| General > General Technical Chat |
| Fix the voltage campaign (Australia) |
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| GlennSprigg:
Some people forget, (or don't realize?) how much the voltage changes during the day/night depending on the present load. When I first started my 'trade' in the 70's with E.T.S.A. (the Sth Aust Power auth then), we had 'O.L.T.C.' (On Load Tap-Changing) Transformers in the main Switch-Yards, that would automatically try to change output Tap voltages throughout the day. Would drop to 230v, kick in to about 250v, drop back to about 240v by evening when everyone is cooking!. Air conditioning was not a major problem back then!! ;) It's sort of like Homer Simpson, saying... "I like to think of speed signs as like a 'suggestion', like wearing pants!" (Regarding the 'latter' in the above line, I just live outside in Jocks & singlet now.. being Australia! 8) ). |
| james_s:
--- Quote from: vk6zgo on December 29, 2020, 01:58:53 pm ---For many years, the standard Mains voltage in Western Australia was 250v, instead of the 240v standard in other States. Electrical & Electronic equipment designed for 240v use had no discernible reduction in life expectancy. Back when we made incandescent lamps in Australia, 240v ones would happily operate on 250v for extended periods, again with no discernible difference in life expectancy. The "bean counters" decided it was cheaper to import lamps from third world countries, so Australian manufacture was wound up. The imported "240v" ones had markedly reduced life times, up to a fifth as long as the old Oz ones. Importers knew a "nice little earner" when they saw one, & specially imported "260v" lamps for WA at a premium price---------- they lasted just barely longer than the "240v" ones! --- End quote --- The original ones were probably good quality 250V lamps which would also run (at significantly reduced efficiency) on 240V in other regions. It's true that a lot of newer incandescent lamps have been low quality compared to those made during the peak but lifespan is only part of the story. It's fairly trivial to make an incandescent lamp that will last 50,000 hours or more, if you don't care how many lumens per watt it produces. The vast majority of the cost of using an incandescent bulb is the electricity it consumes, so it is a false economy to optimize for long life unless the bulb is difficult to change in which case there are better choices these days. There is no conspiracy involved in the 750-1000 hour lifespan, there is simply a tradeoff between lifespan and efficiency and 750 hours is a reasonable compromise that offers reasonable (by incandescent standards) efficiency at an acceptable lifespan. On one end of the spectrum are long life bulbs, you used to be able to get 130V bulbs that would last substantially longer on 120V but they were also quite dim for the wattage. On the other end of the spectrum are photoflood bulbs, I have a few of those and they have a rated life of 6(!) hours but they are very bright and produce a lot of light for the power they consume, again by incandescent standards. If you ignore the cost of your time to acquire and replace bulbs, the optimal lifespan for incandescent is probably around 100 hours or so. Longer life bulbs cost you more in electricity and shorter life bulbs cost you more in bulbs. In the real world the value of the time, effort and convenience shifts things toward longer life. 240V bulbs are also significantly less efficient than 120V bulbs which themselves are significantly less efficient than low voltage bulbs due to the increased thermal losses of the longer, thinner filament required for higher voltage operation. A 240V 60W bulb is pretty close in brightness to a 40W 120V bulb. |
| james_s:
--- Quote from: vk6zgo on December 29, 2020, 02:42:13 pm --- --- Quote from: themadhippy on December 29, 2020, 02:08:26 pm --- --- Quote ---energy guzzling inventions of Satan (or at least Edison --- End quote --- Mr swan might have an issue with that statment --- End quote --- But he wasn't mean to the great god Tesla! --- End quote --- Eh, Swan and Edison independently developed similar lamps over roughly the same period of time, the idea of an incandescent lamp was not completely new and neither inventor started from scratch, they simply perfected a marketable product and while I'm less familiar with Swan, Edison's main accomplishment with the light bulb was not inventing a bulb but developing and marketing the entire infrastructure. A bulb is useless outside of the laboratory unless you have sockets and switches and dynamos, meters, and other components. Edison knew this and put together everything needed for a complete system and got it into production so consumers could actually buy it and I suspect Swan did something similar in that part of the world. Edison was not known for being a particularly nice guy but that's true of countless other accomplished people, nobody remembers Steve Jobs, Bill Gates or even Linus Torvalds for being friendly. Tesla was brilliant but calling him eccentric would be an understatement and in the later part of his life he was downright nutty. He was a showman and enjoyed being mysterious, it can be difficult to separate his actual developments from the rumors and legends surrounding him. Aside from this, I don't think Tesla ever produced and sold a marketable product himself, he wasn't a businessman. A dozen Teslas might develop some really cool technologies but without guys like Edison, Westinghouse and others like them most of these technologies would never evolve into something people can actually buy. |
| cdev:
Do parts of Australia still use the differently phased power grid? I think it used the ground as the return? |
| NiHaoMike:
--- Quote from: james_s on January 11, 2021, 01:36:28 am ---240V bulbs are also significantly less efficient than 120V bulbs which themselves are significantly less efficient than low voltage bulbs due to the increased thermal losses of the longer, thinner filament required for higher voltage operation. A 240V 60W bulb is pretty close in brightness to a 40W 120V bulb. --- End quote --- Back in the day, there were a few "enhanced efficiency" incandescent bulbs that had built in series diodes to lower the effective voltage so that the efficiency can be improved. They were very quickly overtaken by CFLs which offered a much greater improvement in efficiency. |
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