Can't get current from auxiliary relay?

1

Hey guys,

We’re attempting to setup a device which is triggered by one of the auxiliary relays when the user begins using equipment. Through our testing we haven’t been able to get any current measurement from either auxiliary relay; we’ve tested various combinations of hooking up S & O terminals to W with no luck. Do we need to supply an input voltage to activate these relays? In Fabman we have the configuration of the bridge set to “Switch on when busy”. Any advice to measure these relays’ current when activated on a multimeter would be well appreciated!

Here’s what our circuit setup currently resembles:

IMG_20190728_143826
IMG_20190728_1438263120×4160 3.48 MB

Though I could learn from a multimeter, I also wanted to know what voltage the relays would supply in general? The circuit diagram says 250V max. I was hoping to be able to plug this aux. relay into an Arduino, so I was thinking of creating either a voltage divider circuit, or using an opto-isolator such as the one here:

Warm regards,

Cody

2

Hi Cody,

the relais does not output anything, it is just a switch.
‘W’ is the root of the switch, ‘O’ is the normally closed contact and ‘S’ is the normally open contact.
In order to connect the relais to an Arduino it is best to wire it according to this schematic:

IMG_0066
IMG_00662053×1566 340 KB

You do not need an optocoupler, the relais already isolates the Arduino from the Bridge galvanically. The resistor can have any value between 1k and 10k Ohms.

Best,
Christoph

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3

Hey Christoph,

Thanks for your quick response! I hooked it up this way and it worked perfectly the first time. Of course now I understand why the current from the Arduino is necessary, but that was something I was definitely confused about at first. Our project is now nearing completion so I’ll post here soon about what I’m using this Arduino for. Thanks for your help!

Warm regards,

Cody

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