SDG

Designing a CC LED driver - Following on from Part 1, I design some code for a Microchip dsPIC33FJ16GS502 microcontroller to user the high speed PWM module to drive a high power LED at a constant current.
Equipment used:
Rigol MSO1074Z oscilloscope
GW Instek GPS-3303 Power Supply
MPLAB REAL ICE
MPLAB X and XC16 C Compiler #ElectronicsCreators

[@sidyajv]

This channel is so underrated.

[@SmallFlockers]

Well done! I love your bravery of allowing us to fully witness the debugging you went through, including all of the small, silly errors we all make. That helps all of us, especially newbies on what to expect. It would help setting up youtube as a video series so we can advance automatically through each video for a particular project.

[@ajithpinninti8845]

You are amazing, Thanks for all the process you went through to create one..

[@peterdkay]

Excellent video. I love how you show the debug process warts and all. Keep it up I really enjoy your presentations

[@sdgelectronics]

Peter Kay Thank you. I like to show problems as well as it may help someone in the future.

[@DarianCabot]

Excellent video. I'm really glad that I found your channel. Thanks

[@sdgelectronics]

Darian Cabot Thanks Darian

[@Alex-yq2tf]

Any more video updates on the CC LED Driver PCB and assembly? Such a great video series!!

[@dixsusu]

That's just great mate !

[@robertcalkjr.8325]

Thanks Steve.

[@srinivasansg]

Thanks for sharing your knowledge.

[@AmirHakimiRezaei]

Thank you for the tutorial

[@MalcolmCrabbe]

Just subscribed - I skipped through some of the video as the pace didn't hold my short attention span, but loved the bit where you had issues when getting the thing running, only to find you had selected the wrong chip - most would of edited that out, but in reality it shows just how things tend to happen, and how easy it is to make mistakes - well done for showing the process. I cheated with my DIY build for my aquarium lighting unit, I used commercial meanwell LDD drivers, but built a programmable dimmer controller using a PCA9685 chip driven by a PIC micro ? Looking forward to watching your channel expand - keep up the good work

[@sdgelectronics]

Malcolm Crabbe Thanks Malcolm. At the time I was unsure what to put in the video and what to leave out, but I think I'm starting to find a balance now. You should find future videos a bit faster paced without all of the steps.

[@haimt]

Very good job ;-) I can't get the link between the efficiency in the liner regulator (13.75%) to the Duty Cycle at the SMPS ,please could you explain!

[@geo0rpo]

Great Job, Great video! Please tell me, why do you use Fault 2 in CLSRC of FCLCON register? You are using comparator 1 so you should use Fault 1 as the source. Am I wrong? I missed your 3rd video with the dimming. Is it up yet? Thanks!

[@sdgelectronics]

geo0rpo sorry I plan to revisit this soon with part 3 - just moved house. You can remap the fault bits to different pins so it was convenient for layout.

[@GlennPierce]

Thanks for the video. Most informative. Can I ask what would be the advantages of this over a LED driver chip like the PT4115 ?

[@sdgelectronics]

Glenn Pierce Good question, and something that will become clear in future videos - this controller is forming the basis of a connected lighting system in my home using Microchip MRF24J40 RF transceivers meaning the dsPIC will be performing many more tasks than just doing the constant current control. I will also expand the controller for 4 channels per device, allowing for RGB and White LED or just 4 individual controls of white LEDs.

[@GlennPierce]

SDG Electronics Sounds cool. Thanks

[@Maher-]

Hi, I'm trying to control 405nm 3W uv led x30pcs using an led driver, How to control that driver using arduino / ramps 1.4? Hope you can help me, thank you

[@busterzz]

This is like a peak current control, are we controlling the switch current? What if we control the average inductor current directly by placing the sense resistor in series with the inductor?

[@sdgelectronics]

You can monitor the inductor current and control that but the voltage at that node with respect to ground varies, so you will need an instrumentation amplifier with good common mode voltage rejection.

[@dwDragon88]

Any particular reason you like the dsPICs? They looks like really good feature-filled devices, but I've never played with that series.

[@sdgelectronics]

dwDragon88 The use of the dsPIC in this application is purely down to the feature set - these particular devices are designed for SMPSU applications, and in a later video we'll be using 4 independant channels to drive an RGB plus white LED.

[@kamleshchavan7451]

Can't see the circuit diagram clearly

[@fasayakoulouna8987]

Thank you from Algeria.can you please send me a copy of the file named i your video 42oscillator.pdf?thank you.

[@BenjaminEsposti]

What happens if the chip locks up, when the FET is on? Dun-dun-dun!

[@mrlazda]

+Benjamin “Ozias” Esposti This is just simplified example which demonstrate concept, it is not something you will use as final product. Watchdog timer will not help in this case, it have to long timeout to help in most cases (all that can realise blue smoke will do that before WDT reached its timeout). In final product you should find better solution to deal with chip locks up, and better way to drive FET (driving FEST directly from microcontroller/DSP will give poor efficiency, usually SMPS controllers that work on 500 kHz have fet drivers capable providing >1A of peak drive current to be able to fast rise and fall times and pin on microcontroller is capable of 25 mA).

[@desertdave]

Hi, Very nice explanation of the software development, gives an idea of how register values have been decided upon without getting too technical and the overall results were great considering the prototype methods employed, I have my dsPIC33's on order already !, I have added many SM inductors to the shop now and will be offering this dsPIC once they arrive, I am not sure how I can do it but maybe we can set up something where your channel subscribers get free postage or something like that, I located you via a link in MJL channel and with him being outside the UK I have supported him by purchasing from his suppliers before and I love Dave Jones EEVBlog but I do want to support new UK electronics channels via the BasicMicroUK shop, we have so many items now in stock please do call even if you do not see what items you want in our shop, How do you find time to do these projects ?, What do you do for a day job and is it connected to the electronics industry ?, Many Thanks Dave

[@sdgelectronics]

david ellis Hi Dave, Sorry I missed your comment until now - I work full time at an engineering design consultancy developing medical and surgical electronics, so time for videos and projects is limited to the weekend. My wife and I are expecting our first child in a few months so I'll have to work harder to find time to record videos! Thanks for your support!

[@desertdave]

Wow a very busy life and going to be even more busy soon by the sounds of things, Sounds a very interesting day job, we do some work for Phillips Medical on power supplies for mammography scanners, its a system that's fitted in the mobile breast screening clinics you see set up out side doctors surgery's and community centres etc and our power supplies allow the whole system to run from a 240V single phase supply, Another 2 great repair videos, I am pleased you are still finding time to do videos for the public, you lab looks well equipped for a home lab set up, a video of the set up you have a t home and the test equipment your using would be great, what's your lab at work like ?, that may well also make an interesting video, Keep up the great work, Thanks Dave BasicMicroUK

[@Blue.star1]

Making a 50 volt linear driver is difficult, Wanna drive 50 watt, 1.75A , 36V cob from 48V ( should I use 12 X 4 Lead battery , its 7 AH , I want to use 1 extra battery instead of 3 batt @ 36V-39V , battery voltage is 12.5- 13.3 volts for a fully charged 12v lead batt , voltage drops after few hours, Is 48 V correct voltage selection ) , don't wanna use buck regulators, wanna use low resistance mosfet and 1 or 2 LDO V-reg for CC, CV (eg LM 2914, but its max V is 24V ) circuit operates at 48-55V battery . Don't want to use TIP127 ,Bjt due to heat issues, no buck converters , no pwm / inductors.

[@sdgelectronics]

I have a video in a week or so to drive something similar. Stay tuned

[@Blue.star1]

@@sdgelectronics ty , I edited the comment for clarification.