In this post, are shown how it works and how to use the digital voltmeter ammeter. The component I bought is the DE-2645-02.
How it works?
Operation of voltmeter and ammeter
The ammeter measures the current that passes through a conductor in a circuit, while voltmeter measures the potential difference or voltage between two points in a circuit.
![voltmeter ammeter](https://www.electricalelibrary.com/wp-content/uploads/2024/02/voltmeter-ammeter-EN-1024x576.jpg)
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/real-voltimeter-1.png)
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/real-ammeter-1.png)
![voltmeter ammeter D'Arsonval meter](https://www.electricalelibrary.com/wp-content/uploads/2024/02/DArsonval-Movement-1.png)
Digital voltmeter ammeter converts analog values in digital and shows the measurement in a LED display.
The digital voltmeter ammeter
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/voltimeter-ammeter-1.png)
DE-2645-02 model don’t come with a shunt resistor. The maximum current it supports is 10A and maximum voltage is 100V. Other DE-2645-02 parameters are:
- Voltage resolution: 0.1V.
- Current resolution: 0.01A.
- Supply voltage range: between 4.5V and 24V.
- Temperature operation range: between -10ºC and 55ºC (14ºF and 131ºF).
- Dimensions: 50mm (1.96in) width, 20mm (0.78in) thickness and 31mm (1.22in) height.
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/voltmeter-ammeter-back-1.png)
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/voltimeter-ammeter-box-1.png)
Installing the component in a linear power source
I have published a post about the linear DC source, in which was installed the DE-2645-02.
Design and assembling of a linear sourceClick here
Complete list of materials:
- Socket plug.
- Transformer with secondary 12+12V and 600mA.
- 6 1N4007 diodes or similar.
- Switch with 3 terminals and 1 pole.
- 2 1kΩ resistors.
- Red LED.
- 3 electrolytic capacitors: 1 of 470μF, 1 of 10μF and 1 of 1μF.
- 300nF or 330nF polyester capacitor.
- 100nF ceramic capacitor.
- LM317.
- 10kΩ potentiometer.
- L7805CV.
- DE-2645-02.
- Wires.
- Terminal bridge.
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/voltimeter-ammeter-schematics-1-1024x470.png)
In parallel to C1 capacitor, was placed a regulator L7805CV, to provide a constante 5V output to the digital voltmeter ammeter. The 7805’s regulator circuit was the same shown on regulator’s datasheet.
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/complete-circuit-1.png)
![](https://www.electricalelibrary.com/wp-content/uploads/2024/02/linear-DC-power-source-1-1024x633.png)
The following video shows the operation and part of installation of the display to linear power source.