Chagrin:
Endevor:
When I hit the relay to switch off to on, the and vice versa, the article spoke about a build up of electricity and a sudden brief burst to my electronics, which I don't really feel like replacing if I fry. Is there a way to prevent that surge or at least reduce it to a safer level? Or does it really not matter as much?Yes, back EMF does matter and will occur strongly in any type of coil that is switched off rapidly.... but these boards already include a diode to take care of that.
Hello everyone. I am having a similar problem.
I am using an Arduino Mega 2560 to control several PWM LED Drivers and a 8 channel relay board for my wavemaker and heater. Whenever one of the relays disengages, I get a blink on LED lights. I believe this is caused by the surge produced when the relays discharge. On the relay board you talk about above, I see where each relay has a D1, D2, D3, etc .... Is this the diode across the coil that is needed for surge suppression?
I have this Relay Board and I don't see D1, D2, D3, etc, next to each relay. So I assume I don't have surge suppression 
http://www.ebay.com/itm/110983062639?var=410149497719&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
I would rather find a 12vdc 8 channel relay board. Any thoughts on which board I should use with a diode suppression? I found this one on eBay and each relay has a D1, D2, D3, etc .... Is this the diode across the coil that is needed for surge suppression?
http://www.ebay.com/itm/221207713757?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Thanks everyone
Billy