https://en.wikipedia.org/wiki/File:Royer_oscillator.gif I think the transformer phasing dots are wrong. Or, am I wrong?
Royer oscillator - phasing dots
Started by ●June 20, 2020
Reply by ●June 20, 20202020-06-20
On 6/20/2020 12:28 PM, John S wrote:> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif > > I think the transformer phasing dots are wrong. Or, am I wrong?Right transistor collector pulls down, right transistor base gets pushed up, the other vice-versa, looks like positive feedback to me?
Reply by ●June 20, 20202020-06-20
On 2020-06-20 18:28, John S wrote:> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif > > I think the transformer phasing dots are wrong. Or, am I wrong?What an awful schematic diagram. I think you are right, the phasing dots are wrong. Jeroen Belleman
Reply by ●June 20, 20202020-06-20
On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman <jeroen@nospam.please> wrote:>On 2020-06-20 18:28, John S wrote: >> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif >> >> I think the transformer phasing dots are wrong. Or, am I wrong? > >What an awful schematic diagram. I think you are right, the >phasing dots are wrong. > >Jeroen BellemanThe base current has to come from the two (two? why?) resistors from the transformer ct. There are better ways. This is kind of ancient. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●June 20, 20202020-06-20
On 6/20/2020 2:26 PM, jlarkin@highlandsniptechnology.com wrote:> On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman > <jeroen@nospam.please> wrote: > >> On 2020-06-20 18:28, John S wrote: >>> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif >>> >>> I think the transformer phasing dots are wrong. Or, am I wrong? >> >> What an awful schematic diagram. I think you are right, the >> phasing dots are wrong. >> >> Jeroen Belleman > > The base current has to come from the two (two? why?) resistors from > the transformer ct. There are better ways. > > This is kind of ancient. > > >I think the dots are correct, but bases are driven directly from the aux winding on the transformer, a low impedance source and they're swinging up to 0.6v and turn the NPN on and down below ground to...whatever! and the emitters are grounded. The max reverse voltage across the base-emitter junction for most NPN power transistors is not high.
Reply by ●June 20, 20202020-06-20
On 6/20/2020 4:18 PM, bitrex wrote:> On 6/20/2020 2:26 PM, jlarkin@highlandsniptechnology.com wrote: >> On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman >> <jeroen@nospam.please> wrote: >> >>> On 2020-06-20 18:28, John S wrote: >>>> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif >>>> >>>> I think the transformer phasing dots are wrong. Or, am I wrong? >>> >>> What an awful schematic diagram. I think you are right, the >>> phasing dots are wrong. >>> >>> Jeroen Belleman >> >> The base current has to come from the two (two? why?) resistors from >> the transformer ct. There are better ways. >> >> This is kind of ancient. >> >> >> > > I think the dots are correct, but bases are driven directly from the aux > winding on the transformer, a low impedance source and they're swinging > up to 0.6v and turn the NPN on and down below ground to...whatever! and > the emitters are grounded. The max reverse voltage across the > base-emitter junction for most NPN power transistors is not high.that is to say this is an "academic circuit" don't ever build circuits from Wikipedia verbatim, jesus. Even a lot of the stuff from old magazine articles from the 70s and 80s you can find on e.g. seekic.com is generally better at least someone probably tested it.
