It *IS* AC. 10-30kHz AC. And 40A isn't going to cut it. I think Leonardo is mentioning 97A/phase MAINS input. Compute the input power draw. Is typ goes through a high freq stepdown transformer so its only a couple volts AC and hundreds (thousands?) of amps. Takes many many kJ of energy to make that much iron glow in seconds. Simple physics. I used to work w/ a girl (20yrs ago) who did her phd in induction heating and the resonant control of it. The coils are often copper tubing and water cooled. Its very cool to watch work.
On Wed, Mar 11, 2015 at 8:16 PM, rayj <raymo...@frontiernet.net> wrote: > Thanks for the reply. I'm thinking about building a little one for my > home shop, so I'm interested how they do it in the real world. > > If I understand correctly, you're running DC through the coil, and it > oscillates from 0 amps to 40 amps between at a chosen frequency between > 10-30 kHz. > > I'm surprised it's DC, for some reason I assumed it would be AC. > > Thanks again for the reply. Good luck on the project. > > Raymond Julian > Kettle River, MN > > The things we admire in men, kindness and generosity, openness, honesty, > understanding and feeling are the concomitants of failure in our system. > And those traits we detest, sharpness, greed, acquisitiveness, meanness, > egotism and self-interest are the traits of success. And while men > admire the quality of the first they love the produce of the second. > -John Steinbeck, novelist, Nobel laureate (1902-1968) > > On 03/11/2015 01:24 PM, Leonardo Marsaglia wrote: > > 2015-03-11 15:08 GMT-03:00 rayj <raymo...@frontiernet.net>: > > > >> Looks like a good process. What frequency,voltage and amperage are you > >> using? > >> > > > > The heater runs up to 97 amps (per phase) and depending on the lobe to > heat > > we're using it with more or less current. The minimum we're using is > about > > 40 amps. > > > > Voltage is about 650 v when rectified if I'm not wrong because it takes > the > > three phase 380 v from the line. > > > > Frequency goes from a minimum of 10 Khz to a maximum of 30 Khz depending > on > > the coil, because it has a phase locked loop to mantain the resonance at > > all times. Frequency is not that critical, since you can play with the > > amount of power and the heating time to change the depth and the value of > > the hardness to reach. Also an exquisite way of controlling that is to > vary > > the temperature of the water to cool the part. > > > > > > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming The Go Parallel Website, > sponsored > by Intel and developed in partnership with Slashdot Media, is your hub for > all > things parallel software development, from weekly thought leadership blogs > to > news, videos, case studies, tutorials and more. Take a look and join the > conversation now. http://goparallel.sourceforge.net/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
