How to bench test low voltage relay

[passenger1955]

I purchased a low voltage relay. It has a low voltage input, and a higher amperage/volt output. I have this hooked up to a decoder that can trigger the input side. Is there a way for me to hook up a multi-meter to the output side and test this prior to integrating it? Not sure what I should be testing for on the multi-meter. Thanks.

[7j43k]

Hook it up to your decoder temporarily.  Have your decoder activate the relay.  You will likely hear a click.  Deactivate the relay.  You will likely hear another click.

 

If you don't hear a click, you will have to do continuity tests across the various outputs to see if there is a change during your attempted activation.  If there is no change, your relay is not being activated.

 

 

Ed

[RR_Mel]

Use the lowest ohm/resistance setting on your meter, place the probes across the switching contacts of the relay.  With the relay energized the meter should show close to 0.

 

I would suggest you do a bench check to make sure the relay current is below the rated decoder output.  Put your meter on a range of about 100ma, put the meter probes in series with the relay coil.  

 

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[richg1998]

For some years I have used flea clips for doing this. I have a set with plugs for the meter. Very handy with #30 decoder wire.

Clip quite easily to the relay contacts.

http://www.apogeekits.com/images/smd_clip_test_leads.jpg

Some times, clip leads.

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_16395.jpg

Rich

 

[rrinker]

 If using a relay on a decoder output, make sure you put a diode across the relay coil (remember the blue wire is plus on the decoder, so the negative side of the diode goes to the blue wire) or the BEMF from the relay coil can damage the function output.

                     --Randy

 

[richg1998]

Yea, that goes with any DC operated relay.

Rich

[passenger1955]

Good advice on the diode - I would have missed that.

I'm using a 2 amp Tsunami decoder. What would be an appropriate diode? Thanks for all these answers.

[richg1998]

A 1N4001 would be ok. I have the 1N4001 trhough 1N4007 series in the junk box so I would grab anyone.

The 1N4001 is good for 50 volts at 1 amp. I have used many in industrial applications. The stuff I worked with was five volts to around twelve volts DC.

Rich

[passenger1955]

Awesome. Thank you.