induction furnaces (as opposed to induction > stoves) normally operate at an RF of 13.56 MHz. The fifth harmonic > (2^5) of this frequency is 434 MHz...
I think he means a kitchen furnace, those operate at a little above 20 KHz (I only know it is a little above our hearing limit, I do not know the exact frequency). The area is quite large, and having such large coils at this 434 MHz would mean skin-effect losses, that is why the frequency is "low". And you do not need such high frequency's to get Focault-currents anyway. Low frequencys will penetrate the metal to be heated better. However, if he indeed means a 13 MHz system, this could be the problem. And in practice I often see that in systems the 5th harmonic is the most difficult one. > Normally the RF should be a nice sinusodial signal in order to > suppress overtones, but given a high enough energy you can easily end up with a strong set of overtones.... even easier if it's a cheaply > built RF generator, an impedance mismatch between oscillator and > coil,... As the power is so high, 2000 Watt, you can get several saturation effects in the shielding, causing the signal to leak strongly (especially when things get hot - furnace). Regards, Pieter Hoeben http://www.hoeben-electronics.com ______________________________________________ Hoeben Electronics Phone: +31 6 51590081 Ronkert 44 Fax: +31 13 5096025 5094 EW Lage Mierde Private: +31 13 5096200 The Netherlands E-mail: [EMAIL PROTECTED] http://www.hoeben.com ______________________________________________ -- Author: Pieter Hoeben INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
