Point to point or wire wrap?

[Rbeckett]

Yup, got proto boards of all sizes and hole counts. I can also make PCB's here but was looking for something a little different that could be mofified as circuits and components change and improve. I was kind of hoping to build a backwards and forward compatible easilly modified system to test several theories and circuit designs. I was tryng to integrate the PID's into the control loop and base some of the logic decisions from input recieved from them in addition to other data within the system. I was also going to add touch screen control and try some advanced algorythms for controlling the entire brew cycle from beginning (ordering grain) to end (drinking the chilled, carbed product). I have been studying electronics for just over two years at home and have been itching to try a very complex application of all I am learning as a self directed "Final Exam" of sorts. The "test" includes engineering, assembly, coding, logic, analogue, pneumatics and reverse osmosis and systems integration. If it fails to meet my expectations, then I just have more learning and more studying to do, the learning curve and cycle are truly never ending in my current situation.
Wheelchair Bob

 

[carlisle_bob]

Hi

Doing anything complex with a bunch of logic gates and wire wrap is going to be a major chore. Been there done that, to much time spent on stupid errors.

Grab one of the FPGA boards off of eBay and run the free programming software to set it up. That lets you experiment like crazy and there's no wires to move around. You can do a dozen experiments a day *and* you have a schematic to go with every one of them. You'll spend a week or more doing any one of them by wire wrap.

Also - look at the money you'll save on bench stock...

Bob

 

[Rbeckett]

Good point! Never even considered that. I was looking for an easier way than making boards and point to point looked relatively simple, but as you say all of the gates and logic circuits will definately create a birds nest to beat the band. I'll keep tinkering and look at what I already have and possibly veer off in a new direction. I had hoped to employ some circuit building skills, but it appears the complexity of this particular project may preclude that till another day. Thanks.
WCB

 

[Rbeckett]

CB,
Take a look at this developement kit for FPGA's. Apparently there IS a Plethora of available options and pin counts. This set up was recomended along with the Pickit 3 developement board for initial studies into the FPGA system. Here is a copy of the link that was referenced and recomended: http://www.altera.com/products/devkits/altera/kit-cyc2-2C20N.html
Is this wgat you were refering to and recomending? Kinda pricey, but available seperately pretty inexpensively.
Thanks!!!
WCB

 

[carlisle_bob]

CB,
Take a look at this developement kit for FPGA's. Apparently there IS a Plethora of available options and pin counts. This set up was recomended along with the Pickit 3 developement board for initial studies into the FPGA system. Here is a copy of the link that was referenced and recomended: http://www.altera.com/products/devkits/altera/kit-cyc2-2C20N.html
Is this wgat you were refering to and recomending? Kinda pricey, but available seperately pretty inexpensively.
Thanks!!!
WCB

Hi

Cyclone II is a bit old these days. They are on the IV series at the moment. For what you are trying to do - any series will do fine. The nice thing about the older kits - you can find them *CHEAP* on eBay. No need to pay Altera's fancy prices. They all work the same way, the labs all run, and they look like the same boards.


... they are on the V series now, we are on the IV's at work...

Bob

 

[Rbeckett]

CB,
As promised, I have been experimenting with the 30Ga wire wrap tools from Radio Shack. I have had excelent results so far. Once I got the correct stripped length I end up with 1-1.5 turns of insulated and 7-8 turns of non imsulated wire on each post. I have been using both of the wrapping tools that came, the others are on back order and should arrive this week. I would really like to find some 22 Ga wrapping tools too. I think that the 30Ga is going to be too small for any signifigant loads so I would prefer to go to the 22 Ga in the beginning. I'm still looking for a vendor who sells them in that size. I also found a spring loaded semi automatic wrapping gun for a reasonable price, but have decided to hold off till I find 22 Ga tips and dies for interconnect and lead out wiring. So far no issues with breaking the wires or failing to complete a wrap sequence. I got sloppy and did make a few that looked loose, but were still pretty tight on the posts. I think soldering will eliminate any possibility of poor connections too. Thanks for the help and guidance. I am still learning something new everyday.
Wheelchair Bob

 

[carlisle_bob]

Hi

Don't solder anything. The great thing about wire wrap is being able to rip off the wires when you change your mind. You loose that when you solder it all up. Properly done, the stuff will last longer than any of us need it to.

