_the circuit for clapoperated appliance control

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DESCRIPTION The circuit for clap operated appliance control. it comprises a condenser microphone ,transistor BC549,timer NE555,display driver CD4033,decade counter CD4017,set and reset flip-flop CD4013,relay driver uln2803 and new discrete components. CIRCUIT DESCRIPTION The condenser mic pick up the sound of your claps and converts its into a small electrical single that is amplified by transistor BC549. The sensitive of condenser mic is depend upon resistor r1the sound input signal fed to base of transistor t1 (BC549)through the capacitor C1.resistor R2 and R3 form the voltage divider network for this amplified stage. The changes in current get reflected as change in voltage across the resistors . value of resistor R2 control the input current into the devices and gain of T1. The 560kilo ohm value of R2 gives the required gain to drive the next stage The output from the transistor T1 is applied to trigger pin 2 of timer NE555,which is configured as Monstable multivibrator .the time period of the monostable is divider by resistor r6 and capacitor IC3.when the transistor received from the condenser mic it conducts. as a result its collector voltage drop to trigger the Monstable multivibrator

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Page 1: _The Circuit for Clapoperated Appliance Control

DESCRIPTION

The circuit for clap operated appliance control. it comprises a condenser microphone ,transistor BC549,timer NE555,display driver CD4033,decade counter CD4017,set and reset flip-flop CD4013,relay driver uln2803 and new discrete components.

CIRCUIT DESCRIPTION

The condenser mic pick up the sound of your claps and converts its into a small electrical single that is amplified by transistor BC549. The sensitive of condenser mic is depend upon resistor r1the sound input signal fed to base of transistor t1 (BC549)through the capacitor C1.resistor R2 and R3 form the voltage divider network for this amplified stage. The changes in current get reflected as change in voltage across the resistors . value of resistor R2 control the input current into the devices and gain of T1. The 560kilo ohm value of R2 gives the required gain to drive the next stage

The output from the transistor T1 is applied to trigger pin 2 of timer NE555,which is configured as Monstable multivibrator .the time period of the monostable is divider by resistor r6 and capacitor IC3.when the transistor received from the condenser mic it conducts. as a result its collector voltage drop to trigger the Monstable multivibrator (IC1).the pulse at output pin 3 is IC1 is used as the clock for seven segment display driver cd4033 IC2 and decade counter CD4017 IC3

Decade counter cd4017 in the 5 stage divide by 10 Johnson counter with decoded outputs. These counter are cleared to. there zero count by logical high on their reset pin. The advance on the positive edge of clock signal when the strobe signals. Each decoded output remains high for one full clock cycle.

Initially, when a power is switch on sharp pulse is produces by capacitor resistor conneted to the reset pin15 of CD4017 which resets the decade counter .As a result ,q0 output of IC3 goes to high to reset the display IC2 and d flip-flop ic4 through IC7 q1 through a Q9 .Output of D4017 are low. Each of these outputs goes high, one by one, on arrival of a clock pulse at pin 14 of IC3. A clock

Page 2: _The Circuit for Clapoperated Appliance Control

pulse is generated by T1 and (IC1) every time clapping sound is received by the condenser mic. Q1 through Q8 outputs of (IC3) are connected to set inputs ’S’ of CD4013 flip-flops(IC4 through IC7).

The dual D-type flip-flop is a monolithic complementary MOS(CMOS) integrated circuit constructed with n and p channel enhancement –mode transistor. Each flip-flop has independent data, set, reset and clock inputs and outputs. These devices can be used for shift register application and by connecting the Q output of decade counter to the data input, for counters and toggle application Settings and resetting are in dependent of the clock and accomplished by a high level on the set and reset lines, respectively.

CD4013 is configured as set-reset flip-flop, On first clap, a negative pulses triggers IC1 and its output pin 3 goes high for a time period decided by R6 and C3. This provided a positive pulse at clock pin 14 of decade counter IC 4107 (IC3), which shift from high output from Q0 and Q1.The first flip-flop of IC4 is set and output pin 13 and IC4 goes high to energies relay RL1 and thus turn the first appliance on.

On second clap, the clock signal applied to ic3 shifts the high output Using this circuit, you can turn on/off up to nine appliances one by one with each clap. You can know the number of ‘on’ appliances by simply having a look at the 7-segment display.

From Q1 to Q2. The high Q2 output makes pin 1 of ic4 high, which energies relay RL2 and the second appliance turns on. Thus with every clock pulse generated by the clap sound, the relay energies one by one to switch on the respective appliances connected to them.

On arrival of ninth clock pulse, Q9 output goes high to drive transistor T2 into saturation, which energies relay RL9.The tenth clock resets all the flip flops. So all the relays de-energies to turn the appliances off. The process can then restart from the beginning.

ULN2803 is used to drive the relays. It consists of eight NPN type Darlington pairs of transistors, which are suitable of interfacing the low logical level digital

Page 3: _The Circuit for Clapoperated Appliance Control

circuitry with the relay circuit requiring higher current/voltage. All the devices feature open-collector outputs and free wheeling clamp diodes for transient suppression. ULN2803 is designed to be compactable with standard TTL families. Output pin 3 of the mono stable (IC1) is connected to clock pin 1 of decoder CD4033 (IC2). It also provides clock pulse to decoder IC2.

As mentioned earlier, CD4033 consists of a 5-stage Johnson decade counter and an output decoder that converts the Johnson code into a 7-segment decoded output for driving one stage in the numerical display. A high reset signal clears the decade counter to its zero count. The counter is advanced by one count at the positive clock signal transition. The seven decoded outputs (a, b, c, d, e, f, and g) illuminate the respective segments of the 7-segment display, representing decimal numbers 0 to 9.

Resistors R7 through R13 act as current limiters. The displayed count increments with every clock pulse. After tenth clock, IC2 resets and the count number is not displayed.

Construction

An actual-size BCD layout for clap-operated appliance control. And its components layout wire the circuit on the PCB. Use sockets for ICs CD4033, CD4017, CD4013 AND ULN2803.put the ICs into the sockets after checking Vcc, grounding and continuity between the respective connection using a multimeter, connect the appliances to the relay contacts. There is no need to the relay contacts. There is no need to connect free-wheeling diode across RL1 through RL8(as ULN2803 has internal diodes). However, connect the cathode of diode D1 to positive supply and the anode of the diode to the collector of transistor T2.use a shielded cable for connecting the condenser mic.

Page 4: _The Circuit for Clapoperated Appliance Control