 SK1 = Female Mains Socket   Notes: R3 allows fine setting of operating threshold and R2 value can be raised to 150K maximum. Several lamps wired in parallel can be connected to the circuit, provided total power dissipation of the load does not exceed about 300...