Reply by ●June 20, 20202020-06-20
On Saturday, June 20, 2020 at 7:51:09 PM UTC+2, bitrex wrote:> On 6/20/2020 12:28 PM, John S wrote: > > https://en.wikipedia.org/wiki/File:Royer_oscillator.gif > > > > I think the transformer phasing dots are wrong. Or, am I wrong? > > Right transistor collector pulls down, right transistor base gets pushed > up, the other vice-versa, looks like positive feedback to me?It has to be positive feedback. The royer works with collapsing magnetic field in saturation This page is correct: https://www.smps.us/inverters.html Cheers Klaus
Reply by ●June 20, 20202020-06-20
On Saturday, June 20, 2020 at 8:26:08 PM UTC+2, jla...@highlandsniptechnology.com wrote:> On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman > <jeroen@nospam.please> wrote: > > >On 2020-06-20 18:28, John S wrote: > >> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif > >> > >> I think the transformer phasing dots are wrong. Or, am I wrong? > > > >What an awful schematic diagram. I think you are right, the > >phasing dots are wrong. > > > >Jeroen Belleman > > The base current has to come from the two (two? why?) resistors fromNot correct. The resistors are only there for kick starting the royer. One branch will have lower Vbe, so that BJT is turned on first, positive feedback turns it on fully The base drive winding delivers all the base current needed after startup> the transformer ct. There are better ways. >Please show a better solution. I am willing to bet that you cannot find a better solution.> This is kind of ancient. >Ancient, yes. But still very good. Royer Jensen varianter is better (efficiency, short circuit protection) Cheers Klaus
Reply by ●June 20, 20202020-06-20
On Saturday, June 20, 2020 at 10:21:30 PM UTC+2, bitrex wrote:> On 6/20/2020 4:18 PM, bitrex wrote: > > On 6/20/2020 2:26 PM, jlarkin@highlandsniptechnology.com wrote: > >> On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman > >> <jeroen@nospam.please> wrote: > >> > >>> On 2020-06-20 18:28, John S wrote: > >>>> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif > >>>> > >>>> I think the transformer phasing dots are wrong. Or, am I wrong? > >>> > >>> What an awful schematic diagram. I think you are right, the > >>> phasing dots are wrong. > >>> > >>> Jeroen Belleman > >> > >> The base current has to come from the two (two? why?) resistors from > >> the transformer ct. There are better ways. > >> > >> This is kind of ancient. > >> > >> > >> > > > > I think the dots are correct, but bases are driven directly from the aux > > winding on the transformer, a low impedance source and they're swinging > > up to 0.6v and turn the NPN on and down below ground to...whatever! and > > the emitters are grounded. The max reverse voltage across the > > base-emitter junction for most NPN power transistors is not high. > > that is to say this is an "academic circuit" don't ever build circuits > from Wikipedia verbatim, jesus. Even a lot of the stuff from old > magazine articles from the 70s and 80s you can find on e.g. seekic.com > is generally better at least someone probably tested it.I have worked on Royer converters. There is nothing wrong with the circuit. The real life circuit does not have more components, nothing academic about this for once :-) Cheers Klaus
Reply by ●June 20, 20202020-06-20
On Sat, 20 Jun 2020 14:28:34 -0700 (PDT), Klaus Kragelund <klauskvik@hotmail.com> wrote:>On Saturday, June 20, 2020 at 8:26:08 PM UTC+2, jla...@highlandsniptechnology.com wrote: >> On Sat, 20 Jun 2020 19:53:10 +0200, Jeroen Belleman >> <jeroen@nospam.please> wrote: >> >> >On 2020-06-20 18:28, John S wrote: >> >> https://en.wikipedia.org/wiki/File:Royer_oscillator.gif >> >> >> >> I think the transformer phasing dots are wrong. Or, am I wrong? >> > >> >What an awful schematic diagram. I think you are right, the >> >phasing dots are wrong. >> > >> >Jeroen Belleman >> >> The base current has to come from the two (two? why?) resistors from > >Not correct. The resistors are only there for kick starting the royer. One branch will have lower Vbe, so that BJT is turned on first, positive feedback turns it on fully > >The base drive winding delivers all the base current needed after startup > >> the transformer ct. There are better ways. >> >Please show a better solution. I am willing to bet that you cannot find a better solution.Not in that circuit. The base current can only come from those resistors to V+. A better design would center-tap the base winding, and only get a little startup current from V+. Even better, use mosfets. This is my version, back in ancient times when I made CD ignitions for sports cars and motorcycles. https://www.dropbox.com/s/iin7435mgrya5gy/CD_Ign_DCDC.JPG?dl=0 R1 supplies a little startup current, and R2 provides the serious base drive. How much was that bet? -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