You can easily check your technique by trying to pull a few wraps apart. It should not be easy to do, and you should have a bit of a weld at each corner of the post the wire is wrapped on. With 30 gauge it's not as easy to see / feel as with larger gauge. It's those little welds that give you a "gas tight" connection and keep things from oxidizing.

Bob

 

[Rbeckett]

CB,
What do you do to eliminate or minimize the looseness of components going through the board? I was using a few TO 92 3906's for test wraps and they appear to be tightly wrapped, but the component still moves unaceptably within the through hole on the board. Should the components be soldered to the board first then wrapped with the remaining leg? That was the reason I was considering soldering the entire unit once tested and working properly. Ideas, solutions?
WCB

 

[carlisle_bob]

Hi

To do a proper wire wrap, you need a square post with well defined corners on it. The only way to get enough pressure to do a coldweld is to have that edge and good tension on the wire.

Classic solutions to your problem:

1) solder in the bypass parts in a normal pcb fashion (yes it's a board laid out to do that).

2) Mount the leaded parts on wire wrap posts. More or less it's a single pin or double pin IC socket topped with a post rather than a socket.

3) Mount the leaded parts in wire wrap cups. Same idea as 2, only the lead drops into a cup and solders rather than wraps around a post.

4) Solder wire wrap wire to the stuff and then wrap it to the IC's. Don't even bother to wrap the soldered end.

5) Use DIP packaged component arrays for the discrete parts or DIP packaged transistor arrays.

Unless it was some sort of field repair, number 4 above was not very common. I haven't seen the "stuff" to do 2 or 3 above for a lot of years. 1 and 5 were by far the most common approaches. The parts to do 5 are still out there.

Bob

 

[Rbeckett]

Thanks CB. I was kind of figuring that I had to be missing prts or some concept because the connections all work, but the components were loose on the board and I was sure that would lead to wire fatigue and breakage pretty quickly. I am going to try to solder them in place on the perf boards, then do the point to point wrapping on the remaining post from the through hole lead. When I get a board built I will try to get a good close up pic so you can have a look at my technique.
Wheelchair Bob

 

[carlisle_bob]

Hi

If you can still get single posts, soldering the part and the post to perf board, then wrapping to the post will work fine. I haven't gone looking for them in a long time...

Bob

 

[Rbeckett]

CB,
Jackpot!!!!! I found a wire wrapping supplier and they offer every size bit and sleeve for AWG and Metric wire. They also offer multipaks of pins like you suggested ( I ordered a 100 to start with) for use on the perf boards. In case youre interested the company name is OK Industries or Jonard and they are located in New york City. I hunted at great length and they offer electric, pnuematic, manual and hand operated wrap and unwrap tools for a pretty reasonable price. I ordered a pneumatic gun and 3 sets if bits and sleeves to cover 20- 30 Ga wire. The also offer silver plated solid copper core wire at a pretty decent price too. Ebay has the same wire but it is from China so there would be a two week wait for the wire to arrive and I question whether it is really silver from there or not. Just figured that I would let you know that the stuff is still available but you gotta look a little deeper on the web to find it all. Wish me luck!!!! Pic as soon as my inspection scope arrives and I get it figured out and working. 30 Ga is too small to see even with a 2X magnifying glass, you need 5X to see it clearly.( I have poor eyesight in my old age)
Bob

 

[carlisle_bob]

Hi

Even with quadrafocals I still need a microscope from time to time....

