7-segment displays are most popular in panel meters, It can show direct numerical value on display, It’s cost is low and display size bigger than LCD’s. Lets interface four digit display, most of the time four digits are enough to display data. Continue reading Digital Voltmeter using Arduino
Designing of Digital Ammeter is basically a process of converting a voltmeter into Ammeter. We know that V=I x R. From this we can say that Voltage drop across resistor (shunt) is directly proportional to the current (V = I). In ammeter this resistance is called Shunt. Shunt resistance have very small value and it will not affect the load voltage. Most commonly 75mV shunts are available in market. Or you can use low value resistance. Continue reading DC Current Measurement using Shunt Resistor
AC voltage measurement can be carried out by converting AC voltage into proportional DC Voltage using rectifier and filter circuits. For low AC voltage (mili volts) measurement precision rectifier is used as diode knee voltage is 0.7 Volt. Similar to DC voltage measurement Voltage divider is constructed using 47K Ohm variable resistor R1. 5V zener diode is used to protect Arduino from accidental excess voltages. Adjust the resistor R1 (47K) to calibrate the voltage. Here the AC voltage that we can give to transformer is from 50V to 230V depending on its ratings. Rectified DC is fed to the voltage divider circuit. Continue reading AC Voltage Measurement using Arduino
Voltage, also called electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. It is measured in Volts.
In many circuits we need to display battery voltage level, most of the battery operated device need indication for battery level such as solar lamp, charger circuits. LEDs are most popular to show status of system such as power on/off, Level indication Low, High, Medium etc. LEDs are available in various sizes and colors, they are simple to use and offer design flexibility. Let’s start with our first example LED as voltage level indications. This can be useful in battery level indication applications. Continue reading Single LED as Voltage Level Indicator