Switching on the lights

So, once you have a table full of power tools and the right materials to hand, what else do you need to make a home cockpit project go?

Well, obviously you’ll need at least one PC on which to run the Flight Simulator software, and chances are you’ll need three or four, depending on how many screens and instrument panels you’ll have. Speccing PCs, setting up FSX and interfacing controls etc is a subject I’ll come on to another day. For now, let’s look at the electronic side of things.

An aircraft cockpit, even a relatively modern glass cockpit, has a bewildering array of switches and knobs. The aircraft has to be operable even if the main avionics (the package running the glass cockpit) is offline. Very modern fly-by-wire aircraft have multiply-redundant systems, but smaller and less ambitious aircraft have backup instruments and controls. At the very least the aircraft will have a non-glass altimeter and artificial horizon. Fundamental controls like the gear, flaps, light switches etc will always be separate and manually-operated, even if the glass systems can also operate them.

If you’re going for a full airliner sim, say a 737, then you’re going to end up needing a large number of switches and other components, even for a more recent glass cockpit model like the ng-800. There’s nothing hugely special about these switches in the main – they’re parts you can order from many suppliers and are used for many purposes. Most knobs are driving either a rotary potentiometer (a type of resistor that increases or decreases its resistence as you turn the knob), a rotary switch (with a number of switch positions, triggered in turn as you turn the knob), or a rotary encoder (which emits an electrical pulse as the knob turns). All of these can be bought online easily enough (though true rotary encoders are relatively expensive). You’ll need push-button switches and toggle switches, possibly illuminated switches, maybe microswitches. It all depends on how far you’re going to go.

The other thing you’re going to need a bucket-load of is LEDs for light sources. Aircraft cockpits are full of lights as indicators, backlights shining through panels, and telltales of all sorts. Modern ultra-bright LEDs are perfect for this. They’re low-voltage, produce very little heat, and last for many years. Older aircraft used lots of little bulbs and as you can imagine these cause all sorts of problems with heat and burning out, and require much more power. LEDs now come in a startling array of colours, though the most common types are still red and green. For light sources you’ll need white LEDs, which are very cheap nowadays – I use an ‘LED Lamp’ variety which emits a lot of light for a measly 3V. Blue LEDs, while fashionable on all kinds of gear currently, are rarely seen in cockpits; most indicators are red, green, orange, yellow or white.

Even if you’re only doing very simple wiring up of LEDs in strings, it helps to have a base board on which to assemble the parts. Most electronics shops sell hobby boards (sometimes called veroboard) consisting of a fibre substrate with regularly spaced holes (to put the tails of components through) and metallic strips running horizontally or vertically. You can hollow out a dimple in these strips easily with a knife and break the circuit at that point, and you can bridge strips with solder or wire; in this way it’s simple to create quite complex circuits without needing to have PCBs manufactured.

To work with all of this stuff you’ll need a good soldering iron. Don’t kid yourself that the giant spade-blade iron you have in the garage for soldering pipes will work for this. You need a decent, small, low-to-mid-power iron designed for electronics work. Some lead-free solder, a couple of rolls of wire and a wire-stripper, and you’re ready to go.

If you don’t feel confident doing  a bit of electronic assembly, you’re probably not going to get very far in your cockpit ambitions. Practice makes perfect at soldering, and a simple electronics book will tell you what you need to know in terms of resistors, capacitors, voltages and current.

To power all your lights and gadgets you can just take one or more 5V and 12V feeds from a PC power supply – my project will have one ex-computer PSU dedicated to powering the electronics, as well as two others powering the main PCs themselves.

If you’re in the UK, Maplin is the major high-street electronics store of choice. Their catalog is quite extensive, but you need to find a branch with an actual components desk if you can, otherwise they tend to carry limited stock. Ordering online is an option. An alternative is RS Components, a business and industrial supplier; they don’t deal with individual consumers, though, so you need to be able to purchase through or on behalf of a company. Their online store is comprehensive if a little unwieldy and they deliver within 3 business days in most cases.

If you’ve not done electronics before, don’t be put off – you’re not going to be building microcontrollers or USB interfaces; you can buy those from people who know how to make them. Basic stuff is easy and fun, and if you’re into computers – and chances are you are if you’re attempting this – then it’s just an extension of that hobby.