Metronome Beeper

Building and other racing tips and suggestions.
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uavflyer2k
Super Contributor
Posts: 26
Joined: Wed Jul 25, 2012 9:57 pm
Location: Rancho Cucamonga, Ca

Metronome Beeper

Post by uavflyer2k »

There has been some interest in the "Beeper" or metronome I built to aid the caller timing for the 3-1 leg of a lap.

I have sent out a few of the chips to those who have asked and I thought I would put the info here for others to peruse!

The beeper was originally developed in the '80s here in California, as we were racing Q500 and QM15 without lights. This meant that the timing was critical to flying both good times and not getting cuts.

The idea is to give 4 audio beeps with the timing adjustable to fine tune the interval. The 1...2...ready...turn most are familiar with.

the original used a couple of 555 timers and some logic along with a Sonalert alarm beeper, and frankly was a pain in the a** to build.

When I started racing again in 2012, the old beeper still worked but the design wasn't tweakable to the current course requirements.

So here is the new design - which uses a Texas Instruments MSP340 Microprocessor a couple of switches and a speaker. Quite simple to build for those who dabble in electronics gadgets.
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uavflyer2k
Super Contributor
Posts: 26
Joined: Wed Jul 25, 2012 9:57 pm
Location: Rancho Cucamonga, Ca

Re: Metronome Beeper

Post by uavflyer2k »

Here is the schematic and BOM.
Attachments
Beeper Schematic.pdf
(15.24 KiB) Downloaded 296 times
BeeperBOM.pdf
(6.31 KiB) Downloaded 263 times
Last edited by uavflyer2k on Wed Apr 15, 2015 10:28 pm, edited 1 time in total.
uavflyer2k
Super Contributor
Posts: 26
Joined: Wed Jul 25, 2012 9:57 pm
Location: Rancho Cucamonga, Ca

Re: Metronome Beeper

Post by uavflyer2k »

uavflyer2k
Super Contributor
Posts: 26
Joined: Wed Jul 25, 2012 9:57 pm
Location: Rancho Cucamonga, Ca

Re: Metronome Beeper

Post by uavflyer2k »

I updated the "BeeperBOM.pdf" to change a reference to the 2N2222 transistor to a KSP2222 transistor.
The "2N" is not used very often anymore since it's getting a bit long in the tooth, so the suppliers have put a premium price on the "real" ones.
The KSP part is an equivalent that costs like 25 cents vs. 2 dollars.

Those of us electronic guru's know that there are many substitutes for an application like this where it's only used as a switch, they can/will ignore me anyhow.

It's been found that the speaker spec'ed is a bit weak so there is some research going on in that area.
I have found that the shown speaker is sensitive to how, where, or what its installed in, since my simply gluing it into the radioshack box with CA seems to be much louder than the speaker alone or in some other arraignments.

If anyone has helpful info here's my direct email.
ted_burns@charter.net (replace the "_" with a ".")
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