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Building your LOR first kit - my additional tips


sjmiller
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Today was Christmas in March - my first three 16 channel kits were delivered at a little after 7pm and I have completed assembly page 4 of 8 on my first kit.

First off I want to say that the instructions from LOR are great. As I started to build my kit, experience as a technician in the Air Force, Aerospace, and hobbyist came into play and I thougt I would pass it on.

First and foremost, when assembling (soldering) a kit - excessive heat is your enemy. It can cause soldering pads to lift off the circuit board or damage compnents. I'll gve you tips to minimize the chance of that happening.

Presentation - you want your finished product to look like it was done by a professional.

Starting with the tool list - if you don't have a pair of electronic technician needle nose pliers - go to sears or osh and get a pair (Craftsman P/N 45661) they have a tip of approx, 1/16th of an inch - ideal for lead forming.

Have a magnifying glass handy, there was a day when I could read the color code of a 1/4 watt resistor from across the room :shock:

This post will focus on assembly 1 of 8 (page 13) of the CTB16K - Resistors, Diodes, Ceramic Capacitors.

The hole spacing on R7 through R14, and R20 through R27 are identical, take one of the resistors center it between the holes and slide the needle nose pliers between the resistor and the edge of the hole - bend the lead 90 degrees. Note on the tip of the pliers where you made the bend - now put the pliers on the other lead at the same width of the tip of the pliers - and bend it 90 degrees in the same direction as the first lead.

The resistor should now drop into the two holes without forcing it, flip the board over hold the resistor against the boad with your thumb and pull the lead away from the resister body to about 60 degree angle.

I loaded the board up with all of the components from page 13 before doing any soldering.

Time to solder - we want to minimize heat builup so we are going to pick a soldering pattern to do so.

With the board flipped over - I solder the top left lead first, the bottom right lead next, left bottom next, top right, middle left, middle right, next top left, next bottom right. When all of the outside leads are soldered - I trim them and move to the next layer towards the center of the board following the same pattern. We are distributing heat across the entire circuit board - lessening the chance of causing damage to components or the board itself.

The argument may be made that this approach is overly cautious - but I have damaged both circuit boards and components in the past.

Questions are welcomed, as are additional tips.

I will update this as I progress through my LOR kit build.

Steve

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We are now on page 2 of 8 of the assembly, resistor networks, U3 IC, IC Sockets
*** NOTE TO LOR - There isn't a U3 on this page

The NOTE on this page of the instructions state that the orientation of the resistor networks is NOT important. There is a dot on the end of each resistor network, and each installation location has a pin one marking, Whether you need to or not - it is always best to plug pin one of components into pin one locations.

As recommended in the assembly instructions, I use blue painters tape to hold components in place prior to doing solder. My tip here is that the component isn't really held snug to the board, so I hit the solder pad and lead to get the solder to flow then I use a finger to press the component up to the board while the solder is liquid - yes it's HOT!!

My soldering pattern here was (board flipped):
U1 upper rght
U1 lower left

U2 upper right
U2 lower left

R1 Right

R16, 15, 18, 19 top

First pass is done,

now:

U1 lower rght
U1 upper left

U2 lower right
U2 upper left
U2 middle lower
U2 middle upper

R1 middle

R16, 15, 18, 19 middle

Once again the goal is to minimize heat concentration - keep soldering different joints on different components until completed.

We are now on page 3 of 8 of the assembly, Soldered in Integrated Circuits, Switches
*** NOTE to LOR - No switches on this page

The kit I received had all of the IC's leads pre-bent so they just dropped into the board.

Problem - when I placed U20 on the board it didn't drop in. When I soldered R7, the solder flowed and blocked the hole for pin 4 of U20.

The only real option is to remove the solder - one device is a soldapullt (http://www.hmcelectronics.com/cgi-bin/scripts/product/2920-0019/), or another is solder wick (http://www.radioshack.com/product/index.jsp?productId=2062744&CAWELAID=107594598).

Previous tips apply - distribute heat across components and the circuit board.

We are now on page 4 of 8 of the assembly: LED, Headers, Fuse Holders
*** Note to LOR. Your note should read "an outside and an inside edge".

Use the blue painters tape to secure the components to the board. The fuse holders are going to require a ton of heat - solder one tab of one holder - then do a pin on each of the headers and LED. Now solder one tab of the fuse holder on the other side of the board - then do a pin on each of the headers and LED. Repeat until finished.

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Hey Chuck,

It turns out I'm building a different kit - the CTB16Kpcv1 (http://www.lightorama.com/Documents/CTB16Kpcv1_Assembly_Manual.pdf)

From what I see in the manuals, the kit you referenced is a 40 amp controller versus my kit at 30 amps, and there is a delux version of that kit (16KV6) that can have sequences programmed in and run standalone and control other controllers.

