1. says

    Excellent show, nice to hear you at the end of the year. Zachtronics have made some really good full sized games, SpaceChem is totally amazing brain twister available for merely few bucks (4.99$ on Steam)

  2. says

    Dave is (somewhat) incorrect regarding patent law. Ignorance isn’t a defense, but, in the US at least, it is a factor in determining damages. “Willful infringement” carries a 3x increase in damages. A lot of companies tell employees never to read patents to as a precaution against a willful infringement charge.

  3. Erick Moraes says

    The new look of the site is nice, but one thing I don’t like about it is the fact that it doesn’t allow you to play the show on the page, it is necessary to open a new tab.

    • says

      This actually depends on the browser. I was surprised to find this out until after already having tested it on Chrome and it plays directly. I assume you’re using IE/Firefox/Opera?

      • Erick Moraes says

        Actually, I use Chrome too. I just found out that it will play on the page if I am seeing the post’s page. But if I am on the main page of the site, it won’t. Weird.

  4. Simon says

    I like the new look – but where’s the Reddit link? Apologies for taking a ‘man look’ if it’s already there…

  5. John says

    My “Play in new window” window used to have a progress slider and a pause/play button. Those are gone now (linux/firefox). Looks like the stark, bland, chrome look is taking over everything these days.

    • says

      Scientist here, I take a lab notebook approach to keeping track of my projects. I use my website as a sort of public lab notebook. The project pages are based on the info that I had at the time which may have been based on bad assumptions. I try to explain the process and come back later and add a new page if I find something was wrong. Either way the pages stay up so people can see what doesn’t work too. I’ve received several emails from people saying how much they appreciate me showing them my thought process and errors as I go.

      • says

        That’s awesome you go back and append pages. That’s the critical point (even if it’s just referring people to the later page where your best known state is)

  6. Jeff B says

    Hey guys, The Art of Electronics is ~$70 on Amazon right now, probably the cheapest I’ve ever seen it.

  7. Chris says

    You could take a page from the software versioning book, where a final product version number increases when any of its dependencies change. Each dependency has its own version number as well.

    eg: Product version 4 consists of PCB version 3 and BOM version 2., Product v5 = PCBv3 + BOMv3

    • says

      In terms of revisions, what you guys are talking about is known as “Configuration Management”, its a well known and documented discipline and its generally hard for people to do because most people don’t understand it – its actually very simple. EDA can be treated in exactly the same way as software development from a configuration management point of view. Chris is right that *ALL* changes should be recorded in the version control system and each revision should be tagged in an appropriate way. The basic rule for CM is your thing should always have a version that represent and absolute known state.

      The big question that was not really answered is “should the BOM be part of the revision number on the PCB” and thats up to each company. In critical systems, yes I would have thought so, but most people seem to treat the rev number on the PCB as the PCB revision only – i.e. it excludes the BOM which then by definition is changeable on the same rev board.


  8. Rafael Souza says

    Chris, what the heck was that singing at the end?!? Was I the only one that got that? Man, the year end party seems to have been really good! (I am still catching up on AH episodes)

  9. Philip says

    Chris, Dave,

    The 10GHz sampling scope does not use the ADC in the PIC. It only uses the DAC (or PWM + filter, I don’t know which). The sampling takes place in the very first chip at the input SMA, which is an ultra fast comparator. The PIC supplies one of the inputs, the SMA provides the other. The comparator includes a latch input, which is driven by the trigger+variable delay circuit. The comparator output is only updated when the latch input receives the appropriate level. The variable delay is under control of PIC too (probably, but could be the PC). A sample is taken as follows: PIC sets up analog value on one side of the comparator, and sets up the variable delay. The PIC enables the circuit to take one trigger event, which when it occurs will enable the latch input for a very short time, after the variable delay has been met. The comparator result can then be tested at the PIC’s leasure, with the answer being higher/lower. The PIC can then adjust the analog value, and repeat. By this process, is can establish the input value at a given time instant. The search for the analog value at a given time instant might use successive approximation. The vertical resolution depends on the resolution of the DAC, and system noise (both time noise and voltage noise). It then changes the variable delay, and repeats the whole process. This constitutes the horizontal sweep.