09-10-2012, 11:33 AM
CONTROLLING ELECTRICAL APPLIANCES THROUGH IR REMOTE
CONTROLLING ELECTRICAL.doc (Size: 1.46 MB / Downloads: 70)
ABSTRACT
This is an interesting project built with an IR sensor and a decade counter. By using this project, one can control his lights / fans / AC / any electrical appliance with a TV Remote. CD4017 is a CMOS Decade counter. It can detect a clock pulse and the BCD out put will be incremented by one for each CLK pulse. If we observe the BCD numbers, the LSB (Least Significant Bit) of BCD complemented every time. This project uses this LSB to switch ON / OFF an electrical appliance.TSOP1738 is a high sensitive IR receiver which can sense 38 KHz IR light. The electrolytic capacitor (100μF) connected across pin no’s 3 and 1 of TSOP1738 for medium sensitivity. The NPN transistor BC557 is connected as a switch. Whenever an IR signal is detected, the transition is sensed by the PNP transistor and it supplies a CLK pulse to the BCD counter (CD4017). For every clock pulse the LSB (Least Significant Bit) of the BCD output is complemented. This toggling output is given to an NPN transistor through a base resistor.
If logic ‘0’ is applied to the transistor, it will be driven into cutoff region. As the collector current is zero in cut-off region, the relay will not be energized and the electrical appliance will be in OFF mode. If logic ‘1’ is applied to the transistor, it will be driven into saturation region. As the collector current is high in saturation region, the relay will be energized and the electrical appliance will be in ON mode. A diode is connected across the relay to protect the transistor by neutralizing the reverse EMF generated by the electromagnetic relay. An LED connected at pin no.2 of CD4017 to indicate the ON condition of the LOAD. An LED connected at pin no.3 of CD4017 to indicate the OFF condition of the LOAD.
INTRODUCTION
A remote control is a component of an electronics device, most commonly a television set, DVD player and home theater systems originally used for operating the television device wirelessly from a short line-of-sight distance. Remote control has continually evolved and advanced over recent years to include Bluetooth connectivity, motion sensor enabled capabilities and voice control.
The main remote control technology used in the home is infrared. The signal between a remote control handset and the device it is controlling are infrared pulses, which are invisible to the human eye. The transmitter in the remote control handset sends out a pulse of infrared light when a button is pressed on the handset. A transmitter is often a light emitting diode (LED) which is built into the pointing end of the remote control handset. The infrared light pulse represents a binary code that corresponds to a certain command, such as (power on). The receiver passes the code to a microprocessor, which decodes it and carries out the command.
The remote control is usually contracted to remote. It is known by many other names as well, such as converter, clicker, the box, flipper, hoofer-doffer, the tuner, 'the zapper', the changer, or the button. Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems, DVD players and dimmers. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. Earlier remote controls in the 1970s used ultrasonic tones. Television IR signals can be mimicked by a universal remote, which is able to emulate the functionality of most major brand television remote controls.
Block Diagram Explanation:
When we give the signal from remote the IR Sensor receives the singal and it passes to switching transistor CD4017 is a CMOS Decade counter. It can detect a clock pulse and the BCD out put will be incremented by one for each CLK pulse. If we observe the BCD numbers, the LSB (Least Significant Bit) of BCD complemented every time. This project uses this LSB to switch ON / OFF an electrical appliance.TSOP1738 is a high sensitive IR receiver which can sense 38 KHz IR light. The electrolytic capacitor (100μF) connected across pin no’s 3 and 1 of TSOP1738 for medium sensitivity. The NPN transistor BC557 is connected as a switch. Whenever an IR signal is detected, the transition is sensed by the PNP transistor and it supplies a CLK pulse to the BCD counter (CD4017). For every clock pulse the LSB (Least Significant Bit) of the BCD output is complemented. This toggling output is given to an NPN transistor through a base resistor.
If logic ‘0’ is applied to the transistor, it will be driven into cut-off region. As the collector current is zero in cut-off region, the relay will not be energized and the electrical appliance will be in OFF mode.
