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What is the difference between SPST, SPDT, DPST, DPDT and 3PDT switch?

Topics: Other

55 Replies

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1. SPST (single pole single throw)
It simply connects/disconnects a single line (2 pins).

 ->o __ o->
 

2. SPDT (single pole double throw)
It switches one line to 2 different ways (3 pins).

->o __ o->
       o->
    
   
3. DPST (double pole single throw)
It  means  two  independent  SPST in one switch (4 pins).

->o __ o->
->o __ o->


4. DPDT (double pole double throw)
It  means  two  independent  SPDT in one switch. It allows true bypass switching (6 pins).

->o __ o->
       o->
->o __ o->
       o->
       

5. 3PDT
It is basically DPDT with one extra SPDT switch (9 pins). It allows true bypass + additional 
function (LED, ...)


Pole = number of switch contact sets
Throw = number of conducting positions

All of them are produced as either push/stomp, toggle or slide switch.
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Thanks !!!i was in a need for the abv mention !!!
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Good info.
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Excellent answer: simple, clear; your dingbats ( ->o __ o-> ) were brilliant, considering the constraints of plain text formatting.
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You save my life. Fantastic explain. Thanks a lot.
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Really well explained, thanks!
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very clear and concise.thank you.
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Really helpfull, Thanks.
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SUCKS. HORRIBLE JOB
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Very well explained. It cleared all my confusions. Thank you
(Muhammad Khirad Alam)
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Thanks really helps a beginner
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difference BETWEEN LATCHING MOMENTARY
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intermediate switch
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very good.
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Thanks! Very clear information.
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Thanks great explanation... big help
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thanks!
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Thanks! But can you explain "true bypass switching"?
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http://www.electronicorange.cz/en/blog

Really a good set of articles on switching systems ... but it is Google translated from Czech to English, which actually can be a nightmare to read.
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Good but i am not completely clear
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I could use a DPDT in place of a DPST and just leave two of the leads empty, right? When it is in one position, it would supply power, and in the other position it would just be a dead end...that would be just like a DPST, correct?
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This is very helpful, thanks!
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super helpful and easy to understand!!!!!!
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THANK YOU
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thank you very much great explanation
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THANKS A LOT!!
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Excellent explanation...
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good explanation
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galing
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huh couldnt understand anything
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excellent explanation..Brilliant
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woooo hooooooo...
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what about TPST
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Thank you very much ... I got it :-)
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Thank of you for helping us
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thankyou..
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I thank you ,if my boat could ,it would to
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thnxxx
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thanks
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thnx for clearing the concepts in just few lines:-)
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what would you call a generators switch with start-run-off?
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Thanks
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nise explanation....
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its very knowledge full.
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thanks really helpful
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Correction? In #3 above, DPST, wouldn't it be more accurate to say "two *dependent* SPST switches"? The two poles move together.
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Cleared thankx
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Very helpfull thanks alot
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thnax
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so can any one tell me what this means:
Rating Max: 16 (5) A SPST – Single Pole Single Throw but what is the max current is it 16 amps or 5 amps as there is a big difference
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Just a guess... maybe it means max 5amps to operate the relay switch, and max current the relay should conduct safely is 16amps.
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thnx
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Never had it explained so clearly. Thank you.
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Waheguru πŸ˜‡πŸ˜‡
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