I have omron g5le-14 5vdc relay:
Can it be safely used with Arduino Pro mini 5v? I am concerned whether it draws too much amps for Arduino pro pins. It is used only to momentarily turn on and then off the relay.
There is dicussion at Maximum current draw on 5v and vin pins? - Project Guidance - Arduino Forum would suggest I am ok.
Have you read through the documentation packet?
I did not see a input current requirement listed. The input from the Arduino or RC module looks like is it connected to a transistor then to a PIC, so I doubt it will draw too much.
On another note, the intended input is PWM not digital ON/OFF. There are other modules available that use a digital ON/OFF signal with an opto isolator input to protect and control the arduino output pins. I would suggest looking at those options as well.
The relays coil current is 80 mA, twice the absolute maximum for an Atmega328 output pin, you need a switching transistor like 2N3904 or similar, and a spike suppression diode like 1N4148 across the coil, you could power 1 relay from the 5V pin if it's only intermittent.
outsider:
The relays coil current is 80 mA, twice the absolute maximum for an Atmega328 output pin, you need a switching transistor like 2N3904 or similar, and a spike suppression diode like 1N4148 across the coil, you could power 1 relay from the 5V pin if it's only intermittent.
I agree that is a proper way drive drive a standalone relay. That cannot be said of the aforementioned relay module. It looks like it has some smarts and stuff between the Arduino and the relay coil.
adwsystems:
I agree that is a proper way drive drive a standalone relay. That cannot be said of the aforementioned relay module. It looks like it has some smarts and stuff between the Arduino and the relay coil.
I agree, it looks like it has some RC specific components on it.
Hence the part name "Pololu RC Switch w/ Relay"
Tom... 
