JohnMcGowan

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Hi gang,
Im looking to see if someone out there may have a schematic or set of plans to build a 30 second countdown clock with VERY LOUD horn or buzzer attached to it?
It would be ideal to have the horn sound off at the 20 second mark,10 second markas well as when the clock strikes 0.
Anyone got some ideas for me?
Thanks,
John

davidgeorge212

i am working with my friend in our electronics lab at school. He is pretty good when it comes to electronics and we are trying to build up a countdown clock circuit as we speak for this exact purpose. I told him to make it beep at 30, 20, 10, and 5-4-3-2-1. He has got it working good right now. The only downfall to this setup is that there will be no visual clock to look at. Its all done in circuitry and will only be able to be heard when it sounds the horn. I dont know how well this will work or not for our club 40 races. We may have to go to a mechanical clock design.

David G.

JohnMcGowan

My Feedback: (15)

Hi Opie.
Thank you and your friend for attempting this.
I wonder if we could maybe sinc some digital clock with big numbers or even a large analog clock thats resettable to what you are making for some type of a visual ?
The problem with not having a number for pilots to look at is that folks will jump the start for sure since they havent any solid thing to look at and gauge their start by, know what Im saying?
Maybe if he hasnt got too far, have it just like you described but let it sound off at 30 secs ,20 10 , then 5 , then again at zero. With the thing sounding at each of the last 5 seconds, it may be too may sounds for the pilot to keep track of maybe?
But hey, beggars cant be choosers, lets see what you come up with David. Just make the buzzer LOUD as possible for all us deaf folks.

THANKS!!!!

davidgeorge212

Do you remember which intervals Tim Batt's Clock sounded at?I will see what I can do about trying to hook up a visual clock. If what we do doesnt work out, we might still have to find an alternative route. Maybe Tim can find or redraw the plans for his clock.

davidgeorge212

Ok, I just told my friend some of the revisions and he is changing it to 30,20,10,5,0. When it hits zero, it will buzz for 3 seconds due to how the logic worked out. I'm sure it won't be to hard to hook up a clock but ill find out.

Ed Smith

The clock will have to "Buzz" louder than the engine noise on the start line. If not the caller will not hear it and not know when to release the airplane.

Ed s

davidgeorge212

I didn't have a big buzzer with me but I got one from radio shack to test it with. It was actually louder than I thought.it is 108 dB's and sounds like a building security alarm siren. Later on if/when I find something louder, I will swap it out.

JohnMcGowan

My Feedback: (15)

Ed, we do flying starts instead of rise off ground.
The pilot has to watch the clock with one eye as well as watch his diving plane with the other eye so he will not cross the start line before it reaches zero. Jump starts are not the best way for a guy to start out his day of racing

Opie,
the 108 may just be loud enough, thats fairly loud I would say. But I guess we wont know until its on the proving grounds.Alabaster has a race coming up soon on March 10. Think it could be ready by then? We could put it to use under real world conditions there
Thanks David!!!!! Im glad I know at least one smart evil genius person

davidgeorge212

The visual clock that I put on it will have to be an LED 7 segment type of display. I am looking now for LED displays that I can just buy online. What size display do you think we need. The ones I was looking at are I think 6" tall and they use Red LED's. The comments on the website say that you can see them from 100 feet away. Should I look for bigger ones or will these be big enough?


David G.

Edit*
The 6.5" dispays I found before say they are not really visible in the bright bright day light so I found some different ones. They are for outdoor use for people that make scoreboards for sporting events. They are also a little bigger at 9" tall. I havent ordered them yet and Im not sure how fast they will ship. If they ship fairly fast I might be able to have it ready by the first race. Right now, dont count on me having it ready just to be on the safe side. I will keep you up to date though if we do get it finished.

JohnMcGowan

My Feedback: (15)

David,
I would say the bigger and brighter the digits, the better ,seeing how it will be outdoors. Keep up with what you spend and I'll be happy to re-imburse you for all you do.
Thanks for taking on this challenge!!!! What you are construction sure sounds like what we need.
Does the buzzer thingy have a directional cone speaker with it or is it just a box type unit? Im thinking ahead here so bare with me , maybe if it does come with a speaker, would it be possible to mount 2 to the unit( speaker base to speaker base ) that blast 180 ° apart. Point one to the starting line that has the pilots and starting judge as well as the left side line/pole judge , and the other one would be pointed to the far end right side line/pole judge. That way the end judges who normally may not be able to hear the current clock would surely know that the race is beginning to start when they hear this thing of yours.
But, if my ramblings muddies your current plans, dont sweat it.
I appreciate this David!!!!
John

davidgeorge212

I think with the way he is setting it up, we should be able to add or interchange the speakers to whatever we might need. Not 100% sure how its all going to work out yet. So far we have just done several tests while it was hooked up to a trainer board. He took it all home with him and he said when he gets the chance, he will wire it up on a circuit board.

