Segphalt

Member Since: February 18, 2009

Country: United States

  • Product PRT-10592 | about 3 years ago

    I ordered some likes these from digikey and one note for potential buyers. They tend to lift pads, since the battery is being held in by the tension between the board and the contacts on the holder. Even using a through hole point with solder all the way through it will still lift pads on even fab house boards. I have had 2 boards that have never had a single pad lifted by them, and about 10 boards that after a while the pads just pop making them unusable.
    They don’t stay even remotely if you only have solder on one side without the through hole added support.
    My advice, use the through hole parts, they stay in place and if you needed one side nice and flat like I did you can trim the short before soldering and maintain a fairly planar surface on the opposing side.

  • Product TOL-10244 | about 3 years ago

    It isn’t seeed to blame, if you look at the seeed site, they mark it as 200khz analog bandwidth. (the product doc is old.) The amusing part is the o-scope kit from JYE some how costs far less and claims a 1Mhz (I have it 500khz is the only thing I would consider acceptable) analog bandwidth, proof in the pudding in the just because it looks better doesn’t mean it works better. The DSO has more functions though.
    http://www.seeedstudio.com/depot/dso-nano-v2-p-681.html?cPath=174
    If you want an O-scope, go the ebay route, its a better value/cost ratio 9 out of 10 times.

  • Product COM-10574 | about 3 years ago

    AD633 with a 24-32hz sine or triangle wave fed into the the carrier (various chips for this) and a mic into the other inputs + a amp and a few passive components make a good ring modulator for the Dalek voice.

  • Product SEN-10266 | about 3 years ago

    Never mind, apparently my o-scope has a hard time giving accurate voltages at 5mA of current. Those with old cheap o-scopes may wish to keep this in mind.

  • Product SEN-10266 | about 3 years ago

    Is anyone else having a problem getting anywhere near VCC when running this at 5v? I ordered one a while ago but it doesn’t break 2v on out when running at 5 volts, with the recommended cap and resistor and without. I scoped it and it gets the signal just fine and does break the logic threshold for a 3v application however I intended to use it on a 5v supply and logic.
    Did I get a bad part?

  • Product ROB-09549 | about 3 years ago

    This is a good starter kit to teach someone soldering. However, Herbie has some problems for typical home fun. The big one being the motors are just too fast. In a reasonable sized kitchen you will loose Herbie to stray light in no time. There is no easy way to reduce the speed, a resistor even at 100 ohm is keeps the motors from running at all, and a 68 ohm resistor will burn out or catch fire. However a diode or two (better yet a zener diode tested for best results) will reduce it enough to use it in a typical sized room. Problem 2 is the case of the whisker switches, these switches are hair trigger on even the most light bump floor. Tile, wood (older wood floors where the space is defined between boards.) or asphalt will trigger them and Herbie will be going in reverse all the time (This can be solved with some heat shrink tubing.) The best way to modify the board for the diode/s is by not soldering the positive terminal of the battery to the other boards, putting in a separator and and soldering the desired number of power diodes in line. (the other option is to fly the lead that goes to the motors out to the diode and back to the socket but that is risky.) So in short great soldering and basic electronics device, but really not an optimally functioning product. The design might want to consider including a appropriately rated z-diode to reduce the speed so those of us without auditoriums can have some fun with him without a great deal of hacking.

  • Tutorial - Solder Paste Stenciling | about 3 years ago

    I prefer hot air rework as you can see if you messed up on a per part basis. Paste syringes are also pretty cheap considering they say it expires in a year and I don’t do hundreds of board inside that time and one syringe will go a long way. And no need for stencils. You also do not incur the cost of a stencil for a small number of boards. You also can get pretty fast at it (for a hobbyist) I recently did 10 boards that had 11 1206 parts 1 SOIC-8 package a switch (smd) and 2 12mm coin cell holders (Thru hole) paste and soldering in about an hour and a half.
    There is my 2 cents.

  • Tutorial - Solder Paste Stenciling | about 3 years ago

    After a bit of practice you learn the amount needed to prevent bridges and still get enough solder on. In the passive component realm I tend to stick to 1206 packages (More because I don’t like placing smaller parts not because of the paste.) however I have soldered many SOIC and TQFP packages without a problem. Also large in part you can have a thin paste bridge on most parts and it will wick up to the part rather than create a solder bridge. However in small pitch packages it is best to alternate inside outside with your dabs this helps prevent bridging.
    Loosely placed parts also tend to self align in the heating process. (Have to love liquid tension.) I have used this methodology with both just a hot air (I stress low air flow) rework station and with a toaster.
    Continued…

  • Tutorial - Solder Paste Stenciling | about 3 years ago

    I have done both methods stencil and with solder paste plungers. By hand no machines in the mix. My overall thought is, if you are doing less than 100 boards, plunger all the way. Both options do require practice. Stenciling is far more messy and unnerving to do. The dispense control you get from syringes keeps messes low. I am comfortable doing it at the desk I sit at every day. Stenciling I don’t really do anymore because I don’t do mass production but I would never do it at my desk, paste tends to get all over the place.
    With syringes the trick is really to push the tip straight down on the board, this makes the paste stick more to the board than the syringe tip. (Sticking to the tip was my biggest problem early on because I tended to come in at and angle.)
    Continued…

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