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Help regarding possibility and planning
- Thread starter pusur44017
- Start date
hevans1944
Hop - AC8NS
Finding a "reliable, cheap online parts retailer" is a crapshoot. You pays your money and you makes your choices, almost never with a guarantee, although there is some protection provided on Ebay purchases. Caveat emptor (buyer beware) always applies to Internet purchases.
I have never tried to ask online sellers to "make me an offer, I not refuse" although I have on occasion made bids on Ebay in competition with other bidders. The Internet is already very competitive if your look around for "deals". If I don't like the price, or the seller's reputation, I look elsewhere.
A lot depends on whether this is a one-time project you are buying parts for, or whether you plan to pursue a hobby in electronics. If all you want to do is build one clock, and don't much care what the display looks like, a kit is usually less expensive than purchasing the parts individually.
If I am serious about a project, for example if a customer is paying for a specific design, I will use a reputable distributor for parts purchases, building in the price with my quotation. I use Allied Electronics, Newark (element 14), Jameco, and Digi-Key, just to name four. Here is a link to a PDF file naming the "top 50" according to one opinion. All major distributors cater mainly to OEMs (Original Equipment Manufacturers) who purchase in massive quantities and need a reliable source of non-counterfeit parts. It is only within the last twenty years or so that onesie-twosie parts requests have become acceptable, even encouraged, by distributors. Take a look at the price breaks as a function of quantity purchased to see the difference. The shipping costs will usually exceed the parts cost for small quantities, and there are export restrictions for some components.
If you want to do electronics as a hobby, you need to plan for the long haul by purchasing and accumulating a variety of parts, as much as you can afford, in bulk... even if you don't have any particular use for the components right now. There are a lot of vendors who offer a mixed bag of components at a very attractive price. Problem is, most of the time you don't know what exactly is in the bag. It is fairly easy to build up a stock of resistors, capacitors and other two-leaded components to "play" with, but the initial cost can be several hundred dollars or euros or kroner. Even spread out over a period of months or years that can make electronics an expensive hobby. I have been working as well as "playing" with electronics since the 1950s. As a result, I have accumulated a huge stock of "stuff" in my "junque box" that sometimes (if I can find it!) yields a needed component. But most of the time, I have to purchase new in small quantities like every other hobbyist and budget accordingly.
It is not very practical to assemble the components without a PCB. With available free software that you can download from the Internet, a small board can be designed and the design files e-mailed to any of several manufacturers in China for dirt-cheap construction.
However, you could purchase a blank board, without copper on either side, drill a bunch of holes by hand, glue down some sockets, get a spool of 30 AWG insulated wire-wrap wire and make point-to-point soldered connections... that's actually a pretty nice way to spend a cold Norwegian evening or two.
Vector also sells a pretty neat tool for cutting out donut-shaped holes on copper-clad boards to create isolated "island holes" you can solder component leads into. A hand-held high-speed rotary tool with a small ball-cutter tip can do the same thing, perhaps with a bit more effort. You then do point-to-point wiring between the leads, sometimes with wire, sometimes using the existing component leads if the leads are long enough. This method doesn't work very well, or not at all, when using modern, small foot-print, components (like microprocessors) with lots of terminals.
I have assembled many projects this way, but they had only a few dozen point-to-point soldered connections. In lieu of wire-wrap wire, which can be difficult to strip cleanly without nicking the wire (which will cause the wire to break at the nick, usually after all the soldering is complete), I often use solid, tinned, copper wire and apply Teflon insulation tubing of appropriate inside diameter as I attach each wire. It is also easy to "daisy chain" connections. This makes the wiring go much faster because no wire stripping is required.
The advantage to using wire-wrap wire, instead of bare wire with insulation tubing added as you go, is (1) wire-wrap wire is really cheap and (2) you can use wire-wrap sockets for those components that will mount in a DIP socket and do real wire-wrapping with a small hand tool. We once did a wire-wrapped project that involved several thousand wire-wrapped connections on two IBM PC-AT full-length custom boards. Fortunately, I had the services of a technician to do the wire-wrapping. All I had to do was come up with the design and the wire-wrap list.
So, yes, by all means investigate point-to-point wiring. It is really "old school" and a lot of "fun" if you don't mind the labor involved. There are still available a large selection of eyelets or hollow rivets than can be staked or glued onto a circuit board to make common connections easier. You can even purchase individual pin-socket pins that accept various wire diameters that make it possible to board-mount components for easy removal and replacement if the components fail.
I strongly recommend using a separate circuit board to make the transition from the twenty-two closely spaced wire leads on the Russian VFD to an appropriate connector (or connectors) on this board. The connector can be as simple as in-line wire-wrap terminal posts (available in strips of various lengths that you can break apart) mounted on the board, connecting to the VFD wire leads, and mating with a ribbon connector and ribbon cable connecting to the remaining circuit components mounted on another board (printed or hand-wired point-to-point). This simple interface board, either printed or using point-to-point wiring, will allow you to test the VFD with a bread-board setup before committing to a full clock project.
You need to pay close attention to how you make connections to the Russian VFD. There are twenty-two wires to insulate and connect. Several hobbyists with more enthusiasm than experience wound up bricking either their VFD or the driver or both when they carelessly allowed some of the adjacent wires to short together through an over-abundance of solder on each connection.
As I recommended before, purchase two of these Russian VFDs and "play" with one of them to become familiar with the technology. Just because it is old doesn't mean it is easy or simple. Well, pretty simple and pretty easy, depending on your education and experience.
Hop
I must first comment on how happy I am for this help, you and everybody else. I will need to research what I you said here but it might take some time as I've come down with a hefty cold. I probably will just email the PCB schematics if I can find them and start there. As for the parts, I need to find them a bit cheaper and I will look into that, it doesn't have to be dirt cheap but next to the parts I need multimeter, 30W soldering iron and solder, and 2 VFD tubes alone is around 30 USD. Yes I can buy the kit and yes it's cheaper but it's really not the same. There isn't one bit of soldering there... (talking about the kit in the opening post)
-pusur
I went to Digi-Key and choose all my parts, And it's just about 25 USD, less than 1/4th of what I found earlier. The only parts I'm having trouble getting are 2x10 position 0.1" x 0.1" right angle header (JP2 on Adafruit parts list), 6 pin header, 0.1"x0.1" spacing (ICSP), 28-pin socket (IC1') and 28-PLCC socket (IC2'). I've read through the Adafruit assembly guide and the 6 pin header is commented on as a way to upgrade and/or hack the clock. Could I burn the software this way? It possible saves me from having to buy additional tools for this. This will possibly sound stupid but how could I "play" with the VFDs? Do you have any Chinese PCB makers to recommend? I searched for it and got about 50 different new terminologies I'm not used to so I need pointers there too...
-pusur
-pusur
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I am unable to edit, but for clarification, how can I get a power source to work with these?
I've managed to find out that PCB manufacturers need gerber files and I've made those. Do any of you have and PCB manufacturers to recommend? What gerber files does PCB manufacturers need?
-pusur
