T&L Publications

Jwax you are right it is for an adjustable 24v. You realy don't think they would see the 60hz ripple. From what I interperat from the Chinese tech there were a lot of capaciters in there but they removed the guts and put something else in place that is not working for them, they can't dim the bulb e...

Wow thanks Al I was way off on my calculation for amps don't know were I got 1.2 amps from. At first when I read your reply I thought were did he get that from so I did it agian and sure enough your right. This is on a microscope here at work and they need pretty smooth DC because they see the rippl...

How do you size a transformer. Most trans. are rated in KVA right? So say I have a 250 watt, 24 VDC heligan bulb and want to build a power supply for this, I know 250 watts = 1.2 amps. I have tried Googling for my answer, will try more probably not use the right key words. Thanks for any help. Singl...

Thanks Bob that worked for this board. But I will still change the pad size in the library for future boards. By the way Philba my heat sinks will be bolted to the case of the 7805 and a seperated one on the 317 then straight up in the air not tied to the board in any way. On my old power supply I u...

Printed the board out on paper and it just seemed a bit small but I have not tried making a board with them like they are, will try them and see, the pads for the filter cap are very thin those I will change. This Power supply is a redue for my Proto board I made many years ago. Will use digital dis...

Thanks guys, Mike your idea would be a simple solution but I don't think it will work for the 7805 and 317 they are an odd shaped pads. I think for parts like these they should have a larger pad anyway, large filter cap expecially. Changing the library would be a more permanet solution. I don't have...

Is there a way to change the pad size on the board after all parts have been placed and it was routed? The copper left around the holes look to be very thin, would like to beef them up. Its for a power supply board. Or do I have to redue it all and go back to when I choose the package? Thanks for an...

Worked on GE 1050HLX lathe control about 10 years ago. Surprised you still have one working. Whats the problem with it. Will be away for a few days so may not answer. I'll help if I can.<p> Bill

Don't know if you found and answer to your question yet but if not Parallax has a good forum on there web site. Basic Stamps in Class one of there programers answers questions, great support! You should take a look. Bill

Were do you buy ammonium persulfate never heard of it before. Ferric chloride is nasty stuff. Had it ruin a whole tool box and every thing in it once.

Thanks Haklesup I was thinking of a cap too. Would be much less destructive then cutting the trace. Seeing as its under warranty, cap I could remove. Might try the bandaid or cotton first though.

No I'm not sure how its being driven. Its in a microprossesor system its a scoring system has 7 seg. displays and a keypad. When you type on the keys the piezo sound for every touch on the keys, but very load. Don't get me wrong the tape did muffle the sound but its still very erritating. I can cut ...

Well I put 4 layers of tape over the opening and it really didn't lower the volume much, a bit but that was all. Probably because the tape vibrated too???

How does a Piezo work,by frequency and if so how is the best way lower the volume of one with out to much modification of the circuit its in. Tried taping over the opening but that didn't do much. Would adding a capacitor across the contacts of the element work. Resistor didn't help either. Any help...

JasonQ had that happen to me once too. Thought it was strange but it has not happened agian so I didn't worry about it.