DC/DC BUCK Converter Regulator 4.5-40V 12V To 5V/2A USB Charger Voltmeter Display "

product description Size: 4.5-40V to 5V 2A parameter: Input voltage / voltmeter Range: DC 4.5 ~ 40V (please enter the voltage 6.5 ~ 40V, can be 5.0V regulator output) Output voltage / current: 5V / 2A Module Size: 58mm * 21mm * 10mm (L * W * H) Net weight: 13g Instructions for use: After power on, the voltage meter shows that if you need to charge the devices such as mobile phones, tablet PCs, MP3s, etc., press the "Output Enable" button, USB power indicator light, USB output 5.0V; If you need to turn off the digital display, press the "Low Power" button, Then enter low-power standby mode and USB output is turned off. Voltmeter calibration method: 1. When the voltmeter is displayed, press the "Output Enable" button for 2 seconds to release the voltmeter. 2. Touch the "Output Enable" button to increase the voltage by one unit and touch the "Low Voltage" button to reduce one voltage reduction unit (one unit is less than 0.1V) 3. After the voltage adjustment is completed, press the "Output Enable" button for 2 seconds, then release and exit the voltage calibration mode. If the power is off, the parameter settings will be automatically saved. Application: 1. Automotive / motorcycle battery voltage monitor or other voltage measurement 2. USB chargers for cell phones, MP3s, tablets or other electronics Please note: The module defaults to D +, D- short, compatible with most mobile phone charging, If you need to install identification resistance, cut off the red line location Package includes: 1x DC / DC converter Digital voltmeter shows USB charger