Can different DC voltages share a ground?
If the two power supplies share a common ground, or can be made to, then it is no problem. However, the return wire must be sized for the sum of the 8 V and 12 V currents.
Can you ground two batteries together?
You would put batteries in series to supply a higher voltage. In layman’s terms, don’t try tying together the grounds of two batteries connected in series, because you’ll be shorting out the first battery.
What happens if you connect VCC to ground?
In your proposal VCC would be grounded, that means any positive signal applied to VIN will make the diode go into forward mode. This will load the VIN line which is your “databus” limiting the voltages to about 0.7 V. This means your “databus” will not work anymore.
Where do you ground a second battery?
You should ground the second battery to the same point on the engine where the primary battery ground cable does. Use the same size or larger cable as the primary battery does. You should use a larger cable than stock if the length of the cable is going to be a lot longer than stock.
Do you separate ground connections for two different voltages?
I have always been told that if we are using a circuit with two different voltages (say 5V and 12V) we should as much as possible separate the grounds. Is it ok now to use just ONE GROUND connection for both 5V and 12V circuits???
Do you have to connect the grounds together?
Connect the grounds together manually, though, and you reinstate that portion of the loop, making it all work again. So there you have it. If you have multiple power supplies in your project, whatever they may be (except in special circumstances) you must connect the grounds together for it to work.
Can a star ground be used for two different voltages?
If you build your voltage regulator on breadboard or PCB you will probably select a star ground topology If you are using a mixing high power devices and logic, it is a good idea to run the respective grounds separate from each other to the respective devices, i.e. one ground to the high power circuits and another to the logic devices.
What’s the difference between common ground and ground ground?
Like you, I prefer the “common” for the first concept and “ground” (some use “earth” for an obvious reason) for the second. All this signs indicate a specific return path. This is a return through the earth to reference power (lowest potential). Used with true earth ground (NEC) to do absolute voltage measurements.