The Universal Timer

Now, a day automation task is necessity not only in industrial sphere but even in the domestic sphere.

The project universal timer in this website is unique because it offer an ultra wide range of time period having pin point precision anywhere (i.e. not affected by ant physical factor) from one – tenth of a second to hundreds of hours. Due to feature “auto latch” facilities and low power consumption CMOS IC used plus such a low current consumption on that most multimeter would fail to detect it. The above facility with low costlier and familiar design make the circuit “The Universal Timer ” more versatile.

Circuit description of universal timer

High frequency signal of several kilohertz is generated by IC1 CD4060, and VR1 is used to remove device imprecision errors. The internal frequency divider of IC1 divides the base frequency by a factor of 213 times i.e. 16384 times.

The output frequency of 10 KHz from pin 3 of IC1 is simultaneously divided by set of five CD4017 counters (IC2 – IC6) by 10, 6, 10, 6, and 10. Here IC2 to IC6 is configuring in maximum mode and divided-by-six decimal mode respectively where output is selected by range selector switch SW1.

The output time period from range selector of universal timer switch is 0.1 second, 1 second, 0.1 minute, 1 minute, 0.1 hour, 1 hour respectively given to two serial connected counter CD4017 (IC7, IC8). The outputs from range selector provide precise master clock frequency, counted by IC7 and IC8. IC7 and IC8 counts one and ten master pulses respectively.

The timer section of universal timer is control by two rotator switch SW2 and SW3 as shown in circuit diagram figure 1.

NAND gate N1 is used to change the state of output from SW2 and SW3. The feedback diode D1 helps to latches the next NAND gate N2.

Lastly a relay driver transistor T1 is used to drive relay connected to collector of transistor T1. The relay contacts can be selected to switch the load ‘ON’ or ‘OFF’ after the preset time. Switch SW4 (Push-To-On switch) is used to reset the whole circuit. Power supply interruption also reset the entire circuit of universal timer.

NOTE: Connect a device to a timer and set it to short period, say a few seconds, and adjust VR1 till exactly that time delay is obtained. The accuracy on rest of the range will follow automatically.

PARTS LIST

Resistors (all ¼-watt, ± 5% Carbon)

R1 – R4, R10, R11 = 1 KΩ

R5, R6 = 10 KΩ

R7 = 47 KΩ

R8 = 24 KΩ

R9 = 100 Ω

VR1 = 4.7 KΩ

Capacitors

C1 = 0.0001 µF ceramic

C2 = 100 µF/25V electrolytic

Semiconductors

IC1 = CD4060

IC2 – IC8 = CD4017

IC7 (N1 – N2) = CD4011

T1 = BC547 NPN transistor

D1 – D3 = 1N4148

Miscellaneous

SW1 = Single–pole 6–way rotary switch

SW2, SW3 = Single–pole 10–way rotary switch

SW4 = Push-To-On switch

SW5 = On/Off switch

SW6 = SPDT (Single pole double throw)

RL1 = 300 Ω 12V relay

LED1 = RED

LED2 = Green

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XS1B (Motor Bike)Wiring Diagram

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5 channel radio remote control

TX-2B / RX / 2B  5 channel radio remote control.

This article is about a simple 5 channel radio remote control circuit based on ICs TX-2B and RX-2B from Silan Semiconductors. TX-2B / RX-2B is a remote encoder decoder pair that can be used for remote control applications. TX-2B / RX-2B has five channels, wide operating voltage range (from 1.5V to 5V), low stand by current (around 10uA), low operating current (2mA), auto power off function and requires few external components. The TX-2B / RX-2B was originally designed for remote toy car applications, but they can be used for any kind of remote switching application.

Circuit diagrams and description.

Remote encoder / transmitter circuit.

