Patch applied
KiCad / gerbmerge panelization
Sour...
Soylent Green ?
This could cost a lot to fix...
Fixed with Sugru!
Worn saddle with Sugru
Entirely fixed
Colourful but mediocre in taste
Pork belly with sausage
LED-strip PWM / IR controller
Fried meat
Creamy berries
Egg-cited!
FAT with sauerkraut
6-Million-Cent-Man - Rev 0.001
LED_port-status
LED_port-status
Still at rest
Getting there...
Hmmmm
Dark-Star - Bomb #19
Dark Star
Offender removed
Resistor's new home
Tinned
Mask removed
Waiting resistor
Cut trace
About to cut a trace
Planned ESD protection
Hotplate SMD reflow
LED runway
Peppery pork belly
Pushing up the daisies
230V DC motor
Graphite brush
230V DC motor
AC stuff + bridge rectifier
Green PCB
Bread cutter innards
DC motor with fan
Bread cutter innards
Bread cutter - Safety switch
Bye bye wheat...
See also...
Keywords
Authorizations, license
-
Visible by: Everyone -
All rights reserved
-
241 visits
Hopefully fixed - 8 more to go


So far I've managed to kill 5 of these PT4115 LED drivers, and I don't think that I've abused them - at least when compared to what I've done to other devices that survived no problem.
The failure mode is very consistent. Either it stops working altogether (no more switching, output switch permanently open) or the output switch is permanently closed and the LEDs suffer over-current.
Common to both manifestations is that the DIM pin shows unusually low resistance (about 6Ω) to GND. This makes me believe that this pin gets trashed somehow. Therefore I will test if adding a Zener + dropper resistor will help to protect the chip. Voltage clamping at 5V1 definitely works, so lets see how things go.
Adding a Zener + resistor is the way to go. No more premature demise.
The failure mode is very consistent. Either it stops working altogether (no more switching, output switch permanently open) or the output switch is permanently closed and the LEDs suffer over-current.
Common to both manifestations is that the DIM pin shows unusually low resistance (about 6Ω) to GND. This makes me believe that this pin gets trashed somehow. Therefore I will test if adding a Zener + dropper resistor will help to protect the chip. Voltage clamping at 5V1 definitely works, so lets see how things go.
Adding a Zener + resistor is the way to go. No more premature demise.
- Keyboard shortcuts:
Jump to top
RSS feed- Latest comments - Subscribe to the comment feeds of this photo
- ipernity © 2007-2025
- Help & Contact
|
Club news
|
About ipernity
|
History |
ipernity Club & Prices |
Guide of good conduct
Donate | Group guidelines | Privacy policy | Terms of use | Statutes | In memoria -
Facebook
Twitter
Sign-in to write a comment.