There are some threads about this here, but nothing resolved.
Before I purchase a K6714-16 relay board http://www.vellemanusa.com/downloads/0/illustrated/illustrated_assembly_manual_k6714-16_rev1.pdf I have a few questions:
The assembly instructions states that:
Output 12V CC can be used as a power supply for other kits. Does this mean I could power a Arduino Mega with those 12V?
The ULN2803 type transistor array allows you to control the relays directly from a TTL or CMOS. For controlling the relay with open collector control, don’t mount the transistor arrays. How does this apply to the arduino?
And last but not least, I can not figure out if I will be able to control this with my arduino digital outs. Is there enough power there to switch the relays? And do I need something between the arduino and the board?