6 pin DPDT Circuit, what does it mean?

Thread Starter

Travm

Joined Aug 16, 2016
363
This circuit is from a latching DPDT switch. How do I know from this which pins are connected when the switch is in the "in" position?
1658684451911.png
 

ericgibbs

Joined Jan 29, 2010
15,976
Give me a link or a part number and will check.

My latching DPDT switches , the centre pair are the inputs and the outer pairs the A OR B outputs.


EG 1282.png
 
Last edited:

eetech00

Joined Jun 8, 2013
3,302
This circuit is from a latching DPDT switch. How do I know from this which pins are connected when the switch is in the "in" position?
View attachment 272128
The numbers represent the two positions of the contacts, its a little difficult to see but the lines at position 2 are "dashed" lines representing an open contact. Position 1 is closed. Position 2 becomes closed when the switch position is changed. I've cleaned up the drawing a little:

1658686510775.png
Each row represents 1 pole of a two pole switch, hence "double pole". The contacts of both poles change position at the same time with one actuation of the switch, hence "double throw". There is nothing in your image that shows which position is set for the "in" position.
 

Thread Starter

Travm

Joined Aug 16, 2016
363
The numbers represent the two positions of the contacts, its a little difficult to see but the lines at position 2 are "dashed" lines representing an open contact. Position 1 is closed. Position 2 becomes closed when the switch position is changed. I've cleaned up the drawing a little:

View attachment 272132
Each row represents 1 pole of a two pole switch, hence "double pole". The contacts of both poles change position at the same time with one actuation of the switch, hence "double throw". There is nothing in your image that shows which position is set for the "in" position.
That's annoying. I don't want to wait for the parts to arrive before I can accurately design PCB.

I was hoping this was some sort of standard, apparently not.

@ericgibbs
https://www.taydaelectronics.com/el...button-through-hole-2p2t-ps-22f01lp0s380.html

the switch.
 

MisterBill2

Joined Jan 23, 2018
12,678
Normally the switch illustration shows the contacts in the non- operated position. I am guessin that this is a push-on/ push-off sort of switch, so the position shown is the "out" position. That is usually the scheme. Button out is the normal position, button in is the selected position.
Depending on the manufacturer and the supplier detailed drawings of the switch operations may be available. But not if getting it from amazon. They can tell you box size and shipping weight.
 

Ya’akov

Joined Jan 27, 2019
6,260
Am I missing something? Given that it is a locking push button switch is there any alternative other than pushing in to the locked “in” position closes circuit 2 and unlocking it to the “out” position closes circuit 1?

The geometry of the pins and mechanics of the switch seem to preclude any other arrangement.
 

Thread Starter

Travm

Joined Aug 16, 2016
363
Am I missing something? Given that it is a locking push button switch is there any alternative other than pushing in to the locked “in” position closes circuit 2 and unlocking it to the “out” position closes circuit 1?

The geometry of the pins and mechanics of the switch seem to preclude any other arrangement.
So from that diagram you can confirm pushed in is circuit 2 and out is circuit 1?
 

Ya’akov

Joined Jan 27, 2019
6,260
So from that diagram you can confirm pushed in is circuit 2 and out is circuit 1?
Well, I wouldn't bet my life or someone else's money on it but I can't see an alternative.

If the shorting contacts are attached to the plunger, which they must be, then they can only move in one way. When locked in they would be moved to the rear, when out they would be in the front.

Any other arrangement would require a much longer switch body and very different terminal spacing—and be a waste of time to do.

So, I won't "confirm" it, but if I had to make a decision without more information that would be the basis for it.
 

Tonyr1084

Joined Sep 24, 2015
6,954
Am I missing something? Given that it is a locking push button switch is there any alternative other than pushing in to the locked “in” position closes circuit 2 and unlocking it to the “out” position closes circuit 1?

The geometry of the pins and mechanics of the switch seem to preclude any other arrangement.
I would agree. Seems that position #1 would be the normal resting position when the switch is not activated (pushed in). In that scenario #1 would be the active state. #2 would be the alternate state. When pushed in you change the state from #1 to #2, and thus open the contacts from #1 and closing the contacts for #2.

But as Ya’akov suggests,
Well, I wouldn't bet my life or someone else's money on it but I can't see an alternative.
it's not worth betting someone else's money on it.
 

MrChips

Joined Oct 2, 2009
26,784
Toggle switches might operate differently. They might have a spring loaded rocker that connects the contacts in the opposite direction of the lever.

In my experience, the only way to guarantee that you do the board layout correctly is to measure the switch physically in your hand with an ohmmeter.
 

eetech00

Joined Jun 8, 2013
3,302
Am I missing something? Given that it is a locking push button switch is there any alternative other than pushing in to the locked “in” position closes circuit 2 and unlocking it to the “out” position closes circuit 1?

The geometry of the pins and mechanics of the switch seem to preclude any other arrangement.
Understanding how the switch works isn't the issue. The switch's schematic doesn't indicate a direction of movement that maps to the physical part. It's better to confirm with the manufacturer and remove all doubt.
 

BobTPH

Joined Jun 5, 2013
5,453
My problem with the datasheet is that it gives no clue as to which pin is which. You can rotate their diagram 180 and the outside pins will be reversed.
 

Thread Starter

Travm

Joined Aug 16, 2016
363
Well, I wouldn't bet my life or someone else's money on it but I can't see an alternative.

If the shorting contacts are attached to the plunger, which they must be, then they can only move in one way. When locked in they would be moved to the rear, when out they would be in the front.

Any other arrangement would require a much longer switch body and very different terminal spacing—and be a waste of time to do.

So, I won't "confirm" it, but if I had to make a decision without more information that would be the basis for it.
This sounds good, I'm not working on anything that would be problem if I got it wrong, but I would like it a certain way.
 

Jon Chandler

Joined Jun 12, 2008
292
I have a dumb question. Is the switch symmetric,, as these type often are? One position is center pins connected to one side; the other position is center pins connected to the other side. Just rotate the switch 180° to swap pushed/non-pushed action.
 

Thread Starter

Travm

Joined Aug 16, 2016
363
I have a dumb question. Is the switch symmetric,, as these type often are? One position is center pins connected to one side; the other position is center pins connected to the other side. Just rotate the switch 180° to swap pushed/non-pushed action.
It's a 90deg switch so it's not completely symmetric. It can be turned, but then the switch points the wrong way.
 
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