Where are the electronics?

[Mike Hawkins]

With the Catch 22 thread I said that I would help with the designing of a lost model locater. I was hoping the PIC's would turn up today (the delay is my fault not the chip provider). I have a circuit drawn, code is pretty simple and pretty much done, all I need to do is build it, make sure it works then I can share it with everyone.

One project I had thought of making is low air pressure switch for air operated undecarriage. The idea being that you hook up the module between the receiver and the servo for the air valve, with a tee-piece in the air line to give somewhere to measure from. When air pressure is fine signals go straight to the servo, if it is low (say 50 psi) the module sends the signal to the servo telling the gear to be retracted.

Why not combine some of Richards ideas along with a lot of others and make our own data logger.

[Former Member]

[This posting has been removed]

[Mike Hawkins]

Yes Eric it would. I knew what I was thinking, I just wrote the opposite.

[Mike Hawkins]

I think the best first project for the magazine (first electronic project for a while) would be a power supply. Using something like a LM338 you could have adjustable voltage output at up to 5A, add some circuitry fo a circuit breaker, meters etc and it would be ideal for taking the mains power and bringing it to a level useful for battery chargers as well as being extremely helpful for testing circuits that have been suggested above or any others. Obviously you will need to test a circuit with a battery pack before you put it in your plane, but there is nothing more frustrating than fiddling with a circuit for a while then realising it wasn't working because you had a flat battery.

[Richard Sharman]

good idea! An adjustable bench power supply (with readout?).  Better check that there isn't already a cheap commercially available device, or no one will be interested. 

[Martin Shoebridge]

Exactly....... plus many more here http://www.rapidonline.com/Electrical-Power/Power-Supplies/Bench-PSUs/100W-Switch-mode-bench-PSU/78617

[Former Member]

[This posting has been removed]

[Mike Hawkins]

Even though they are so cheap I think I will make my own anyway. We made one at school 1.2V - 35V and 1A, and to make just the circuit to have 1.2 - 20V 5A smoothed rectified input, variable voltage, adjustable current, input short circiut protection, thermal overload protection for about £5 - £10.

The problem I find with commercial power supplies is selecting the voltage you want with a rotary dial, on the school project we used a 12 way switch to select common voltages. It might be a idea to use a digital potentiometer seeing as you will probably need a PIC to control the LCD anyway.

[Vic Driver]

hi,just caught the thread so here's my small comment.

of course there's the old standby,converted pc power supplies.I've been using a six amp charger off one for the last three years.

[Nik Harrison]

Might be a bit late with my comments, but . . .

The PIC is great for modelling projects.  I've done a few as the need arose.  First one was to practise single engine flying on a twin.  Never fancied making one engine stop in mid air as I might not like the result, so I  programmed a PIC so that I could fix one engine at whatever speed I choose and have throttle on the other.  The flap channel was used to enable this to be switchable in flight and also to decide which engine to "fix".  I did finally end up able to do circuits on one engine and then I set the flap to mid position and I've got both engines in sync again.

The trouble is the fun is in the programming as much as anything.  The component count is 3 - the PIC itself is a small 8pin device [they make an even smaller one] so to actually make a servo project is not difficult nor does it take much time.  It's a bit like an ARTF and a proper build job.  Well actually an ARFT may take longer than a PIC project.  You will not encourage people to get involved with electronic if making these devices is just a bit of soldering.  The same physical device can do many different things.  The function it does is all in the programming.

If you need a servo reverser, or whatever, most people will just buy one.  I think the days of RCM&E explaining how a circuit works are long gone except in general terms of do's and dont's when sorting model electrics.  There are too many other specialist magazines for that.  I don't think anybody will be rushing to make their own speed controller not counting the fact that you can't buy the components for the price of a completed one.

Think I might do myself a servo slow though.  I've just the job for one.

[Crash dummy]

I hate to admit it, but Alistair has a valid point .........

 However, being a child of the 60s and fearing the onset of dementia within days, i decided to convert a Black&Decker tool box into a flight box. As luck would have it, i still remember what it`s for!

Many people have looked at this and gone away to make their own version .. .. At least thats what my nurse told me!

Regards,

um um .... oh yeh, John.

[Nik Harrison]

Here are some of the circuits that I made to solve various model problems.

Twin Throttle Selector - this was made so that I could practise single engine flying on an IC twin.

Servo Toggle - made so that I could use the flap signal to switch the landing lights on.  It also switched the navigation lights.

Servo Rocker - made so that a servo signal could be used to switch a servo to cycle backwards and forwards. Used to make a model pilot wave!

Servo Slow - slows down a servo to full movement of around 3secs.

If anybody is interested I will supply the HEX file of the program.  Program this into the PIC processor and it will do the required function.  Each circuit has its own HEX file.

I have .pdf files of all these circuits but I've not found a way of up loading .pdf files.

Timbo - could you help please!     

[Tim Mackey]

Sorry Nik, but at the moment the only way to attach anything other than a JPEG is via Email .

I ask people to contact me with their email address and then return it like that.

Hopefully the new improved site early next year will offer these sort of enhancements.

[Phil Winks]

I wish I'd seen this thread earlier it's just taken me 30 mins to read through. some very valid points about cost and convenience but equally I think the sense of pride in achievement would spur many of all age groups to undertake these sort of projects and just thinking of my todo list can think of several that I'd love to have a go at 1stly a servo slow / sequencer for the undercarriage on my soon to arrive Bristol Blenheim if it'll stand retracts so if anyone has a really simple circuit for this please pm me especially if it doesn't require to much messing with the computer to prog chips

[Andrew Peel]

@Martin Shoebridge, @Johan Bach, @Richard Sharman, @Timbo, @Mike Hawkins

I'm 31 and still growing up and was so glad to find this article, and I would like to encourage it's continuation. I've been out of RC since I was @Mike Hawkins age and looking at with a new intrigue - and I can afford my own gear, which, since i no longer get pocket money, is a great thing.

Newly discovered the massive PIC, STAMP, Arduino electronic hardware programing movement around the world and see the overlap between electronics and RC to be quite seemless these days. As I read this thread it seemed like a way to bring in the young blood and teach some dogs some new tricks.

A development project which i've started was given new life after seeing @Ken Hewitt's (http://www.hewittonline.net/) PC to RC buddy cable solution from 2001. Given my huge lack of knowledge, would love to contact any of you regarding a PC to RC solution that would be as compatible with as many Tx as possible.  

Johan? Martin? Richard? Mike?

Thanks for reading, love to hear your thoughts.

Andrew 

dotandpixel - at - gmail - dot - com

Sydney, Australia

Sydney Hackerspace  - www.robotsanddinosaurs.org