Author: Chris Gammell

Chris Gammell is an engineer who talks more than most other engineers. He also writes, makes videos and a couple podcasts. While analog electronics happen to be his primary interests, he also dablles in FPGAs and system level design.

Categories
Analog Electronics Engineering Interview

Featured on EE Web!

I was contacted a while ago and dragged my feet, like any good engineer. But today I was the “featured engineer” on EE Web! Exciting!

Aside from the fact that it was very nice of them to think of me, I’m just as excited to be featured on there along with friends from the electronics scene! My co-host of The Amp Hour (who probably won’t let me forget who was interviewed first), Dave Jones has been featured in the past. My co-conspirator for the recently completed 555 contest, hackmaster elite Jeri Ellsworth has been featured. And someone else I really respect from the hobbyist scene, Limor Fried of adafruit.

If you haven’t checked out EE Web, I suggest it. They have a really clean interface which I like for browsing their articles. The forums are still a bit light on participation but hopefully will fill up with knowledgeable people soon. Thanks again to EE Web for featuring me!

Categories
Blogging Conferences

Can’t ESCape Wanting To Go

Horrible pun in the title, my apologies.

However, the exciting news is that I will be attending ESC Silicon Valley in a few weeks! I just worked out the details for my trip and will be there from Tuesday, May 3rd until Thursday May 5th.

I’ve been to ESC Chicago and ESC Boston in the past year, but the Silicon Valley version seems to have more seminars, a bigger show floor and more going on in general. That’s to be expected in relation to the relative number of attendees that will likely be there. And of course each time they have a different ESC, some of the courses and people speaking seems to change at least a little to keep up with new technology.

This is exciting for me personally because I’ve never been to Silicon Valley before. Even more puzzling, I’ve never been to the Bay Area or even California before. I’m such a homebody. But I’m looking forward to seeing what’s out there, enjoying the beautiful weather and hopefully seeing some of the local sites.

How did I get the chance to go? Element 14 is sending me as part of their Roving Reporter program. I’ll have video, audio and written updates from the show floor each day. I’m also planning on sitting in for Brian Fuller’s live streaming and interviews from the conference. And of course no trade show would be complete if I didn’t try and record an episode of The Amp Hour with Dave!

My co-conspirator for the recently completed 555 contest—Jeri Ellsworth–will be there also. Jeri is a keynote speaker on Thursday morning of ESC and will also be a roving reporter. We’ll try and show the conference from an engineer’s perspective and have some fun.

If you know of any must-see places in San Jose, I’d love to hear about them. And if you’re going to be around the conference, let me know! I’d love to hang out and talk or even grab a beer. There’s at least one beer-themed event called “Beer and Boards” which will probably be a good time to hang out and talk about nerdy stuff.

I’ll try and post links here (and definitely on my Twitter account) to the stuff I produce for Element 14. I’m really looking forward to seeing what this Silicon Valley thing is all about!

Categories
Economics Engineering Life

Closeout Deals From The Industrial Past

This past weekend I stopped into HGR, the local industrial surplus company in Northeast Cleveland. This place has industrial equipment from all over Ohio, unfortunately from plants closing down. Check out the pictures of all the machinery for sale…it’s enough to build one HELL of a workshop (and even a great new workbench!).

 


This Place is Monstrous


OK, I really would love a robot


The Roof Could Use Some Work


Reflow Oven For Sale (You Transport)


Because honestly, you never know when a machinist might want to get some exercise


A Heidelberg Printing Press

Categories
Analog Electronics Engineering Work

My Electronics Workbench

Aside from the 555 contest I mentioned in my last post, my February was spent building the workbench I drew in Google Sketchup. It was built partially for The Amp Hour, partially for circuits I plan on building and showing off on here and partially for my new business, Analog Life, LLC.

So for today’s show and tell, I’ll premier the first video ever with me in it on YouTube:

I also had a couple snapshots of the bench in progress:

So my bench is done now and I’m off to put it to good use!

