Sound Activated Switch | Electronic Project Circuits

Posts Tagged ‘sound activated switch’

Night Alert

Idea of this circuit came to me at midnight when my pet dog started barking continuously on sensing a moving shadow, perhaps that of an intruder. Dogs have a night adaptation capability to maximise the sensitivity of vision in low light. They are well adapted to see moving objects rather than stationary ones in darkness. This circuit turns a lamp ‘on’ for a short duration when the dog barks, giving an impression that the occupants have been alerted.

The condenser microphone fitted in the dog’s cage senses barking 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. The input trigger pulse is applied to the collector of transistor T3 and coupled by capacitor C3 to the base of transistor T4 causing T4 to cut off. The collector voltage of transistor T4 forward biases transistor T3 via resistor R8. ….
Warning:
Since the circuit uses 230V AC, many of its points are at AC mains voltage. it could give you lethal shock if you are not careful. So if you don’t know much about working with line voltages, do not attempt to construct this circuit. EFY will not be responsible for any kind of resulting loss or damage.
Author: D. Mohan Kumar – Copyright: Electronics For You Mag
Read more Source: http://www.extremecircuits.net/2010/06/night-alert_04.html

Be the first to comment - What do you think? Posted by admin - October 1, 2010 at 1:11 am

Categories: Detector, Electronic Control, Lighting Tags: condenser microphone circuit, night alert, sound activated switch

Sound SCR Switch by IC 1458 & SCR C106D

This is Electronic Switch, Control by Sound. It is mini Circuit and easy, use IC 1458 or 4558 or LF353 , SCR for Switch Electronic = Relay Switch. Volt supply 9V.
You can see LF353 in many circuits.

Circuit Sound SCR Switch by IC 1458 & SCR C106D

PCB Sound SCR Switch by IC 1458 & SCR C106D

Source: PK Kit Circuit

Be the first to comment - What do you think? Posted by admin - May 22, 2007 at 11:17 pm

Categories: Circuit diagram, Electronic Control Tags: scr control circuit, sound activated switch, Sound-Switch

Hand Clap Electronic Control

We have all seen the commercial on TV ………. CLAP – ON – CLAP – OFF – THE – CLAPPER ………… well here is a circuit that will perform that same function.

Circuit operation is as follows. A single hand clap will be picked up by the electric mic which is coupled through C1 into the op amp IC1. The output of IC1 triggers the 555 IC timer IC2 which is configured as a monostable multivibrater. The trigger pulse is stretched by IC2 and outputs a pulse to IC3 a D type flip flop. Because of the three state counter arrangement of IC3, two sharp claps are required before IC3 will output a high to Q1 which will turn on K1 relay and any device connected to K1′s switch contacts. Two more claps will clock IC3 again and will turn off Q1 and any device connected to the K1′s contacts. I had my unit connected to my xmas tree lights so that I wouldn’t have to crawl behind the tree to turn the lights on and off. Sensitivity for the circuit is R3 and should be adjusted so that the circuit ignores normal room noise.

From :: http://home.maine.rr.com/randylinscott/dec97.htm