Timeline for Selecting transistor base resistor for LED switching application based on datasheet
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Apr 13, 2022 at 16:31 | vote | accept | Nihat | ||
| S Apr 6, 2022 at 21:34 | history | suggested | Theodore | CC BY-SA 4.0 |
update title to reflect the question actually being asked.
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| Apr 6, 2022 at 21:21 | review | Suggested edits | |||
| S Apr 6, 2022 at 21:34 | |||||
| Apr 5, 2022 at 12:34 | comment | added | George | Oh, I may have misread the power requirements. | |
| Apr 5, 2022 at 8:51 | comment | added | Nihat | @George I am not sure whether I'm looking at the right datasheet but according to the 2N2222 and 2N3904, the \$I_{C}\$ should be 600mA and 200mA at maximum, respectively. How am I supposed to control 3A with such a specification? | |
| Apr 5, 2022 at 6:53 | comment | added | George | You don't need a Darlington BJT for LED switching/dimming, especially not when dealing with 3.3V logic - simple 2N2222 or 2N3904 would suffice. Use appropriate current limiting resistor for the LED - taking into the account VBE, and use a base resistor to limit the current draw from the MCU to some safe level. | |
| Apr 5, 2022 at 6:31 | history | edited | Nihat | CC BY-SA 4.0 |
added voltage of pi as requested
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| Apr 5, 2022 at 6:29 | comment | added | Nihat | @Theodore GPIO pin supplies 3.3V with 16mA maximum. LED does not have a datasheet, unfortunately. It is from a local store which I had to make customization on it. Nevertheless, I can provide that it works under 12V/3A. | |
| Apr 4, 2022 at 21:17 | comment | added | Theodore | Please update your question to include the logic voltage of your R Pi so we don't need to look it up. It makes a difference for the base resistor calculation. A link to the LED datasheet would be helpful too. | |
| Apr 4, 2022 at 20:58 | answer | added | GodJihyo | timeline score: 3 | |
| Apr 4, 2022 at 20:37 | history | edited | JRE | CC BY-SA 4.0 |
added 11 characters in body; edited title
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| S Apr 4, 2022 at 20:29 | review | First questions | |||
| Apr 4, 2022 at 21:03 | |||||
| S Apr 4, 2022 at 20:29 | history | asked | Nihat | CC BY-SA 4.0 |