Help with voltage regulator

Hi,

I am using BLtouch for bed leveling and it works really good most of the time. However, sometimes it can malfunction and I assume it is due to a voltage problem (the red light flickers when the hotend is heating, so it is being influenced by components which draw current). I am using a voltage regulator to convert 12 volts to 5 volts but I think it would be better to use the voltage regulator at this link

I have a simple question: The voltage regulator has 2 inputs and 2 outputs as you can see on the picture at the link page. The input is easy: A positive and negative wire from the PSU. For the output, I only need the positive 5 volts to connect it to the RAMPS but I have no idea if I need to connect the negative input wire to somewhere (the simple LM7805 I am using right now has only a positive output so I don't have this problem on it). Can I connect only the positive wire and leave the negative connector alone?

Thanks.

Quick answer would be yes always hook up the ground wire.

So I reading your info I am thinking that your power supply is the same one that you are feeding 12 volts to the Ramps with and that you want to give the Ramps board a nice clean 5 Volts.

So first step would be to make sure you D1 diode has been removed from the Ramps board that will cut the connection.

So the official instructions say to power it via the USB plug for 5volts after you cut that connection, so you could make a little adapter cable to the regulator board.

So the rest of this is use at your own risk, but think your already using at least one of the pins. I use the Aux-1 pins for 5Volts and Ground you can see them on this image Link. I had tried other pins but these ones gave me the best results with a LCD display. I had issues with it getting scrambled so move the 5 volt source plug as close as I could to the display.