http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: RF interference en Wed, 13 May 2026 03:31:25 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-47944 Fri, 25 Nov 2011 01:21:39 +0000 Instography 47944@http://citycyclingedinburgh.info/bbpress/ <p>I'd keep watchy for you. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-47937 Fri, 25 Nov 2011 00:55:46 +0000 Cyclingmollie 47937@http://citycyclingedinburgh.info/bbpress/ <p>If I was 17 again I'd flypost that around Edinburgh. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-47934 Fri, 25 Nov 2011 00:29:30 +0000 kaputnik 47934@http://citycyclingedinburgh.info/bbpress/ <p><em>Brompton folds you</em></p> <p>How could I <strong>NOT </strong>be tempted to do something with that!</p> <p><a href="http://www.flickr.com/photos/kaputniq/6397034339/"><img src="http://farm8.staticflickr.com/7174/6397034339_52f6db3351.jpg"></a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-46351 Sat, 12 Nov 2011 17:08:34 +0000 amir 46351@http://citycyclingedinburgh.info/bbpress/ <p>Fixed! Using loads of aluminum foil. At least in daylight. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-44525 Fri, 28 Oct 2011 13:35:13 +0000 spitters 44525@http://citycyclingedinburgh.info/bbpress/ <p><em>anyone who has take the time to invent and then learn the art of bike-fu has plainly gone brainwrong to the point of danger</em></p> <p>I'll get me coat.</p> <p>Anyone wishing to learn on the other hand get in touch by PM ;) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-44479 Fri, 28 Oct 2011 10:07:55 +0000 amir 44479@http://citycyclingedinburgh.info/bbpress/ <p>Oooh - that's something to think about. Also I might be able to justify buying biscuits ;)</p> <p>Cheers alibali </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-44477 Fri, 28 Oct 2011 09:59:28 +0000 alibali 44477@http://citycyclingedinburgh.info/bbpress/ <p>High beam might saturate the swtching inductor causing it to leak more field. You might find more foil sheilding doesn't do the trick in that case.</p> <p>A steel sheet (biscuit tin lid, for example) located between the lamp and the computer would be an interesting (temporary!) experiment if that turns out to be the case. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215&page=2#post-44469 Fri, 28 Oct 2011 09:02:53 +0000 amir 44469@http://citycyclingedinburgh.info/bbpress/ <p>First time out on the blue bike with the lamp shielded. It seemed to work reasonably well with the light on normal beam, but on full beam I quickly increased my speed to 60 or 90 mph. Discounting the possibility that finally all the criding have been doing has finally had some benefit, I think I'll need to put more foil on (and test it properly this time).</p> <p>Interesting that on switching down from high to normal beam, the speedometer took some time to settle down. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-44067 Tue, 25 Oct 2011 14:20:25 +0000 amir 44067@http://citycyclingedinburgh.info/bbpress/ <p>The battery hatch is hinged. The serious electronics is well in front of this and cannot easily be accessed. I'd be relunctant to hack the light apart. Besides the silver foil gaffer-taped to the light adds a bit more personality to my ride.</p> <p>BTW - one layer of aluminium foil doesn't work - you need several. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-44065 Tue, 25 Oct 2011 14:12:22 +0000 kaputnik 44065@http://citycyclingedinburgh.info/bbpress/ <p>perhaps you could disassemblate the light and get the foil on the inside? although then you have to be careful that the foil doesn't touch any of the internal electronic witchcraftery and cause a short. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-44053 Tue, 25 Oct 2011 13:00:00 +0000 alibali 44053@http://citycyclingedinburgh.info/bbpress/ <p>would metallic spray paint work?</p> <p>Worth pointing out a detail here. As Arellcat says, conductive paint will work but metallic paint is not usually conductive.</p> <p>Conductive paint is usually quite expensive as it has enough metallic (often silver) content for all the bits to touch a neighbour. Metallic paint just has to look nice. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-44023 Tue, 25 Oct 2011 11:22:47 +0000 Arellcat 44023@http://citycyclingedinburgh.info/bbpress/ <p><em>As Wingpig says it's the inducer in many of the circuits that causes the problem even running in solid mode it will still be running at many hertz to change the voltage from the battery voltage to the led's voltage.