| ??? 07/14/04 18:17 Read: times |
#74244 - RE: Ramping instead of zero-crossing Responding to: ???'s previous message |
Kai:
1. an enormous amount of axtra costs will result, and The (wrong?) assumption was that the extra cost is several lines of code. 2. that now an over-stress condition somewhere else must be kept under control! like the power plant or the nearest power supply station with heavy "industry quality" equipment meant to withstand much more, and owned by the power provider company, instead of the "consumer electronics", expensive and fragile and expensive to repair - for us. Besides, we are talking about controlling the process in such a way that the over-stress doesn't occur. Erik: I'm not talking about running 10A through a device that provides 1Kohm resistance at that moment (that would be about 1000V) but simply over short time (100ms?) decrease the resistance. Let me count then... Assuming 10A at 230V that is 23 ohm receiver and ramping from 1000 ohm to 0 in 0.1s, that is about 260J to dissipate within 0.1s - 62 calories or 1cc of water by 62 degrees up within 0.1s, that IS some serious thermal shock, but first, it's the whooping 10A we're talking about, second, once it happens, we have all the time we want to dissipate the heat. I'd say this is walking on thin ice already, but doesn't sound impossible enough not to be worth a thought. |
