A More Efficient Bridge Rectifier?

They wouldn't hire UAW members.

Except then you still have to replace the Schottky diode in the SEPIC with a synchronously controlled FET circuit ;-)

If money were infinite I suppose you could build such a grid, too. Otherwise it's as silly as using PV or wind to generate electricity.

Like I said earlier, the stupid greenies want us all to move into caves.

You should be the first to kill yourself. Show us all the one, true, way to salvation.

Can't be idiot-proof. You're still here.

...as long as you're in charge, everything will be just fin, right?

My sig says it all... ...Jim Thompson

How about doing a Gallagher on them?

We don't need green police. Mother nature is the ultimate enforcer of the laws of physics and economics. More frequent disasters such as the earthquake in Haiti and the AGW-induced record snowfalls in the Eastern US are just a taste of what is still to come. Our economies are strained and faltering as we attempt to clean up and return to the relative normalcy we had before, and our resources are quickly depleting as we seek to extract more fossil-fuel energy by waging war on foreign powers.

And indirectly we are waging war on our own people by creating an unhealthy environment. We have not properly cleaned up for even the Exxon-Valdez oil spill, and the real damages to the people affected were never repaid while Exxon-Mobil reaped record profits. The common people of New Orleans have not recovered from their tragic disaster. Most Americans have suffered permanent economic setbacks because of greed and irresponsibility of government and big business. And the majority of the world's population are rightfully jealous of those who flaunt their lavish lifestyles.

Being green is just the right thing to do. But at this point it may be just a personal decision of ethics and morality, and gratuitous opposition by those who smugly think they know it all will defer any hope of effective change until it is too late, as it may be already.

Don't worry about the Earth. Our planet and natural phenomena have eliminated other species before, and no doubt humans will be similarly eradicated by our own hand or by events too powerful for our technology to control, and those few who may survive will revert to living in caves.

Paul

In terms of rectification efficiency alone, the doubler has only one rectifier in the current path. There are other advantages that shouldn't be ignored for lower voltage mains. If you're doing PFC, you should check some of the actual requirements, in light of the performance of low frequency switched doublers.

Above 80V and at low frequency, average-current-sensitive rectifiers still have the advantage over active fet rms-sensitive substitutes. One trick is to make the bridge do inrush limiting duty, removing losses from that function, at the temperature derating required for scrs.

Simple low frequency rectifiers are more efficient when running hot, so whatever the losses end up being, don't be so anxious to keep this part cool, just make sure it doesn't infect other less rugged parts in the neighbourhood.

RL

Imagine the no input ripple version of the transformer coupled SEPIC circuit. ie: there are 3 windings the third being the isolated output. Now take the power MOSFET and replace it with a pair in series source to source.

This circuit can be connected directly to the unrectified maines. It makes an isolated squarewavish wave form. This can then be run into a sychronous rectifier to make a DC output.

All this involves no diode drops from the mains to the DC output.

Why not model it in a spice program (eg like the free LTSpice) to prove your theory. Then build it.

Joe\

Time-of-use meters are pretty standard fare here in California, don't=20 know about the rest of the states. IIRC a handful of people in this=20 NG have done variable rate meters.

According to one study, California just needs a major north-south power line to do it. The wind is always blowing somewhere with enough energy to power the whole state easily. It is the case in nearly any place that extends far enough north and south in the temperate zone. The winds have to average out because of the global air flow.

er.

Yes, it requires some good timing control on the fets and a pair of perhaps 600V MOSFETs. This is two less of the costly parts than the MOSFET bridge idea.

It can be a PFC replacement for the transformer, bridge and capacitor style power supply. The SEPIC doesn't put all that high of demands on the core. It only has to hold the energy of one cycle plus a little to make the current continuous to keep the ripple at zero.

No, until the full solution is really done, we can't claim it is. I am in favor of atomic power plants. I don't like the Yucca mountain project because I don't believe the way too smug of claims made by the "experts". My pet solution is to drop the waste into subduction zones.

On Feb 13, 12:29=A0pm, "Paul E. Schoen" wrote: [....]

