Hello everyone! I'm working on a project using an Arduino Mega, and I've bought (not received yet) a 16 channel relay board like this one : http://ra.gy/4cifY . It says that it may be used directly with Arduino, but it doesn't seem so in every case as it says that the relays need a 15-20mA per channel, which would make a maximum of 320mA if I have all my relays on, which is way out of the Arduino Mega limits. So I was thinking of using a simple non inverter buffer chip, like three 4050 (http://ra.gy/9wE6j) between the Mega and the relay board. (each pin would go to a non inverter buffer before going to the relay board, which would make the 4050 sink the current instead of the Mega). As the 4050's maximum output per pin is 25mA, there should not be any problem for the 4050?relay board part. But I couldn't find the data to be sure that my Mega would be able to send enough current to the three 4050 to activate all relays at the same time.
Does anyone have an idea about that? Am I right in the global approach of the problem?
Thanks for your time! Brice
Edit : Quick answer for those interested The board doesn't really use those 15-20mA per channel, but only 4mA, which makes it possible to use it directly for the Arduino's outputs (more info on why in the conversation). Thanks everyone