In message <[email protected]>, dated Mon, 24 Nov 2008, Kevin Richardson <[email protected]> writes:
>I have a client who has a 4 channel, professional lighting dimmer >device, designed to be used for small stage productions (schools etc). >The device is failing 61000-3-3 flicker requirements. This device is >designed to switch the lighting outputs on and off at high rates - >potentially 7 times per second, and the result naturally is a poor >result in the flicker tests. The user is in direct control of the >switching rate and therefore the potential resulting "flicker" detected >on the mains. I am surprised that such a facility is offered, due to the risk of inducing seizure in persons with photo-triggered epilepsy. This would be particularly unwise in a product for use in schools. For example, a student might not have previously been diagnosed with the condition. > >As I understand it, 61000-3-11 also includes requirements for >"conditional connection" devices and that devices that can not comply >with 61000-3-3 can be covered under 61000-3-11 as a "conditional >connection" device. > >My questions: >* Am I correct in assuming that this device would need to comply >with >the "conditional connection" requirements of 61000-3-11? Yes. >* Can anyone give me a rough idea of the "conditional connection" >restrictions/requirements? A rough idea, yes, but you need to read the standard. You have to specify the maximum supply impedance that allows the flicker requirements to be met. This is bound to be lower than the 'standard' impedance specified in IEC/EN 61000-3-3. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