Categories
Analog Electronics Learning

The 555 Contest

I’m guessing if you follow me at all on Twitter or Facebook or just about anywhere else on the internet (I’m not too hard to find), you might know about the 555 contest. I have been talking about it quite a bit on various channels, all except here.

So I thought I’d discuss some of the aspects I might not discuss on other forums because they wouldn’t be relevant. But since this site is basically about me and my interests…well I get to write whatever I want! Sweet!

First off, I thought I should mention Jeri. Honestly, I didn’t know her well when we got started working on the contest. Mostly just talking on Twitter and watching her videos. It’s been nice getting a chance to chat though. She’s just as bright as her videos let on. And it’s always interesting meeting new engineers with similar past experiences. Many of the same struggles I’ve gone through in the past, she has as well. Since she has more experience than me, I’ve been learning stuff from her. When I’m not learning from her, we usually make fun of Dave together! (kidding Dave!)

Next, I thought I should mention the spontaneity of the articles about us and the contest. Have a look at some of them:

So here’s the dirty little secret: we know most of the people that wrote about us. Yup, it’s true. But the interesting part for me is thinking just how often this kind of things happens. A friend/acquaintance calls up and tells you about an upcoming design contest, you might want to write about it, right? Welcome to the world of PR! I’m super happy all these wonderful people decided to write about us, and I don’t think they would have unless we had something fun and intriguing; but still, I thought it was interesting and wonder if the contest could be even bigger if bigger names were setting up the contest in the first place.

And finally, I should point out that as much as I enjoy working on the contest, it’s a ton of work! I’m not trying to complain but it makes me appreciate those that run other similar events (and in the past I didn’t consider it). Sending emails alone and trying to coordinate sponsors across distances can really wear on you. If nothing more, it’s a lot of typing! So not difficult per se, but time consuming.  Not to mention my stellar timing of jumping into this project a week after EngineerBlogs.org started; I really set myself up for a bit of time sitting in front of a computer.

So that’s all from me for now. In case you’ve been lamenting my lax writing schedule, I’m signed up for at least one post a week over at Engineer Blogs, usually on Wednesdays. And I can continue to be heard weekly on The Amp Hour radio show. And if you really want to grab my attention, be sure to check out the 555 contest site and start your entries today!

Categories
Engineering House

A Proposed New Bench, Brought To You By Amazing Tools

After talking about my planned bench on Episode 26 of The Amp Hour, I thought it’d be fun to animate the finished versions of my plans (or at least where I’m happy with for now). I know Dave likes making fun of me, but the implications of such free and powerful tools cannot be understated. Even 10 years ago, CAD programs were inaccessible to the layman. Now, a very simple and intuitive program like Google Sketchup is letting someone like me design something like this. Amazing. It’s a subtle message for engineers to keep increasing their values and their skills over the years, as skills that were once coveted become more mainstream and commoditized.

Also, I should explain before I get more questions about it. The thing hanging off the left side of the bench is to hold the mixer for recording music and The Amp Hour. My drumset usually is just to the left of that and I’d be able to control it while sitting and playing as well as when recording the radio show.

Basically, I’m continually amazed at the power of the tools available to us today. If you’re not already taking advantage, I’d suggest giving it a try.

What kinds of tools do you use that you continue to marvel at their ability and power?

Categories
Blogging Engineering

Burning The Candle On A Third End

Hey Folks!

Because my brain decided I didn’t have enough going on already (and a healthy dose of thinking “wow, that’s a good idea” when Cherish mentioned it to me), I’ve started EngineerBlogs.org with a couple other engineer bloggers! I’ve already mentioned it on Twitter, but I thought I should write about it here as well.

The lineup right now is me, Cherish, Fluxor and FrauTech.  But we’re looking for more! If you’re interested, check out the “Write For Us” page on the site and fill out the form there. We have some requirements, but if you’re a good writer and have been doing it for a little while, we’d love to hear from you.

As for me, hopefully posting there on a schedule (a requirement) will get me back into the swing of posting here. If not, you can always read some of my stuff over there or just listen to my nasally voice on The Amp Hour. Hope you enjoy the new site!

