Adjustable resistor / indicator
+ +1 General
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+
- DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE +COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE +DESIGNS AT YOUR OWN RISK. + + +
- This design is released under Creative Commons Zero (CC0) license. + + +
- Author:
+
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+
- Svjatoslav Agejenko
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- Homepage: https://svjatoslav.eu + +
- Email: svjatoslav@svjatoslav.eu + +
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+
+ - Svjatoslav Agejenko
+
- See also: + + +
2 Project description
++I needed a way to experimentally find resistance that works best in +certain circuits. Usual potentiometers could not handle required power +dissipation and were not precise enough. +
+ ++Solution is to build adjustable resistor: +
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+Logically there is series of resistors that increase in resistance in +the power of 2: 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512. Each +resistor can be enabled or disabled by a switch. This makes entire +range of 0 – 1023.5 ohms available with the 0.5 ohms precision. +
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+Schematic:
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+Here is front panel for switches:
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+Download: +
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- FreeCAD project + +
- STL file + +
+Sometimes I would like to use lightbulbs with various parameters as +test load/indicator. Current device has 4 of them included. +
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+Here is front panel for light bulbs:
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+Download: +
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- FreeCAD project + +
- STL file + +
+After assembly using prototype PCB:
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+Following body is used as a case and PCB support:
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+Download: +
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+Result:
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+Cover on the back:
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+Download: STL file +
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+Button covers:
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+Download: +
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+
- FreeCAD project + +
- STL file + +