ElectroMech Lab

Arduino millis() vs delay() Arduino is a hardware & software based platform, which gives a great opportunity to the hobbyist, students to learn and create interesting projects. However, by being expert with Arduino you can make advance projects as well.   In this article I am going to discuss about delay and millis() functions. When we can use these functions to generate delay.   What is the millis() & delay() function in Arduino? This function gives the time value in milliseconds since board was started. Advantage of using this function is program does not stop during delay. Other task continue to take place. While if you use ‘delay’ function, then program is paused for the time set in delay function. For example. If I use delay (5000) Then program will be paused for 5000 milliseconds or 5 seconds. To save the value of millis(), you should use variables of ‘unsigned long’ type because the value is in milliseconds and it increases very fast. For ex

Many times we need to control a single electrical machine from different location, means we can make the Fan (for example) from three different locations. We can do this with the help of PLC, Smart Relay. I am using Zelio Smart Relay, SR3B261B. Open the ZelioSoft2 and select for Ladder programming. Select the Input from the option and click on input and drag it to the input place as shown in the below picture. Double click on Input-1 and give a name to it “Start-1”, and continue for other inputs, Input-2, Input-3, as well as shown in the below pictures. Now, you have three Inputs, as Start-1, Start-2, and Start-3. Now take three more inputs, Input-4, Input-5, and Input-6 and connect them in series mode. Right click on the Input-4 and select “Normally closed” to make it NC. And do the same for other two inputs and give names to Inputs 4, 5, 6 as Close-1, 2, 3 respectively. Select an Output from the Menu and put it to Coil. That is our output. Select ‘Contact’ of output Q1 and drag i

  Ø   Opto-coupler is an electronic component that transfers electrical signals from one circuit to another circuit with isolation Ø   These are also known as Opto-isolator, photo coupler, and optical isolator     Uses Ø   Isolation between circuits Ø   It prevents damage in one circuit due to damage in another circuit Ø   Prevention of unwanted noise Ø   Both circuits can work on different voltage levels   Opto-coupler: PC 817 Ø   It has four pins Ø   Pin-1 is Anode & 2 is Cathode of the LED Ø   Pin-3 is Emitter & 4 is Collector of the Photo Transistor Ø   When light of LED falls on the Phototransistor base it conducts Ø   If there is fault in either circuit, another circuit will remain safe Ø   This is 4 pins opto-coupler component Ø   Pin-1 is Anode & 2 is Cathode of the LED Ø   Pin-3 is Emitter & 4 is Collector of the Photo Transistor Ø   Mark on top-left, shows that pin counting starts from here Ø   SMD version is also availabl

What is an MOV? Metal Oxide Varistors AKA MOVs are electronic devices designed to suppress surges in electrical and electronic circuits.   A Metal Oxide Varistor is a non-linear surge suppressor device, which is used to suppress sudden, high abnormal voltage transients or surges, especially during the power ON of a switch or natural thunder lightening situations. This is mostly used in sensitive electronic circuits to make them safe against such catastrophic occurrences. MOV is a non-polar device, which means you can connect it with any side. It is a voltage dependent device, which means this device will react to the changes in voltage conditions. Therefore, MOV is specified to trigger whenever the rated voltage magnitude across their connections is exceeded. The voltage rating at which an MOV may be defined to fire and short the transient to the ground is called its ‘clamping voltage’ . For an example, if the clamping voltage rating of an MOV is 420V then i

  Hello friends, ceramic capacitor are widely used in electronic circuit. But when it comes to know the value of the capacitor it becomes difficult sometimes, since on ceramic capacitor value is not written directly. There is a code on the capacitor and you have to decode that code to know the value.                                  So how can you know the value of ceramic capacitor? Before moving ahead get to know some units used in capacitor values. Unit of capacitor is Farad. But lower value of capacitors are used in circuits. First is Pico Farad, 1 pico is equal to 10 -12 Second is Nano Farad, 1 nano is equal to 10 -9 Third is Micro Farad, 1 micro is equal to 10 -6 A ceramic capacitor, usually, have 3 digit code, for example we have a capacitor having code 105. First 2 digits (1 & 0) are significant figures, and third one (5) is multiplier. Multiplier is considered with power of 10 as 10 5. After putting all values we have the value in pF (picoFarad) Pattern