The TX-2B forms the main part of the circuit. Push button switches S1 to S5 are used for activating (ON/OFF) the corresponding O/P channels in the receiver / decoder circuit. These push button switches are interfaced to the built-in latch circuitry of the TX-2B. Resistor R7 sets the frequency of the TX-2B’s internal oscillator. Resistor R1 and Zener diode D1 forms a simple Zener regulator circuit for providing the IC with 3V from the 9V main supply. C2 is the filter capacitor while C1 is a noise by-pass capacitor. D2 is the power on indicator LED while R6 limits the current through the same LED. S1 is the ON/OFF switch. The encoded control signal will be available at pin 8 of the IC. The encoded signal available at pin 8 is without carrier frequency. This signal is fed to the next stage of the circuit which is a radio transmitter. Crystal X1 sets the oscillator frequency of the transmitter section. R2 is the biasing resistor for Q1 while R3 limits the collector current of Q1. The encoded signal is coupled to the collector of Q1 through C3 for modulation. Transistor Q2 and associated components provide further amplification to the modulated signal.

Remote receiver / decoder circuit.

The remote receiver circuit is built around the IC RX-2B. The first part of the circuit is a radio receiver built around transistor Q1. The received signal is demodulated and fed to pin 14 of the IC. Pin 14 is the input of the built in inverter inside the IC. R2 sets the frequency of the IC’s internal oscillator. O/P 1 to O/5 are the output pins that are activated corresponding to the push buttons S1 to S5. Zener diode D1 and resistor R12 forms an elementary Zener regulator for supplying the RX-2B with 3V from the 9V main supply. C12 is the filter capacitor while R11 is the current limiter for the radio receiver section. Diode D2 protects the circuit from accidental polarity reversals. C15 is another filter capacitor and C14 is a noise by-pass capacitor.

Notes.

§  This circuit can be assembled on a vero board or a PCB.

§  Use 9V DC for powering the transmitter / receiver circuits.

§  Battery is the better option for powering the transmitter / receiver circuit.

§  If you are using a DC power supply circuit, it must be well regulated and free from any sort of noise.

§  Both ICs must be mounted on holders.

Interfacing relay to the RX-2B output.

The method for interfacing a relay to the output of RX-2B is shown below. When push button switch S1 of the transmitter circuit is pressed, pin O/P1 (pin 7 of the RX-2B) goes high. This makes the transistor 2N2222 to conduct and the relay is activated. The same technique can be applied to other output pins of the RX-2B. The relay used here is a 200 ohm type and at 9V supply voltage the load current will be 45mA which is fine for 2N2222 whose maximum possible collector current is 900mA. When using relays of other ratings this point has to be remembered and do not use a relay that consumes a current more than the maximum possible collector current of the driver transistor.

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Seven Segment Counter Display Circuit

Here is the circuit diagram of a seven segment counter based on the counter IC CD 4033.This circuit can be used in conjunction with various circuits where a counter to display the progress  adds some more attraction.
IC NE 555 is wired as an astable multivibrator for triggering the CD 4033.For each pulse the out put of CD 4033 advances by one count.The output of CD 4033 is displayed by the seven segment LED display LT543.Switch S1 is used to initiate the counting.Diode D1 prevents the risk of accidental polarity reversal.

Seven Segment Circuit Diagram with Parts List.

 

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IR Burglar Alarm for Basic Home security system

IR based entry detector alarm is useful for someone crosses the Gate or door of house when is left open.. It can alarm you and notify you that someone entered into the door or place.. This project will be used at Doors/ Entrance of office to get alert the owner or admin to notify someone crossed the gate or door of the location.

IR LED will send and receives signal when some one interrupts the IR signal alarm will be started to make alert of any burglar or theft.

 

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Cable LAN Tester Circuit

Here iscable LAN testercircuit. Thecable LAN testercircuit can also to test cable on telephone, coaxial cable, Lan cable and other. Thiscable LAN testercircuit using led for main indicator device. This simple cable LAN tester circuit, can be make in home. Designed initially for my intercom, but can be used with alarm wiring, CAT 5 cables and more. As the 4017 has limited driving capabilities, then each output is buffered by a 4050. This provides sufficient current boost for long cables and the transmitter and receiver LED's. The receiver is simply 8 LED's with a common wire…read on. The cable LAN tester circuit comprises transmitter and receiver, the cable under test linking the two. The transmitter is nothing more than a "LED chaser" the 4011 IC is wired as astable and clocks a 4017 decade counter divider. The 4017 is arranged so that on the 9th pulse,the count is reset. Each LED will light sequentially from LED 1 to LED 8 then back to LED 1 etc. Note also that as the CMOS 4050 is only a hex buffer, you need 8 gates so two 4050′s are required, the unused inputs are connected to ground (battery negative terminal). Please note that for clarity this cable LAN tester?circuit has been drawn without showing power supplies to the CMOS 4011 and CMOS 4050 IC’s. The positive battery terminal connects to Pin 14 of each IC and negative to Pin 7. The CMOS 4017 uses Pin 16 and Pin 8 respectively.