</em></p> <p>You can see this effect on modern LED traffic lights, and particularly when the red man on the pedestrian control box is illuminated. Flick your gaze quickly left and right and you can see a line of discreet red men as the LEDs flash on and off.</p> <p><em>would metallic spray paint work?</em></p> <p>Conductive paint with a foil-backed cover plate is often what luthiers use to shield a guitar's control cavity from RF. Others prefer to line the cavity with very thin copper sheet, soldered at all the joins. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43990 Tue, 25 Oct 2011 09:56:25 +0000 kaputnik 43990@http://citycyclingedinburgh.info/bbpress/ <p>would metallic spray paint work? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43963 Tue, 25 Oct 2011 07:14:57 +0000 alibali 43963@http://citycyclingedinburgh.info/bbpress/ <p>"Aluminium foil works!"</p> <p>That is good news, so the question now is how to make a practical screen that lets the light out and offers access to switches and batteries etc.</p> <p>I thing aesthetically pleasing might be out of reach..</p> <p>Probably the simplest route would be sticky aluminium or copper tape, as mentioned by custard. This is available for exactly this application and you can probably get some at Maplin, but the 2" tape on custard's link looks OK.</p> <p>Alternatively, a metal box to put the light in would work. Maybe a shortbread tin, for example with a hole for the light.</p> <p>I guess higher output LED lamps probably use some kind of switch-mode regulator to convert the battery voltage to a current suitable for the LED(s) with the switching for battery saving mentioned by wingpig and steveo on top of that. Nowadays these switchers usually operate in the 100kHz (long wave) to 1MHz (medium wave) band (to keep the inductor steveo mentioned small and cheap) but with fast switching (for efficiency) can generate really broad band interference.</p> <p>Which is a long-winded way of saying you can probably gauge how well your screen works by placing an AM radio close to your lamp and tuning it for maximum noise. Then see if your screen reduces the noise... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43947 Mon, 24 Oct 2011 20:07:02 +0000 Cyclingmollie 43947@http://citycyclingedinburgh.info/bbpress/ <p>In Russia Brompton folds you. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43944 Mon, 24 Oct 2011 19:59:32 +0000 Uberuce 43944@http://citycyclingedinburgh.info/bbpress/ <p>Newps, I meant the D lock or chain, although anyone who has take the time to invent and then learn the art of bike-fu has plainly gone brainwrong to the point of danger.</p> <p>I'd pay money to see someone twirling a Brompton about like a pair of nunchucks, mind. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43939 Mon, 24 Oct 2011 19:48:39 +0000 Cyclingmollie 43939@http://citycyclingedinburgh.info/bbpress/ <p>Ha! I take it the "a great big swingable chunk of metal" is the bike. I'm not sure with my puny upper body strength I could wield a bike as a weapon. But Bicycleworks did once try using my bike as a tool by clamping a seized crank in a vice and trying to turn the bike. It didn't work. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43936 Mon, 24 Oct 2011 19:32:12 +0000 Uberuce 43936@http://citycyclingedinburgh.info/bbpress/ <p>I utterly love the fact you've given your bike a tinfoil hat. </p> <p>Any day now it'll be talking about the flag waving on the Moon landings...</p> <p>I was talking to the lady that inexplicably still associates with me about how civilised this forum is. I reckon, cynical old trout that I am, that it stems in part from the fact that everyone knows that the person you're considering insulting only lives a handful of minutes away and will, quite legally, be carrying a great big swingable chunk of metal when he/she arrives. </p> <p>"You call fixed gear a hipster fad again and..."</p> <p>"Blah blah blah. You'll be telling me you rode fixed before it became cool"</p> <p>"RIGHT! That's it!"</p> <p>"What you gonna do, ride over here?"</p> <p>"Yes. It'll take me about eight minutes."</p> <p>"Would only take you five and half riding geared."