Relays
A relay is used to isolate one electrical circuit from another. It allows a low current control circuit to make or break an electrically isolated high current circuit path. The basic relay consists of a coil and a set of contacts. The most common relay coil is a length of magnet wire wrapped around a metal core. When voltage is applied to the coil, current passes through the wire and creates a magnetic field. This magnetic field pulls the contacts together and holds them there until the current flow in the coil has stopped. The diagram below shows the parts of a simple relay.
Operation:
When a current flows through the coil, the resulting magnetic field attracts an armature that is mechanically linked to a moving contact. The movement either makes or breaks a connection with a fixed contact. When the current is switched off, the armature is usually returned by a spring to its resting position shown in figure 6.6(b). Latching relays exist that require operation of a second coil to reset the contact position.
By analogy with the functions of the original electromagnetic device, a solid-state relay operates a thyristor or other solid-state switching device with a transformer or light-emitting diode to trigger it.
How it works?
When a clock signal (square wave pulse train) is provide at pin 14(clk input) , each of the other 10 output pins goes to logic 1 inturn. At any time only one output pin can be at logic 1: all others remains at logic 0.If LED’s were connected to each output each to light up inturn. If there were placed in a straight row in the correct sequence the effect would be for a ripple of light to run through the row.
Explanation of Each Sensor:
Temperature sensor:
An analog temperature sensor is pretty easy to explain, its a chip that tells you what the ambient temperature is!
These sensors use a solid-state technique to determine the temperature. That is to say, they dont use mercury (like old thermometers), bi-metalic strips (like in some home thermometers or stoves), nor do they use thermistors (temperature sensitive resistors). Instead, they use the fact as temperature increases, the votage across a diode increases at a known rate. (Technically, this is actually the voltage drop between the base and emitter - the Vbe - of a transistor. By precisely amplifying the voltage change, it is easy to genereate an analog signal that is directly proportional to temperature. There have been some improvements on the technique but, essentially that is how temperature is measured.
Because these sensors have no moving parts, they are precise, never wear out, don't need calibration, work under many environmental conditions, and are consistant between sensors and readings. Moreover they are very inexpensive and quite easy to use
Magnetic sensor:
The reed switch is an electrical switch operated by an applied magnetic field. The basic reed switch consists of two identical flattened ferromagnetic reeds, sealed in a dry inert-gas atmosphere within a glass capsule, thereby protecting the contact from contamination. The reeds are sealed in the capsule in such a way that their free ends overlap and are separated by a small air gap. The contacts may be normally open, closing when a magnetic field is present, or normally closed and opening when a magnetic field is applied. A magnetic field from an electromagnet or a permanent magnet will cause the contacts to pull together, thus completing an electrical circuit. The stiffness of the reeds causes them to separate, and open the circuit, when the magnetic field ceases. Good electrical contact is assured by plating a thin layer of precious metal over the flat contact portions of the reeds. Since the contacts of the reed switch are sealed away from the atmosphere, they are protected against atmospheric corrosion. The hermetic sealing of a reed switch makes them suitable for use in explosive atmospheres where tiny sparks from conventional switches would constitute a hazard. A reed sensor is a device built using a reed switch with additional functionality like ability to withstand higher shock, easier mounting, additional intelligent circuitry, etc. In production, a metal reed is inserted in each end of a glass tube and the end of the tube heated so that it seals around a shank portion on the reed. Infrared-absorbing glass is used, so an infrared heat source can concentrate the heat in the small sealing zone of the glass tube. The thermal coefficient of expansion of the glass material and metal parts must be similar to prevent breaking the glass-to-metal seal. The glass used must have a high electrical resistance and must not contain volatile components such as lead oxide and fluorides. The leads of the switch must be handled carefully to prevent breaking the glass envelope.
INFRARED IN ELECTRONICS
Infra-Red is interesting, because it is easily generated and doesn't suffer electromagnetic interference, so it is nicely used to communication and control, but it is not perfect, some other light emissions could contains infrared as well, and that can interfere in this communication. The sun is an example, since it emits a wide spectrum or radiation.
The adventure of using lots of infra-red in TV/VCR remote controls and other applications, brought infra-red diodes (emitter and receivers) at very low cost at the market.
From now on you should think as infrared as just a "red" light. This light can means something to the receiver, the "on or off" radiation can transmit different meanings.Lots of things can generate infrared, anything that radiate heat do it, including out body, lamps, stove, oven, friction your hands together, even the hot water at the faucet.
