Adding a beeper...more help please..

After reading the thread a day or two ago here about adding a beeper..I decided to try to add my own. I bought a Radio Shack 273-059 3 to 20 v dc beeper for $3.50. It only draws 10 ma at 12 vdc. and works fine on the two cell Lipo at 8 volts or so. It has a great tone and should do the job.

I was hoping to plug it into the AUX port of my Spektrum radio receiver( AR6000) and, using the AUX switch shown on my DX6 Transmitter's instructions..be able to intermittently flip the beeper on and off.

Unfortunately the two different ways to hook it up from that port...#1 leaves the beeper on all of the time...#2 doesn't activate it at all. Any ideas on how I can switch it on when the plane is "lost"...or...any way to, at least, make it an intermittent beep, rather than one long sound? Thanks for any and all help. rich

Reply to
richg99
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On Wed, 27 Aug 2008 12:56:24 -0500, "richg99" wrote in :

The trouble you're having is that the information transmitted on the channels is designed to drive servos by the use of digital encoding.

The "always on" circuit is probably just a connection between the positive and negative poles of the battery.

The "never on" circuit is probably the signal line to ground. The signal line carries a series of pulses in frames that identify the channel and then the position that the servo should take (0..255, 0..1024, and maybe nowadays even 0..2047). It's not a matter of raising the voltage on the signal line to the point where it will drive the servo. All that it does is convey a directive that circuitry in the servo then uses to pick and hold a position.

So take apart a servo and see if you can substitute the beeper for the servo motor. Find out whether you can get it to make noises on demand. You won't be getting feedback from the potentiometer, unfortunately, which may lead to an "always on" or "always off" condition. I've never done this experiment to see what would happen ...

The more I think about it, the more I doubt you could get what you want from the cannibalized servo. Even when the servos are not being commanded to move, there are pulses of power to the motor holding them in the commanded position (resisting air pressure and/or vibration).

Marty

Reply to
Martin X. Moleski, SJ

Thanks, Marty....especially for the second part of your answer..which, when I re-read your first part...makes sense that the receiver/servo is not the way to go.

My next thought is those little Christmas tree on-off lights. They heat up..open the circuit...then cool off ...close the circuit ( or maybe the other way around). Of course, all of my Christmas stuff is 1200 miles away.

Anything that is cheap, and would cause an on-off condition with some modest controllable resistance would be what I am now seeking?? It seems like it would work and just give me an intermittent beep. What say you? Rich

Reply to
richg99

On Wed, 27 Aug 2008 14:46:37 -0500, I said, "Pick a card, any card" and "richg99" instead replied:

Rich,

What you need is a missing pulse detector circuit to watch the spare channel output. If you turn off your transmitter, you get no pulses to the servo channel output and that would turn on the beeper.

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The circuit at the link above can be run from a single 9 volt battery. The 555 is robust enough to drive a beeper or even a relay. Your pinout from the servo would depend on the brand. Generally, black is ground, red is the power and the remaining color is the wire that has the pulse on it. Connect the black wire to the bottom terminal on the circuit. Leave the red wire alone and connect the pulse line to the second from the bottom terminal; the base of the transistor.

You may need to invert the input if you can't adjust the trigger to accommodate the signal but it should work.

-- Ray

Reply to
Ray Haddad

It's not quite that easy. Your receiver outputs a pulse signal to the servo, not a simple on/off signal. If you want to switch the beeper on and off from the transmitter, you must make a device which is able to detect the changing width of the pulses.

If your radio system does not have a failsafe built-in, the receiver will stop sending pulses to the servo when the transmitter is turned off. This is quite simple to detect. I have made a simple circuit to do the job. Go to

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and download "planefind.zip" if you want to have a look.

Reply to
H

I may have found a cheap solution...on eBay. I am checking to see if it will work with my DX6 Spektrum and AR6000 receivers. The notice says that..after the first item, all additional items are shipped at $1.50...so it is very cost effective if it works. rich

p.s. I put another plane into a soybean field today. Way too windy for me to be flying, that is for sure. Spent twenty minutes finding it. Finally found it by the "clicking' of the servos.

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Reply to
richg99

| I may have found a cheap solution...on eBay. I am checking to see if it | will work with my DX6 Spektrum and AR6000 receivers. The notice says | that..after the first item, all additional items are shipped at $1.50...so | it is very cost effective if it works.

If it truly works with PCM like the ad says, then it should work with any of the spread spectrum stuff.

However, I'd say the odds are pretty good that it really doesn't work with PCM, and if the seller doesn't understand how it works, he may just say `yes, it works' without really knowing for sure.

PCM systems always send a valid signal to the servos, so the only thing for an alarm to trigger on would be either 1) this servo being specifically meant to turn on the alarm, or 2) this servo not moving for more than X minutes. The Hobbico Air Alert uses #2. Spread spectrum systems are probably the same, though I haven't verified this myself.

| p.s. I put another plane into a soybean field today. Way too windy | for me to be flying, that is for sure.

Strongest winds I've flown in were 45 mph steady, gusting to 55 mph or so. Flying a basic flying wing (like a zagi) off a hill. Had a significant portion of my tool box taped to the bottom of the plane for ballast. Now THAT was frickin' nuts -- and yet a blast!

Alas, that hill was sold, a very sad say in Central Texas sloping.

Reply to
Doug McLaren

I received the beepers and they work GREAT! Can't beat them for $6.00 each.

You simply plug one end into the radio on ANY servo slot ( I have a DX6 2.4 GHz Spektrum radio) ..and the other reconnects to the servo lead itself. If that particular servo has NO movement at all for one minute...the device starts beeping

The only hang up is...if I plug the battery in on our "ready bench"... ..and then dawdle while walking to the flight line...one minute can pass and the beeper starts on its own.

Either of two solutions work. One is to move the stick a bit ( assuming you have it on the elevator) while walking.....or..... don't plug the battery in until you are ready to launch.

The beepers are a good solution for my situation and I fly with more confidence now. Clearly, if I had a very expensive plane, or a different field arrangement...I would go up to the radio device finder style. They seem to be only $80.00 or so and have two tabs to cover two planes. regards, rich

Reply to
richg99

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