OK stuff should be perfectly fine. They have been doing wire wrap for a long time. The thing to watch for with the silver wire is tarnish. Don't keep the wire in the kitchen when you are cooking a big batch of tomato soup (or playing with fuming nitric acid...). The plating is pretty thin and the tarnish will essentially dissolve it.

Glad you found a better supplier than you had. I think that 24 ga is probably a reasonable target for wire. For high current, solder something.

Hope it gets there soon!

Bob

 

[Rbeckett]

CB,
I bid on a few items tha don't end for a few more days, the stuff I got on Buy it now should be here by Monday or Tuesday. I found the machined pins with the solder holes on top to mount the components and the nice sharp square psts for the wraps. I think that will solve most if not all of the issues I had to begin with. I'll let you know how the OK stuff works once it all gets here. Heres my solution to the quad focals: http://www.ebay.com/itm/251096296369?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649. Those are 20X and have lenses for both eyes. I ordered 2 pairs since they were really cheap and I had to wait to get em...
WCB

 

[carlisle_bob]

Hi

If you ever come across one at an affordable price, these are pretty nice:

http://www.visioneng.com/mantis-elite-stereo-inspection-magnifier-overview.php

A bit big, but nice.

Bob

 

[Rbeckett]

CB,
That looks like a rich mans toy to me. It's huge too. I would have to clear out 1/2 of my office to use that one. I did find something a little more reasonably priced in a more usable size though. I'm not sure I am willing to put even that much into a viewer though. I'll just have to wait a while till my eyesight gets that bad...
Heres the link to the items I found.
http://www.ebay.com/itm/10X-30X-BIN...658?pt=LH_DefaultDomain_0&hash=item3a7713b60a

Bob

 

[carlisle_bob]

CB,
That looks like a rich mans toy to me. It's huge too. I would have to clear out 1/2 of my office to use that one. I did find something a little more reasonably priced in a more usable size though. I'm not sure I am willing to put even that much into a viewer though. I'll just have to wait a while till my eyesight gets that bad...
Heres the link to the items I found.
http://www.ebay.com/itm/10X-30X-BIN...658?pt=LH_DefaultDomain_0&hash=item3a7713b60a

Bob

Hi

The thing is indeed huge. Even at 10 cents on the dollar I couldn't afford one. Of course you never know what might show up in some surplus shop...

Bob

 

[Rbeckett]

Yeah, I have found some really good prices lately on machine tools like lathes and mills. They seem to be appearing more often as the economy drags along. The last one I picked up was just about the price of scrap iron by weight. I cleaned it up and lubed it down and it works nicely for what I do in my little shop. Before I got jacked up I was building a metal fab shop with a CNC plasma cutter, and all manner of metal tools like lathes, mills and wheels. Being a former welder also brings all of that equipment to the mix too. If I ever get well enough I will restart my shop and do a little side work when I feel like.
Bob

 

[carlisle_bob]

Yeah, I have found some really good prices lately on machine tools like lathes and mills. They seem to be appearing more often as the economy drags along. The last one I picked up was just about the price of scrap iron by weight. I cleaned it up and lubed it down and it works nicely for what I do in my little shop. Before I got jacked up I was building a metal fab shop with a CNC plasma cutter, and all manner of metal tools like lathes, mills and wheels. Being a former welder also brings all of that equipment to the mix too. If I ever get well enough I will restart my shop and do a little side work when I feel like.
Bob

Hi

All you need to find is one outfit that was doing some sort of assembly with them that's now out of business. They are big enough that I doubt people will be going crazy to get them. You might wait a while until they pop up though...

Bob

 

[Rbeckett]

Electric wire wrap gun and 30+ tips arrived today. Plan to do some experimental wrapping tommorrow after I get the mower going. Promised Momma she could mow this weekend. The dogs will be pleased, they dont like poopin in tall grass.
WCB

 

[carlisle_bob]

Hi

On a really good wrap, you can feel the welds breaking every 90 degrees as you un-wrap the wire. Admittedly it's a destructive test, but it's a good way to check things out.

