16 Channel Relay shield problem

Using Arduino Project Guidance
21

I found problem.

First I burn my Arduino and 16 relay shield because I connect 12V to shield VCC and GND. I don't know how it burns but it does.

Then I build my own relay 13 relay shield using 5V relays and transistors to open 5V to relays. But then I open all relays I get same problem...not enough power and start blinking (all shield power I use from arduino).

Then I cut 5V power from arduino and use other 5V power supply and problem was solved.

So first then I connect 12V to 16 relay shield was wrong because I use 5V to open relays from arduino. I had connect 5V not 12V to relays shield VCC and GND.

22

The 16 relay shield has 12V connectors, where a 12V source should be connected. Vcc is the logic power, probably connected to the Arduino Vcc (5V).