Just a short analyzing of your Solar Lights. 1) You have 4 LEDs (5mm). Standard 5mm LED's maximum current is usually 20mA. According Data-Sheet of QX5252F if you use 33uH inductor it gives 110mA. If we divide 110mA between 4 LEDs. In parallel connection, each LED takes 110mA/4 = 27.5mA which more that the 20mA, max current which they can take. It might shorten the life of LEDs. And if the AA 2500mAh battery is fully charged then it is going to last 2500mAh/110mA = 22 hours (more than enough). In this condition, I would suggest to use 47uH inductor, because it is gonna give you 75mA which is gonna be 75mA/4=18.75mA for each LED. And it is going to last 2500mAh/75mA = 33 hours. 2) You have 24+3 = 27 LEDs. if one LED's max current is 20mA then 27x20mA = 540mA is max requirement. But you used 33uH which which gives 110mA. I would suggest decrease the inductance of inductor. Please let me know if I made any mistake. Thanks
Thanks for your comments and analysis. You are of course right, I wanted maximum brightness and a good illuminated duration. The lights are still going, changed a battery or two. I have some new lights now with my own PCB....They are really bright RGB LEDs and they go through the night too. I might do a video soon. One comment from me, calculations are all good, but the sun has to shine for any solar light to work. Too many grey days and they will not get charged fully and the calculations for duration go out the window.
Thanks PSO for your interest, might be a new series coming soon using the YX8018 driver chip wired to a 5v 240mAh (1,2Watt) Solar panel. The YX8018 chip can handle higher input/output.
Hi Fred, I have a solar cell (5V / 200mA) and i need to drive 4 white 3mm leds (20ma) all night long. I am thinking about use this 5252F and 3 paralel 1,2v 600mah Nimh battery. Can QX5252 handle 5V 200mA input ? Thanks a lot.
The 1N4148 diode is a fast switching diode. Datasheet www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf It does seem to build up the voltage before letting it through to the LED, voltage seems to double or treble..mAh reduce accordingly.
Hi mati211p, I was playing around and noticed that the diode placed before the LED seemed to make the LED shine brighter and the battery lasts longer. I think now that the inductor pulse frequency is reduced allowing the charge to build up a little more thus the LED is brighter. It might just be me...I am no electronics genius.
@@MrFreddiew1 I remember i tried to do color changing LED by only capacitor and battery last 2 hours, when i add diode it lasts all night. But not color lights shine all night. Must do some measurements with and without diode.
Hello, Can the battery be replaced with an 18650 ( 4.2v) battery? If not, there is a possibility to use 18650 in this configuration or another? Thank you for sharing!
Hi...No, the QX5252 chip has a charge current disigned for 1.2v NiMH batteries. There is a chip out there that has capability for Lithium 3.7V & LiFEPO4 3.2V charging...Checkout Bigclivedotcom video here. ua-cam.com/video/kqmdIV_gBfo/v-deo.html This chip should be the one you want, however I did not find a source at the time of the video, maybe Alibaba?
I learn many things from you Thanks
Just a short analyzing of your Solar Lights.
1) You have 4 LEDs (5mm). Standard 5mm LED's maximum current is usually 20mA.
According Data-Sheet of QX5252F if you use 33uH inductor it gives 110mA. If we divide 110mA between 4 LEDs. In parallel connection, each LED takes 110mA/4 = 27.5mA which more that the 20mA, max current which they can take. It might shorten the life of LEDs. And if the AA 2500mAh battery is fully charged then it is going to last 2500mAh/110mA = 22 hours (more than enough).
In this condition, I would suggest to use 47uH inductor, because it is gonna give you 75mA which is gonna be 75mA/4=18.75mA for each LED. And it is going to last 2500mAh/75mA = 33 hours.
2) You have 24+3 = 27 LEDs. if one LED's max current is 20mA then 27x20mA = 540mA is max requirement. But you used 33uH which which gives 110mA. I would suggest decrease the inductance of inductor.
Please let me know if I made any mistake. Thanks
Thanks for your comments and analysis. You are of course right, I wanted maximum brightness and a good illuminated duration. The lights are still going, changed a battery or two. I have some new lights now with my own PCB....They are really bright RGB LEDs and they go through the night too. I might do a video soon.
One comment from me, calculations are all good, but the sun has to shine for any solar light to work. Too many grey days and they will not get charged fully and the calculations for duration go out the window.
@@MrFreddiew1 Thanks. Waiting for more videos.
Cool Videos! I watched all of them and hope for more :-)
Many greetings to you!!!
Best regards
Rene
Thanks PSO for your interest, might be a new series coming soon using the YX8018 driver chip wired to a 5v 240mAh (1,2Watt) Solar panel. The YX8018 chip can handle higher input/output.
Hi Fred, I have a solar cell (5V / 200mA) and i need to drive 4 white 3mm leds (20ma) all night long. I am thinking about use this 5252F and 3 paralel 1,2v 600mah Nimh battery. Can QX5252 handle 5V 200mA input ? Thanks a lot.
Hi Mrshark..I expect you will be OK, the 5252 is rated for a bit over 5v, if system charges toomuch, the LEDs will light up in the day too !
Vielen Dank Mr Fred. I will try and let see what comes on. I appreciate your answer.
What does the 1N4148 do? Is it a blocking diode or is it used to build up the charge. Great modification.
The 1N4148 diode is a fast switching diode.
Datasheet www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf
It does seem to build up the voltage before letting it through to the LED, voltage seems to double or treble..mAh reduce accordingly.
Why there is resistor on board? If you are using QX5252F you don't need resistors. And what you got by adding 1N4148 diode to LED+?
Hi mati211p, I was playing around and noticed that the diode placed before the LED seemed to make the LED shine brighter and the battery lasts longer. I think now that the inductor pulse frequency is reduced allowing the charge to build up a little more thus the LED is brighter. It might just be me...I am no electronics genius.
@@MrFreddiew1 I remember i tried to do color changing LED by only capacitor and battery last 2 hours, when i add diode it lasts all night. But not color lights shine all night. Must do some measurements with and without diode.
@@mati211p Might need a resistor/poti to bring the higher pulse voltage down a bit to suit the RGB/Color changing LED.
Hello, Can the battery be replaced with an 18650 ( 4.2v) battery? If not, there is a possibility to use 18650 in this configuration or another? Thank you for sharing!
Hi...No, the QX5252 chip has a charge current disigned for 1.2v NiMH batteries. There is a chip out there that has capability for Lithium 3.7V & LiFEPO4 3.2V charging...Checkout Bigclivedotcom video here.
ua-cam.com/video/kqmdIV_gBfo/v-deo.html
This chip should be the one you want, however I did not find a source at the time of the video, maybe Alibaba?
nice light
It's too bad you can't draw the schematic.