Re: [EE]: Design challenge - switching regulator by Roman Black .

Russell, what did you think of my self-excited oscillator idea? This can be made to startup at 2v and will work fine to 130v with a simple on/off voltage regulation. I see so many self-ex switchmode primaries lately when fixing VCRs. They use one transistor/fet, one optocoupler and a few passives for the whole primary! You don't need the expense of a controller chip, unless you need really tight output voltage regulation. -Roman Russell McMahon wrote: {Quote hidden}> > > So, again my ideea is good then ! You need a circuit just for power-up > >the driver at the begining of the regulation process. A small oscillator > >to keep the driver supply until the feedback regulation voltage may > >supply continuously the driver. > > Yes, that is one approach I'm looking at BUT it is unfortunately not quite > that easy in this application. > While there IS nominally a battery present with a 9v rating (dropping to > more like 5 volts in some cases) the presence of a battery may not be relied > on. > The alternative source is the wide ranging 0 to 130 volt supply. > If I voltage double off this supply I will get operation at about 5 or 6 > volts which is acceptable BUT I will then need to disable the voltage > multiplier as I do NOT want it to multiply the 100+ volts to 200+ :-) > > An alternative is ICs like the UCC3802 family (upgradeds alternatives to the > 3842) some of which have 5 volt operation. Unfortunately they are several > times the price of the industry very-standard UC3842 series and much less > available. > > > I don't understand how you manage one decade input voltage variation > >(10...100V) but this is your business... > > Alternator powered by a person exercising :-). > User speed varies and load varies which alters the terninal voltage seen by > the equipment. > Voltage is typically 10 to 50 volts at light loads and 5 to 15 at very heavy > loads but can rise to 130 volts with VERY enthusiastic user at zero load. > Worst case user MUST be designed for :-) > Under heavy loads 10 volts plus is not reached until an unacceptably high > user speed. > > RM > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.