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NPN switch question (2 wire sensors not suitable. Use 3 wire sensors)

Discussion in 'Controller Boards' started by OberSchutze, Aug 1, 2019.

  1. OberSchutze

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    I set my jumper to 24v and connected the wires to v+ and gnd and put a 2.2k resistor between gnd and sig and I keep cooking my sensor, am I doing something wrong or are my sensors junk?
     
  2. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Resistor? Why?

    V+ to Pos (brown)
    Gnd to Gnd (blue)
    Sig to Sig (blck)

    No extras
     
  3. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    inuctive.png
     
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  4. OberSchutze

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    It was a 2 wire sensor, I just bought some 3 wire ones.
     
  5. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Yeah you need 3 wire. Npn type. 6-36v. SN04s are great
     
  6. OberSchutze

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    Do pnp sensors also work? I have some in my shop?
     
  7. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    It was designed and tested with NPN. Dont let the magic smoke out of your blackbox.
     
  8. OberSchutze

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    I installed my sn04 sensors and they light up when metal gets near them however it doesn't trip the limit even though the sensor light comes on. My limit switch sensor setting work with contact switches.
     
  9. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    1) check that you have $5 set correctly (play with =1 and =0 respectively)
    2) monitor the Troubleshooting tab to see if they trigger
    3) tripple check that the Black wire is in signal
    (Post pics of wiring if you need me to check too)
     
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  10. OberSchutze

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    Had black and blue switch and had to set $5=1
     
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  11. OberSchutze

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    So I have used 3 sets of the SN04 sensors and they run great for a week or two then they go up in flames for no reason.
     
  12. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Chinese Quality Control in action (; often cheap because its rejects.

    Consider Xtension Limit Switch Kit
     
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