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Analog Angle Blog

Analog Components We’ll Miss – or Maybe Not?

While doing some cleaning through boxes of old components, I came across a ten-turn potentiometer from a previous life (see Photo 1). These pots were a common component of precision test and measurement units, as well as commonly the front panel of oscilloscopes to allow users to set precise time delays and trigger parameters.

Photo 1: A ten-turn pot such as this unit was a key element in a precision analog circuit or instrument; it has a smoothness in its rotational feel that matches its function.

Photo 1: A ten-turn pot such as this unit was a key element in a precision analog circuit or instrument; it has a smoothness in its rotational feel that matches its function.

As I turned the shaft, it rotated with just the right amount of smoothness and slight, consistent friction, with no jitter, and no axial radial play. This particular unit was from Bourns, rated at 1 kΩ, ±10% tolerance, and ±0.5 % linearity (it was very easy to determine those parameters, because they are written on its body). The ability to indicate these specifications simply by looking at the unit is one of its many virtues.

These pots were often coupled with a turns-counting dial (mine has gone “missing” — Photo 2 shows is a typical one), which lets you know where you were in the multiturn rotation with precision and repeatability, and also allowed you to lock the shaft. Together, the ten-turn pot and counting dial were a potent and welcome addition to the precision T&M toolkit, and also inherently provided a nonvolatile way to store a user setting.

Photo 2: The ten-turn pot was usually used with a turns-counting dial, a combination that gave the user settability, repeatability, and a turn-locking mechanism.

Photo 2: The ten-turn pot was usually used with a turns-counting dial, a combination that gave the user settability, repeatability, and a turn-locking mechanism.

While I was looking for the missing turns-counting dial, I also came across a small panel of basic toggle switches from previous project (see Photo 3), undoubtedly taken from some military equipment. I know it may seem weird to be lyrical about mere toggle switches, but these were the nicest I have ever used. Their feel and action are simultaneously easy and smooth, without feeling cheap. The switches have a subtle and satisfying clunk at either end of travel, which conveys with certainty but not harshness that the internal mechanism has seated properly. They provide a comforting, visceral feeling of assured performance, as strange as it sounds (and believe me, I know it does sound somewhat strange).

Photo 3: These 'simple' toggle switches provide a basic on/off function with a satisfying feel and sound in their click-over action.

Photo 3: These “simple” toggle switches provide a basic on/off function with a satisfying feel and sound in their click-over action.

You don’t see many of these components anymore, for many reasons. They are fairly costly, large (both in front of and behind the panel), inflexible, single-purpose, and non-reconfigurable. Reality is that they are simply not needed in many of today’s designs, where a pushbutton and software can replace or emulate their function, and also do so much more.

Do I miss these components? I have mixed feelings, to be honest. On one side, they provided certainty in use, a sort of “WYSIWYG” of settings and stability, with no worries about volatility, power loss, software bugs, and other misfortunes. On the other hand, we had to abandon them and go to software-based functions, soft buttons, and touchscreens, often with menu-based dynamic reconfiguration of the switch functions, to get the designs we now want and can realize.

Are there some analog components — switches, pots, or others — that conjure up memories of days past? Are there any that you miss, or also some to which you are truly happy to say goodbye?

22 comments on “Analog Components We’ll Miss – or Maybe Not?

  1. fasmicro
    May 2, 2014

    >.They are fairly costly, large (both in front of and behind the panel), inflexible, single-purpose, and non-reconfigurable. Reality is that they are simply not needed in many of today's designs, where a pushbutton and software can replace or emulate their function, and also do so much more

    Transistors opened a new vista in the industry. Jack Kilby followed by finding a way to integrate them. At the end, we have ICs which have found clever ways to do away with many of the bulky inefficent yet expensive components. Let them enjoy the museums as they are better off there than in our modern devices.

  2. fasmicro
    May 2, 2014

    >> Are there some analog components — switches, pots, or others — that conjure up memories of days past?

     

    Increasingly we are not using those big books to find components. That is one thing I think I have missed. Sure – they still send them. The probem is that if you depend on them to design, by the time you check online, the parts may have finished. The best is to use online tool where you can know if they have quantity available for purchase.

  3. Netcrawl
    May 3, 2014

    @fasmicro, the real electronics development that what its is called today was started after the  “transistor effect”, which opened the road for a whole new era for electronics. More importantly it introduced us to the complex world of computing.

    The history of electronics is a vast area and widespread, the massive changes 20th century are due to electronics effect, from satellite to modern-day devices, they are all electronics. 

  4. fasmicro
    May 3, 2014

    >> @fasmicro, the real electronics development that what its is called today was started after the  “transistor effect”,

    Shockeley in Bell Labs began that movement when he invented the transistor – the active device and set the word in motion.

  5. Davidled
    May 5, 2014

    Print Datasheet is also useful as Index of print book could save the time for searching the components. Also, a few vendors send the Newsletter for the updated components.

  6. Netcrawl
    May 5, 2014

    @fasmicro Yes its the Bell Labs, the birthplace of IC technology, actually Shockley has left the Bell Labs and started his own company-Shockley Semiconductor. Gordon Moore and Robert Noyce joined his company there, where Noyce made some great contributions to the IC industry.  