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Mobile incoming call indicator

Description.

This circuit can be used to escape from the nuisance of mobile phone rings when you are at home. This circuit will give a visual indication if placed near a mobile phone even if the ringer is deactivated.

When a call is coming to the mobile phone, the transmitter inside it becomes activated. The  frequency of the transmitter is around 900MHz.The  coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at  its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call.

Circuit diagram with Parts list. 

Notes. 

• The coil L1 can be made by making 150 turns of 36 SWG enameled copper wire on a 5mm dia plastic former.Or you can purchase a 10 uH coil from shop if available.
• The circuit can be powered from a 6V battery.
• Assemble the circuit on a good quality PCB.
• C1 & C3 are to be polyester  capacitors.
• The electrolytic capacitor C2 must be rated 10V.

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Static 0 to 9 display

Description.
The circuit shown here is of a simple 0 to 9 display that can be employed in a lot of applications. The circuit is based on asynchronous decade counter 7490(IC2), a 7 segment display (D1), and a seven segment decoder/driver IC 7446 (IC1).
The seven segment display consists of 7 LEDs labelled ‘a’ through ‘g’. By forward biasing different LEDs, we can display the digits 0 through 9. Seven segment displays are of two types, common cathode and common anode. In common anode type anodes of all the seven LEDs are tied together, while in common cathode type all cathodes are tied together. The seven segment display used here is a common anode type .Resistor R1 to R7 are current limiting resistors. IC 7446 is a decoder/driver IC used to drive the seven segment display.
Working of this circuit is very simple. For every clock pulse the BCD output of the IC2 (7490) will advance by one bit. The IC1 (7446) will decode this BCD output to corresponding the seven segment form and will drive the display to indicate the corresponding digit.

Circuit diagram.

Notes.

§  The circuit can be assembled on a perf board.

§  Use 5V DC for powering the circuit.

§  The clock can be given to the pin 14 of IC2.

§  D1 must be a seven segment common anode display.

§  All ICs must be mounted on holders.

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UM66T MELODY IC

 The PCB contains just 2 components:


1. 10uF electrolytic capacitor
Make sure you insert this component with the positive lead (the long wire) facing right, with the strip on the body facing left. Push it most of the way into the PCB.

2. M66T IC
This has 3 wires. Spread the wires slightly and insert it with the flat
part of the case facing left. Push it about halfway into the PCB


CONNECTING THE SPEAKER


Now connect 2 solid core wires of about 30mm in length to the speaker terminals. Solder the other end to the large copper pads on the underside of the PCB.

POWER SUPPLY

 Left shows how to connect the battery, switch and PCB together.
You will need to either cut the positive lead, or add another wire to link the micro switch to the PCB. It depends how much wire you need.
Connect the power leads by feeding them up through the large hole first, then through the smaller holes.

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TOUCH SWITCHS

TOUCH SWITCH 1

This circuit detects the skin resistance of a finger to deliver a awfully tiny current to the super-alpha try of transistors to show the circuit ON. The output of the "super transistor" activates the BC 557 transistor. The voltage on the highest of the world is passed to the front of the circuit via the 4M7 to require the place of your finger and also the circuit remains ON.

To turn the circuit OFF, a finger on the OFF pads can activate the primary transistor and this may rob the

"super transistor" of voltage and also the circuit can close up.

TOUCH SWITCH 2

This circuit detects the skin resistance of a finger to show the circuit ON for concerning one second. The output are often taken to a counting circuit. The circuit consumes no current when in quiescent mode:

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