DD39ajpa FAQ

DD39ajpa dc-dc buck/boost module; I purchased this for a product that I am creating. Additionally, I will need to order hopefully many more depending on how well my product sells, but I am having an issue with your board and I don’t know if I bought a defective one or if I’m doing it wrong. Supposedly it can be adjusted from 20 to 5 V or it might even go down to 3 V. I’m not sure but no matter how much I turn the little gold dial. I can’t get it to go any lover then 13.5 and when I turn it off and come back later, it’s always back up to 18 V. Do I just have a defective unit? Is all I’m supposed to do to change the voltage rotate that gold screw in the blue plastic box? Please let me know if I have to find another one or if I’m doing something wrong with this one

Under no-load conditions, the output voltage may be different.
1 Please connect a 1K ohm resistor in parallel to the positive voltage output port, and then adjust the potentiometer.
2 If you need to measure the negative voltage output, please connect a 1K ohm resistor in parallel to both the positive and negative voltage ports.
Tips:

1 Although the input voltage range is wide, the recommended input voltage is DC 9-15V.
2 Only when the positive and negative voltage outputs are the same load, the negative voltage can output the correct value.