http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: LED bulbs en Wed, 13 May 2026 03:27:56 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=4518&page=2#post-48018 Fri, 25 Nov 2011 14:55:51 +0000 steveo 48018@http://citycyclingedinburgh.info/bbpress/ <p>I've got a couple of drivers going spare they're about the size of a penny and a few mm deep, you could probably find a home for one and still keep the batteries in the casing. They are only Buck regulators but there isn't really much power left in a AA battery once it drops to about 1.1v and even then the regulator swaps to what is called direct drive mode where regulator circuits are bypassed and the power is taken as is from the battery. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518&page=2#post-48015 Fri, 25 Nov 2011 14:32:25 +0000 wingpig 48015@http://citycyclingedinburgh.info/bbpress/ <p><blockquote><em>"...the only time a buck/boost regulator would be useful would be with a 3xAA battery..."</em></blockquote></p> <p>I've a couple of casings for 3*AA incandescent lights sitting about which I was wondering about doing something with, though would probably use the casing for circuitry and have the cells sitting somewhere else (probably bolted to the downtube bottle bosses, where I can't put a bottle as they tend to be wheeched off by the cuffs of my shorts) so that I can still get some use out of some older cells or those which were stranded as singles after a pack of four was used to power a three-cell light. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518&page=2#post-48007 Fri, 25 Nov 2011 13:58:06 +0000 steveo 48007@http://citycyclingedinburgh.info/bbpress/ <p>You can get buck/boost drivers that control the out put at voltages both under and over the leds range. A good white led needs about 3.5v at 500ma so when the battery is &gt;3.5v the voltage is reduced (buck) and once the voltage drops below 3.5v it is boosted to continually meet the current requirements. These are pretty uncommon because they're (relatively) expensive, not very efficient and not all that useful. Once a NIMH battery voltage drops to about 1.1v its as good as flat and the only time a buck/boost regulator would be useful would be with a 3xAA battery since the starting voltage is about 4.2v and the dead voltage is 3 volts.</p> <p>TBH nimh don't <em>really</em> need to be discharged fully and its harmful to Lithium batteries. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518&page=2#post-48005 Fri, 25 Nov 2011 13:56:13 +0000 duncans 48005@http://citycyclingedinburgh.info/bbpress/ <p>There are quite a few 'voltage boost' circuits that will give a steady 5v for -whatever- input, until the bitter end, when they suddenly drop out. </p> <p>I've had some good experiences with this:</p> <p><a href="http://www.hobbytronics.co.uk/components/voltage-regulators/pololu-5v-boost-regulator" rel="nofollow">http://www.hobbytronics.co.uk/components/voltage-regulators/pololu-5v-boost-regulator</a></p> <p>...which I'm using to supply my cheapo keyfob headcam doodat.</p> <p>These are great things, you can run a 5v circuit from a single 3.7v, 1.5v or 1.2v, no problem. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-48004 Fri, 25 Nov 2011 13:47:26 +0000 wingpig 48004@http://citycyclingedinburgh.info/bbpress/ <p>I'm intrigued by various claims along the lines of "contains fancy circuity to keep the output at the right level until the cells are completely dead". Has anyone had any experience of lights/component LEDs which keep going at a reasonable level, ekeing every coulomb out of the cells until dropping suddenly dead? It would remove the need for the winter chore of leaving lights on throughout the day on the desk until they're fully discharged, ready for recharging. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47996 Fri, 25 Nov 2011 12:58:15 +0000 steveo 47996@http://citycyclingedinburgh.info/bbpress/ <p>Oops I think that is my fault, I've got dynamo lighting on the brain at the moment...</p> <p>Er yeah it'll work fine from batteries a couple of good quality rechargeable AA's in C/D adaptor cases and they'll be right. If its just a "be seen" light then I wouldn't worry about the beam pattern the LED will be much more spread out but that'll just help you be seen from the sides.</p> <p>Worth bearing in mind though that if its more than a couple of pounds for the bulb you'd probably be better getting a new light. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47992 Fri, 25 Nov 2011 12:47:27 +0000 Its_Me_Knees 47992@http://citycyclingedinburgh.info/bbpress/ <p>Not intending to use a dynamo - C or D batteries in a couple of old lights (ever-ready stylee) is all I'm looking at. Did wonder about the beam pattern right enough, but prepared to see if that remains useable/legal... </p> <p>From the replies thus far, I take it no-one has actually done this...? