RaceMaster 4 DIY from Bosworth??? Anyone have success build

DIY timing systems
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jgedmin81
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RaceMaster 4 DIY from Bosworth??? Anyone have success build

Post by jgedmin81 »

I found the following drawings for a Lane Judge titled "RaceMaster IV"...

http://home.simplyweb.net/bosworth/timers&.htm" target="_blank

It seemed pretty straight forward until I started putting it together. I started with the 555 timing circuit to dial in the frequency... the resistors they called out were way off. I fixed it to output 7.4kHz as per the drawing. (edit: updated freq... had previously labeled as MHz)

I figured I already had the parts available, and some free time, so I put the rest together on a breadboard for testing. So far not too much luck. I have to double check my connections, but otherwise, when powered up, the LED's display random numbers, then go blank when reset is pushed. From there... nothing.

There were a lot of inconsistancies with the drawings and the BOM.

FYI... i am not an EE or anything... just enjoy tinkering here and there. I know enough to follow schematics and assemble circuits, but not if they don't work due to design error.

Was wondering if anyone here has had success and/or advice with this setup.

Thanks

Jason
Last edited by jgedmin81 on Thu Oct 13, 2011 3:32 pm, edited 1 time in total.
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gpraceman
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by gpraceman »

You can try getting a hold of Larry Bosworth, as he seems to be the author of those plans. His email address is posted on that site.

FYI, some people think that since that timer uses a DB9 connector that it has a computer interface. That is not the case. That is to connect the track sensors (PhotoSensor Schematic) to the timing unit.
Randy Lisano
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jgedmin81
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by jgedmin81 »

The fact that it is not reliant on use of a computer is what I liked about that setup. Our derby will only have about 40 entries... so we don't need anything too sophisticated. We have always used paper to track results, but this year we are going to try using a spreadsheet to track, and with the help of this circuit... things should go smoothly.

I was looking over my setup last night and realized when I transferred the 555 circuit to the big breadboard, I somehow missed the power hookup for it. I haven't set up the photo sensors yet, but the circuit works great with pushbutton switches.

FYI... the email address on that site doesn't work.
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by *5 J's* »

jgedmin81 wrote:I was looking over my setup last night and realized when I transferred the 555 circuit to the big breadboard, I somehow missed the power hookup for it. I haven't set up the photo sensors yet, but the circuit works great with pushbutton switches.

FYI... the email address on that site doesn't work.
Jason - first welcome to DerbyTalk. :D

After you finish your timer it would be nice to write up a post with the details of your build and the changes from the plan you made. Pictures are always a nice addition ;)
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by quadad »

I don't want to throw water on anyone's creativity or desire to reduce expenses, but I think the MicroWizard kit timers, which tell you order of finish without a computer, are pretty affordable in the ~ $50 - $60 territory (have to check current pricing). How much time/money is the Bosworth option taking ?

Its really hard to beat getting a proven and supported design, a printed circuit board for reliable construction (should this be for a Pack), easy to build (only need a soldering iron and wire stripper) with part placement identified on the board, all the right parts, etc. for that kind of money. I did that and I am capable of designing and building one of these myself.
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by gpraceman »

quadad wrote:I don't want to throw water on anyone's creativity or desire to reduce expenses, but I think the MicroWizard kit timers, which tell you order of finish without a computer, are pretty affordable in the ~ $50 - $60 territory (have to check current pricing). How much time/money is the Bosworth option taking ?

Its really hard to beat getting a proven and supported design, a printed circuit board for reliable construction (should this be for a Pack), easy to build (only need a soldering iron and wire stripper) with part placement identified on the board, all the right parts, etc. for that kind of money. I did that and I am capable of designing and building one of these myself.
I do agree on the value, support and ease of assembly that you get with the MW kits. For a few bucks more you can get their "Cheap Kit with Computer Serial Interface", so you have the flexibility of using software to read from the timer and compile race results now or later in the future.
Randy Lisano
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by jgedmin81 »

quadad wrote:I don't want to throw water on anyone's creativity or desire to reduce expenses, but I think the MicroWizard kit timers, which tell you order of finish without a computer, are pretty affordable in the ~ $50 - $60 territory (have to check current pricing). How much time/money is the Bosworth option taking ?

Its really hard to beat getting a proven and supported design, a printed circuit board for reliable construction (should this be for a Pack), easy to build (only need a soldering iron and wire stripper) with part placement identified on the board, all the right parts, etc. for that kind of money. I did that and I am capable of designing and building one of these myself.
I appreciate your input. The knowledge I'm gaining by building this myself, and showing my boy a thing or two about electronics far outweighs the ease of a pre-fab kit. With all the components available at a very reasonable price, cost isn't an issue. I am only out my time invested if it ends up not working out.

An update on my progress....

So far on breadboard, I have the circuit working, including the photo sensors at appx. 4" separation. I have had to make a few vital changes to the original plans posted, that without the aid of an electrical engineer, would not have been possible. I have also modified the plans to run off standard 110AC power rather than a battery pack. When I am all done, I will post up as much as I can about this setup.
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by gpraceman »

jgedmin81 wrote:I have also modified the plans to run off standard 110AC power rather than a battery pack.
I assume that you mean an AC to DC power supply. I certainly hope you aren't supplying 110V to that circuit. :eek:
Randy Lisano
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by jgedmin81 »

gpraceman wrote:
jgedmin81 wrote:I have also modified the plans to run off standard 110AC power rather than a battery pack.
I assume that you mean an AC to DC power supply. I certainly hope you aren't supplying 110V to that circuit. :eek:
haha.... yep. 110VAC to 5VDC power supply. Don't have to worry about batteries dying and a power supply puts out a lot cleaner and consistant power.

I switched most of the chips from HC family to LS family as well mainly due to part availability, but also HC chips aren't required for this setup.
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by jgedmin81 »

Testing completed. Wish I would have laid out the LED drivers a little better... would have made for less wires. Otherwise it works like a charm.

Image
jgedmin81
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Re: RaceMaster 4 DIY from Bosworth??? Anyone have success bu

Post by jgedmin81 »

Things got hectic as usual, but I was able to complete this project. Only lost 1 nights sleep and a smal bit of my sanity. Total time invested was well over 30 hours between the breadboard build and final build. Using this and a computer with an MS-Excel tracking matrix made our event run like a charm.

I do not suggest attempting this build unless you have extensive experiance with electronics. There are a lot of other choices out there that are cheaper and easier to assemble.

I have a complete build sheet and my notes which i will post soon.
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