Feature: LCD input and output voltage, output current output power; Input anti-reverse protection, reverse connection will not burn; Can be step-up and step-down, the output voltage 0.5-30V arbitrary regulation, limiting the current 0-4A arbitrary regulation; Output anti-intrusion, the battery charge without additional anti-reflux diodes; Button control output ON / OFF status, and you can set the power-on default is ON or OFF; Ascending and descending chip used as the main controller, external 60V 75A MOS tube as a switch, double 60V 5A SS56 Schottky rectification, 60V voltage value, superior to the market immature XL6009 / LM2577 program (a lot Device pressure value is not enough, MOS tube and Schottky diode pressure value must be greater than the input plus input voltage value); Output ripple small, LC filter; With heat sink, send module support isolation column. Specifications: Input voltage: 5.5-30V (input voltage 5V, you can normally achieve, but the voltage and current meter values are not accurate; less than 4.7V, undervoltage protection) Output voltage: 0.5-30V Output current: long-term stable work in 3A, strengthen the heat can reach 4A Output power: 35W natural cooling, heat dissipation to enhance 50W Voltage display resolution: 0.05V Current display resolution: 0.005A Conversion efficiency: about 88% Soft-start: Yes (very powerful with load startup, startup may fail) Input reverse protection: Yes Output anti-intrusion: Yes Short circuit protection: yes Working frequency: 180KHZ Size: 6.6*4.8cm/2.6*1.89inch Function Description: Module has IN / OUT, ON / OFF two buttons: IN / OUT button to switch the input voltage and output voltage display, long press to switch the output current output power display; ON / OFF button control output ON or OFF, long press Set power on default output status is ON or OFF. CC is the current setting potentiometer, clockwise rotation, can increase the set current, when the load current reaches the set current, enter the constant current state, CC constant current indicator (red) lights up; the right CV is the voltage setting Potentiometer, clockwise rotation, can increase the output voltage. ON indicator is the output status indicator, when the output voltage is on, otherwise off. How to use: Used as an ordinary module with over-current protection capability (1) Adjust the CV constant voltage potentiometer so that the output voltage reaches the voltage you want. (2) Measure the output short-circuit current with 10A current meter (connect the two test leads directly to the output end), and adjust the CC constant current potentiometer to make the output current reach the preset over-current protection value. (For example, if the current value displayed by the multimeter is 2A, the maximum current will only reach 2A when you use the module. When the current reaches 2A, the red constant voltage and constant current LED is on, otherwise the LED is off) Caution: When using in this state, there will be a voltage drop of 0 ~ 0.2V due to the current sampling resistor at the output. At the same time, the input and output leads will have a certain linear voltage drop This is a normal phenomenon 4.2. Used as a battery charger Without constant current function of the module can not be used to charge the battery, due to the power of the battery and the charger pressure drop is large, resulting in charging current is too large, causing damage to the battery, so the beginning of the battery to use constant Flow charging, when the charge to a certain extent automatically switch back to constant voltage charging. (1) Determine the float voltage and charging current for which you need the rechargeable battery (if the lithium battery parameter is 3.7V / 2200mAh then the float voltage is 4.2V and the maximum charging current is 1C, ie 2200mA) (2) Under no-load condition, the multimeter measures the output voltage and adjusts the constant voltage potentiometer so that the output voltage reaches the float voltage. (If the 3.7V lithium battery is charged, adjust the output voltage to 4.2V) (3) Measure the output short-circuit current with 10A current meter (directly connect the two test leads to the output terminal), and adjust the constant current potentiometer so that the output current reaches the predetermined charge current value; (4) Connect the battery, charging. (Steps 1, 2 and 3 are as follows: input termination power supply, the output is not connected to the battery load) Used as LED constant current driver module (1) Make sure you need to drive the LED operating current and the maximum operating voltage; (2) Under no-load conditions, the multimeter measures the output voltage and adjusts the constant voltage potentiometer so that the output voltage reaches the maximum operating voltage of the LED. (3) with a multimeter 10A current measurement out