EK Technologies

L293D The L293D is a 16 pin motor driver integrated circuit used to drive motors. It consists of two H-bridge embedded in a single chip. The L293D is capable of running two DC motors independently and also able to reverse or change the direction of rotation of the motor. The IC can supply a motor with operating voltage of up to 36V with a current . L293D motor driver Pin1 ( Enable 1,2):  Enables input 1 and input 2. So when high, left part of the IC is enabled and when low left part is disabled Pin2 ( Input 1) :  when high, current flows through output 1 Pin3 ( Output 1):  Connected to one terminal of the motor, M1 Pin4 (Ground):  Connect to the ground Pin5 (Ground):  Connect to the ground Pin6 ( Output 2):  Connected to the other terminal of the motor, M1 Pin7 ( Input 2):  When high, current flows through output 2 Pin8 ( Vcc2 (Vs)):  Voltage to be supplied to the motor Pin9 ( Ena...

Why transformers work only with AC and not with DC The first thing to know here is the meaning of AC and DC. AC means Alternating Current. That is the current changes direction DC means Direct Current. That is unidirectional current or single direction. With the understanding of this meanings, the main reason why a transformer works only with AC is because, the AC causes a changing magnetic field and hence a flux which in turn links the secondary winding and hence an induced emf and current can flow. Meanwhile DC, does not cause a changing magnetic field hence no induction into the secondary winding. So this is a phenomenon of Faraday's law of electromagnetic induction

Wiring a One way switch in a lighting system A one way switch is a switch which is used to control a lighting point from a single position. A one way switch can be of one gang, two gang or three gang. See the image below. A one way switch has two terminals namely : ( COM and L1 ) or (  L1 and L2 ) see the image below The switching mechanism is such that when the switch is on, COM and L1 is connected. And when OFF, there is no connection between them. See below Wiring of a one way switch Connect one of the terminal to the live and the other terminal to lamp. By convention, connect the live (phase) to the COM and L1 to the lamp. Then connect the other terminal of the lamp to the neutral. See the connection below one way switch wiring Here, the switch (S1) is in the OFF position  and the LAMP (H1) is OFF. one way lighting, showing Lamp ON Here, the switch (S1) is in the ON position  and the LAMP (H1) is ON. Bravo hope you can now connect ...

Voltage regulator A voltage regulator is one of the most widely used electronic device in an electronic circuit. Its main function is to keep the terminal voltage of the DC supply constant. A regulated voltage (no fluctuations and noise levels) is very important for smooth functioning of electronic devices. A non-regulated voltage will cause an electronic circuit or device to function abnormally due to unacceptable variations of the signals. There exist two main types of voltage regulators; the linear voltage regulator and the switching voltage regulator. Our interest here is with the integrated circuit (IC) based voltage regulator which can be of linear type or switching type seen below. 1) Linear voltage regulator Linear regulators are step-down converter system used to maintain a steady voltage. In a linear voltage regulator, the resistance of the regulator varies with respect to the load. The variable conductivity of the active pass element (usually a bipolar junction tra...

Working Principle of an IR sensor An IR sensor used as an object detection sensor consist of an IR LED used as a transmitter and an IR Photodiode used as a receiver which is sensitive to infrared light of the same wavelength as that produced by the infrared transmitter. The IR transmitter emits IR radiations and when reached or blocked by an object, some of the radiation is reflected back towards the IR receiver. Based on the intensity of the reception by the IR receiver, the output of the sensor is defined. This combination can be categorized as an Opto-coupler. The figure below illustrates on how the sensor senses. Illustration of sensing by IR sensor when no object is present Illustration of sensing by IR sensor when object is present Obstacle Sensing Circuit or IR Sensor Circuit A typical IR sensing circuit consists of an IR LED which emits infrared light, a photodiode which detects the infrared light, an IC OPAM which is used as a voltage comparator, a potentiome...

Types of IR Sensors Infrared sensors can be classified into passive or active infrared sensors. 1) Passive infrared sensor These are IR sensors which do not have an infrared source but detects energy emitted by obstacles. They are of two types namely: Thermal infrared sensor: use infrared energy as a source of heat and are independent of wavelength. Quantum infrared sensor: The photo-sensitivity of quantum type detectors is dependent on the wavelength and are perform better than thermal infrared sensors. Passive infrared sensor 2) Active infrared sensors These are IR sensors which contains an infrared source and infrared detector. The infrared source is an IR LED and the receiver can be a photodiodes or a phototransistors. These sensors can be used in object sensing, obstacle avoidance robot, motion detectors, measurement of distance, smoke detection etc. The figure below show a typical photodiode infrared sensor. A typical infrared sensor Relate...

IR Sensor An IR sensor is an electronic device that emits and/or detects infrared radiation produced in order to detect some parts of the environs or surrounding. In other words it is an electronic device which is used to sense heat & objects. It works by sensing IR radiations and variation of heat to detect some part of the surrounding. So they can be classified as a thermal infrared sensor which detects the change in heat from its nearby objects and as photo IR sensor which uses a photo diode to sense IR radiations. An Infrared sensor ( photo IR sensor) Infrared transmitter An infrared transmitter is a light emitting diode (LED) which emits infrared radiations. These IR radiations are not visible to the human eye unlike simple LEDs which emits visible light. The picture of a typical Infrared LED is shown below. IR transmitter consumes about 3 to 5 mA of current when operated at the nominal voltage (5V) and can be modulated to produce particular frequencies of infrare...

Actuators and types of actuators An actuator is a device that controls or moves mechanisms or systems by converting energy into motion or force. This energy can be obtained from electric current, air or liquid . Actuators are used in diverse fields such as electrical and electronic engineering, mechanical engineering. They produce either linear motion, circular (rotary) motion or oscillatory motion and are used in many machinery for provide a motion or force in processes such as braking, sorting, driving disk drives, printing etc. One of the earliest uses of an actuator (pistons) was in steam engines in the mid-1670s designed by a French physicist and inventor, Denis Papin. A block view of an actuator system Types of actuators There exist four main types of actuators namely the: ·          Electric actuator ·          Mechanical actuator ·        ...

Conveyor systems and conveyor belts There are two main industrial classes of conveyor systems;  Those used in general material handling such as moving boxes along in a factory. Those used in bulk material handling such as transporting industrial and agricultural materials or products, such as grain, coal, ores, etc. they are generally used in outdoor locations. Conveyor belts Conveyor belts were used since the 19th century. In 1892, Thomas Robins began a series of inventions which led to the development of a conveyor belt used for carrying coal, ores and other products. In general, a conveyor belt consists of two end pulleys, with a continuous loop of material that rotates round these pulleys. The pulleys are used for providing the drive to the belt through a drive unit gear box powered by an electric motor. The forward movement of the belt is as a result of the friction generated between the pulley and the belt. One or both of the pulleys can be powered and it a...

Insulated Gate Bipolar Junction Transistor structure, modes of operation, characteristics, and applications Introduction