Find out resistor values from your iPhone

Computers & Mobile Technology
Find out resistor values from your iPhone

“iResistors” is a handy iPhone application for any maker with an iPhone. The free app lets you drag your finger across the color bars to pick the right color combination of the resistor in question. Pretty handy if you are not near the Internet and you need to check your values.


20 thoughts on “Find out resistor values from your iPhone

  1. noname says:

    I thought the iPhone came with teh Internets already!?

  2. The Oracle says:

    It’s a fairly simple scheme to convert from colour bands to the value. It was originally designed for an engineer to do in their head as quickly as someone could read a printed number.

    This app does sound useful as a portable quick reference, but if we’re at a point where an average person who would actually use a resistor needs to check online, then I’m very worried about our future.

  3. MikeDC says:

    To: The Oracle

    Then you should be worried, I have not used a through hole resistor in years. All SMT, so now I completely forgot that wonderful mnemonic…. how does that go again :-)

  4. The Oracle says:

    @Mike – The one I learned was Bad Boys Rip Off Young Girls But Violent Guys Win. Not sure how approprite it is for mixed company, but the person I learned it from had been an Engineer at GM, and you can imagine the culture there.

    The all SMT fact shouldn’t really be an issue. The tool is for people using through hole, and even now, most people learn on through hole devices.

    And I admit I can’t read it as fast as numbers anymore, it takes me a good 5 seconds to read a resistor these days. Not because of SMT but because I use a lot less resistors because parts counts are so low now.

  5. Dave says:

    Yeah, this is pretty sad, if today’s hardware folks can’t remember a simple color code mnemonic. At first glance, I thought it used the camera to actually read the bands. With my poor color vision (and worsening *vision*), that would actually be useful!
    Another related app that I’d find handy would be a 5%/2%/1% decade chart, to find the closest available stock value. Corollary to that, a ratio calculator that picked the closest stock value pair…

  6. Gilberti says:

    Black Beer Rots Our Young Guts But Vodka Goes Well. Very useful for the electric circuits lab I’m taking this semester.

  7. dnny says:

    some other iphone apps that makers might find usefull

    SignalSuite adds precision signal generator capabilities to your iPhone or iPod touch.

    SignalScope turns your iPhone into a powerful real-time spectrum analyzer and oscilloscope.

    for resistor calculation there is also “better”(faster to use) apps than the posted.

    Resistance calcultor

  8. samurai1200 says:

    as a computer engineering undergrad, i have taken 4 EE classes thus far… none of which have attempted to teach me the color coding. if i really need to figure it out, i just use the chart that is posted in all the labs. if that’s not available, web. if that’s not available, DMM… cuz that’s ALWAYS available.

  9. Anonymous says:

    Yeah, if this used the camera on the phone, it might be interesting. But this is just lame.

  10. miketells007 says:

    Really good app you have there. But I think other calculations like inductance and capacitance should also be included. Check this app in the app store..

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