CONTROLLING ELECTRICAL.doc (Size: 1.46 MB / Downloads: 70)
ABSTRACT
This is an interesting project built with an IR sensor and a decade counter. By using this project, one can control his lights / fans / AC / any electrical appliance with a TV Remote. CD4017 is a CMOS Decade counter. It can detect a clock pulse and the BCD out put will be incremented by one for each CLK pulse. If we observe the BCD numbers, the LSB (Least Significant Bit) of BCD complemented every time. This project uses this LSB to switch ON / OFF an electrical appliance.TSOP1738 is a high sensitive IR receiver which can sense 38 KHz IR light. The electrolytic capacitor (100μF) connected across pin no’s 3 and 1 of TSOP1738 for medium sensitivity. The NPN transistor BC557 is connected as a switch. Whenever an IR signal is detected, the transition is sensed by the PNP transistor and it supplies a CLK pulse to the BCD counter (CD4017). For every clock pulse the LSB (Least Significant Bit) of the BCD output is complemented. This toggling output is given to an NPN transistor through a base resistor.
If logic ‘0’ is applied to the transistor, it will be driven into cutoff region. As the collector current is zero in cut-off region, the relay will not be energized and the electrical appliance will be in OFF mode. If logic ‘1’ is applied to the transistor, it will be driven into saturation region. As the collector current is high in saturation region, the relay will be energized and the electrical appliance will be in ON mode. A diode is connected across the relay to protect the transistor by neutralizing the reverse EMF generated by the electromagnetic relay. An LED connected at pin no.2 of CD4017 to indicate the ON condition of the LOAD. An LED connected at pin no.3 of CD4017 to indicate the OFF condition of the LOAD.
INTRODUCTION
A remote control is a component of an electronics device, most commonly a television set, DVD player and home theater systems originally used for operating the television device wirelessly from a short line-of-sight distance. Remote control has continually evolved and advanced over recent years to include Bluetooth connectivity, motion sensor enabled capabilities and voice control.
The main remote control technology used in the home is infrared. The signal between a remote control handset and the device it is controlling are infrared pulses, which are invisible to the human eye. The transmitter in the remote control handset sends out a pulse of infrared light when a button is pressed on the handset. A transmitter is often a light emitting diode (LED) which is built into the pointing end of the remote control handset. The infrared light pulse represents a binary code that corresponds to a certain command, such as (power on). The receiver passes the code to a microprocessor, which decodes it and carries out the command.
The remote control is usually contracted to remote. It is known by many other names as well, such as converter, clicker, the box, flipper, hoofer-doffer, the tuner, 'the zapper', the changer, or the button. Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems, DVD players and dimmers. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. Earlier remote controls in the 1970s used ultrasonic tones. Television IR signals can be mimicked by a universal remote, which is able to emulate the functionality of most major brand television remote controls.
Block Diagram Explanation:
When we give the signal from remote the IR Sensor receives the singal and it passes to switching transistor CD4017 is a CMOS Decade counter. It can detect a clock pulse and the BCD out put will be incremented by one for each CLK pulse. If we observe the BCD numbers, the LSB (Least Significant Bit) of BCD complemented every time. This project uses this LSB to switch ON / OFF an electrical appliance.TSOP1738 is a high sensitive IR receiver which can sense 38 KHz IR light. The electrolytic capacitor (100μF) connected across pin no’s 3 and 1 of TSOP1738 for medium sensitivity. The NPN transistor BC557 is connected as a switch. Whenever an IR signal is detected, the transition is sensed by the PNP transistor and it supplies a CLK pulse to the BCD counter (CD4017). For every clock pulse the LSB (Least Significant Bit) of the BCD output is complemented. This toggling output is given to an NPN transistor through a base resistor.
If logic ‘0’ is applied to the transistor, it will be driven into cut-off region. As the collector current is zero in cut-off region, the relay will not be energized and the electrical appliance will be in OFF mode.
Relays
A relay is used to isolate one electrical circuit from another. It allows a low current control circuit to make or break an electrically isolated high current circuit path. The basic relay consists of a coil and a set of contacts. The most common relay coil is a length of magnet wire wrapped around a metal core. When voltage is applied to the coil, current passes through the wire and creates a magnetic field. This magnetic field pulls the contacts together and holds them there until the current flow in the coil has stopped. The diagram below shows the parts of a simple relay.
