Hello,
I'm trying to convert a basic garden solar light.
The standard garden light uses 1 led and i converted it to 3 leds.
I applied different joule thief circuits to the leds but it's just not bright enough
The standard garden light uses just 8 ma and i want to get more light with the 3 leds with the same (or less ;D) amp draw.
I already used the basic joule thief circuit (amp draw 40ma >:()
Basic joule thief with secondary (not bright enough)
Backwards Joule Thief from kooler (not bright enough)
Has anyone got a good circuit for me to try???
PS.
I'm using lidmotors solar circuit!
Is there nobody here who has a good idea???
Should be sombody who has a good circuit which uses less then 8ma p/led!!!
I only need to drive 1, 2 or 3 leds with lets say 20ma for 3 leds.
Please help me with a good circuit!
PS.
Leds should be at least 80% bright
The way to get three leds to light off of the solar cell, is with the backwards JTc or Hartley type oscillators. And the three leds in Paraallel
Kooler had made a tiny oscillator circuit that lit three leds in Parallel, off of a 1.2 volt button cell (for 7 months). I'm still trying to replicate that circuit...
I personally have not had luck with Kooler's circuit yet, but I'm trying to get all the exact same parts, and try again. I think that it's an important one to be able to get the concept right, and working right also, using only MicroAmps.
It seams that the backwards JTc feeds-back to the battery, and can almost self perpetuate, or close to it.
I would suggest the MK1 JT circuit. You can add a bunch of leds off the pick-up coil and not up the Ma draw.
Bill
@NickZ
Thank you for your reply.
Do you have a link for me where to find the circuit?
Regards,
Flux
Quote from: Pirate88179 on May 21, 2011, 10:55:50 AM
I would suggest the MK1 JT circuit. You can add a bunch of leds off the pick-up coil and not up the Ma draw.
Bill
Bill,
I tried to find the MK1 JT circuit, but i failed to find the schematic.
I searched this forum by user MK1 and keyword joule and jt and thief, but no luck ???
Can you point me in the right direction?
Regards,
Flux
Here are a few. you can find these, and many more in the JT diagrams topic area. It is a locked topic I started to place schematics and photos from the large JT topic area.
I hope this helps.
Bill
Hi bill,
Thank you for posting those circuits.
The 3th one looks interesting, but i fail to see where the leds should be on that one!
Yesterday i build koolers BWJT with 5 - 11 turns and a lot of turns on the secondary (75 - 100). Changed the cap to a 471 instead of a 104. It's drawing between 8 and 16 ma and lights up 3 superflux leds. I chose for 16ma draw because leds are at full brightness and that's 33% less draw as the original jt circuit from the factory (8ma for 1 led). Further more these superflux leds are rated at 30ma each in stead of 20ma.
Regards,
Laurens
I finished my solar garden light today.
Thank you Kooler for your help.
I will post the solar circuit tonight or tomorrow, i made my own circuit in stead of using lidmotors circuit.
I have a new laptop and need to install software to shrink the pictures first.
Also i will take a tew foto's tonight (dark action foto's).
Regards,
Flux4Energizer
As promised here are the foto's (circuits included).
Joule Thief Circuit (by Kooler (just adjusted it a bit).
The Solar "ON" "OFF" switch circuit i thought up.
And some building PICs and a test action foto ;D ;D
If someone has a better Solar "ON" "OFF" switch circuit please let me know.
The circuit works, but there is a downside with it.
When you have tuned the JT to the right amp draw vs light output and you hook up the solar switch circuit the LEDs turn a lot dimmer.
When i tested the JT circuit the LEDs were blazing at a amp draw of 16ma.
But now the LEDs are dim :confused:
If anyone has an idea i would like to hear it.
Regards,
Flux
@Flux4nergiser... Just noticed your thread! Your solar switching circuit appears to have an error!! this may be the reason that you led is dim. The second transistor from the left in your drawing needs a resitor in it's collector to limit the current both through the collector and also to provide the correct bias current for your switching transistor. A 1k should do the trick, but you can go higher by experiment. I assume you have built the switcher as per diagram drawn... or have you drawn it wrong? As it stands the second transistor is switching directly across it's supply line when turned on!!! Kind Regards
Quote from: crowclaw on May 24, 2011, 03:03:25 PM
@Flux4nergiser... Just noticed your thread! Your solar switching circuit appears to have an error!! this may be the reason that you led is dim. The second transistor from the left in your drawing needs a resitor in it's collector to limit the current both through the collector and also to provide the correct bias current for your switching transistor. A 1k should do the trick, but you can go higher by experiment. I assume you have built the switcher as per diagram drawn... or have you drawn it wrong? As it stands the second transistor is switching directly across it's supply line when turned on!!! Kind Regards
Crowclaw,
Thank you very much for seeing that flaw.
That's really a stupid mistake. I corrected it by putting a 1500 ohm resistor there (between positive and the collectie). Leds are a lot brighter now ;D.
Regards,
Flux
how much current does your setup pull in off mode..
i been using the photocell or the way lidmotor used alot..
and it pulls 800 ua's down to 720 ua's..
i would like something that pulled 120ua's or close..
flux.. i like your setup i never used a secondary on my coils in my solar setups..
i always used the pulse's going back to the battery to power my leds..
once i get the hot glue off my old 10 led solar lite i will get a pic or two of it and the circuit..
for the life of me i can't remember what hartley circuit i used in it..
last 4 months i even been forgeting ppl's names.. weird..
robbie
Kooler,
I didn't measure the circuits consumption when it's turned off because i only measure the battery draw.
When the circuit is off the battery recharges from the solar panel.
But i did remember that i measured the 100K pot and it's at approx. 10K so the circuit would be pulling about
2V (solar panel) / 10K -> approx. 200ua (not considering the base).
It could be even better to put a resistor on the base af the first (left side) transistor but i don't know that for a fact.
In the next build i will experiment with that and let you know.
I would start out with a 1K resistor just to give it a try.
But kooler, are you still busy designing new JT circuits? I'm asking because i think your JT circuits rock man.
They work really well and i hope you will come up with new circuits which will be even better (in terms of less amp usage at full brightness).
Regards,
Laurens
Quote from: Flux4Energizer on May 25, 2011, 05:36:22 AM
It could be even better to put a resistor on the base af the first (left side) transistor but i don't know that for a fact.
In the next build i will experiment with that and let you know.
I would start out with a 1K resistor just to give it a try.
Hi Laurens... Yes you will need something like a 1K in the base of the first transistor also to limit the base current. Missed that one!! otherwise your solar panel will discharge through the base junction. Regards Merv
any updates for this? Especially schematics?