Timeline for What is the second resistor for in this potentiometer reference circuit?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 26, 2019 at 0:40 | answer | added | Locked | timeline score: -1 | |
| Jan 24, 2019 at 21:14 | vote | accept | D. Patrick | ||
| Jan 23, 2019 at 15:35 | answer | added | Dave Tweed | timeline score: 4 | |
| Jan 23, 2019 at 13:12 | comment | added | d-stroyer | To me it is a nonsense to add RL = 100xR into this circuit. I adds no functionality whatsoever. I could see a reason to keep a current in the "S" branch, to avoid oxydation of the contact. | |
| Jan 23, 2019 at 6:08 | comment | added | Jack Creasey | All they are really showing is that to have a linear or log pot meet their profile (or nearly so) you need to be aware of the input resistance of the load. A good rule of thumb is to ensure that the wiper load (input impedance/resistance of following circuit) is 100 times the pot value | |
| Jan 23, 2019 at 5:48 | comment | added | pipe | I think it's distracting if you start talking about what you're building. It will invite people to not answer the question but instead say "I would do it like this". It's a good and clear stand-alone question. | |
| Jan 23, 2019 at 5:21 | history | edited | D. Patrick | CC BY-SA 4.0 |
Changing 'third resistor' to 'second resistor' because there're only 2 resistors. When I was thinking of the question, I was thinking about the voltage divider and I mentally split R into R1 and R2. My bad!
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| Jan 23, 2019 at 5:20 | comment | added | D. Patrick | Heh, @jsotola, sorry. :) In my head I was thinking voltage divider and so R1 and R2. I'll change the title. This is going into an analog input pin of an ATTiny85 to set the brightness of an LED. | |
| Jan 23, 2019 at 5:05 | comment | added | jsotola | what are you building? | |
| Jan 23, 2019 at 4:59 | history | asked | D. Patrick | CC BY-SA 4.0 |