High Power LED Mood Lamp

[audioguru2]

A 0.1uF/50V ceramic disc capacitor is fine as a supply bypass capacitor for the project.
Do you have a 5.0VDC/500mA regulated power supply for it?

 

[nefelodamon]

I ve only found a 4.5VDC /500mA but I'm not sure I will be able to find one. But I will continue to search in stores here.

 

[audioguru2]

The project will work with a 4.5V regulated supply but the LEDs will operate on much less current and will be dimmer.
It is easy to make a 5.0V/500mA regulated supply. Use a 8VDC to 10VDC /500mA unregulated wall-wart adapter and add a 7805 regulator IC with a small heatsink.

 

[nefelodamon]

I want the pcb to be as smaller and compact I can so a regulator with a heatsink is a little "heavy" for me : But if I don't find a regulated 5V  power supply I will think that option!

This is the next version of the pcb ( including the supply bypass capacitor- no air wires required  ;D ).

Any furhter suggestions?

View attachment 39987

 

[audioguru2]

Hi Nefelodamon,
Your pcb layout looks good. ;D
Did you purchase and receive the Chinese LED? Does it look like it needs a heatsink? The project's author bolted his prototype LED to a metal heatsink.

 

[nefelodamon]

I ordered 2 leds from Ledsee electronics and I m waiting to get them in my hands. I also wait the pic samples from microchip! Until that moment I hope to have the board ready for soldering!!!
When I get it to work I will try to make some temperature measurements to see if a heatsink is necesery.

And a final question: what settings I must use to Eagle to export the PCB for printing in actual size?

 

[nefelodamon]

Hello again!!!

I've managed to build the pcb and program the pic but there seems to be some problems...
None of the green or blue led seems to be saturated (except the red one) and they don't  work as in the project description. There are no random colors and the changing pattern does'nt work.  The pcb and the wiring is correct. I only used some bc338 transistors intead of the bc337 described on the project.
I can only pinpoint the problem to bad programming of the pic. Is there any posibility to be programmed wrong using wrong fuses?
When my friend tryied to programme the pic none of the recomended fuses or the oscilator appeared but instead some others did (wich I can't remember). I sugested to change them to the ones the project describes but I get the above malfunctions ???
The problem now is that I can't reprogram them because my friend that owns the pic programmer is out of town
You think that using the fuses the binary aks for will solve the problems?

 

[audioguru2]

The microcontroller does whatever it is programmed to do.
It does not do what it is not programmed to do.

 

[MP1]

Nef,
If you did not set the fuse bits correctly, the micro is not going to work correctly. You need to re-program the PIC before you can do much else.

MP

 

[nefelodamon]

More dissapointing news ???
Every time I try to program the PIC16F628A I'm using I end up with only the red led to fully work. Blue and Green are working very strange. When I choose the pattern G->GB->B->BR->R->RG-->>G effect there is no light when green and blue should be on.
The only saturated color is red. When I choose the random effect I only get pure red and white (either the red led is on OR all three together).
I have used the Velleman K8048 programmer with the original software (Progpic2 and Picprog2006 both with latest updates) and even IC-PROG.
The PIC is really programmed ok because it verifies ok and when I read back the code the fusses are set correctly.
I can only now pinpoint the fault in the hex program itself.
Any advise?

 

[nefelodamon]

I don't know why but today it worked.... ;D
All of a sudden I reprogrammed the pic once more and it worked perfect!!!
I even build a second pcb and it worked without any problems!
Thank you all!
Here is the pcb of the project!!!

led.mood.lamp.rar

 

[lolong]

hi! the code of this project is correct? i think it´s bad, because i simulated with Oshon Pic Simulator IDE. Only on the red led.

 

[lolong]

hi! i have a 12v and 500mA transformer, and i had to use a L7805CV for convert 12v to 5v, but the current that pass by any resistor of collector is about 30mA. Anyone can say me why is?

 

[audioguru2]

Hi Lolong,
I started this thread to hopefully prevent the dim problem you are having. I said:
"The value of the base resistors for the transistors is much too high and stops the transistors from conducting anywhere near the high current rating of the expensive LED. Therefore the expensive LED will operate fairly dimly like cheap LEDs."

Change the 10k base resistors for the BC327 transistors to 680 ohms for much higher current in the transistors and in the LEDs. Then the red LED will have a current higher than its max allowed so the 4.7 ohm resistor should be changed to at least 8.2 ohms.

Try it and let us know if it fixed the dim problem. Then we can get the project fixed. 

 

[nase]

Hi @ll,
can someone please check my modyfied layout for the advanced Mood Lamp with 6DIP switches made by Kade (see org. site). It's the first time that I've made a layout and I'm not really familiar with electronics ;D
Etching is not the problem...

There are two versions... with 7805 (55x42mm) and without (52x42mm).

Any help would be greatly appreciated

nase

Edit: Schematics removed

 

[audioguru2]

Hi Nase,
Welcome to our forum. ;D
I noticed that you use 100 ohms base resistors for the transistors. Then the max output current rating of the PIC is is exceeded. Its absolute max output current rating is 25mA and yours is 43mA. Our project has the base resistors much to high at 10k. The author first tried no resistors and some people smoked their PIC. In this thread I explain why and recommend 680 ohms.

Sorry I didn't check your pcb.

 

[nase]

@audioguru,
thanks for the friendly welcome. You must have looked only at the schematic and this is not mine.... it's from Kade. He made the advanced version with a total different pinout and new code.

In the PCB's above, I have taken your advise. sorry for confusion ;D

I would like to know if my routing and the general layout is ok, because I mixed three into one. Normally I took a ready made layout etch it, order the necessary parts, solder it and hope that everything goes well :
I really have no clue of all the different parts/values and stuff :-[

Thanks nase

 

[audioguru2]

I really have no clue of all the different parts/values and stuff :-[

The same for the programming experts the author of this project Toon, and Kade who made some more programming changes and additions.

In the author's forum, two other guys agree with my change of the base resistors but I have never been on that forum.

 

[MP1]

I noticed that you use 100 ohms base resistors for the transistors. Then the max output current rating of the PIC is is exceeded. Its absolute max output current rating is 25mA and yours is 43mA.

This is not a steady DC voltage. It is a pulsed voltage. It is calculated differently. Your output is a factor of the on state vs the off state.

MP

 

[audioguru2]

This is not a steady DC voltage. It is a pulsed voltage. It is calculated differently. Your output is a factor of the on state vs the off state.

MP

Its manufacturer warns that it might  blow up if its absolute max rating is exceeded. We are talking about current, not heating.
The PIC does not have a higher current rating for pulses like the transistors and LEDs do.

It is not necessary to exceed the 25mA max output current rating. A 680 ohm resistor limits the current to only 6.3mA and still allows the BC337 transistors to conduct the max 350mA for the LEDs.View attachment 40410