DPDT Brain f##t

[Sam Staton]

I am using a VPX-Pro, and individual landing and taxi lights. I have set up a DPDT (ON-OFF-ON) to control them. I know there is a way (or at least I remember that there is) to wire the switch so that in one position all I get is taxi light and in the other I get both... CAN'T REMEMBER HOW! Can someone help a brain-dead builder? Thanks in advance!

 

[rzbill]

The wiring schematic depends on the guts of the 3 position switch.
The switch you described appears to have a simplistic center off position.

You have the 3 connections for the left pole and 3 connections for right pole.

SO, power goes into the center of both poles. For the taxi (call it left pole), a jumper from bottom to top and a lead (from either bottom or top) going to the taxi light. For the landing light (on the right), a lead from either top or bottom. Depends on which way you want the switch pointing when both are on.

You will have center off, down taxi and up taxi + landing (if you choose to do it that way)

There are other 3 position switches that are called progressive transfer switches that can be wired such that down is off, middle is one function and up is both.

The Aeroelectric book is your best guide for this.

 

[Walt]

There are other 3 position switches that are called progressive transfer switches that can be wired such that down is off, middle is one function and up is both.

The Aeroelectric book is your best guide for this.

Agree, down should always be off (the flap switch should be the only center off switch).

 

[WenEng]

Sam. I sent you a post from the VPX forum

Of course, with the VPX there are no hot wires from the switch, just signal grounds. But it looks like you jumper the middle grounds (off).
Then you jumper the upper landing switch input wire to the bottom opposite side for taxi only. Across from that taxi only jumper, you run your taxi only switch input wire to the VPX, just like the upper landing switch input wire.
So, then throwing the switch up signals VPX to light up both lights because of the jumper. Hah. You know what that means coming from me.

 

[Sam Staton]

Thanks Guys!

I knew the forum would come through! Got just what I need. Thanks again!

 

[MCA]

Sam,

The drawing on the forum shows a center-off switch but you can use the same schema for a switch where bottom is off and middle-up are on.

 

[Hangar 1271]

The wiring schematic depends on the guts of the 3 position switch.
The switch you described appears to have a simplistic center off position.

You have the 3 connections for the left pole and 3 connections for right pole.

SO, power goes into the center of both poles. For the taxi (call it left pole), a jumper from bottom to top and a lead (from either bottom or top) going to the taxi light. For the landing light (on the right), a lead from either top or bottom. Depends on which way you want the switch pointing when both are on.

You will have center off, down taxi and up taxi + landing (if you choose to do it that way)

There are other 3 position switches that are called progressive transfer switches that can be wired such that down is off, middle is one function and up is both.

The Aeroelectric book is your best guide for this.

This is an older thread but does anyone know where to find a double pole, three position, progressive transfer switch. They don't appear to common. Thanks.

David

 

[Mike S]

This may help

http://www.aeroelectric.com/articles/Progressive-Xfr_Split-Rocker_Switches.pdf

 

[Mich48041]

B and C part number S700-2-10

 

[Hangar 1271]

Thanks Joe.

Okay. Went to the B&C website and the -10 is on-on-on. Shouldn't it be the -11 which is off-on-on?

 

[Flying Canuck]

I've got a Copal ET210PA12-Z (DigiKey p/n 563-1873-ND) DPDT on-on-off switch that I use for my battery/alternator switch. It connects terminals 5&6 in the center on position and connects 5&6 and 2&3 in the top on position. Nice switch, works great, <$12 Cdn. It doesn't have a DC current rating, but that doesn't matter for VP-X applications.

 

[Mich48041]

No, a switch is only on when there is a wire connected to the terminal. The switch might be closed, but without a wire, the circuit is open. Wire the switch according to Bob Nuckolls' Z-11 schematic for the battery master switch. Notice in his schematic that the switch is labeled, "2-10". I would prefer that Bob labeled his switches per industry standard, SPST or SPDT or DPST or DPDT.

Went to the B&C website and the -10 is on-on-on. Shouldn't it be the -11 which is off-on-on?

 

[Hangar 1271]

Thanks Claude. They are about $8.50 now.

Thanks Joe. I get it. It could be on if I wired something to it but with nothing there, well, if a tree falls in the woods and nothing is under it nothing gets smushed.