All, Nitpicking here, but the correct term is "Capacitance", not "Capacity". Regards, Jim ----- Original Message ----- From: "Rich" To: "Microcontroller discussion list - Public." Sent: Sunday, August 10, 2008 12:23 AM Subject: Re: EE >I wonder if I am mistaken here. The transformer primary is an inductive > element. True, there is distributed coil capacity, and a frequency > component that makes the system complex. So there will be some "natural" > resonance that may not be at 100 KHz and may have a very low Q, regardless > of the fact that the transformer was designed to operate at 100 KHz. But > by > adding the properly selected components, could one not design starting > from > the LCR characteristic of the primary winding to create a tuned circuit at > 100 KHz and 50 ohms Z? Also, would it be true that if the Q is high the > stability of the oscillator must be high in order to stay within the > resonant bandwidth? So, a high Q may not be desireable and the R > component > would be a factor? All comments, criticisms, "Oh what stupidity" comments > are welcome. > > > ----- Original Message ----- > From: "Vasile Surducan" > To: "Microcontroller discussion list - Public." > Sent: Saturday, August 09, 2008 9:07 AM > Subject: Re: EE > > >> Nice way of computing... A square signal bumped with a positive glich >> at the end of the rising edge will increase the current with 10-20% at >> the same secondary load. >> Does the primary impedance seen by the driver will be different ? >> >> Vasile >> >> On 8/9/08, Apptech wrote: >>> > Where did you get 16 ohms from? >>> >>> R = V/I. >>> The driver sees the load reflected via the transformer. If >>> 230 VAC causes 14 amps to flow then the AC is seeing 230/14 >>> ~= 16. >>> >>> In the absence of load the actual transformer impedance will >>> be seen but it will very usually b swamped when loaded. >>> >>> >>> Russell >>> >>> >>>> I have to drive a transformer primary at 230 VAC @ 14 >>> >>>> Amps @ 100KHz. I have not yet measured the primary >>> >>>> impedance, but I will. >>> >> >>> >> The impedance you see will be about 16 ohms - ie the >>> >> load, >>> >> more or less regardless of the transformer's unloaded >>> >> impedance. >>> >> >>> >> >>> >> Russell >>> >>> -- >>> http://www.piclist.com PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist