can I use Two Same Power supply sharing input in single circuit?

Thread Starter


Joined Dec 17, 2018
I currently have a circuit which consists of two different boards.
In the main board, there is a 230V ac supply, a 230V to 12V dc power supply, a 7805 linear voltage regulator and other components as transistors biased on their collectors by the 12V dc generated in the main board itself. On the another board there is a controller, powered from the 5V supply generated by the main one: this controller drives the transistor located on the main board.
Now I want to use a separated 230V to 12V dc power supply for the controller board, so I'll be able to power my controller board from a 3.3V power supply produced by using another regulator. So there will be two 230V to 12V dc regulators, one located on the main board and another on the controller board. Now my question is:

Is it OK for the controller to drive transistors whose 12V collector bias is generated from a different, separated regulator, however sharing the same 230V dc grid voltage,?
I am also using an ADC which is measuring the output of a temperature sensor powered by the main board 5V supply and sending its output to the controller board: could this create any problem? should I short the gnd terminals of both boards? Do I need to do anything else? Is this operation safe?