Steve

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Steve,

I see now that they are different kits. From your statement in the earlier post you make it sound like LOR did not call out a U3 for soldering. There is not even a U3 in the parts list. This might be that the PC version that your building was designed with more the home user in mind. And therefore much of the engineering was with the version I choose to build. I would guess that since they use the U3 on the larger version it was easier to use the same part designators between the 2 kits. Since the PC does not use a U3 it was just not included versus renumbering all the chips.

I can see there this would add potential problems for the people that pack the kits. And for aseemblers as well.

Chuck

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The PC series is definitely the economy version. Spade lugs are much cheaper than the screw terminals, and since they are not all in a row along the bottom, they can leave out a lot of real estate on the card that is required to get the 8A channels down to the bottom edge. Similarly, they leave out all the traces for the deluxe version components, and while it is in the standard parts kit, one of the primary reasons I see for a shift register (U3) in that portion of the board would be to read the ID switches. However it may also serve some purpose with regards to the expansion header, or other functionality...

But in general, looking at the manual, there are more similarities between the two versions than differences. All components that I checked that are in common are numbered the same... Since they also run firmware that apparently is only slightly modified for the PC version, there may be comments in the code that reference signal lines by part numbers, and thus renumbering could impact all those comments, as well as any advanced troubleshooting tools they may have that work for both cards.

So I consider the lack of U3 to be just a design deletion from the base design, coupled with electing, for whatever reason, not to renumber the components. Not a big deal in my mind.

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Being that I'm so new at this - and it is my first LOR kit build I initially thought I bought the wrong kits:shock: The title of the instruction page 2 of 8 calls out a U3 and 3 of 8 calls out for switches - your right they are not on the parts list or on the board layout.

So I read both manuals... and determined the higher end kit has switches for setting the unit ID - I have to program each of mine individually, it can handle more amps, and can run stand alone sequencing.

I'm happy with 48 channels as my first real entry into high end holiday lighting, I finished assembly of the first board tonight and plan on testing it this weekend.



Steve

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You know, I've built a dozen of the PC series controllers, and I never caught the page titles that still list the components from the CTB-16D... Good catch..

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I forgot to add what I consider as another "best practices" when building/soldering circuit boards.

Everytime you solder a lead to a pad, the flux starts coating the board on surrounding areas to the point that the build up on adjacent pads will actually prevent the solder from flowing freely. This problem really became apparent when soldering the spade lugs and the triacs, you can use excessive heat to melt the flux residual (not recommended) or clean it off and then solder.

When you start soldering the first components, the circuit board has a polished gloss look to it, as you solder the leads you will see a film form on the board that is slightly sticky to the touch and smears as you rub a finger across it.

Back in my technician days we used trichloroethylene to clean flux from circuit boards, it's now a controlled chermical due to environmental law. My solvent of choice to clean rosin based flux is acetone (available at your local hardware store). When you go to the harware store to buy your acetone, buy a pack of acid brushes (usually in the plumbing section near the torches and solder). Prepare an acid brush for cleaning by trimming the bristles to about a 1/4 inch in length.

Make a note that acetone is a very powerful solvent (flammable) and will destroy most finished surfaces.

After a soldering a few leads (one round of the outside layer), I have a scrap piece of plywood covered with a rag. I place one edge of the circuit board on the rag and tilt the other end up about 80 degress (solder side down)- dip the acid brush in the acetone and lightly scrub the circuit board around the area where I soldered - I keep dipping the brush in the acetone, I am flushing the flux off the board by it flowing onto the rag.

Time for a teaching moment..

I used my test circuit board to deterine how to clean the flux residue after soldering a few leads.

- I first tried distilled water - the flux didn't dissolve

- Next up was isopropal alcohol - the flux didn't dissolve

- Same story with denatured alcohol.

This told me I was dealing with a true rosin based flux, rosin flux has it's origin in pine tree sap. I'm sure everyone reading this has experience getting pine sap on your hand - it doesn't wash off, you need a solvent.

- Acetone cleaned everything up - and with my magnifing glass I could inspect my solder joints!

The question is why worry? If you do not remove the flux residue it can cause other solder joints to not flow easily without excessive heat, in the long run it could provide a path for the elements (water vapor or pollution) to cause an electrical short.

Acetone flushed the flux residue away, my soldered side of the crcuit board looks factory fresh glossy:D

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Steve two points. I think that when you where talking about cleaning the flux off of the board. While you were trying to paint a picture of how you hold the PC Board on the plywood and rag you said to "hold it with the solder side down" and at a 80 degrees. Would this not put it at a position so that one could not see the joint well enough to able to see if the flux has dissolved?

