I have a 5V 4 Relay board connected to an Arduino:
Looks like each relay activation doesn't consume more than 20mA, but if I activate more than two at the same time, Arduino resets automatically after one or two seconds that relays stay activated. I don't know if it's a kind of auto-protection or similar.
But those auto-resets when three or four relays are activated at the same time only happen when I'm supplying Arduino through the V-in pin with 16Vcc (it's a power supply with 3 Amp, it should be enough by far). If Arduino is connected to USB works perfect and I can activate all 4 relays at the same time without resets.
Any idea of what happens? Are there differences in maximum output consumption if USB power supply is used or it is through V-in??
Thanks a lot in advance,