4.5-40V DC 12V DC 5V Volt Step-down Module Practical USB charger Buck Converter modules LED Voltmeter HW-318 Limit Voltage

Integrated voltmeter, buck voltage converter and 5V USB charger port, multifunctional and practical.
Wide voltage measurement / input range: DC 4.5-40V; self calibration, with high accuracy.
“Enable output” button for usb output and “low power” button for low power consumption mode.
With reverse connection, over current and over temperature protection, it is therefore safe for use.
With LED indicator for USB power supply and wiring terminals, easy and convenient operation.

Parameters:
Input voltage / voltmeter range: DC 4.5 ~ 40V (please input voltage 6.5 ~ 40V, then you can get a 5.0V stabilized output)
Output voltage / current: 5V / 2A
Module dimensions: 58mm * 21mm * 10mm (L * W * H)
Net weight: 13g

Instructions for use:
After the power is turned on, the voltmeter displays, if you need to charge devices such as phone, Tablet PC, MP3, press the “output enable” button,
then USB power indicator lights, USB output 5.0 V;
If you need to turn off the digital display, press the “low power” button,
then enter low power standby mode and USB output shutdown.

Voltmeter calibration method:
1. When the voltage meter is displayed, press the “output enable” button for 2 seconds, then the voltmeter flashes.
2.touch the “enable output” button, the voltage increases one unit, touch the
“Low power” button, decrease one voltage reduction unit (one unit is less than 0.1v)
3. After voltage setting is completed, please press “output enable” button for 2 seconds, and then leave the output voltage calibration mode.
If the power is off, the parameter setting is saved automatically.

Applications:
1. car / motorcycle battery voltage monitor or other voltage measurements
2.USB charger for mobile phone, MP3, Tablet PC or other electronic products

Please note:
This module is D +, D-short circuit, compatible with most mobile phone charging default,
if you need to install the ID resistor such as iPhone, please cut the red line position

Package include:
1x DC / DC converter digital voltmeter display USB charger