5V Mini-relay module

Other Hardware General Electronics
1

Hello everybody.

I usualy find myself the answer, but this time i need you because i'm stuck as hell.

I bought this 16 mini-relay module, but i just can't make it work as i wish.

The problem is that the documentation is completly unclear:
http://www.elecfreaks.com/wiki/index.php?title=16_Channel_Mini-Relay_Module

According to the documentation, the relays are supposed to accept 5V or 12V in order to work.

I'll make an history of what i've done :
So i plug each "end pins" like so : VCC to the board 5V supply and GND to board GND.

When i plug the middle pin of a channel relay, the activation led shows up, but nothing happen. I think that the 5V isn't enough for the coil. I'm guessing that this only works for 12V.

Then I tried to plug a 12V supply on with + on VCC and - on GND, and tried to pilot de middle pin (yellow) with an output of the Arduino, but this time, nothing happens at all, no activation.

I just can't find out how to make this work properly, please help me :cry:
(sorry for my bad englsih)

2

650px-BK_SRD_04.jpg

This mostly unhelpful image does not indicate where the signal goes on the relay board, but it indicates that the digital signal is enough. So no 12v needed to drive the relays.

3

That's exactly what i thought, but this don't show how to wire it to the actual board... And i managed to make the channel activation LED light, but no relay noise (in 5V).

4

Hi,
I think the attached schematic it is for your board. Check it to make sure it match your board.

16_Relay.pdf (127 KB)

5

Okwolus:
According to the documentation, the relays are supposed to accept 5V or 12V in order to work.

Relay coil voltage should be printed on the relays in code. e.g. model nr. ending in 05 or 12.

I would not buy this board without seeing the circuit diagram.

Not sure how the relay coils are powered.
You definately shouldn't use Arduino's 5volt pin to power this 16-relay board.

  1. No more opto isolation if you do.
  2. Could be 16*75mA= 1.2Amp if all relays are engaged. That will fry the Arduino.
    Leo..
6

If the diagram from post#3 is the correct one, then we're looking at another bad 16-channel relay board.
Same as the Sainsmart 16-channel model, the relays are like tits on a bull.
VCC is connected to the LED part of the opto as well as the transistor part of the opto.
No extra safety/opto isolation layer.
Apart from that, the relays are always on without input signal, using max power from the supply.
Leo..

7

Hi,

Quote from "I would not buy this board without seeing the circuit diagram" I always been doing what you advice. No schematic no buy.

He has one option, If he change the transistor from NPN to PNP he maybe able to save the board.