connecting a relay board

Question on connecting a 4 channel relay board.

What do the pins connect I assume IN1, etc... are the input pins from the digital output pins, GND goes to Arduino GND what does the VCC goto?

pins on relay board

GND IN1 IN2 IN3 IN4 VCC

also on a separate set of pins that have a removable jumper

JD-VOCC VCC

That are jumped

The Vcc pin wires to the arduino's 5V pin to supply +5vdc power to the relay coils. If you remove the jumper you can if you wish use an external regulated +5vdc supply to power the relay coils, so then you can wire the power supply's positive terminal to the JD-VOCC pin and also wire the external supply's negative terminal to a ground pin.

Lefty

Here is the linkfor the relay board

http://www.ebay.com/itm/221162886568?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Powering the coils from the Arduino will not harm it? does it need anything in the power or control lines, resistors?

Thanks Dan

dfargo5133: Here is the linkfor the relay board

http://www.ebay.com/itm/221162886568?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Powering the coils from the Arduino will not harm it?

Well worst case current draw if all four relays are turned on at the same time is about 300ma. That is within allowable limits of the 5V pin but doesn't leave a lot left over for any other external items requiring 5vdc power. It will work OK but watch how much other stuff you starting adding like shields, lots of leds, etc. Otherwise use an external supply and unload the load from the arduino. It is cutting it close current wish but doable, but so much depends on what else you may have wired to the arduino board.

does it need anything in the power or control lines, resistors?

No the current limiting resistors are already installed on the relay board for the four channels. Keep in mind that like most of the Asian relay modules you turn on a relay by outputting a digitalWrite (pin#, LOW) to turn on the relay and write a HIGH to the pin to turn it off. Lefty

Thanks Dan

It will work OK but watch how much other stuff you starting adding like shields, lots of leds, etc. Otherwise use an external supply and unload the load from the arduino. It is cutting it close current wish but doable, but so much depends on what else you may have wired to the arduino board.

It will be just the relay board and maybe a push button switch to cycle the display.

Keep in mind that like most of the Asian relay modules you turn on a relay by outputting a digitalWrite (pin#, LOW) to turn on the relay and write a HIGH to the pin to turn it off.

Would have been my next question

Connecting the relay board pins

One video I saw looked like they were using an old computer ribbon cable with the old plug plugged into the relay board and then male to male jumpers plugged into the other end of the cable and the arduino.