5V Voltage Regulator GND?

I got told in a previous thread that I had the GND of my 5v voltage regulator connected up incorrectly. Should the GND of my voltage regulator be bolted to the side of my casing, as in bolted just like an old vinyl record player, or can it be left like it is in the diagram?


I think you've left out at least one wire in that diagram - ie how the GND of your regulator and the battery pack is connected to the rest of the circuit. You need to connect all GNDs together so in that circuit you might tie the GND on the top side of the breadboard with teh one on the lower side and you'd have a circuit, in a similar way to how the 5V rails are connected to each other.

I am not sure what you mean by your "bolted" question however.



Thanks for the reply, sorry I meant bolted like you see the GND connections on cars, etc where they are literally bolted to the chassis :slight_smile:

Ah, okay so do you mean this as in take the other GND of the Arduino to the power rail that the voltage regulator is in:


Thanks for clarifying. If your regulator is an L7805 the heat sink is electrically connected to GND so you certainly can bolt it on, however make sure that middle leg is connected to your other grounds as that bolted connection can be impacted by corrosion, the bolt coming loose etc and you'll lose your circuit. Not all linear regulators have the heatsink electrically GND though (eg LM1117-5.0 the heat sink is electrically 5V!) so be sure to check the data sheet for the component you are using.

The easiest way to make sure your circuit in that fritzing output will work is simply to have a wire from the 5V and GND rails on each side connected to their relative rail on the other side of the breadboard.

Cheers !

Thanks for the reply again.

I've just checked the model of the regulator and its an L7805CV from Cool Components. I'm only going to be running a few basic sensors with an sd card logging the data.

I've reworked my diagram, so when I go to solder, I should start like this:

Looking better - but not sure your GND rails on each side are connected to each other yet.

As a general rule... you should always run a wire between +V and GND power rails on each side of the Solder-less breadboard. There is no connectivity from top rails to bottom rails unless you manually do it.


Cheers guys,

I think I have it now, will this be sufficient:

Spot on

Great stuff :slight_smile:

Just got it all my sensors on test data logging with x6AA batteries running through the voltage regulator. I figured if I used a separate VC it would save burning up the little tiny one on the Arduino Pro Nano.