Categories
Consulting Life Podcast

So Chris, Where Have You Been?

Well,  a lot of places.

But not around here too much. And when I’ve been here, it hasn’t been the most in-depth writing I’ve ever done (except my unusually thought out post comparing engineers to a fictional character, check that out if you haven’t, not many people noticed it). I can’t say I will be writing again full time in the near future, but maybe in the future after that. So here’s a quick rundown of where I’ve been and what I’ve been doing if you don’t already know:

The Amp Hour

Reading through a few posts or sidebars on this site and you may have noticed The Amp Hour, my weekly radio show with Dave Jones of EEVblog. It’s been going really well so far I think. We just finished episode 23 and have about 1000 regular listeners. It’s been really interesting getting my thoughts out in a different manner than writing and I’d be lying if I didn’t mention that I’m now spoiled by getting my thoughts out “Off The Cuff”. However, there is still a place for planned out articles and this is the place I intend to put those thoughts.

Consulting

Earlier this year, I started a company, Analog Life, LLC. I began consulting for projects outside of my day job (in a non-related industry, with full approval of my day job, of course). I hadn’t really mentioned it on here before, but since it’s already linked in multiple places and listed on my LinkedIn profile, I figure I can explain myself.  This has been the biggest consumer of my time lately outside of work and has been a wonderful learning experience. From the business side of things, to the work I am doing, to the juggling of tasks outside of regular work, all have been new experiences for me.

Pondering My Future

In the remaining hours of my days before collapsing into bed at night, I have been thinking about long term plans and how it might affect the path I am on currently. First and foremost are my personal relationships. If you’re working 14 hour days (effectively) and don’t think your relationships will suffer…well, you’re probably working with the other person. And even then, the relationship can be strained. So I’ve been talking over and considering how working more will cause tradeoffs in my personal life. Am I willing to give up time with my family in order to pursue work that might advance my career? Is the work I’m doing actually advancing my career or just making me money? If it’s the latter, is the money justification enough for not spending time with them?

In talking with others in my field about this subject, other questions have bubbled to the surface, some even relating to consulting. Why am I consulting and what is the eventual goal? Will I need more education to continue in a technical role in engineering? Is consulting enough of a real world education in order to not require an MS in engineering?

Onward

There is really one question that drives all other conversations: What do I want to do (when I grow up)?

I like the idea of being my own boss and owning a business and even selling some sort of product someday (aside from design services), but right now I have neither enough experience with it to say if I like it nor any idea what kind of product I might sell someday. The latter isn’t too much of a concern, but not knowing if I desire that lifestyle could influence my present day decisions.  Here’s the highest level decisions I see myself having to make in the near future:

  • If I plan on being in a technical role at someone else’s company (i.e. employed by a corporation that is not mine) for an extended period, I should go get a Master’s of Science Degree.
  • If I plan on moving into a management role at someone else’s company, I should go target an MBA or a Master’s of Engineering degree (somewhat like a combo MS and MBA).
  • If I plan on consulting for a while longer, I should continue to build relationships and seek out new clients for more work (an ongoing struggle from what I hear from my consulting friends).
  • If I plan on trying to start my own company with a viable product, I should get on my way trying and failing (believe me, I don’t expect to succeed at that at first if I do it, but I understand the value of failing in electronics). I should also begin learning to pitch to investors, as I realize this is the most critical skill of starting a business.
  • If I plan on being a technology media personality, I need to work at it more. It would involve trying to make revenue through blogs, videos, sponsorship, advertising, etc. If this is the case, I had better post more often than once a month, eh?
  • I could not worry about this for a few years, keep my head down, keep learning and hope I’m rewarded for my efforts through my day job. While this is part of any of the plans above, I don’t really feel like this is a “plan” (though I’m sure some would advise me to do just that).

I love hearing peoples’ advice and stories about their own careers, but I’m very realistic: no path is the same and what is good for someone else is not necessarily good for me. That doesn’t mean I won’t listen though, because in talking to a just a few people, I have learned SO much. So I guess for anyone else out there wondering the same things as I’m wondering, my advice would be talk to people. Weird advice from an engineer, I know, but I’m not your standard engineer, am I?