Operation:
When a current flows through the coil, the resulting magnetic field attracts an armature that is mechanically linked to a moving contact. The movement either makes or breaks a connection with a fixed contact. When the current is switched off, the armature is usually returned by a spring to its resting position shown in figure 6.6(b). Latching relays exist that require operation of a second coil to reset the contact position.
By analogy with the functions of the original electromagnetic device, a solid-state relay operates a thyristor or other solid-state switching device with a transformer or light-emitting diode to trigger it.
How it works?
When a clock signal (square wave pulse train) is provide at pin 14(clk input) , each of the other 10 output pins goes to logic 1 inturn. At any time only one output pin can be at logic 1: all others remains at logic 0.If LED’s were connected to each output each to light up inturn. If there were placed in a straight row in the correct sequence the effect would be for a ripple of light to run through the row.
Explanation of Each Sensor:
Temperature sensor:
An analog temperature sensor is pretty easy to explain, its a chip that tells you what the ambient temperature is!
These sensors use a solid-state technique to determine the temperature. That is to say, they dont use mercury (like old thermometers), bi-metalic strips (like in some home thermometers or stoves), nor do they use thermistors (temperature sensitive resistors). Instead, they use the fact as temperature increases, the votage across a diode increases at a known rate. (Technically, this is actually the voltage drop between the base and emitter - the Vbe - of a transistor. By precisely amplifying the voltage change, it is easy to genereate an analog signal that is directly proportional to temperature. There have been some improvements on the technique but, essentially that is how temperature is measured.
Because these sensors have no moving parts, they are precise, never wear out, don't need calibration, work under many environmental conditions, and are consistant between sensors and readings. Moreover they are very inexpensive and quite easy to use
Magnetic sensor:
The reed switch is an electrical switch operated by an applied magnetic field. The basic reed switch consists of two identical flattened ferromagnetic reeds, sealed in a dry inert-gas atmosphere within a glass capsule, thereby protecting the contact from contamination. The reeds are sealed in the capsule in such a way that their free ends overlap and are separated by a small air gap. The contacts may be normally open, closing when a magnetic field is present, or normally closed and opening when a magnetic field is applied. A magnetic field from an electromagnet or a permanent magnet will cause the contacts to pull together, thus completing an electrical circuit. The stiffness of the reeds causes them to separate, and open the circuit, when the magnetic field ceases. Good electrical contact is assured by plating a thin layer of precious metal over the flat contact portions of the reeds. Since the contacts of the reed switch are sealed away from the atmosphere, they are protected against atmospheric corrosion. The hermetic sealing of a reed switch makes them suitable for use in explosive atmospheres where tiny sparks from conventional switches would constitute a hazard. A reed sensor is a device built using a reed switch with additional functionality like ability to withstand higher shock, easier mounting, additional intelligent circuitry, etc. In production, a metal reed is inserted in each end of a glass tube and the end of the tube heated so that it seals around a shank portion on the reed. Infrared-absorbing glass is used, so an infrared heat source can concentrate the heat in the small sealing zone of the glass tube. The thermal coefficient of expansion of the glass material and metal parts must be similar to prevent breaking the glass-to-metal seal. The glass used must have a high electrical resistance and must not contain volatile components such as lead oxide and fluorides. The leads of the switch must be handled carefully to prevent breaking the glass envelope.
INFRARED IN ELECTRONICS
Infra-Red is interesting, because it is easily generated and doesn't suffer electromagnetic interference, so it is nicely used to communication and control, but it is not perfect, some other light emissions could contains infrared as well, and that can interfere in this communication. The sun is an example, since it emits a wide spectrum or radiation.
The adventure of using lots of infra-red in TV/VCR remote controls and other applications, brought infra-red diodes (emitter and receivers) at very low cost at the market.
From now on you should think as infrared as just a "red" light. This light can means something to the receiver, the "on or off" radiation can transmit different meanings.Lots of things can generate infrared, anything that radiate heat do it, including out body, lamps, stove, oven, friction your hands together, even the hot water at the faucet.