We probably will have to at least add more speakers or get a bigger one. I alsmost didnt think about having the outer pylon judges here it. The siren I have now is really loud but it would probably only be good for letting the pilots and center judge here it. Im not sure the pylon judges will be able to hear it.

still4given

I'm not sure why you don't just use a recorded countdown like the one we use for RCPRO Warbird and club 40. A pilot can't really watch a stationary clock and fly his plane. He can easily listen to a verbal countdown. Ours counts down from 45 seconds and announces the time every 5 seconds until it gets to 10 and then counts each second down to zero.

You can download the software program here for free.
http://www.nmpra.org/software.htm

Or, you can just record your own and play it over the PA system.

Tbatt

My Feedback: (4)

I made a CD to do just that. The problem is that not all clubs have a PA system and a boom box just isn't loud enough.

My clock that I designed does the following:
It has a 24 inch analog sweep hand painted day glow orange.
The horn sounds at the start, at 30 seconds, 20, 10, 5, End
The horn is LOUD. It is a Harbor Freight mini "Bull Horn" that cost around $10 ($4.99 on sale, buy two!) The horn runs off of 6 VDC.
To trigger the horn I use a cam wheel that runs the sweep hand that triggers a series of micro switches. The motor that runs the sweep hand is a two RPM motor available from Edmund Scientific and runs off of 12 volts DC. Simple.

cutaway

It seems to me a standard 8-bit count up/down latch (with preset capability), tickled by a one half of a dual 555 timer setup for cyclic 1-sec intervals, with comparators on the latch outputs for 30/20/10/5/4/3/2/1/0 values, would do it. When a comparator pops, it hits the other half of the dual 555 setup as a 1-shot timed for 1/4 sec (or however long you want your audible signal to sound) driving the horn.

With the countdown's outputs latched, fed through a 7-segment decoder, then fed to line drivers/amps you could use that output to drive relays/contactors that would be able to drive a countdown display of any magnitude/power/brightness

Scorpion Racing

We use a 60 second digital count down clock for the spotters/callers to see. The starter raises the green flag over his head at 5 seconds to go, and drops the flag at zero. No horns or PA system needed. Much simpler and everyone can see the flag in the air and when it drops.

lookilook

Hi, i am not sure if this is close to what you are looking but we use this during our funfly competitions for precision timed landings and maneuvering.it is a countdown digital timer that talks and every competitor hangs it on him when it is his turn, i hope it helps or give you a starting point...

http://www.ebay.com/itm/VL-Viewloade...item58921a5cef

reg
Nik

davidgeorge212

Just ordered the digital LED numbers yesterday. Surpisingly I just got an email with a tracking number that says they will be here tommorrow. They are coming all the way from somewhere in Hong Kong so I would say thats pretty fast shipping.

JohnMcGowan

My Feedback: (15)

Hummmm? From Hong Kong to here in a day? I dont know about that but maybe if its coming via the now non-flying Concorde or Superman himself is bringing it personally wrapped up in his cape, maybe

What size digits did you finally decide to use?
Thanks again David. Are you thinking about flying C40 this year(hint,hint,hint) ? We miss you not being out there with all of us turning and burning.
JMc

davidgeorge212

yep, I just double checked and it was wednesday that I ordered them and the email says they will be here on Friday. I was looking at the 9" numbers but they would have been coming from Austrailia. The guy told me in an email he couldnt guarentee I would have them very fast so I decided to pass on them. I found 8" nubers on ebay. They had two things going for them. 1. They said for super bright outdoor use and 2. Fast shipping. Now I just have to get them to my friend and see if he can wire them up.

I will definitely be out at most of the local races to help out, I dont know yet how many I will enter in and race though. I probably will race in the Bham race that our club has.

davidgeorge212

Later on, if we find that we need bigger numbers, we can just order whatever size we want. We will just have to do a couple test trials at the field before race day and see if its going to work for us.

davidgeorge212

It's been a long while but I think I finally have a working and fully programmable home made count down clock. Here is a YouTube video of some initial test runs. It still needs to have some more tweaking done on it. The size is just as bg or maybe bigger than Tims clock. The numbers are 2 feet tall and really bright. I haven't decided yet what color to make the lights yet, that's why one is red and one is clear

davidgeorge212

http://m.youtube.com/watch?feature=mhee&v=t6grsnNJ80Y

davidgeorge212

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Plane Insane

My Feedback: (4)

Nice work!

davidgeorge212

I tried my timer outside With the horn hooked up. Its not quite as good as being inside but it still looks ok. The horn is a low tone car horn that's pretty loud.
Didnt want to test it very long because it might annoy the neneighbors on what is an otherwise peacefully Sunday afternoon


http://m.youtube.com/watch?v=t7cg4ITbOFE