Bob

 

[Rbeckett]

CB,
Just did a few practice wraps on 30 Ga and they are awesome. I destructed them and got a god look at the effect and every where the wrap bent around the edge of the pin it kind of crimped into the wire a bit. Tried to slide the wires up or down and no luck. The gun is pretty fast so it is gonna take a little practice to get the "knack" of it and get really consistent. I am very happy with the results so far. The Ebay deal I picked up had 30+ bits and sleeves so I am going to try some different guages and see how well they do too. I picked em all up for 10 bucks off of Ebay and OK industries gets 40 bucks a pop for em each, so I did good I think. Some of the tips have some wear, but for the money I can afford to tinker with the step and see if I can square it back up with a jewelers file to get the profile back right. Over 1/2 of em were still new in the packing tubes with cosmoline so it will be a while before I have to file or tinker with anything yet. Looks like it was one of those sell everything deals and they were just trying to avoid loading it all in a dumpster. I have a couple of more bids out on some more stuff that will end today and tommorrow, so depending on that outcome I will be well equiped soon I hope. I also found a vendor that was selling the bits new on a card for 6 buck each and I bought all of them too. Just figured I would let ya know it is working well so far.
Bob

 

[carlisle_bob]

Hi

The little crimp in the wire is actually a weld (if everything is working). It's a microscopic sized weld, but it is fused metal. Without it, you have the possibility of oxidation on the connection. With low level stuff (like logic) that can be a pain.

Sounds like you done good!

Bob

 

[Rbeckett]

CB,
I am thrilled. The pins I found arrived today. The appear to be gold plated and have nice sharp square edges. They fit snug in the pre-drilled PCB boards and hold the through hole component leads nicely. It adds an extra step, but improves the overall connectio 100+%. The OK model 21 gun is pretty trick too. I have to get used to it's speed, but that is a function of practice.. I am hoping to hear back from the vendor of the pins because I would love to see what he wants for a couple of thousand or so. I can see using the 100 I got in no time at all on a complex board or anthing very large.
WCB

 

[Rbeckett]

CB,
Check this out. Got both for way cheap with bits and sleeves.
http://www.ebay.com/itm/350582015585?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Figure I will set one at 30 Gaa, one at 22-24 and one at 20 and call it good. Yeah, I know I am addicted to this stuff as bad as I am addicted to home brewing too. Sooner or later I will have an automated control system for the three tier I am assembling in my shop. Been too hot for me to play in the shop lately, but it is getting cooler in the evenings and taking a bit longer to get stupid hot in the AM so I will be back at it again soon.
Bob

 

[carlisle_bob]

Hi

Setting up a gun for each gauge is the right way to go. That way you aren't fiddling with stuff all the time. It's a *lot* easier to see the "30 GA" marking sticker on a gun than that little print on the bits...

My Raspbery Pi came in to day and I'm wondering how best to use it. Yes indeed it is an addiction...

Bob

 

[Rbeckett]

Oh yeah, I just can't find a needle big enough for a new microscope yet.... Now that I have three guns, I will color code them and use some cheap Ebay light yo-yo's and hang em over my work area. Then I can just reach up and pull the gun I need down, use it, and let it go back up when I am done. I just got a really good write up on the Rasberry stuff from Design Spark and they have a lot of positive stuff to say about them so far. When I get everything hung up and functioning I'll shoot a pic and post it up. My electronics lab is rapidly becoming a "Dexters Laboratory" look alike. My shop has been going that same way for about 10 years now, so you know it is filled with all kinds of weird and usefull tools of all descriptions and designs. I just can't seem to get enough, theres always something new or neat coming available here or there. Holler at ya later.
Wheelchair Bob

 

[Rbeckett]

Quick update!!!
A close freind fabbed me an 17.5X12.0X8.0 electronics enclosure. He made it from 20 Ga cold rolled sheet and spot welded all the corners. He then made a top the fits perfectly and secures down to the lip on the box at all 4 corners. He also installed a rolled edge false bottom to allow the surface components to not protrude through the back of the enclosure. The plan is 2- 60 MM cooling fans, 2 Power supplies (5VDC & 24 VDC), SSR's and PID's. all running through a 40 pin PICMicrochip 16f877A. Gonna have a fairly decent amount of working room for the electronics, electrics, Pneumatics and water controls. Pics to follow soon of the control build out.
Wheelchair Bob

 

[carlisle_bob]

Hi

Sounds good!

