wah started soldering already?...
muz be quite pro

juz curious... done ur printed circuit board already?

haiyo... thats y i asked whether u all have done the PCB
u guys got the wrong type.. nvm let me share abit.. i am not a pro in this but i am an engineering student..

the right 1 should be made of 2 layers.. a layer of copper and a layer of plastic..

Introduction to the making of PCB
- basicly you are to draw on the copper layer.. the drawn lines will add a carbon layer or equivalent on top of the copperlayer... then the dip the PCB into acid.. where the copperlayer without the layer of carbon will be removed.. and leave only your desired conductor lines..

note : in this case u will leave the drawing of lines to the phototstat machine.. and the transfer the drawing into the board through a plastic transparency.. by using an iron (for ironing clothes)

Guide to making a PCB
1. print out the PCB layout from your respective source..

an example of a PCB layout
[attachmentid=102031]

DO NOT resize it.. just print it out in a normal A4 sized paper first.. make sure that your printer ink depth is dark enough.

2. u may need 2 transparancies for this step... (or u may cut the 1 transparancy into 2 to save $$). Photostat the PCB layout on the 1st transparency.. then inverse the 1st transparency and photostat the layout again into the 2nd transparency.. your final outcome in the 2nd transparency should be a mirror image of the original layout... in anycase of this step make sure that the ink depth is dark enough n make sure that there is no missing lines or so...

3. Transfer the PCB layout drawing from the 2nd transparency onto the PCB board.
put the 2nd transparency on top of the PCB board.. and then a piece of newspaper on top of the transparency... make sure your iron is heated up... then begin ironing... if you are doing well... the carbon on the transparency should be transfered onto the PCB board... and when u should be able to see a dark light reflective carbon layer.. otherwise use a marker pen n redraw the lines.

note : any missing lines at this point may be crucial.. but if there are some slight disconnects, u may join them back by using a marker pen..

4. Once u are satisfied.. dip the board into acid.. (not sure how dense the acid should be.... hehe).. i would say thick enough to wash away the copperlayer lo..

5. Drill holes.. the holes are for component legs

-End of the guide-


Hope this will help =)

note : this post is quite long n boring... kindly ignore this post if you think that its too long n boring
- sorry for the long post

hmm.. honestly i dont know wut DPDT,SPST or 3PDT .. but after reading some data sheets i learn a little... DPDT stands for Double Pole Double Throw, SPST - Single Pole Single Throw and 3PDT - Tripple Pole Double Throw...

The number of poles determines the number of input..
eg : double pole - 2 inputs
single pole - 1 input only
tripple pole - 3 inputs

The number of throws determines the switch ability
eg : single throw - switches between on or off (basicly open or close circuit)
double throw - switches between x or y (x to y may be any connection connected the circuit)


These switches could be in of anyform as long as they perform the task which they are designed to do... it could be a simple toggle switch, electromagnetic relays to Intergrated Circuit, IC(CMOS).

The url u have found is the IC type (CMOS)
http://geofex.com/Article_Folders/Milleniu...20Millenium.pdf
http://pdfserv.maxim-ic.com/en/ds/MAX4699-MAX4702.pdf
Basicly are high performance switches... with switching delay in nano seconds (10^-9 s) .. therefore the most expensive type..

The electromagnetic relay type... the following example
http://www.hobbytron.com/NTE/relay/pdf/R10.pdf
This is a lower performance swich.. with swiching delay in mili seconds (10^-3 s).. much cheaper

and the toggle switch type.. the following example
http://www.hobbytron.com/NTE/relay/pdf/R10.pdf
This type... no performance rating..a simple switch therefore, cheap..

conclusion :
if it is juz a bypass switch... the simple switch will do
otherwise if your circuit requires the switch for other purpose.. u may have no choice but to bare the cost..

as for the cost between DPDT and 3PDT... i dont think there should be much difference in terms of cost...

This post has been edited by shouta: Apr 19 2006, 08:36 PM

wah.. so expensive ler
i think the construction circuit only cost around rm30.. provided if u didnt use expensive components ler...

but rm30 for a 1 switch... so expensive ler..
no other alternative meh?
maybe local, taiwan or china made switches