alarm

From circuits in Figure 1 is the motion sensor circuit. The working of circuit to start from when we apply a power supply 12 volt to input point 12 volt. Then the electrical flow through a diode D11, that is protector the wrong electrodes of users.
When current flowed through diode D11 will be filtered to smooth by C16 then is divided into two way are first to the relay RY1 and other way into an input of IC4 to reduce voltage from 12 volt only remain 9 volt, This level voltage will be supplied to many the circuit s.

On begin the circuit is delayed with these components are IC3/4, R23, C13 and D10. Which the IC3/4 will apply voltage to pin 13 of IC2/2, that has voltage more than pin 12. So as a result to pin 14 of IC2/2 has logic into “0”. The does not works,although it is moving. But when at pin 10 of IC3/4 changed a logic state from “1” into “0”, since C13 begin charged fully the voltage. IC2/2 will release a working to normal. This section circuit will delay the time about 10 second to who switch ON this project had a chance to leave the area. Before it will be ready to detect motion.

When has a thunderstorm. Electrical is off, or power surges the extreme, but sometimes we need to use the electrical appliances. And in sensitive electrical appliance damaged easily. Power surges a little. Might make it wastes. In particular surge. At you firstly turn on the switch. Should have the power to delay, gradually release it into these appliance. I would like to introduce the concept of a two ac delay circuits. Which both two circuit is designed in easily ideals for all people.

Protection Surge with Delay the relay using ic 4011

This circuit can be used to delay other appliances connected to the output of the relay. After working set To prevent equipment damage from pressure.
Surge.
The IC number is 4011 Nand Gate CMOS .When switch S1 is current through R1. To charge at C1.This takes time to fully charge, and when a voltage input
Pin 1 and pin 2 of IC1.The output from pin 3 through a logic “0″ Volts to the control relay contacts to control the relay to work editing equipment, external works.That the time delay relay set from T = R1 x C1 x 0.85 is measured in seconds.

Read more source: Diy surge protector circuits

This is danger beep circuit. It use 555 integrated number circuits build to are a stable mutivibrator that be valuable duty cycle 5% driver loudspeaker 8ohm 0.25W sizes. By change transistor BD136 will get danger beep use make person penetrate a hole is frightened or call for the interest from a neighbor for asks for help. Because of use part a little , then have small-sized and use current just 50mA from a place turns on the power supply 9Volt only.

Read more and see circuits at source : http://www.eleccircuit.com/555-timer-audio-alarm-circuits/

This is asimple siren sound that high power output and very noisy. ICs, Digital ICs are easy to use number CD4046 Inverter circuit and four transistor power increase current out to horn speaker 20 watt 4ohm – 8ohm.
How This Circuit works
Operation of the circuit when the circuit is connected to power. Frequency generator circuit starts, the cycle will be the second frequency generator set to a first set of IC1 / 1, R2, C2 generator frequency 1Hz.Output can be modulated. With integrated suite 2, which is R3, R4, C3, ZD1 the modulation and frequency of Set 2 is the origin of IC1 / 2, R5, C4 are the output out of pin 12 of IC1 / 2 to Pin 1 of IC1 / 3.The output from the pin 2 is connected to IC1 / 4, IC1 / 5 and pin B of the Q1 output of IC1 / 4, IC1 / 5 is connected to pin B of Q2. we can observe that Q1 and Q2 will run switch. Well, if work makes Q1 Q4, Q5 run a current through the speakers and will work if Q2 Q3, Q6 running a current flowing through the speakers. The nature of the circuit of Q3-Q6 will result in high currents flowing through the speakers, the sound of the siren is very loud.

Read more and see circuits at source :http://www.eleccircuit.com/high-power-siren-circuit-using-cd40106/

This is Sound effects two tone circuit, which generally abound measure various both of kinds use IC frequency origin oruse the transistor. The sound will that is proportionate big depend on the value of R and C. For this circuit is will building sound of pale long tail or clock ancient sound.
The work of the circuit, when , build the circuit suits power supply have current change R1,VR1 go to charge at C1, enough C1 have volt fall straddle arrive at 0.7V make Q1 begin the work bears fruit to make Q2 work with LED1.

Read more and see circuits at source: http://www.eleccircuit.com/sound-effects-two-tone-circuit/