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47991 Fri, 25 Nov 2011 12:36:24 +0000 steveo 47991@http://citycyclingedinburgh.info/bbpress/ <p>Weight (kg): 0.0005 </p> <p>Just imagine how many of them will fit in a packing container! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47990 Fri, 25 Nov 2011 12:30:36 +0000 chdot 47990@http://citycyclingedinburgh.info/bbpress/ <p>"<br /> Country of Origin: TW Taiwan<br /> Country in which last significant manufacturing process was carried out<br /> "</p> <p>How in the 'real world' can you make something, ship it half way round the planet and retail it for 31p!!</p> <p>Yeah I know. It's the global economy we're all in it together with. </p> <p>Not even as though Taiwan is a low wage economy anymore. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47987 Fri, 25 Nov 2011 12:10:20 +0000 duncans 47987@http://citycyclingedinburgh.info/bbpress/ <p>'Build a rectifier'!?</p> <p>Just buy one, for example:</p> <p><a href="http://uk.farnell.com/fairchild-semiconductor/mb1s/bridge-rectifier-0-5a-100v/dp/1467483" rel="nofollow">http://uk.farnell.com/fairchild-semiconductor/mb1s/bridge-rectifier-0-5a-100v/dp/1467483</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47986 Fri, 25 Nov 2011 12:09:39 +0000 kaputnik 47986@http://citycyclingedinburgh.info/bbpress/ <p>I have to say with the price a new semi-decent LED light can be bought for, with someone else doing the electronic gizmodgery for you it might be quicker and cheaper in the long run (and get you a better light) to buy a new one. You can get something pretty good for around the £20 mark and they'll probably throw in some batteries too. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47979 Fri, 25 Nov 2011 11:55:19 +0000 alibali 47979@http://citycyclingedinburgh.info/bbpress/ <p>Another issue is the beam pattern, if that matters to you. The reflector in your lamp will not be effective for a front firing LED with a lens like that. If there is a lens glass, that will work OK provided the LED is pretty much where the fillament was before.</p> <p>I think it's worth a try, but only with a rectifer (cheap) to supply DC to it. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47952 Fri, 25 Nov 2011 10:15:27 +0000 steveo 47952@http://citycyclingedinburgh.info/bbpress/ <p>It probably won't work for long any way, it really depends on the electronics in side. Your dynamo is out putting a very wide range of AC voltage the electronics for this device are expecting max 9v DC. </p> <p>The cheaper and simpler way is to make a bridge rectifier and find a simple way of fitting a single emitter into the body, It'll be brighter and there is no way you'll blow it. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47946 Fri, 25 Nov 2011 08:07:40 +0000 custard 47946@http://citycyclingedinburgh.info/bbpress/ <p>well the listing makes them look good<br /> If it were me I would give one a shot</p> <p>had a look on DX?</p> <p><a href="http://www.dealextreme.com/c/led-light-bulbs-907?page=1&amp;pagesize=52&amp;pagesort=price" rel="nofollow">http://www.dealextreme.com/c/led-light-bulbs-907?page=1&amp;pagesize=52&amp;pagesort=price</a></p> <p>might get a cheaper option </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47941 Fri, 25 Nov 2011 01:12:09 +0000 Its_Me_Knees 47941@http://citycyclingedinburgh.info/bbpress/ <p>This is the £12 bulb on ebay <a href="http://www.ebay.co.uk/itm/TTS-1WCREE-1-Watt-CREE-2-9V-LED-Torch-Flashlight-Bulb-Replacement-Upgrade-/280746485262?pt=UK_SportsLeisure_Camping_LightsLanternsTorches&amp;hash=item415dcb660e#ht_1641wt_952">here</a>.</p> <p>It's not a screw fit, but would fit some of my older bike lights that I'm trying to 'refurbish'... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47939 Fri, 25 Nov 2011 01:06:09 +0000 seanspotatobusiness 47939@http://citycyclingedinburgh.info/bbpress/ <p>Hi, have you got a link?</p> <p>I found this: <a href="http://www.ebay.co.uk/itm/Pk-2-6V-White-LED-MES-Bulb-100-screw-MES-Lamp-/130560966203?pt=UK_BOI_Electrical_Components_Supplies_ET&amp;hash=item1e660a3e3b">http://www.ebay.co.uk/itm/Pk-2-6V-White-LED-MES-Bulb-100-screw-MES-Lamp-/130560966203?pt=UK_BOI_Electrical_Components_Supplies_ET&amp;hash=item1e660a3e3b</a> (and a few similar) but they're a lot cheaper than whatever you've found and not very bright at all. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4518#post-47930 Fri, 25 Nov 2011 00:09:07 +0000 Its_Me_Knees 47930@http://citycyclingedinburgh.info/bbpress/ <p>Has anyone tried to replace an old incandescent bulb in a bike light with an LED one? I see such bulbs exist (ca. £12 on ebay) and they 'should' provide longer battery life and much brighter light, but I was wondering if they are worth the expense? </p>