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Gromit
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Hi everybody, and Merry Christmas!
Has anyone made a battery charger with DS2711 chip? If so, please, tell me:
1) I intend to make a parallel circuit as in page#7 of datasheet (see attachment) - what transistors can I use instead of FCX718 - I prefer non-SMD transistors that can handle, say, 1Amp of current (2-3 A even better)?
2) Can I use other type of thermistors, like <http://www.futurlec.com/Thermistors.shtml> from futurlec.com (with same 10kOhm value, of course)?
3) What to do with "ICHG" and "IFB"? I assume that ICHG is for connecting power for charging batteries - is 5V sufficient (for 2 bat. in parallel)? IFB is tied to CSOUT pin of IC - how can I use it? Can it stay "floating"? As it is "Current Sense Output" maybe this pin outputs some feedback voltage that can be processed with some MPU or so?
4) Can I use wirewound sense resistor and what power should it have?
Thanks in advance! -
Thanks for fast replies!
@gogo2520: As I said I found this on site http://www.solidfluid.co.uk/sfsite.php/0000027F . I contacted Mr.Andy from SolidFluid and you can see what he answered to me in attached TXT file! I did not want to discourage you about the use of carbon paper - maybe my carbon paper was not the right type. About "gummed paper"; according to the dictionary "GUM=any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying" - hence the name. It is an ordinary sheet of paper with water activated glue layer on one side - it can be white (you can find it on ebay, just type "gummed paper") or colored collage-paper (for children :)) that I use. You print on glue side: it seems that this layer of glue very well attract the toner particles! After laminating (or ironing) starch-based adhesive is dissolved in water leaving pure toner image on copper without traces of paper (very important if you use TRF White for silk-screening!). Any eventually remaining pieces of paper you can easily put away by rubbing with finger. Btw. I am surprised that you are not satisfied with the laminator - which type you use? It must be with two heated rollers (I use GBC).
@Hero999: This is what makes me really wonder! Of course, it is possible that I contaminate the toner after printing, BUT as I said it seems that the toner stick to the copper extremely well! You can scratch it, scrape it, brush it (I do not know more English words for this :(), put PCB in cold and hot water and even 0,1 mm tracks remain intact!?! But when the PCB comes in acid some of traces simply detach from copper!? You can see in the picture that I attached before: for example "U-shaped" trace marked as 0,20 mm completely separated from board while very close traces (including letters) remained! Perhaps the acid was too strong, I really don't know...
Any suggestions would be appreciated! -
Well, I tried to use carbon paper, but to no avail. I just got a lot of mess. The dye from CP is spilled all over the PCB. I had a lot to clean with a toothbrush and detergent to remove CP pigment from it! I have no idea is some of pigment remained on toner. In attached image you can see final result - left half of the PCB was covered with carbon paper! Left image is scanned after laminating, right image after etching! I don't see any differences.
On the other hand gummed paper proved to be good - you can see the lowest part of PCB where is the larger area of copper - there is no pitting at all, but on some traces there are still more or less "rashes"! After laminating (10 passes, just to be sure) PCB is left in the water to soak for about 10-15 minutes, and then gummed paper fall off by itself in one piece! Only pure toner remains, without paper residues.
Now another problem emerges (that problem has appeared before also - with different types of paper): even after very aggressive cleaning with toothbrush traces REMAIN UNDAMAGED, BUT when I put the PCB in acid (HCl+H2O2 @ 25
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Yes, I agree that paper residue isn't a problem... It is only important when
applied TRF (or, maybe, carbon paper) - then it must be pure toner on board.
gogo2520 has problems with applying TRF White - TRF does not work except
with clear toner... -
Ok, I will not give up - after all some PCBs have turned out quite well...
@gogo2520: If you are using magazine paper you will always have white residues of paper,
and white TRF certainly won't stick to PCB! I use gummed paper for this (it's much cheaper than
Pulsar's) - dextrin coating dissolves in water and only pure toner remains. -
Thank you all for your answers! I found it on http://www.solidfluid.co.uk/sfsite.php/0000027F
The reason I ask this is because I can't get a uniform results: sometimes is pitting minimal with one sort
of magazine paper, sometimes is PCB unusable... (I always use laminator with same settings). -
Hi,
I'm interested if anyone tried to use ordinary carbon paper instead of
the much more expensive Pulsar TRF Green?
THX!
Sensor for Weller LR21 needed...
in Sell/Buy electronics - Job offer/requests
Posted
Hi!
I wonder if anybody has faulty Weller LR21 soldering iron, but with working sensor (22 Ohm), and if he/she are willing to give it away ;), please let me know! The new one costs $$€€$$!!!
TIA!