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    Repairing a CFL that stopped working after a few hours of use

    A long time ago I bought a multipack of CFL bulbs and I no longer have the receipt. I put one of them into service and after a few hours of use (and about three ignitions) it has stopped working. I've opened it up and I see nothing obviously wrong. What parts can I test? How many hundreds of...
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    Seeking help reverse engineering laptop screen inverter sans datasheet

    I have a few inverters from broken laptop screens (Dell Latitude LS model) and there are no datasheets that I can find for the controller IC (3972 OAW). There are only four input pins for the inverter board and I think that it might be possible to figure enough out to connect it to power without...
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    What way around are these voltage regulators?

    I think these two black components with 1Aomega written on them are voltage regulators. Can anyone advise me what the pinout will be? I've tried searching for a pinout for a SMD voltage regulator with a dot on it but failed. Thanks!
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    Using CCFLs from broken laptop screens - how well matched do tubes and power supplies need to be?

    I've taken apart some broken laptop screens to get the CCFLs and their power inverters. Most of the CCFLs are matched with their inverters but some came to me already separated. Are they likely to work with each other's inverters? Realistically, is a CCFL liable to explode with another CCFL's...
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    Gold-coloured areas on laptop circuit boards - gold or pyrite?

    I'm taking apart some broken laptop screens I received for free so I can get the CCFLs. I figured I'd also retain any gold plated connectors which I want to save until I have enough to recover the gold and buy a burger! There are some things that are gold-coloured but I wouldn't expect to...
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    How to get 3.3 V from a charged LiPo battery?

    I would like to power an Arduino Mini/Nano at 3.3 V using a LiPo phone battery with max 4.2 V. How do I render the voltage from the battery suitable for the Arduino? 4.2 V seems to be less than the minimum for all the regulators I've looked at. What should I look for? Thanks!
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    Confused by circuit. A to B and B to C implies A to C?

    I made a simple circuit to take current from my dynamo to charge batteries and power lights in parallel. I'm having a problem that doesn't make any sense to me. For simple wires (semi-conductors) I would expect that if A and B are connected (<2 ohms) and B and C are connected (<2 ohms) then A...
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    How to determine voltage on transformer

    I have what I think is a transformer and I've got mains voltage going in at the top of the image and I'm trying to measure the voltage that I get from the bottom of the image with a DMM set to 500 V AC. The top resistor is 33K and the bottom resistor is 20R. When I apply mains voltage to this...
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    Will measuring the resistance of a capacitor damage it?

    If I put a DMM across a capacitor (say 10 V rating) and measure the resistance, will the DMM increase voltage beyond the rating of the capacitor and cause damage?
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    Changing the timer of an old battery charger to a longer time

    I have a Uniross X-press 300 battery charger and it just like this but I think I have an older version with lower current: The selector switch toggles between a six or nine hour charge time and since battery capacities have increased significantly since I bought it about 15 years ago, it...
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    Why isn't this image showing up?

    http://imgur.com/ml4OtBM.png
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    Where to count legs from for TO-94?

    Is it customary to print labels on the backs of TO-94 packages? So the beveled edges are on the back? So the flat unlabelled side is where I should start counting the legs from the left?
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    Why are mains plug pins usually made of brass in the UK?

    Why are mains plug pins usually made of brass in the UK? They're usually a silver-coloured metal in other countries, right?
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    Can an old Ni-Cd battery charger be used for Ni-MH batteries?

    I have an old Vidor model RX PC battery charger which is for charging Ni-Cd batteries. It charges at 150 mA for AA, 50 mA for AAA and 10 mA for 9V/PP3. Can it be used to charge Ni-MH batteries? If not, can it potentially be modified to do that? It just seems a waste to discard it if it can still...
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    Could a consumer electrical power meter measure power used by a dehumidifier?

    I want to be able to measure the average power used by a dehumidifier. Could this kind of power meter do that? I've read that they may not be accurate for "reactive loads".
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    Would variations in weather temperature shorten life of LED bulb?

    I was considering replacing the bulb in my mother's outdoor lantern with an LED one. Will the driver circuitry in the base of the lamp be adversely affected by the yearly variations in temperature (country is United Kingdom)? I'm not sure what kinds of components are usually found in the base of...
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    Want to increase brightness of LED headlight

    I have one of these magnifiers and they're sort of almost useable at 2.5x but the light isn't very bright at all. I attached my bench power supply and determined that at 3.6 V a current of 20 mA would flow which is my guess at what the LEDs are rated for (maybe it's not; all I know for sure is...
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    What is this weird plug/transformer?

    I have an electrical plug and I don't understand what it's all about. It looks a lot smaller than a transformer usually does and although it says DC5 on the side, I outputs about 4.8 V AC. If I wanted to find out about its use what would I need to type into Google? What usees 4.8 V AC? I have...
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    UT61E multimeter - milliamps function not working

    I have a UNI-T UT61E multimeter and the mA function was working earlier today but now it isn't and I'm not sure why. The fuse installed is 500 mA instead of the original 1 A but that doesn't compromise protection and that fuse is not blown and I'm pretty sure I haven't subject it to more than 1...
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    Varnish vs enamel

    Hi. Is this product the same as enamel on enamelled wires or is varnish something different?
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