Timeline for MOSFET blowing when soft starting a motor
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 12, 2020 at 18:00 | history | tweeted | twitter.com/StackElectronix/status/1337819538277216257 | ||
| Dec 11, 2020 at 23:42 | history | became hot network question | |||
| Dec 11, 2020 at 23:09 | comment | added | DKNguyen | Just so you know, that's not really considered a soft-start, at least not a proper way. If it's considered a soft-start then it's the kind so crude that very few would ever consider actually using it. | |
| Dec 11, 2020 at 17:11 | answer | added | Andy aka | timeline score: 13 | |
| Dec 11, 2020 at 17:03 | vote | accept | ChrisTanner | ||
| Dec 11, 2020 at 16:15 | answer | added | RoyC | timeline score: 8 | |
| Dec 11, 2020 at 16:15 | comment | added | TimWescott | If you PWM the thing at a high enough frequency, you can PWM -- and if you do it right, you can probably use the itty bitty FET to do it. | |
| Dec 11, 2020 at 16:14 | answer | added | TimWescott | timeline score: 5 | |
| Dec 11, 2020 at 16:09 | comment | added | Justme | Do you have part number for the PSU? But yes, turning a FET on slowly causes it to dissipate a lot of power. In your case, the resistors and 100uF capacitor will turn FET on extremely slowly, and it will dissipate too much power and melt. The 1n4148 is also incapable of repetitively handle the 1A peak currents when FET turns off. | |
| Dec 11, 2020 at 15:58 | comment | added | ChrisTanner | @TimWescott I don't but it's very similar to a 540; it's in a small submersible motorhome water pump. The problem appears to be with a few different pumps of a similar size. I would have thought a large starting current would be worse when I hard-started the motor rather than soft start with a voltage ramp? | |
| Dec 11, 2020 at 15:51 | comment | added | TimWescott | Do you have the part number of the motor? | |
| Dec 11, 2020 at 15:40 | history | asked | ChrisTanner | CC BY-SA 4.0 |