Mutchus

    While connecting field devices to Programmable Logic Controllers we always get confused about sinking and sourcing operations. Also this sinking & sourcing concept is useful to answer PLC interview questions . Sinking and sourcing operations refer to electrical configurations of the circuit in the module & field input devices. When a device provides current when it is ON it is said to be sourcing current . When a device receives current when it is ON it is said to be sinking current. There are both sinking & sourcing field devices as well as sinking & sourcing input module. But it’s a common practice to use input module in sinking current mode. ·         Field devices on the positive side (+VDC) of the field power supply are sourcing field devices. ·         Field devices on the negative side (DC COM) of the field power supply are sinking field   devices. ·  ...

Joe Collier and Kai Wei Tang created a concept cell phone Light Phone size of a credit card, which is connected to the main cell phone and has only the function calls. 

Line Follower Robot Sensor Concept - Sensor line detector is used in line follower robot is usually based on the principle of light reflectionto distinguish the line with the background color. In the dark color of the light absorption is greater than that of white light reflected to the sensor becomes smaller. Position sensor to track the trajectory and the example circuit. Line Follower Robot  Sensor  Concept Light used for the introduction of the line is usually visible light and infra-red. Sensors for visible light are commonly used are LDR (Light Depending Resistance), while for the infrared light is atransistor and photo diode (photodiode). Sensors placed at the bottom of the frame to hang the robot, so that its position can be located just above the track to be read.