Beginner here, so this problem came up:
I got a 250vac 30A relay board which seems to require 5v to be driven.
It has 4 input pins: GND, IN-, IN+, VCC
What are the IN- and IN +?
My rpi output pin does not seem to be able to triger the relay when connected in the IN+ (although the board's led does turn on and off)
Here is a pic of the 4 pins: Here is the ebay link: Ebay Item Link
The manufacturer page: chinalctech Link
Please note that my relay (pic #1) has 4 connection pins while the other two (pic #2 and #3) have 3 pins.
Thanks for the plenty of answers, I went through all of them, then went back and tested the things you guys suggested.
The GND and IN- pins are indeed connected through the jumper present in just behind them. I think it's in place in case you want to power the 5v input from another source on VCC and GND, then fire the relay with the IN+ and IN- connected to the GPIO and GND respectively.
That said, it seems like although i am powering the board with 5v on its VCC and GND, the switch wont fire unless it has 5v on IN+. I tried connecting the board to a usb 5v source like this (jumper shorting GND:IN-):
5v+ : VCC GND : GND
Then got a wire of the same 5v+ and touched the IN+ pin. The switch fired whenever the pin touched 5v.
I tried to replicate the same connection on the RPi 5v rail, (5v:VCC, GND:GND, test 5v: IN+) the relay does not fire. (jumper shorting GND:IN-)
I guess i reached the bounds of my E.E. knowledge, please advise, what am I missing?
Is it an Amperage issue?