portable electric foil fencing

[Tim McMackin]

Is the .1 capacitor on pin 5 connected to anything else? I don't know a lot about ICs, but I know capacitors need to be attached to something on each side.

Also, is a one meg ohm "pullup" resistor any different from a regular resistor? I can't place the term "pullup."

Originally posted by kestrel:

1) Between the 100K resistor and Pin 2: add a .001 uf in-line capactor and followed by a 1Meg pullup resistor to the 9V rail.

2) Add a .1uf cap to Pin 5
3) Add a .1uf cap between Pins 1 and 8

This will reduce the retriggering effects and give you a one second buzz regardless of the length of time that the tip is depressed.

[kestrel]

Sorry for the less than obvious statement.

The "pullup" is a statement of function and it is just a 1Meg resistor with the other end tied to the 9V supply.

The other lead of the 0.1uf cap on Pin5 would be tied to Gnd.

[BarryTice]

Hi, all. I'm glad people are finding a way to make my the box circuit I posted work for them, and I'm sorry there are problems with it at all.

As Mergs said, I didn't design the circuit myself. An EE friend drew it up for me about a half dozen years ago, and I put it together then. I've long-since lost his original instructions, but when someone asked for a circuit to create a foil box, I took mine out of the box and drew one up from the one I've been using.

When Mergs reported problems, I contacted the guy who originally drew up the circuit and had him take a look at what I had posted. He said it looked right to him, and he makes a living designing circuit boards. So perhaps it is just the right combination of buzzers, etc.

I'll take my box back apart and into Radio Shack when I get a chance (since that's where I got all my parts originally) to see if I can match the buzzer up with what their current part number is.

And you're right, Tim. A resistor in series with the LED would do wonders for your LED life expectancy.

Stay tuned here for what I can find. Also, I'll update the pdf with Radio Shack part numbers if I can track them down.

-- Barry Tice

[BarryTice]

OK, everybody. I have a Radio Shack parts list of the parts I used in my buzz box. (I don't know for sure that the part number for the project box is correct. The local store didn't have the same project box in stock, so I had to guess at it from the catalog.)

Perfboard * 276-1935 $2.19
Sockets * 276-1995 .59/2
Switch 275-617 1.69
Piezo mini 273-074 2.99
10 microFarad cap. 272-1013 .59
100K 1/4-W res. (2) 271-1347 .49/5
Banana jacks (2) 274-725 .99/2
555 timer IC 555 1.19
Project box 910-1078 4.29

The first two items (*) are optional. I socketed my 555 because I'm not that good with a soldering iron and didn't want to toast the chip.
The resistors I used are 1/4-watt. You can get 1/2-watt resistors for the same price, if you like (271-1131).
The project box I used is about the size of a deck of cards. It includes a compartment for a 9-volt battery with a cover that comes off for changing the battery. It also included the 9-volt battery lead. If you use a different project box, you'll need to provide your own connection to the battery.
I also recommend you take a look at the switch options available. The one I used works fine, except it has a tendency to get bumped in my toolbox, setting the buzzer off. I combat this by disconnecting the battery when I'm not using the box. A different switch (or a different switch placement) might fix this.

I hope this helps everyone. For what it's worth, I've updated the pdf file on the website with this parts list.

-- Barry Tice www.pointcontrol.com

[introspective]

i've thought about this alot, and after serious consideration, i feel it is only possible to market this device only if it emits a sigh.

[BarryTice]

... or an expletive.

[FencerInUS]

How about if it emits a small explosion?

------------------
F.I.US.
Parry, THEN riposte
--)--------

[Zelda]

I say a nice little electric spark, it looks pretty and you can feel the feedback!