switchable landing lights

[Roderic Craig]

May2011issue describes a circuit forto operate retracts . I thought I would use this same circuit to operate my landing lights ie substitute the landing lights instead of the retract servo. I have done that but find that the lights won't switch off. When I use the main on/off switches ,I can switch the lights on and off whilest still maintaing power to the main servos. I have tried using both the gear and flaps chanels on my Futaba6EX transmitter to no avail.I have removed the positive as shown and have both circuits swithed ON but still no joy. Any ideas Rod Craig

[Allan Bennett]

I'm not quite sure what you're doing there. Can you give more details of the circuit you're talking about?

 

You certainly can't simply substitute lights where a servo is supposed to go. But there are circuits which you can plug into a switched channel on your receiver to control led lights.

[Cyclicscooby]

I don't know what circuit you're on about either..?? You can't simply connect an LED to a servo socket, and expect it to switch..

The signal wire pulses high, once every 20ms or so, but only goes high for 1-2ms so you cant use it directly for what you suggest.. If the PWM was longer, you could use it.. I use PWM on my PIC lighting, but it wont do owt as a servo output..

 

HTH's

 

 

Luv

Chrisie.. xx.

[Peter Beeney]

It’s possible to construct a little circuit using an op-amp as a comparator to switch a transistor to turn on the landing lights using a switched tx channel. Or even more simple, a micro switch operated by a servo. One that I’ve not tried, but I’m sure would be fine, is a reed switch, CL38R or similar from Maplins, also operated by a servo. These are rated at one amp; and cost about £1:50; plus they require a small magnet to operate. As there would be very little load on the servo the very smallest and lightest might be sufficient, a quick spot of trial and error would soon show if it worked or not.

I’ve no idea what voltage you would be using for the landing lights supply, I’d be tempted at 12, but I’d personally prefer not to use the rx pack whatever. For me, safety plays a part, and a loss of radio power due to a malfunction on the landing lights, or any other ancillary unit come to that, is something I’d definitely try and avoid!

PB

[andy watson]

On my stuka I used a multiplex switching unit- it cost about £15. It plugs into the rx, and can run 2 circuits- I had a siren on 1, the landing light on another. Both were running @12V using a seperate 3S LiPo, and both are controlled from the tx.

[GONZO]

What about one of THESE

[Roderic Craig]

Thanks guys. I sorted the problem by using an old micro servo and soldered a couple of bits of copper strip into the circuit , one on the servo arm and the other onto the top of the servo casing making a very satisfactory on/off switch!! works well!! I am using a seperate battery for the lights . I like the Turnigy switch Gonzo suggested. Many Thanks, Roderic.

[Peter Beeney]

Roderic,

Sounds like an excellent little idea, minimum cost and effort. Maybe it could be used on a throttle servo too, to drive the glow on low throttle for a four stroke. Or, indeed, any other ancillary device that needs an on/off switch.

Nice to see you still upholding the principle of economy as envisaged by the medieval sage William of Ockham, his little gem was known as Ockham’s Razor, - Entia non sunt multipicanda praeter necessitatem - which in recent times has been very loosely translated by the laconic gentlemen at NASA as KISS, we Keep It Satisfactorily Simple! Or something…

Keep up the good work!


PB