Hi, I tried to search the forum but did not find anythig useful yet. I'm kind of a newby with electronics, so please forgive me if what I'm asking is not so smart.
I have built and started using a controller for my acquarium. I use:
Arduino mega 2560 LCD shield + keypad RTC 1307 8 channel Relay module Thermistor Distance sensor External wall mount transformer 9v 2A
All is working properly but Arduino voltage regulator is getting hot.
I suppose the relays are using too much power: they have optoisolation and the pin themselves are rated at 20mA current, so not much. What I fear is that the power for the whole relay bank (I connected it to +5V pin of the arduino) is sucking too much. When the arduino is powered via USB, when more than three/four relays are open, the RTC clock does not work well, so I suppose the 1000mA I am supplying are not enough... The relay module has 10 inputs: GND, VCC, 8 signal pins. Do you think it is possible to supply an external power +5V to the relay module?