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Dear Dave,Can u kindly share the measurements of the 330uh coil used ?I mean the details of NO.of turns,length of the wire, diameter of the coil (of the 30 gauze wire)
"Joule Thief" circuit in a Flashlight Bulb? Yes!!!
"Joule Thief" Circuits, crude to modern...
Sorry, tilak1I know nothing about the different readers. When I bought my reader, I thought that I only had a choice of just one.I would have gladly picked the cheaper device, had I known better.
Sir,will the readers like MFRC 522 and EM 18 readers modules will also work in ur case ?can u tell a specific reason why did u use ID 12 LA (a costlier one than the other two ) ?
Thnx for the info
Without the capacitor present to resonate with the coil at 125 kilohertz, the energy picked up would be shorted out and not passed to the LED. Small transistor radios work the same way - they have a coil AND a capacitor. Using math, I tried to match the needed capacitance for the coil that I had wound. After it worked, I adjusted the capacitance a bit by trial and error and got the LED to light up brighter.Increasing the range would require different/better hardware. I THINK that chips having much longer range operate at a much higher frequency - short wave and also UHF.The hardware I purchased came with a RFID chip. This hardware get connected to a Windows PC that can read the number sent from the hardware to the PC after reading the RFID chip.Hope this helps a little...
mguima has a point. One can use the LED leads themselves as sort of a platform for the ic. The regular sized ic is shown used here but a SOT SMT device has also been used by another person, using very careful soldering...
Ur project is simply amazing first of all congo for that. Second is im having some small doubts. What is the use of capacitor here and what will happer if i remove it.Third: How to increase its range to 30-40 cm.Fourth: can i add a Rfid chip to this.Need sooner reply for this project
How to build a simple JT in a flashlight lamp:http://www.bigclive.com/joule.htmIf you want the JT to be small, you should not use a PCB.
Turns out it will light up in the sun if the solar panel is any higher than 1.5V. Even at 2V the red flashed off & on (no blue or green).
Thanks to both of you for the advice. Guess I'll go with a smaller solar panel since it needs to fit in an old round solar light top I have. Amazingly, it will actually light up 5 color changing LED's before the blue starts to "fade out". I'm impressed !!
The suggestion by tkennaugh below looks pretty solid, although I haven't tried it. You could connect a 1 to 10 k ohm potentiometer across two 1.5 volt batteries hooked up in series. Then connect the pot adjustable wiper lead to the solar cell input with the negative of the batteries going to the negative of the IC. Of course, remove the solar cell. Using a multimeter, you could adjust the voltage going to the IC and see what voltage causes the LED to light up, just what tkennaugh is talking about below. Wiring the solar cells in parallel may be just what you need to do...
From the circuit iIt looks like the ic relies on the input voltage from the solar panel being less than the forward voltage of the led. You will therefore need a panel with a maximum voltage around 2.5V. You would be able to increase the capacity of the solar panel by connecting multiple 1.5V solar cells in parallel.
Hi Dave,I'm a newbie to all of this. I think I did the wiring right for the slow color flashing LED circuit you show, I'm including a drawing of what I did.My problem is when the switch is turned OFF and the sun is shining on the solar panel, the LED stays lit.Putting a smaller solar panel (1.5V 200mA) on the circuit, and the LED stays off in the sun.But I still wonder if it is still putting out power which is just not enough to make the LED light up, meaning power is still going thru it somehow?Did I do something wrong?
Hi Dave,I'm a newbie to all of this. I think I did the wiring right for the slow color flashing circuit you show, I'm including a drawing of what I did. Problem is when the switch is turned OFF, and sun is shining on the solar panel, the LED lights up. Putting a solar panel with less output on the circuit (1.5V) and the lights stay off in the sun. But I still wonder if it is still putting out power which is just not enough to make the LED light up and power is still going thru it somehow?Did I do something wrong?
Thanks Dave!Great minds think alike.. We had a old $1.00 solar pole light with a failed battery. I brought into work to examine it and than I read your email this morning. Not knowing any better, I used the o-scope on the direct output of the little panel and only looked at AC. I used the Fluke meter on every thing else. The 60 mV p-p is normal when comparing the two little solar panels. Had I checked the DC right at the panel, I would have found 1.5 to 2 volts (depending how close my light source was to the panel). Both panels checked the same. I am not familiar with solar panels (as you can tell) so this was a fun learning experience. The four pin IC chips used on the solar products had different numbers. I could not find the pin layout for the HW012. Both solar units had different style 1.2 volt batteries. I threw dice and installed the chip with the different numbers. One of the posts on your site said to be careful on chip replacing because the writing on these Chinese chips could be on either side; no marking for Pin #1. I followed your sites advise and just did a quick ohm job between the two different style boards. I checked to see what pins were connected to what part of the circuit. Sure enough the writing was on the opposite side of the HW012 as compared to the QX5252F. Its works like a champ now! Thank you so much for sharing your technical expertise without hesitation. Have a Safe and Happy Fourth! John with the lit up porcupine....
Dave,My wife got a little cheapy, solar light (2 led) cement animal from Menards. It has never worked. It is a seasonal thing so Menards have no more. I thought I would see if I could fix it. I replaced the 1.2 volt watch type battery. Nope, no help there. The solar panel puts out a uniform sign wave at 50 mV p-p. Is that too low? Is the solar panel bad? This was checked with an oscilloscope. With the new battery in place, I measure 1.2 volts dc at the leds with the switch turned on. 0 volts with the switch turned off. I tried a digital Fluke meter and a scope. I see no sign of any kind of AC waveform present at the leds. Is the QZ5252F chip bad? I know that I am knuckle head to spend time on a $3.00 cement porcupine, but I am the curious kind. Thanks for any light you can shed on this. John Lowell, Indiana
Thank you for the tip. I found pretty much what I needed as far as spec sheet. I even was able to make a little EXCEL sheet comprising a compilation of different spec sheets Data and some schematic. I am glad to share it for anyone interested. This attachment is an EXCEL file.
Denis Rev Sorry I'm Not sure how to make a drawing yet but i'm learning, dpp is a drawplus program I will attach a pdf file that should open easily.Regards
Hello J, I read that you got your hand on the spec sheet of this 5252F. Would you mind letting us know how we can get this spec sheet? I tried looking up the WEB unsuccessful. Thanks, Pierre - pierr2323
Dave,There are two observations. All the parts are new. The inductor is not the "seafoam green" but brown and I can't seem to find what those differences if any are. I have some smaller inductors coming. The first day or two no doubt were sunny and they certainly got a good charge but if I measure the batt voltage I get more than a volt(AA). One I had on a bread board and the other I soldered up. Neither will stay lit for more than a few minutes now. In fact to get the one that is solders up I have to flash the light in the dark room on to trigger it. Any thighs would be appreciated. I'll put together some others and see what happens.
Dave,I found the spec sheet for the 5252f says it switches off at .9v so that must be what is happening so I'm going to replace with a new akaline battery(its raining today) and see how long it lasts. I'll also build a new circuit with a switch from the battery so I can save the batt and turn off the light. I'm hoping this will be the fix! Thanks for your help and I'll let you know what happens this weekend
Dave, I've been using the "nocturnal solar lamp" instructable and when I first built them they worked flawlessly. I was just trying to prototype before I built them into a container and they charged up during the day and lasted all night till the morning came and they turned off. Now they only come on for shorter and shorter periods of time. The battery shows 1.4 volts and the Solar Panels are 3 volts an 70ma. I have a 330uh inductor and a 0.5W straw hat. I can't work out why this is happening. Any ideas?
"Joule Thief" - no IC and no Transformer
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