Now you need to figure out what you are going to use for connectors. D-Sub's are popular, but you need strange cutouts for them. They also aren't great on current rating. CPC from TE / used to be AMP are a relatively cheap alternative. They get you up to some major current capability (likely way more than you need). They also mount in nice round holes.

Of course you probably have a robotic death ray laser there, so weird shaped holes aren't an issue!

Bob

 

[Rbeckett]

I wish, I had the death ray, but my plasma table will just have to do. I plan to use all round connectors that I picked up off of Ebay. They are keyed and secure with a threaded ring so they will be pretty moisture and vibration resistant. I have a collection of 2, and 3 pin set ups and all sizes of molex and IDC connectors for the internals. Hoping to get started on the box package soon. I will post up some pics as I go. I'm excited to finally start making a little progress again, being ill and down has been a real drag lately, but I have started home dialysis, so I will have more time available to tinker and do some of the projects I have accumulated.
WCB

 

[crane]

Quick update!!!
A close freind fabbed me an 17.5X12.0X8.0 electronics enclosure. He made it from 20 Ga cold rolled sheet and spot welded all the corners. He then made a top the fits perfectly and secures down to the lip on the box at all 4 corners. He also installed a rolled edge false bottom to allow the surface components to not protrude through the back of the enclosure. The plan is 2- 60 MM cooling fans, 2 Power supplies (5VDC & 24 VDC), SSR's and PID's. all running through a 40 pin PICMicrochip 16f877A. Gonna have a fairly decent amount of working room for the electronics, electrics, Pneumatics and water controls. Pics to follow soon of the control build out.
Wheelchair Bob

I'm curious to know what you are doing with the PIC if you are also using PIDs. Why wouldn't you implement the PIDs with the PIC?

 

[Rbeckett]

My plan is to use the PIC as a logic control that will recieve info from the pids and send control outputs to relays and SSR's as needed. I am hoping that the ability to use the chip as a decision maker will enhance the repeatablility of my brews over time. As the system evolves I will need the PIC to open and close valves and turn on the pumps or control the flow rate in a IC for best results. As I learn more electronics I will add more automation so I went with a flash programable chip that can be reconfigured pretty easilly when it is time to make changes to the basic and advanced routines. Sound about right?
WCB

 

[crane]

So for the temperature control is the PIC going to simply decide what SSR to send the PID output to or is it going to try to do something more sophisticated? If its only acting as a switch that makes sense. Otherwise if you are trying to parse the duty cycle of the PIDs output and make decisions based on that then it doesn't make sense.

 

[Rbeckett]

Yes the pic will selesct the SSR to send the PID output to based on time, temp and stage of the process. It will also select the pump and circulate the steeping mash through a coil in the HT to maintain the mash temp and control the valves to direct the flow of water to all three vessels. I'm probably making it more complex than it really needs to be, but I am doing this as an experiment to apply the stuff I am learning in electronics to real world applications too. When I started teaching myself basic electronics I got involved in home brewing and decided to build a wheelchair freindly brewing rig that eliminates lifting and reduces or eliminates the need to stand to complete a batch of brew from start to finish. I also have incorporated several safety features that will be controlled through the chip also. Things like the system will not turn on unless the legs are fully extended and locked or a dry fired vesel preventative. Eventually I think I will go all electric, but for the time being I am using propane.
Wheelchair Bob

 

[crane]

I'm still a little confused about the PIC making decisions based off of temperature. For every temp sensor you have going to a PID are you going to have a second sensor at that same location going to the PIC?