So go forth! And chattify! Or chat in the comments. Yes, I prefer that actually. Thanks for reading.

Categories
Analog Electronics

Makeshift Current Sink

I’m working on a new switcher design and need to be able to test the total current coming out of a boost converter. Here’s what I’m looking at:

  • 0-60V rails (out of the boost converter)
  • 0-350 mA
  • No access to the load that will eventually be connected to the switcher

So what do I need? I need something that can sink current and dissipate any heat that will be generated. If the load is dropping the entire voltage at the top current, that will be:

$$!60V * .350 A = 21W$$

This is quite a bit of power. I was using the TIP41A that I have on hand, a power NPN transistor in a TO-220 package. With this amount of power, a heatsink is most definitely required. Here’s the simple circuit:

In this circuit, the divider from the incoming source (the top rail) sets the current going to the base ($$i_{B}$$) and this times the $$beta$$ (in this case anywhere from 15-60) equals the current down through the collector ($$i_{C}$$). This is not the optimal way to sink current from your source, but it’s a start. The fact that I’m dialing in the current with a potentiometer in a divider that is also connected to the incoming load is not great, but again, this was a quick and dirty way to get up and running. But wait, you think that’s a makeshift circuit? Check out my heatsink:

Yup, that’s a crowbar.

Close up of the attached BJT

I didn’t have any proper heatsinks laying around, so this became my hacked version. During testing, I was looking at 30V across the TIP41A and roughly 300 mA through it. The heat was transferred well from the TO-220 case to the crowbar and the dissipation was decent (heatsinks with fins are better at dissipating the heat). Next I need to step it up and see if this simple circuit can perform under full load. If there was perfect contact between the case and the crowbar, we should see roughly:

$$!Power * R_{theta_{j}} = Delta ^{circ}C$$

$$!21W * 1.92 ^{circ}C/W = 40.32 ^{circ}C$$

I wouldn’t be putting my tongue on the crowbar anytime soon, but I think that’s reasonable enough to handle this situation.

Now, there are much better ways to do this. I really like my co-host at The Amp Hour, Dave Jones’ video about a programmable dummy load. Hell, he even has a legit heatsink! There are advantages to using a MOSFET over a BJT as well, but I went with a BJT for this situation. Mostly I was just giggly about using a crowbar and thought others might enjoy. So…hope you enjoyed! If not, check out Dave’s video below:

Categories
Analog Electronics

Fast Design

I’m finally starting to get it.

Apparently in the past the design work I’ve been doing is too slow. It’s too methodical, I have too much time to question my decisions. Well not anymore.

I’ve been working on a time sensitive project recently (sensitive enough that I feel bad writing this post at 9 pm on a  Saturday) and I’ve finally started to understand the reason the part vendors come to talk to me about power module this and fast design that. They come in with these nearly-done solutions and try pushing them on me, only to hear me say something like,  “Wow, I’d never use that”. I mean, where is the fun in using a power switcher that is damn near complete?

But now that I’m in a situation where I feel the need. I feel the question rising in me…”WHERE IS IT?!”  I expect the answer, the part I’ve been looking for to be sitting in large quantities, in stock at Digikey. I figure I have a very simple, very common problem that needs to be solved not just by me, but by many other engineers the world over.

Honestly, I was looking for a completely integrated module that converts from a 24V bus voltage down to a 5V bus voltage to then be branched with various linear regulators. But there’s nothing out there. No turnkey solution. No simple-as-hell solution. But I want it. I’m willing to pay for it.

And now finally I’m starting to see why they create modules with built in this or that. It’s because there are tons of people out there like me, just trying to move on and get the job done. I’m not quite ready to pay the $20+ price tag certain vendors want, but I’m considering it.

So kudos to all those chip makers out there who recognized the need. But until you have exactly what I want, I’ll be elbows deep in datasheets if you have a new part to show me.