Browse Search Popular Register Upload Rules User list Login:
Decade Resistor Selector Switch

screenshot of the scene

Author: Xray

Group: Default

Filesize: 0.79 MB

Date added: 2019-10-15

Rating: 6.5

Downloads: 2199

Views: 282

Comments: 9

Ratings: 4

Times favored: 0

Made with: Algodoo v2.1.0


Scene tag

Q: What is this?
A: It is one resistor selector switch including its associated resistors which are part of an electronic testing device known as a resistor substitution box.

Q: What's a resistor substitution box, and what is it used for?
A: When an electrical engineer or technician is designing or repairing an electronic device, it is sometimes very handy and convenient to try different resistor values in order to determine how the electronic device will behave with different resistor values. The resistor substitution box is basically a large number of individual resistors that can be selected simply by turning knobs on the box. When the electronic device under test is behaving as desired, the engineer can read the resistance values that the knobs are pointing to, and can then install that value resistor by soldering it into the electronic circuit.

Q: What's so special about this particular type of selector switch, and why is it different from most other standard selector switches?
A: In nearly all low-cost or standard "hobbyist" resistor substitution boxes, they use what are called "single pole, 10 position rotary switches" which add or subtract a single resistor of equal value with each switch detent (position). The diagram in the lower-right portion of the scene shows how a standard or traditional rotary switch in a resistor substitution box is wired. Notice that there are nine resistors and ten positions, which provides resistance values of zero to nine, or zero to 90, or zero to 900, etc.

The rotary switch in this scene is special because of the way that it functions, and it also requires a total of 5 resistors to produce the same 10 resistor values (including zero) as noted above. It does this by alternately switching the "units" value resistor in and out of the circuit. In other words, at every even position of the switch (0, 2, 4, 6, etc), the units resistor is short-circuited via certain contacts on one of the copper tracks. At every odd position (1, 3, 5, 7, etc) the units resistor is allowed to be in series with one or more of the other resistors.

Q: Wouldn't such an unusual or "custom made" switch be much more costly than adding a few more resistors and using a standard single-pole switch?
A: Yes and No! For a low-cost or hobbyist type of box, such a switch would be way too expensive to use, considering the fact that high tolerance resistors (greater than 1%) are very cheap. But when a high precision, high current substitution box is required, then the cost of low tolerance (typically 0.1% or less) and high current (many amps in some cases) resistors has a considerable impact on the total cost of the box, and therefore saving money by using fewer resistors and using special switches makes sense.

Q: Why did I make an Algodoo scene of a resistor substitution box switch and its associated circuitry?
A: Because I thought that this switching arrangement was a very clever mechanical and electrical design which I wanted to share with others who might appreciate it.

Feel free to leave questions in the comments section if you don't quite understand how this works, and would like some additional explanation. In case you haven't figured it out, the fast moving white tracer shows the circuit paths that the electrons would take at different switch positions. This is just one switch with associated resistors in a substitution box which typically has anywhere between 3 or 4 to as many as 10 or more switches. Also, you are looking at the REAR portion of the switch which is hidden inside of the box. The switch is turned through a shaft and a knob which extends outside of the box. You can see many types of resistor and capacitor substitution boxes by searching for them on Google Images.
Last edited at 2019/10/15 05:45:13 by Xray
Please log in to rate this scene
Similar scenes
Title: Path Tracer
Rating: 6.1111
Filesize: 93.75 kB
Downloads: 74
Comments: 4
Ratings: 3
Date added: 2019/10/18 13:07:16
Made with: Algodoo v2.1.0
Rating: rated 6.1
Title: A resistor AHOX
Rating: 5
Filesize: 280.93 kB
Downloads: 489
Comments: 1
Ratings: 1
Date added: 2009/10/17 18:56:25
Made with: Algodoo before v1.8.5
Rating: rated 5
Title: NG-SMG-1 Mlitary Final Version
Rating: 5
Filesize: 1.78 MB
Downloads: 736
Comments: 0
Ratings: 1
Date added: 2013/10/18 20:42:07
Made with: Algodoo v2.1.0
Rating: rated 5
Title: Short Recoil, OBA Shotgun
Rating: 5.625
Filesize: 61.3 kB
Downloads: 1604
Comments: 2
Ratings: 2
Date added: 2012/03/05 07:09:12
Made with: Phun
Rating: rated 5.6
Title: Working HK 416 V.2
Rating: 6.3
Filesize: 243.57 kB
Downloads: 2329
Comments: 5
Ratings: 4
Date added: 2010/08/13 09:54:49
Made with: Phun
Rating: rated 6.3
Title: NG-AR-2 with Xray's scripted selector
Rating: 5
Filesize: 207.89 kB
Downloads: 1082
Comments: 8
Ratings: 1
Date added: 2014/01/15 15:07:01
Made with: Algodoo v2.1.0
Rating: rated 5
Nice work. I've used resistor substitution boxes before, but never knew how the switch worked. I agree that the switch is a very clever mechanical and electrical design. From a manufacturing standpoint, it's easier to stock two resistor values than nine. I like your circuit path tracing tool. Congratulations on being the first person in Algobox to completely fill the Description box.
Quote: Nice work.

Reply: Thanks!

Quote: Congratulations on being the first person in Algobox to completely fill the Description box.

Reply: I'm not so sure that I am the first because I have seen a few others that were quite wordy. I've always wondered what would happen when the description box becomes overflowed with text. Will the Algobox world implode into a black hole and cease to exist?
Cool! :tup:
Thanks Ken3344. :)
Wow, this is the legendary expriement ever! it's looks abouselty legendary so much i have to rate it!
Grade: S+
YeetBoi1 quote: "it's looks abouselty legendary so much i have to rate it!"

I don't see that you left me a rating (1 thru 10) in the Algobox scene rating chart. That's what counts, not the "S+" rating that you gave it. I don't even know what that means! So, it would be awfully nice of you if you were to press that left mouse button when the cursor is hovering over the "10" box at the far right side of the rating bar graph. Thanks!
okay, i'll rate yours a 10.
i rated it :tup:
Thanks, YeetBoi1. :)