Timeline for What is the reason my ULN2003A overheats?
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
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| Mar 7, 2015 at 15:32 | comment | added | Dwayne Reid | The voltage rating that you are referring to for the uln2003 & uln2004 are for the INPUT (control) voltage. These are open-collector devices and the maximum voltage they can switch is the same for both devices. | |
| Mar 7, 2015 at 14:41 | comment | added | user69385 | I am new to microcontrollers; and found the answers interesting and informative. however isn't the ULN2003 rated for 5V; and it's the ULN2004 rated for 6 - 15V ? Just a thought...maybe driving 12V fans is too tasking for a 5V device. I found a datasheet on Darlington's here: <verical.com/pd/…> Or is it necesssary to run an ULN2003 because it's TTL ? Thanks, | |
| Jul 7, 2014 at 18:45 | vote | accept | haimg | ||
| Jun 29, 2014 at 20:56 | answer | added | Dave Tweed | timeline score: 3 | |
| Jun 29, 2014 at 18:53 | answer | added | Andy aka | timeline score: 7 | |
| Jun 29, 2014 at 18:46 | comment | added | haimg | @Andyaka: Fans draw around 0.2A each, and PWM frequency is 32kHz now. The capacitors were put there to reduce audible noise from fans, initially the PWM frequency was much lower. | |
| Jun 29, 2014 at 18:43 | history | edited | haimg | CC BY-SA 3.0 |
Added more info.
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| Jun 29, 2014 at 18:03 | comment | added | Andy aka | Try removing those 2.2uF caps too. You can't sensibly PWM directly into a capacitor, that's asking for trouble. What PWM frequency are you using and what is the expected fan current on 12V dc? | |
| Jun 29, 2014 at 17:36 | comment | added | Olin Lathrop | Darlington switches are not a good idea here. | |
| Jun 29, 2014 at 17:30 | history | asked | haimg | CC BY-SA 3.0 |