DPDT on off on

[jc69817]

Hi guys. What is the difference between a DPDT switch and a double pole ON-OFF-ON switch ?
Is on off on triple throw ?

Thanks in advance

 

[EFLImpudence]

DPDT (double pole, double throw) doesnt have the off position in the middle and and on-off-on might only be one pole.

 

[jc69817]

Thanks pal. Bought the wrong bloody one. Wanted on off on double pole but got DPDT when I saw 6 terminals on the back thought they were the same.
Why would a DPDT switch have 6 terminals but only 2 positions on the switch ? Surely 2in 2out is all that’s needed

 

[rsgaz]

 

[JohnW2]

Thanks pal. Bought the wrong bloody one. Wanted on off on double pole but got DPDT when I saw 6 terminals on the back thought they were the same. Why would a DPDT switch have 6 terminals but only 2 positions on the switch ?

It has 6 terminals since each of the poles is 'double throw' (i.e. 'changeover') - in other words, the middle terminal from the set of 3 for one pole is connected to one or other of the 'outer' terminals for that pole, depending ion the position of the switch (and the same for the other pole, with its set of 3 terminals).

However, you can use the DPDT switch as a DP on/off one - just ignore one of the 'outer' terminals for each pole (the same one for both poles).
Edit: per rsgaz's diagram, just use 3 & 5 for one pole and 4 & 6 for the other pole, and ignore 1 and 2.

Kind Regards, John

 

[EFLImpudence]

...

 

[jc69817]

Would I be right in saying in a on off on double pole
1&2 in
3&4 out
5&6 in
If so could I connect 1&6 and 2&5 to reverse the polarity (12v dc by the way)

 

[EFLImpudence]

Yes, if you connect 1 & 6 to Positive and 2 & 5 to Negative.

Edit - I see you have edited to say that.

 

[Jackrae]

Commonly referred to as "DPDT - Centre OFF"

 

[JohnW2]

Commonly referred to as "DPDT - Centre OFF"

Just to clarify fopr the OP - a "DPDT =- Centre Off" switch is what you described as a "double pole ON-OFF-ON" switch (with 3 switch positions, the centre one being 'OFF' - i.e. none of the terminals connected together). What you have, with just two switch positions, is an 'ordinary' DPDT switch, the functionality of which I described earlier - and which, as I said, can be used as a DP on/off switch simply by ignoring two of the terminals.

Kind Regards, John.

 

[jc69817]

Yes thanks John. I actually wanted the on off on double pole but bought the wrong one. I’m now looking for the right on in a small circular rocker. Oh well I’ll keep on looking.

Thanks everyone for taking the time.

 

[JohnW2]

Yes thanks John. I actually wanted the on off on double pole but bought the wrong one. I’m now looking for the right on in a small circular rocker. Oh well I’ll keep on looking.

Fair enough. Does it have to be round? As I suppose you know, if one searches on eBay there are 1000+ double-pole on-off-on rocker switches (mainly 'small') but the first few dozen I looked at (before getting fed up!) were all rectangular. Conversely, all of the small round on-off-on ones I found were only single pole.

Kind Regards, John

 

[rsgaz]

They exist, will try and find a UK seller...

https://vetco.net/products/dpdt-round-rocker-switch-on-off-on-16a
https://www.globalsources.com/gsol/I/Illuminated-rocker/p/sm/1035719581.htm#1035719581

One last thing though, did you want it to be retractive? (i.e. it returns to centre off automatically as soon as you take your finger off)

 

[jc69817]

It does need to be round to match others, but no I need it to stay on. It’s for a fan in my camper conversion. Extractor or inlet.
Thanks for advice guys it’s invaluable

 

[jc69817]

I know they exist I found one on eBay but thought £14 was a bit excessive