And from my past experience. I usually make sure that my acid brush is well wetted. Like dripping wet. Hoping to keep the area damp on the PC Board. I like to do a flush to help removed the dissolved flux off of the board. Otherwise the whole board is now tacky in my opinion.

If you guys use acetone or any other solvent. Please get gloves that will not be dissolved by the solvent. Even if it is alcohol, wear some kind of gloves. And do this in a well ventilated area, like the garage. And no open flames in the same room. Heck I would not even have a lit cigerete or resistive heater in the same room.

And I agree, Alcohol should have worked. Worked at McDonnell Douglas Electronics plant. Once the circuit boards had been wave soldered. They went into a vapor degreaser that was heated alcohol in a controlled enviroment. That was a werid feeling, both hot and cold at almost the same time. Ya I was maintence and sometimes I had to fix something that was in the cleaning zone.

Max

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After you mount the PC board in it enclosure and all wire installed. Make sure you put an insulated spade on the bare hot jumper if you are not using it for your safety. I didn't see this in any of the manuals. I could have over looked it.

Yes I'm new at this hobby.

Thomas

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There are lots of other hot 110V points on the circuit card that are exposed. It can't hurt to insulate this connector, but in general it is a good idea to plan for keeping fingers off the card when power is applied.

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I tried 70% isopropyl alcohol, and 190% denatured alcohol - all it did was make the flux residue sticky. It might depend on the flux core - resin or rosin when it comes to cleaning. I was just reporting what worked best for me.

Max - If the circuit board is standing on it's edge perpendicular to the plywood it would be at 90 degrees, if you tilt it 10 degress with the solder side down - it's at 80 degrees. What I was saying was crystal clear in my mind - I just didn't do a good job of writing it in the post:?


Steve

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I second klb, there is never a good reason to touch any component or lead on a live circuit board. (There are exceptions if you are a trained tech/engineer)

There are a few basic rules when working with exposed electronics on circuit boards:

- remove rings, neck chains, metal braclets, watches before working on live electronics

- you should NEVER have both hands close to the board, it's called the pocket rule - one hand goes into your pocket or behind your back while testing voltages

- Always assume all leads are hot - and touching them is potentially lethal.

Safety first!

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sjmiller wrote:

I second klb, there is never a good reason to touch any component or lead on a live circuit board. (There are exceptions if you are a trained tech/engineer)

There are a few basic rules when working with exposed electronics on circuit boards:

- remove rings, neck chains, metal braclets, watches before working on live electronics

- you should NEVER have both hands close to the board, it's called the pocket rule - one hand goes into your pocket or behind your back while testing voltages

- Always assume all leads are hot - and touching them is potentially lethal.

Safety first!
Don't forget about destatictize your self on a ground point. ex..touch a screw on the wall plate of a switch or outlet.
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My first controller is 100% assembled and tested! I'm totally jazzed - no arcs, sparks, or smoke - a good thing! I'd pull out 16 christmas light sets for a full test - except the wife is still mad that I bought 3 controllers...

Two to go, Hmmmm, there is the June special sale - another 32 channnels would be sweet!

Steve

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Hi Steve,

As for the board position, thats what I thought you were saying, but wanted to make sure I was reading it right. Don't know or remember where you said you got your techinical training. But I can see by a few things you have said, that you have had to have gotten some somewhere.

Glad to hear you didn't let the smoke escape and the board is working well.

Max

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Max,

The "smoke test" on a newly assembled/repaired crcuit board can be interesting, I tend to like boring - it works as designed!

What started out as a hobby in Jr High school has pretty much been my path in technology. Hobby Electronics to a semester in an EE program - dropped out to take an Electronic techncians job, enlisted in the Air Force (Precision Measuring Equip. Specialist), then on to Aerospace for 20 years. Real time missle test systems was my main forte - with a migration to Information Technology in the late 1980's...

Steve

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  • 5 weeks later...

I made two stupid mistakes while building LOR controller #2.

The first is that there are 5 sip resistor networks that need to be soldered to the board, I'm starting with R1 - the 4.7K resistor network. I soldered t in the slot for R16 - I broke two leads while trying to remove it, had to buy another resistor network to replace it.

The second as dumb as the first - the transformer will install upside down and the pins fit perfectly - I KNOW from experience. I was able to use my solder removale tool and recover.

I got complacent, and didn't double/triple check before soldering. On the bright side - when I tested LOR #2 with 1,600 lights tonight it worked like it should!

Steve

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