 

[Rbeckett]

No I had planned to use the signal out from the PID to tell the PIC that the temp was in or out of range and start the timer for the boil based on reaching 212. I also have a safety interlock that will not allow any thing to turn on untill the legs are fully extended and locked and there is liquid present to prevent accidental dry firing a kettle. It will also drive the status LEDs to indicate what is on, what is off and which valves are opened and closed so I can determine the direction of flow in various parts of the system like the immersion chiller, and the RO boost pump. Now that I have an enclosure large enough to accomodate the control systems I can start drilling the holes and wiring it up, when I get over this issue I am having with my health again. It is really a pain right now till I get that back under control and better managed. Fluid overload is a huge drag.
Wheelchair Bob

 

[carlisle_bob]

Hi

Yes indeed, this is a bit picky. Feel free to ignore the input.

I'd set your boil point sensor to something like 208 F to start the timer. It's "close enough", and takes care of things like slop in the calibration.

Bob

 

[Rbeckett]

Bob,
I really value all of the input you have given me so far. I started this project just blindly ordering parts that I thought might work together and have been refining the idea based on you input and questions. Without you input God knows what kind of non working monster I would have cobbled together and gotten frustrated along the way. My original plan is somewhat still the same. I want to create a wheelchair freindly tower that does not require the brewer to lift or stand during the entire process. I want all of the valves to be electronically controlled in the future to control all aspects of fluid from from coming into the system from the well to going out the tap into a glass. I want the Heat, strike, Sparge, Vorlauf, Lauter and boil to be controlled by a logic circuit that selects the correct valves and times all critical steps. It must be safe to prevent tip over and dry firing and must not allow unauhorized users to attempt to use it. That is whay I am attempting to integrate the PID's with the PIC's and drive the relay boards and the SSR's. The relay boards are to allow me to step up the voltage to operate the valve coils and the SSR's are to provide power that is already at or mear line voltage and AC. I am sure I have confused you and others since I have not drawn a logic flowsheet or circuit concept, but it all fits together in my head (which is a scary thought indeed). So don't hesitate to nit pick and ask questions because every time you have asked I have found a need to improve some aspect of the attempt to make it better or safer to operate.
Wheelchair Bob

 

[crane]

Yeah I am asking questions not only to try to understand your concept but also to see if there is something that doesn't make sense once you put your ideas into words.

I am still hung up on the idea of using both PIDs and a micro. The problem I see is that you have two guys trying to control one thing and I don't see how that can work unless you have fancy PIDs that can operate in a slave mode over RS232 or some other comm protocol.

Let's take bringing wort to boil as an example. I am assuming that you only have the output of the PID as an input to the PIC and no RS232 or anything else so all you know from the PID is whether you are at the set point or below it.
1. You set the PID to 208 or 212 to bring the wort up to temp.
2. The wort reaches temp and now you have to change the PID over to manual mode to throttle back the boil. The PIC knows its reached the set point temp and can sound an alarm and disable the output but you still need to manually configure the PID for the next step.

There are ways to work around this example but what if you want to do a step mash and don't want to change temp values on the PID at each step. If you got rid of the PIDs and implemented the temp control in the PIC you can now have a more automated system. Without doing this I don't see how you can avoid manual intervention in between each step of the process that PIDs are involved in.

 

[Rbeckett]

I see your point now. I don't mind the intervention too much, but I wuld like to have enough room to eliminate those kinds of intermediate steps in the future. I would love to build a system like Kladue with grain hoppers and all the gee whiz, but I am not that smart yet. Eventually I'l get there, but I wanted to start while I was still revved up so I would complete most of it pretty quickly and make improvements and upgrades from there. Thanks for all of the help and questions, they have really helped and made me think a little more in linear terms to complete each task.
Bob