I have recently purchased an 5V 8 channel relay board. ( see attachement)
there were no specs on the board and also no schematic.
i am going to use the relay in a high noise environment directly off my arduino UNo rev3.
I am wondering if somebody could give me some advice on the following:
would it not be better to use 12 V relays opposed to 5V relays. (a similar board is available in 12 V)
but then would the 12 V relay board require a 12 V signal as opposed to a TTL signal which is available on the arduino.
These kinds of boards have buffers, usually a single transistor per relay (see the 3 terminal devices between the relay banks), between the control signal and relay coil, so even if it used 12V relays, you would still provide a 0-5V type signal to control the transistors. Best bet is to run shielded cables between arduino and the board with the shield grounded on one end.
You're talking about noisy (both electrically and acoustically) mechanical relays, being powered by constant voltage and switched by hard on/off digital logic. It isn't an FM receiver.
I don't think they will care about stray electrical noise, but use shielded cables if you want.
