I can't speak for other countries, but here in the UK I used 240V +-7% (223V to 257V) for normal service but for brown to peak I used 240V +-10% (216 to 264V), which is very rarely seen here. The 264V is used to test safety trips and the like according to British Standards such as the the generic BS3456. Factoring Europe into the equation, I reduce the lower band to 198V (220 - 10%), so, my designs covered 198 to 264V for safe and reliable operation. In practice, the lower end often extended to 186V (-15%). This puts quite a burden on dissipating heat at the top end when using linear supplies, but is the penalty when designing for extremes if switchmode cannot be used. Hence tapped transformers to cope with local supplies.
Being aware of this, I have always been wary of generators when /P or dxpeditioning and with valve linears getting the heater voltage right with a true rms voltmeter has always been a concern for me. Small generators often produce more of a triangular waveform and are poorly regulated well beyond +-10% key up to key down. With a transistor linear I am concerned about the peak of the triangle which is higher than that of a sinewave of the same rms voltage, so, component ratings are very important. On full load, the problem is distortion as the incoming voltage drops. Some generators also slow down, increasing the ripple triangle and current into the reservoir caps. David G3UNA My previous email on this didn't appear on the list, perhaps stuck in cyberspace. snip from Juergen Hi Albert The old standard of 220,230,240 volts +- 10% has been gradually deteriorating to plus minus anything! The mains voltages in many places now goes up to and regularly runs at 260 volts! The global de-regulation and privatization of power assets globally has seen standards go down the drain everywhere. Most quality switch mode power supplies are designed for voltages as high as 260 high volts with a plus 5% rating. Many designers and export countries have not caught up with the global deregulation of mains voltage standards. In many places this has been allowed to happen in the hope that a global standard will develop. . 73 John ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
