Find your way into flight simulator cockpit construction
6.1 Switches
Within a cockpit there are many switches to make a selection varying from "on" and "off" for a landing light to the selection of the use of 1 of 4 available fuel tanks. In this section a basic overview of the most common categories of switches is given. Take a look at the online switch catalogue of for instance Apem to get an overview (and pictures) of various available types of switches. See Cole Switches for an extensive glossary about switches.
6.1.1 Switches for making a selection
Toggle switches, Rocker switches, Push button switches
These switches are typically used to switch a device (e.g. light) "on" or "off".
The toggle switches have a more classic style, the rocker and push button switches
are more modern. When selecting these switches it is -
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left position |
middle position |
right position |
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on
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-
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off
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This is the basic scheme for many switches. In left position switch is on, in right position switch is off.
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on
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-
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on
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Also common variant.
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on
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off
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on
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Also common variant.
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(on)
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-
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off
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The indication "(on)" means "momentary" often also indicated as "mom". When pressing the switch to the left side contact is made, but when released, the switch goes back into "off" position.
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(on)
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off
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(on)
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Also common variant.
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on
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off
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(on)
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Also common variant.
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In case it is relevant you will find within the above schemes the use of different number of pins, often 3 or 6. This table lists some examples, other combinations are possible too, however some times you really have to search to get them. | |||
For the rocker and push button type of switches there are also switches with build in lights.
There is a variation in the way switches can be mounted. In general you will need switches that you can mount on (in) the surface of a panel (and not directly on a print).
There are many (local) suppliers of switches, search with Google etc. An interesting special type of switch is offered by NKK Switches and ScreenKeys. On the site of Jeroen op den Akker an instruction can be found on how to make Korry switches yourself (browse the builders list in section 2 for more examples).
Rotary switches
By turning the knob on a rotary switch you can select 2 or more positions. Each position has its own contact pins and represents a specific selection. There are 2 groups of rotary switches:
- Shorting: also known as "make before break", when moving from position A to position B the switch will "short" A and B. The current is not interrupted.
- Non-
shorting: also known as" break before make", when moving from position A to position B the current is interrupted.
On some panels the rotary selector switches have a specific number of degrees per step. For Boeing this is often 30 degrees, for Airbus it is often 45 degrees. In general switches are supplied with a fixed number of positions, but some suppliers offer a user selectable number of positions (e.g. Grayhill).
A special version of the rotary switch is the thumb wheel switch to make for instance a more clasic looking radio stack. Examples are: GTF31 (DD Comercio), Pushwheel Selector Switches (Cherry) and Thumb Wheel Series (EECO).
It is worth the effort to search for specific switches. For example a rotary ignition switch can be found on AircraftSpruce.
6.1.2 Switches to create pulses
Within an average cockpit there is a considerable amount of rotary type knobs (rotary switches) to tune instruments, radio equipment and navigation equipment. In a flight simulator cockpit this type of tuning is often processed by generating pulses that in turn drive for example a keyboard emulator. There are basically three types of rotary switches that generate pulses.
Rotary pulse switches
The basic principle of these switches is that they have 4 pins (A,B,C,D). If you turn clockwise a pulse (contact) is made on the pins "A" and "B", if you turn the other way around (counter clockwise) a pulse (contact) is made on pins "C" and "D". For many applications related to digital control these switches are very useful / practical and not expensive. Rotary pulse switches are a bit harder to find, examples are: MRP (Knitter), R1010E (Hung Ta), SRBM (ALPS) and BTSR10H (Belton).
Incremental rotary encoders
These are more complicated rotary switches. On 2 pins 2 streams of pulses (block waves) are generated which have a difference of in general 0.25 cycle. On clockwise rotation pin "A" leads pin "B" on anti clockwise rotation it is the other way around. The downside compared to a rotary pulse switch is that they are much more expensive to use. Additional logic is needed to translate the 2 pulse streams into a single pulse for a clockwise "click" and a single pulse for an anti clockwise "click". Examples that offer full solutions: Rotary 5 (Hagstrom Electronics), ENC351 and ENC302 (CSI) and 8X Rotary converter (Blue side up).
There are cockpit builders with home build solutions, browse the builders list in section 2 for examples.
Absolute rotary encoders
With an absolute rotary encoder instead of a "pulse" the absolute position is given. Based on the number of steps 4, 6, 8 or more pins each representing a "bit" make out a digital "word". Based on this the exact position is known and a clockwise or anti clockwise rotation can be recognized. For applications as tuning a radio, this functionality is an overkill. But for modeling full turning knobs with positioning indicators these type of switches may be very useful.
