Site news archive - PCB Heaven

Posted on Feb 5, 2014

I designed the simplest remote-controlled autocue system possible with materials that i unburied from my old-and-busted bin, my old P4 laptop, a totally broken USB keyboard, a piece of plexiglass. A foot-switch controls the scrolling of the text in the autocue screen. The first revision of the BJT Transistor Theory e-book has been released. One ma

Site news archive - PCB Heaven
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jor error have been corrected in one image (thank you Nash). The first chapter has been re-written. Download and share for free. I used a piece of aluminum to mount the hot air gun on the carriage, and also i improved the coupling of the stepper motor with the threaded rod. The rod now revolves smoothly, there is no grinding sound from vibrations and the motor stays in position. Heading towards an end, i mounted the stepper motor and the driving pair, an M6x1 threaded rod with an M6 nut will do the job perfectly and with an easily calculated step (1mm per cycle = 1mm per 200 motor steps = 0. 1mm per 20 steps) The soldering reflow process is usually the only way to go if QFN packages are used. To properly reflow a QFN one has to follow a reflow chart provided by the manufacturer. The process takes some 6 to 7 minutes to fulfill, which is a lot for doing it by hand. Plus it is not easy for one to follow the temperature chart precisely. Therefore, i built this NC machine to do the reflow job automatically. I wrote the second page of the first circuit to support the TEDIE Book. In this page I take some measurements on the DC Transistor load switch. More calculations are coming up next. Some time ago I uploaded a video explaining how one can remove the various components from an old PCB fast and easy. It seems that many people misunderstood the purpose of this video. One gains more than just economical profit from salvaging...

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