| ??? 11/18/09 16:47 Read: times |
#170939 - If you were to adopt this technique ... Responding to: ???'s previous message |
Sr King said:
hi again,
about wire wrapping, I had not heard about wire wrapping but similar thought had come to my mind, however i gave up on the idea thinking it may not be as robust as a solder-less board. Now since you have mentioned it, after studying about wire wrapping on the internet I have one question left, what kind of poles to be used? can i use a thick ( 240 volts rating ) copper wire cut into 1 cm length as a pole, and use thin single strand copper wire for wrapping? i have a drill with 0.5mm drill bit and a wooden sheet of around 3-5 mm thickness wont cost much, should it be enough? i.e. : thin wooden sheet, thick solid copper wire poles and thin copper wire for wrapping, 40 pin socket , 4mhz crystal connected to socket (xtal pins) through very short (< 0.5cm) thin copper wire + caps. clarification my target was for a simple functioning circuit of 89s52, thats why all the code does is switches on the led. I wanted to have a basic understanding of 89s52 hence the breadboard was used. when i said it even works without decoupling, it is similar to a car being crash tested and the manufacturer saying you have a chance of surviving that in X percent cases, I simply wanted to find out the different outcomes, similarly i tried the 4aa batteries, i was only trying to find if there is any possibility of its working say 1 in a 100 times with that voltage. if you ask me what standard circuit i have chosen for my actual(non experimental ) application of 89s52? well , I still have to finalize it yet, however it will have proper decoupling for sure, and proper power input etc. So you see guys i really meant it when i said i was fairly new to this. hence i need to experiment more to understand what all you great intellects have already understood and are generous enough to share with me. by experimenting just with simple program, i have been able to solve problems in advance, imagine a complex program and a lot of modules etc with a complex circuit, imagine the time you would have taken to understand the problem, imagine the irritation I would have gone through to type all this and that etc. now at least i will be sure that the power supply area , coupling etc. will not be the cause for a problem if it arises in the future circuits, that i may design. once again thanks for all the help, for giving me good luck and for time spent on reading this particularly lengthy post. Why not simply use the components intended for this sort of work? The easiest way to proceed, though it imposes some limits, is to use a "standard" wire-wrap board with individual pins installed in it by the manufacturer. If you do that, choose one with lots of ground and power plane on the board. No board is perfect, but these, if you choose the most suitable type, will serve well. Another option is to use the popular colander board, i.e. one with lots of holes and a ground plane on one side and power plane on the other. With these you use a wire-wrap socket into which your component is plugged, and make the interconnections with any of a number of tools, some of which are still widely distributed. Wire-wrap has fallen from favor, so wire-wrap-specific components are becoming more and more scarce. However, since they're reusable, one doesn't have to struggle with supply issues too much, aside from the wire. I'd recommend wire-wrap sockets with "2-level" pin length rather than "3-level" types. The pins on the "3-level" sockets are excessively long and that often causes problems. Properly constructed wire-wrap circuits always have minimal path lengths between connections. Wires are "pulled tight" though not excessively, in order to keep the lengths minimal and thereby ensure ramdomization of noise within the circuit and maximize density. Pulling on a shorter pin minimizes the risk that it will be pulled into proximity with another pin. There is never need for more than two connections per pin, though sloppy procedure makes more of them tempting. I'd recommend using only colander boards with ground and power planes. You may find it easier to use the more ubiquitous boards that lack those, but you'll regret it! Making your own boards manually will provide much frustration and eventually cause you to give up. If you can't find wire-wrap sockets, point-to-point soldering is still much better than using solderless breadboards, and, infinitely better than trying to drill your own wire-wrap board with a hand drill, as it's nearly impossible to drill a straight hole by hand. RE |