  7. amrutah
    May 6, 2014

    Bill, Thanks for sharing this blog post.

    Well I have seen and operated pots like the one you have shown, but I have never used the vaccumm tube diodes or transistors, does anybody still use them.

  8. Bill_Jaffa
    May 6, 2014

    Billions of small-signaltransistors and diodes are still sold every year. Transistors such as the 2N2222 and diodes such as the 1N914 have been around for decades and are still needed and used. And vacuum tubes are used in many specialty applications, such as higher-power RF, where solid-state can't do it yet. Plus there is a vacuum tube in every microwave overn–it is the heart of the unit.

  9. Davidled
    May 6, 2014

    Whenever building the prototype, these components are critical used in analog circuit such as Diodes, Potentiometer, and Transistor (NPN or PNP), and other components that I cannot image on top of my head are very frequently used. But, in the future, all analogy components would be changed toward the small scale size and better performance for analog engineer. I expect that all these parts are not obsolete parts.

  10. Netcrawl
    May 7, 2014

    @Bill vacuum tubes helped push the development of computer, its one of the most imporatnt creation of modern electronics. Vacuum tubes played a key role in the emergence of home electronics and laid the foundation for modern electronics. 

  11. Sachin
    May 7, 2014

    We had to abandon them and go to software-based functions, soft buttons, and touch screens, often with menu-based dynamic reconfiguration of the switch functions, to get the designs we now want and can realize.

    With a massive evolution in the IC technology, many things have changed and for a good reason many technological changes have occurred. It is true that the old transistors have their advantages but in the present IC world I think and certainly sure that they cannot fit to the standards needed to create a perfect design. We can just miss them but we cannot use them for a serious project.

  12. amrutah
    May 7, 2014

    @Bill:

      2N2222 and 1N914 are the devices that have semiconductor transistors or pn junctions,  I was talking more like the vaccumm tube based diodes/transistors or circuits.  Sorry for the confusion.

  13. yalanand
    May 10, 2014

    When it comes to Networking hardware; that is, equipments facilitating the use of a computer network. Like; routers, switches, access points, network interface cards and other related hardware. You will find that many people are not using these books to find them, in real sense, the old versions of these equipments are available and thanks to the online tools that have made these books electronic and easily accessible.

  14. Davidled
    May 10, 2014

    Online tool provides E-datasheet and engineering tool virtually. Then, sometime, engineer does not need to buy tool and just get service through internet whether it is free or charged.

  15. RedDerek
    May 16, 2014

    I do like the “clunk” of the big toggle switches. Don't forget about the multi-bank rotary switches that Grayhill produces (http://www.grayhill.com/products/rotary-switches/). Somewhere in my box I should still have my 8 bank, 12 position rotary switch.

  16. fasmicro
    June 3, 2014

    >>  Also, a few vendors send the Newsletter for the updated components.

    Do we really use that? I hadly refer to that bulky document as most of the parts seem to be gone when you get to their sites.  The best way to check is to go online where everything is up to date.

  17. fasmicro
    June 3, 2014

    >> Gordon Moore and Robert Noyce joined his company there, where Noyce made some great contributions to the IC industry.

    Gordon Moore did his PhD post-doc in the Johns Hopkins Applied Physics Lab and then went back to the Valley and together with his pals, they changed the world. Despite the technology, it was the business acumen of Intel founders that made all the difference. Shockley was a poor manager and could not do much in the business arena.

  18. goafrit2
    June 3, 2014

    Plus there is a vacuum tube in every microwave overn–it is the heart of the unit.Plus there is a vacuum tube in every microwave overn–it is the heart of the unit.

    Some of these areas are less competitive as they are not trendy as in the DRAM memory business with new aggressive competitors. It is possible that the companies making these tubes and transistors are doing really fine. All they need to do is sell millions of these products.

  19. goafrit2
    June 3, 2014

    But, in the future, all analogy components would be changed toward the small scale size and better performance for analog engineer. I expect that all these parts are not obsolete parts.

    I think ICs and more density will always triumph the applications of these isolated discreet components. Besides the trouble of connecting and wiring them, they make systems bulky and take spaces. More integration even in the analog domain is the heart of this industry.

  20. goafrit2
    June 3, 2014

    >> Vacuum tubes played a key role in the emergence of home electronics and laid the foundation for modern electronics. 

    That is true. In the 1920s before the advent of the transistor, vacuum tubes were used in “computers” and electronics. Transistors simply put them in the museums in most cases.

  21. goafrit2
    June 3, 2014

    It is true that the old transistors have their advantages but in the present IC world I think and certainly sure that they cannot fit to the standards needed to create a perfect design.

    I think the same way. There are just limited applications of these transistors in some really great products. Integration which is IC is the future and will continue to drive the industry.

  22. goafrit2
    June 3, 2014

    in real sense, the old versions of these equipments are available and thanks to the online tools that have made these books electronic and easily accessible.

    That is true – it is the fact. Online tools have since evolved as the preferred way to search for components and special products. The era of felling trees to print always out of sync inventory is gone for good.

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