I recently ordered a 50 pack of relays on sale for 5 dollars at electronic goldmine. They have 9 pins each and they are labled rk1-24v Ark112 910 25m. I know that they require 24 volts but I can't figure out where the coil is and where the connections like NO and NC are, nor can I find a datasheet that tells me this. I tried hooking up 24 volts to different pins, but I heard no click. So how can I find the right pins to hook the relays up?


1 Answer 1


If you have 50 of them, one easy way to figure the pins out would be to crack one open and have a look inside. The coil and connections should be clearly visible.

Another way is to use some Google-Fu and try the code or parts of it (you can add "relay" or "datasheet" to help narrow things down) and you may come up with something. I just had a go and I think this looks like your part's datasheet.


It should look something like the above if it is the right datasheet.
If you look closely you can see a similar format for rest of your code on the package example (the ARK-110 612 25W bit)

Since yours appears to the "single side stable version", this should be the pinout for it:

Relay Pinout

  • \$\begingroup\$ Figured it out, I guess polarity matters on this relay! \$\endgroup\$
    – skyler
    Dec 27, 2012 at 2:25
  • 2
    \$\begingroup\$ @skyler - If that's true, they probably have a built-in flyback protection diode. \$\endgroup\$ Dec 27, 2012 at 3:17
  • \$\begingroup\$ So what do they mean by high frequency? Is it \$\endgroup\$
    – skyler
    Dec 28, 2012 at 17:58
  • \$\begingroup\$ The time that it takes it to switch between it's two states? \$\endgroup\$
    – skyler
    Dec 28, 2012 at 17:59
  • \$\begingroup\$ @skyler - No, it means it's capable of passing high frequencies through it, i.e. it has a high bandwidth (up to 1.5GHz according to the datasheet) This is why it says it's a "Microwave Relay" and mentions typical applications of satellite tuners, test equipment, etc. It's not a "typical" general purpose relay (e.g. for power switching), it's for switching signals, hence the 50/75 Ohm impedance and low current specs. \$\endgroup\$
    – Oli Glaser
    Dec 29, 2012 at 10:56

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