Input voltage range : 3-34V DC
Output voltage range : 4-35v DC adjustable
Output current:3A
Voltmeter range:0 to 40V,error +-0.1v
Multiple output regulator.
One button to switch input and output voltage display.
Power-down memory function.
Press the button for 3 seconds can turn OFF/ON the LED display.

Features :
Multiple output regulator.
One button to switch input and output voltage display.
Power-down memory function.
Press the button for 3 seconds can turn OFF/ON the LED display.
With wiring terminal.
When adjusting the blue potentiometer, please use a multimeter to monitor the voltage
Rotating Clockwise can raise the voltage while rotating counterclockwise could lower the voltage
When the module output voltage cannot be adjusted ( the output voltage is always equal to the input voltage ) Please adjust the potentiometer counterclockwise 20 laps (20 turns) or more till it works.

The LM2577 3A DC-DC Step UP LED Voltmeter 3-34 to 4-35V Adjustable Boost Converter module is a 150 KHz fixed frequency PWM buck (step-down) DC/DC module. Requiring a minimum number of external components, these regulators are cost-effective, and simple to use.
Together with its high precision multi-turn potentiometer, this means any desired output voltage within its supply range can be set without the need for an external voltage meter. The module also boasts a very high operating range with a DC input supply range of 3 – 34V and an adjustable output range of 4 – 35V.