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Analog Angle Blog

When an Improvised Solution Is ‘Good Enough’

I often hear the comment, “That's just a Band-Aid solution. You haven't really gotten to the source of the problem.” Usually, the person making the comment has no real idea of the nature of the problem, its subtleties, or what's involved in trying to fix it. An improvised solution often is both a good one and all you're going to get, given the time, budget, and technical constraints.

I was reminded of this when I replaced the digital clock in our shower. It's one of those cheap $4 battery units. The problem was that these units are not designed for the humid conditions of a shower. They were failing every 6-12 months, with corrosion on the battery contacts, display-digit segments going bad, and some sort of mold or crud inside. (I didn't bother to analyze this substance further.)

My initial thought was to make some sort of waterproof enclosure, but a simple zipper-lock bag was too big and lacked the optical clarity I needed. As I delved further into the alternatives, the various solutions I scoped out were bigger than the problem I was looking to solve. Finally, I said, “What the heck? I'll just wrap the clock in some heavy, clear plastic wrap,” which I had on hand. It wasn't a true waterproof solution, but it was worth a try.

I'm happy to report the problem seems solved. It's not that moisture can't get past the imperfect seams and openings in this wrap. It certainly can. But most of the humidity from the shower is condensing on the outside of the wrap. Very little is getting inside to cause problems. It looks as if the Band-Aid solution is working. Though it is not the solution I originally was seeking, I'm OK with that.

This is a common engineering situation. You have a problem, and either the exact cause and mechanism is unclear, or implementing a complete solution up front is difficult. So you try a little of this and that and hopefully put together enough pieces to give you a satisfactory solution.

Think about an elusive EMI/RFI problem where the source is hard to find or the path it takes into your system is hard to pin down. You add extra bypass capacitors in various places, maybe some strategically placed ferrite beads, and perhaps even some shielding. Somehow these all add up to reducing the noise.

Are these steps a Band-Aid solution or just good engineering practices? It depends on your perspective, I guess. Have you ever been criticized for trying such a solution? Have you ever criticized someone else's improvised solution?

11 comments on “When an Improvised Solution Is ‘Good Enough’

  1. DEREK.KOONCE
    June 18, 2013

    Brad, I see your point. I have, in the past, added a cap here or there in a circuit in the effort of cleaning up some noise or improve response. But in the process of doing so, by understanding the results, one can discover the path to the true fix. Once all the band-aids have been added, and things look good, I start to remove ones that I believe may not have had much effect. This way component count and board area can be reduced.

    Even the mechanical engineer can implement band-aids for thermal, moisture, dampening, and other aspects of the mechanical system.

  2. eafpres
    June 18, 2013

    Like most engineers I have to look at everything for potential upgrades. For the shower clock I might have tried spraying it with that clear instant bandage stuff you use for large abrasions. Should seal it but still allow opening later. More elegant than plastic wrap. Of course I might have considered just not having a clock in the shower…

  3. Brad Albing
    June 18, 2013

    You can always just yell to your significant other, “Yo, what time is it?” Of course, that may elicit a response such as, “Time to shut up and get clean.” So proceed at your own risk.

  4. bjcoppa
    June 18, 2013

    Can you offer a more detailed case study from your work experience? I am interested in hearing more specifics on a bandaid solution that worked in a company and one that failed. That would enlighten the readership more.

  5. Davidled
    June 18, 2013

    I might overview cost and metal in board (MIB) for final solution. First, design optimization for cost might be concerned related to keeping the same performance as that of original. Cost might be compared between adding passive component and different IC chips requiring less passive component in the power electronic. Second, metal in board might be considered with thermal dissipation plane.  

  6. Scott Elder
    June 19, 2013

    I'll post a band-aid solution gone wrong.

    Early in my career there was an engineer that reverse engineered the PCB design of a micro computer.  There was this odd capacitor hanging off an address enable line.  Nobody knew why it was there.  Intel didn't advise the use of such a component.  So the wise engineer just dropped it off the BOM.

    Well, advance the clock forward a few months and several hundred computers later the field starts reporting wierd anomalies with the computers every now and then.  To shorten the long story, all of the computers had to be brought back to the factory to have that little useless capacitor added back on to the address enable line.

    So bandaids are okay for the person who knows why it was added.  But they should be left alone by persons who don't know why it was there.  If you're going to copy someone elses work, you must copy everything.

  7. Brad Albing
    June 19, 2013

    That's the problem with “copying” (stealing?) a design – you don't get to see the change orders that were issued that would include the reason why the change was implemented.

  8. Brad Albing
    June 24, 2013

    @eafpres – kidding aside, I do like some of those silicone sprays or dips – various viscosities for different applications; transparent, mostly. Good stuff for apps like this.

  9. jkvasan
    June 26, 2013

    “So bandaids are okay for the person who knows why it was added.  But they should be left alone by persons who don't know why it was there.”

    @Scott,

    Aptly said. 

    For an EMC problem, we just tried everything – the caps, beads, etc and still the problem wouldn't die. It turned out that the front panel plate where panel sticker was stuck had no connection with mains earth. This was missed by oversight and the penalty paid was almost two weeks.

    Band-aid solutions may look simple or sometimes even not so pro, yet , I have seen several Band-aid engineers perfecting the art to provide a lasting solution with great repeatability.

  10. Brad Albing
    June 26, 2013

    @JK – you've touched on very important areas there – the need to document things properly or deal with consequnces (which started with Scott's comments regarding the perils of using someone else's design that is not well documentated); and the perils of radiated or picked-up noise, i.e., EMI/EMC.

    I'll see if I can write or get more blogs on these topics.

  11. jkvasan
    June 27, 2013

    @Brad,

    Many of us understand documentation on versions of software, hardware, etc. It would be great to know how a team working primarily on analog designs, document their work and keep track of revisions, etc. Blogs on this subject would be very helpful to budding engineers.

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