Rotary Switch

[Sadlercomfort]

Hi Guys,

I'm looking for a Rotary Switch on F@rnell to use for a project.. I've never used one before so the terminology is confusing me slightly.

I understand the concept, but dont understand things like n.o of poles, switch positions and angle of throw.

I need one that clicks in aswell. This will be used to control an LCD Menu Interface so dont need anything complicated. Just something like the above graph.

 

[Minder]

That is known as a quadrature encoder, the pulses are 90deg apart, it is used for speed and direction and is rated in pulses/rev, this number applies to either chA or chB, not both additively.
That may not be the type you are looking for?
M.

 

[dorke]

Here are some links that may help you:
Poles and Throws
In rotary switches Angles

BTW,
you can use a simple momentary SPST push button for controlling menus.
They are much smaller and cheaper.

 

[Sadlercomfort]

Thanks I've used push buttons before.. now want to try a rotary encoder. A little bigger but only need one so use much lets space.

I'm not sure what type I need

 

[Sadlercomfort]

I believe the quadrature encoder was what I was after

 

[dorke]

Yes,
you do need to define your requirements before you can select a switch.
Will this switch be the only one used?
In what manner? etc.

 

[Minder]

Hi Guys,

I need one that clicks in aswell. This will be used to control an LCD Menu Interface so dont need anything complicated. Just something like the above graph.

Why do you need a quad encoder, it could be done either with a simple single wafer multi position switch, there is also coded versions such as BCD etc if needed .
M.

 

[Sadlercomfort]

This will just be used to cycle through different menus, a default menu will be display with some information. Once the encoder button is pressed it will enter the menu.. then when I rotate the encoder it will cycle through until i press the button. I will also use a keypad if I need to type in any numerical information.

Isn't the single wafer multi position switch the same?

 

[Minder]

Are you operating this switch manually or is there another means used?
How many menu's does it cycle through?
M.

 

[hevans1944]

Perhaps this 360 degree, continuous rotation, rotary encoder with 20 detent positions AND a push-button will do it for you.

 

[Sadlercomfort]

Its manually operated.. 8 menus or less

 

[dorke]

What you need is called "Incremental Encoder".
You can actually build an optical one yourself just for the fun of it,
Opto Transmit/Receive and a slotted rotating disc( slots can be less than shown ) .

 

[Minder]

Its manually operated.. 8 menus or less

So I still really don't know why you need a quadrature/incremental encoder for this function, it is not standard practice for the application you seem to need,
And a little over-complicated method.
A 8 position wafer selector switch is the customary way, there are many manuf. of these, Grayhill for one.
M.

 

[Sadlercomfort]

I'm not looking a simple method here, it's supposed to be an advanced project. Its a university project

 

[hevans1944]

You don't need two optical "tracks" to build a rotary optical control. One track of alternating opaque and reflecting (or transparent) segments and two appropriately angular spaced optical sensors (reflective or transmissive) will suffice. One sensor should be adjustable with respect to the other one to adjust for a quadrature relationship in their signals. You can add a second track if you need an "index" mark, but that sounds unnecessary for your application.

It would be easier to just spend the three bux plus some change to purchase this one off of eBay. Twenty positions per revolution with detents at each position, plus a push-switch built into the shaft that you can use to enable and disable menu selection. What's not to like?

Back in the day, Centralab sold wafer switch components that you stacked up and assembled to make just about anything you can imagine, with or without a detent mechanism. Two wafers, each single pole with multiple positions and continuous rotation could be wired to produce the wave forms you show. So, twelve positions over 360 degrees would give you three cycles if appropriately wired. I'll leave that wiring as an exercise for the student. Don't forget to "condition" the switch transitions for bounce-free performance in whatever logic you add to the switches.

 

[Minder]

I'm not looking a simple method here, it's supposed to be an advanced project. Its a university project

There is also a thing know as 'Over Engineering'
M.

 

[hevans1944]

There is also a thing know as 'Over Engineering'
M.

Yep. Bet he's gonna construct a furnace and zone refine and dope his own silicon transistors too. Or maybe build a particle accelerator and implant ions for a planar structure. Lots of ways to over-engineer this project.

 

[dorke]

Hop,yes he can.
But looks like @Sadlercomfort wants to be flamboyant in his project.
Or maybe,It may be a project requirement to use a rotary switch.

I still think a momentary push button is the way to go, total software controlled,simplest and cheapest .
Say like:
Short push/release to toggle menus and a long push(say 2 seconds or more) to activate the selected menu .

 

[hevans1944]

@dorke I really like rotary incremental encoder controls. Hardly anything to wear out, silent, good resolution... yada, yada, yada. However, buttons are appropriate for some functions too. My KX3 transceiver is a mixture of both and I wouldn't want to have it any other way. Tuning and menu selection is with optical encoders, while selecting a menu option requires a button press. All feedback is via the backlit LCD screen, or really tiny LEDs here and there. It takes two simultaneous button presses to turn it off or on. Way cool. I love it! Oh, and you can download macros to program the buttons to do things besides their factory programmed functions.

Hop - AC8NS

 

[dorke]

Hop,
Agree with you tuning of transceivers is the easiest with an optical encoder.
Long long ago I worked with some WJ receivers and later on with iCOM receivers which had great rotary encoders for tuning + a button to select the "digit of tuning"and a number pad for direct frequency entry.