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Old 06-17-2012, 03:44 PM   #11
Rbeckett
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Crane, and CB,
Thanks for the help on the board deal. I knew solder wasnt meant to draw with, but figured a small hole to hole bridge would be fairly simple, especially since I seem able to do it accidently pretty often. After that exercise in Frustration I decided to do something similar to Cranes wired board in the second pic above. I have several colors of solid and stranded wire from Radio Shack so unraveling the wiring will be one order of magnitude easier if needed. I also try to follow standard wiring conventions like red is Pos, Black is Neg, Green is ground, and signals are various other colors. Helps a lot. The biggest issue is trying to install too many components at the same time instead of following the normal electron flow in each circuit. It is certainly a study in patience and tolerance to say the least. But...This is why I wanted to learn electronics in the first place. I really love the Dr Frankensteeen look and feel of doing stuff like this from scratch too. Thanks for the help and input, because I never built anything with a practical real world application before this. I did the "Hello World" and flashed the LED's in all of the experiment texts from All About Circuits which gives a pretty strong practical application to basic electronic theory, with a working circuit to experiment with. Then it becomes an exercise in succesfully putting a bunch of circuits together to do something usefull. Thanks for the Help and encouragement.
Wheelchair Bob


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Old 06-18-2012, 04:21 PM   #12
carlisle_bob
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Hi

If you take a close look at the picture of the board, there's a meathod to the madness of wiring it.

You use a spool of bare solid wire and a spool of teflon tubing. Wire goes down / cut to lenght / cut tube to lenght / put on wire / solder other end.

Much easier than any form of insulated wire. The teflon is almost impossible to melt with a soldering iron. No matter what you bump, no charred insulation. A 1 lb spool of bare wire lasts pretty much forever. Teflon tube is a much smaller spool, so you might go through one a year.

Bob



 
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Old 06-18-2012, 04:29 PM   #13
weirdboy
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I did a bunch of wire wrap stuff back in the day, and I think it's great for prototyping, but ONLY for prototyping. All my old wire wrap boards fell apart after a while.

 
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Old 06-18-2012, 04:44 PM   #14
Rbeckett
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CB,
do you have a vendor that you use to get the teflon tubing from? I can get the enameled wire or bare wire from Radio Shack, but much prefer the concept of no charred insulation too. TIA for the info.
WCB
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Old 06-18-2012, 05:08 PM   #15
carlisle_bob
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Hi

Both the teflon tube and the solid wire are a Mouser item:

Wire:

http://www.mouser.com/ProductDetail/...K%2fV3w%2fA%3d

Tube:

http://www.mouser.com/ProductDetail/...db25BsLkU7Q%3d

(yes you want the tube to be "to big" for the wire)

I suspect there are cheaper places to buy either one (like eBay...).

Bob

 
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Old 06-19-2012, 03:59 PM   #16
crane
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Quote:
Originally Posted by carlisle_bob
Hi

If you take a close look at the picture of the board, there's a meathod to the madness of wiring it.

You use a spool of bare solid wire and a spool of teflon tubing. Wire goes down / cut to lenght / cut tube to lenght / put on wire / solder other end.

Much easier than any form of insulated wire. The teflon is almost impossible to melt with a soldering iron. No matter what you bump, no charred insulation. A 1 lb spool of bare wire lasts pretty much forever. Teflon tube is a much smaller spool, so you might go through one a year.

Bob
Exactly how I did it. I used the same Teflon insulation that is reference later. For most of the connections I use the extra lead from the through hole components where I pull the component lead through the hole and bend it over in the direction of where it is going then solder down the lead in that hole. I then cut to length, cut insulation, slide insulation on, and then solder other end on lead. I only used bus wire on a handful of the longer runs.

As CB explained the Teflon doesn't melt like regular wire insulation. I have had the frustration of having the insulation on regular wire melt back exposing more of the bare wire causing it to short to something else.

You could easily color code the Teflon insulation with a sharpie to make debugging easier. For these simple circuits I don't find that necessary but on larger things it can be very helpful. I bought a kit car once where the guy before me replaced all of the wiring with red wire. I went mad trying to find a short in the dash.

Quote:
Originally Posted by weirdboy
I did a bunch of wire wrap stuff back in the day, and I think it's great for prototyping, but ONLY for prototyping. All my old wire wrap boards fell apart after a while.
I have seen computer chassis that have spent years in military aircrafts where wire wrapping was used on the backplane for configuration jumpers. If you use a wire wrap tool it can withstand the intense vibrations that these aircrafts endure. But I agree that for our applications point to point soldering is much more practical.

 
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Old 06-19-2012, 04:36 PM   #17
carlisle_bob
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Quote:
Originally Posted by crane View Post
Exactly how I did it. I used the same Teflon insulation that is reference later. For most of the connections I use the extra lead from the through hole components where I pull the component lead through the hole and bend it over in the direction of where it is going then solder down the lead in that hole. I then cut to length, cut insulation, slide insulation on, and then solder other end on lead. I only used bus wire on a handful of the longer runs.

As CB explained the Teflon doesn't melt like regular wire insulation. I have had the frustration of having the insulation on regular wire melt back exposing more of the bare wire causing it to short to something else.

You could easily color code the Teflon insulation with a sharpie to make debugging easier. For these simple circuits I don't find that necessary but on larger things it can be very helpful. I bought a kit car once where the guy before me replaced all of the wiring with red wire. I went mad trying to find a short in the dash.



I have seen computer chassis that have spent years in military aircrafts where wire wrapping was used on the backplane for configuration jumpers. If you use a wire wrap tool it can withstand the intense vibrations that these aircrafts endure. But I agree that for our applications point to point soldering is much more practical.
Hi

There are a lot of DEC PDP-8's and PDP-11's still running around with the original wire warp backplanes. The stuff can be reliable. It's just painfull to trace out when you have twenty layers of wire running around ...

Bob

 
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Old 06-20-2012, 11:33 AM   #18
Rbeckett
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Quite a few military wiring panels are wire wrapped. They appeared to have been wrapped with a special tool to insure tightness and then soldered. Multiple levels are a PITA, but can be overcome by using a terminal strip with loops to split the wiring neatly and in a logical manner. This also gives you a circuit test point for troubleshooting later on. Just some thoughts on simplifying a complex wiring pattern.
Bob
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Old 06-20-2012, 03:22 PM   #19
crane
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The special tool is just a wire wrap tool. sparkfun has a cheap one. They can get quite a bit more expensive.

http://www.sparkfun.com/products/68

They work by striping an inch or more of single strand wire. The bottom of the tool has 2 holes, one in the middle and one off to the side. Stick the entire inch or more of stripped wire into the hole off center. Then place the header pin in the center hole. Hold down the wire by the base of the header and twist the tool until all of the stripped wire is wound around the pin. Its quick and easy. All the wire wrap tools I have seen have a wire stripper built into the side of the handle.

I have never seen them soldered though. The wire wrap tool will hold it on good enough by itself.

 
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Old 06-20-2012, 03:28 PM   #20
carlisle_bob
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Hi

The *good* wire wrap tools are air dirven

To get a tight wrap you need to properly match the bit on the tool to the post size and the wire diameter. You also need to replace them when the go/nogo gauges say so. Yes that's all expensive to do...

Bob



 
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