</p> <p>*cartoon punchup sound effects* </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43935 Mon, 24 Oct 2011 19:25:59 +0000 custard 43935@http://citycyclingedinburgh.info/bbpress/ <p>could you open it and tape the inside of the case?</p> <p><a href="http://www.ebay.co.uk/sch/i.html?_from=R40&amp;_npmv=3&amp;_trksid=m570.l2736&amp;_nkw=aluminium+tape" rel="nofollow">http://www.ebay.co.uk/sch/i.html?_from=R40&amp;_npmv=3&amp;_trksid=m570.l2736&amp;_nkw=aluminium+tape</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43933 Mon, 24 Oct 2011 18:42:16 +0000 amir 43933@http://citycyclingedinburgh.info/bbpress/ <p>Good news (in voice of the professor in Futurama - currently being repeated on pick tv). Aluminium foil works! The lamp looks really ugly but the foil does seem to shield the emanations </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43932 Mon, 24 Oct 2011 18:39:01 +0000 amir 43932@http://citycyclingedinburgh.info/bbpress/ <p>chdot thanks to you and ant, on almost the second anniversary </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43931 Mon, 24 Oct 2011 18:08:03 +0000 chdot 43931@http://citycyclingedinburgh.info/bbpress/ <p>"<br /> BTW I don't think that I could have got such intelligent or generous responses on other cycling forum!<br /> "</p> <p>Don't think it's just cycling forums either. </p> <p>Rules here are simple</p> <p>RULES No personal insults. No swearing.</p> <p>Seems to be enough to have attracted a wide range of (intelligent and generous) people who ride bikes for sensible and fun reasons - ie getting around, seeing things and even taking part in some endurance activities!</p> <p>It started with emails to my contacts and anth's CityCycling mailing list and built with people logging on, seeing how it works - politely, usefully and randomly - and then joining in. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43927 Mon, 24 Oct 2011 16:22:41 +0000 amir 43927@http://citycyclingedinburgh.info/bbpress/ <p>BTW I don't think that I could have got such intelligent or generous responses on other cycling forum! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43926 Mon, 24 Oct 2011 16:20:57 +0000 amir 43926@http://citycyclingedinburgh.info/bbpress/ <p>Thanks JP. Will let you know. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43925 Mon, 24 Oct 2011 16:19:10 +0000 steveo 43925@http://citycyclingedinburgh.info/bbpress/ <p>As Wingpig says it's the inducer in many of the circuits that causes the problem even running in solid mode it will still be running at many hertz to change the voltage from the battery voltage to the led's voltage.</p> <p>I'm not sure but a 3aaa battery light should be ok since these are generally "direct drive" and use very simple tech to regulate the power from the battery to the led, though all bets are off if you put it in flashing mode. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43924 Mon, 24 Oct 2011 16:02:12 +0000 Jackson Priest 43924@http://citycyclingedinburgh.info/bbpress/ <p>I've got a spare computer with wire - Cat Eye 8 I think - if you want it. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43923 Mon, 24 Oct 2011 16:00:34 +0000 amir 43923@http://citycyclingedinburgh.info/bbpress/ <p>My CREE based torch, which I used to supplement the Ixon on dark roads/paths, can trip up the computer from even further away. I think it is the circuit but I am definitely outwith my area of expertise (as always) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43922 Mon, 24 Oct 2011 15:59:52 +0000 wingpig 43922@http://citycyclingedinburgh.info/bbpress/ <p>Whilst some modern lights' improved runtimes are achieved through flickering them on and off quickly, imperceptibly to the non-epileptic eye but easily visible by waving them around quickly in front of a camera doing a long exposure, that would only be in the order of hundreds of Hertz, though it could still be irritating the computer. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43921 Mon, 24 Oct 2011 15:57:11 +0000 kaputnik 43921@http://citycyclingedinburgh.info/bbpress/ <p>I assume it is the part of the circuit that times the pulse, as it has to have some sort of frequency to it. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=4215#post-43920 Mon, 24 Oct 2011 15:55:30 +0000 Cyclingmollie 43920@http://citycyclingedinburgh.info/bbpress/ <p>I didn't know LEDs created electromagnetic interference. I know a spark does and a current through a wire etc. but what's causing it in a diode? </p>