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Forum Index : Electronics : CFLs
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rustyrod Senior Member  Joined: 08/11/2014 Location: AustraliaPosts: 121 |
In my quest for AMPERAGE saving lighting I discovered these CFL units. They are 24 volt and draw 250 ma. I purchased 20 at about $10.oo each, this seems a lot of money but at the time the government said “YOU NEED CFLs” and at the supermarket or at the hardware the 240 volt units were around the $7.00 each. On arrival and plugging in, I found some did not work and a few exploded internally on contact. Unbelievable amount of the “smoke” came out. In no time, more blew up or just didn't come on. I sent some back by registered mail, believe it or not they came back by registered mail, marked “Not known at this address” Return to sender. Hmm something strange here I thought. I was unable to contact the supplier. 
THE WIRES I eased the “did not come on” units apart to find the STEEL wires from the tubes were wire wrapped to the circuit board. Through the small gap,I put a drop of bakers on them and soldered it up. All the units came to life, BUT alas over time some returned to not coming on and some blew up. 
Months later I tried to contact the supplier again, inquiring if he had any more? Reply “Yes Mate containers of them $1.00 each” “How many you want?” So I got another 20 and 10 X 12 volt ones too. I immediately soldered them up and same thing, some worked, some blew up. I bought in new transistors, fitting them, same thing, some work, some immediately blow up. Like I mean the transistors literally explode. I started testing the transistors and fitting them in pairs. No better luck. 
THE CIRCUIT The circuit is so simple. The diodes all test fine. The caps all test fine. The chokes and transformers all test the same uH. The D822 transistors are rated to 30 volts so I have made dam sure no one turns them on during the day when the solar panels have the battery voltage up. Drastic, but I was removing them from the light fittings every morning. Now to throw a question mark into the whole works, there are 5 (five) still working and get used most nights for about coming up 3 years. Go figure that. I am not game to pull them apart. Why have they lived and all the rest have died? I have spent around $300.oo for five lights, they need to last 50 years even then,considering my age, I personally will not get my money's worth. I have not tried the 12 volt ones at all. Has anyone any experience with low voltage cfls? Any suggestions? Always Thinking |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi Rod I did go through 3 12v CFL's from Jaycar a few years ago. They worked for a few months, but eventually gave up. Problem was usually over heating causing dry joints around the transistors, or the fluro tube was just overdriven to the point of failure. In the end I used a couple of the repaired circuit boards to drive a 24 inch and 48 inch fluro tube. The 48inch tube was about half normal brightness, but the 24 inch is near full brightness and is connected as a night light under my house. It runs of my 12vdc system, turns on at dusk and off at dawn, and has been running like this for over 3 years now. The circuit board just fitted into the 24inch fluro fitting, and I think having the extra space around the circuit board has helped to keep it cool and given a long life. So thats my tip. The circuit board from a 12v CFL can drive full sized tubes. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| VK4AYQ Guru  Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Rod I had the same problem and on 24 volts they overheated badly and soon cooked I got some 12 volt ones off ebay and they did better but out of ten 4 where faulty from new, in the end I set up the lights to run of a little 600 watt mod sign wave Inverter and that worked good, running the 240 volt globes and fluros in the house until some idiot (no names mentioned) shorted it out and let out the magic smoke. It ran on two old batteries resurrected from the tire service with one 80 watt panel and a desulphator hay wired up to them. I am now going to convert all the house to 12 volt lighting using led 12 volt lights I have some 240 volt ones running but not very reliable, China rubbish, cheap and nasty. The lights are good but the circuit drivers cook up as did the CFL ones, the components in the circuit are badly undersized and chosen from the reject bin I am sure. Just a suggestion on your circuit of the light inverter, you could try a bridge rectifier on the inpot and that will make the circuit not polarity sensitive and also give a bit extra voltage drop into the circuit and a series resistor as well to drop the voltage a bit more as it looks to me that it could overvoltage things fairly easily. All the best Bob Foolin Around |
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powerednut Senior Member Joined: 09/12/2009 Location: AustraliaPosts: 221 |
hate to plug them, but check out your local bunnings. They sell 12V CFLs. I've bought 2 which have been running for about 4 years now (most nights). The jaycar ones blew after about 3 months. You can also get 12V LED downlights, which seem to work quite well for me. These arn't the same brand I bought but might be worth a crack at $15 for the 4 pack: http://www.bunnings.com.au/ledshine-3w-led-mr16-4-pack-globe s_p4331145 |
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