I don't call some of what has happened "human error". The Chernoby reactor was being "experimented" on in a way that the engineers advised against. The Browns Ferry candle incident showed up two things (1) a really dumb procedure and (2) a really dumb design choice. I will take only the procedure for further discussion.

Atomic power plant minders come in shapes and sizes. Some are smarter than others. Selecting people and training them and then paying them to do the job is part of the cost of running the plant. How safe you want the plant to be is a function of how much you are willing to spend on these folks. The people running the system accepted a level of risk by accepting a level of idiot operators. The incidents are thus the result of a choice and not really an error.

Bullsnit! Decommissioning is the last step other than moving the fuel (which should have been done *long* ago - or better, reprocessed) and that is a POLITICAL problem. Your position is a self-fulfilling Demonicrat prophecy (no surprise, coming from you); "it's not complete because *we* say it's not complete". IOW, a bald-faced lie.

Of course, you, like all leftist losers, believe in it all sorts of real solutions, except for their implementation. What an ass!

------------------------------------------------------------------- I don't call some of what has happened "human error". The Chernoby reactor was being "experimented" on in a way that the engineers advised against. The Browns Ferry candle incident showed up two things (1) a really dumb procedure and (2) a really dumb design choice. I will take only the procedure for further discussion.

Atomic power plant minders come in shapes and sizes. Some are smarter than others. Selecting people and training them and then paying them to do the job is part of the cost of running the plant. How safe you want the plant to be is a function of how much you are willing to spend on these folks. The people running the system accepted a level of risk by accepting a level of idiot operators. The incidents are thus the result of a choice and not really an error.

-------------------------------------------------------------------

The bottom line is that major disasters have happened without any deliberate action, and chances are that others will occur in the future. People making poor choices, accepting certain levels of risk, and increasing the number of facilities combine to making it a matter of time before another major accident. And the dwindling number of intelligent, educated, responsible, and motivated people who are available to run these plants adds to the probability of another major problem. Add to that the apparent increase in cases where seemingly normal and highly trusted individuals have gone berzerk in schools, military bases, and the workplace. And factor in the very real threat of terrorism and the unwillingness to use profiling and other indicators in the name of political correctness.

On the day before the Exxon-Valdez disaster, oil company executives bragged that not one drop of oil would ever be spilled. Then they made a big show of their clean-up efforts, which were largely ineffective and caused severe health problems for those who participated in the charade. That accident could be covered up with media spin, and forgotten by the general public, but a nuclear disaster will have much more devastating, far-reaching, and long-term consequences that will affect us all.

Big businesses are always making choices that balance their profits against the cost of work-related sickness and death of employees, and to a lesser extent the effects on the general population and the environment. They calculate the legal expenses of fighting claims for damages, and ultimately fall back on the certainty that those highest up will be protected from responsibility if the worst should occur, and that the government will step in to clean up the mess they have created.

If these incidents were not the result of human error, then, even worse, they were due to greed and irresponsibility and callous disregard for human life and a healthy environment.

Paul

It depends of the size of the largest high pressure areas, the middle is calm, but the wind blows around it. A network 1000-2000 km long should usually suffice.

Solar electric and solar thermal systems are useful for running the air conditioning, since the production and consumption i quite well correlated. However, there is not much point in producing more solar electricity than the day/night difference in consumption.

Yes, it requires some good timing control on the fets and a pair of perhaps 600V MOSFETs. This is two less of the costly parts than the MOSFET bridge idea.

It can be a PFC replacement for the transformer, bridge and capacitor style power supply. The SEPIC doesn't put all that high of demands on the core. It only has to hold the energy of one cycle plus a little to make the current continuous to keep the ripple at zero.

-------------------------------------------------------------------------

I still say that the bridge rectifier, or perhaps a doubler circuit, will be the most efficient solution if one takes into account cost, complexity, and reliability. One or two volts drop on 120 or 240 VAC mains is at most

Even better overall efficiency may be obtained by converting our electrical distribution system to DC. There will be less losses due to EMF effects. Most appliances can be made to use DC directly. Anything with a switching power supply can bypass the input rectifiers, and induction motors can be driven by PWM bridge controllers. And of course lighting and heating work as well on DC as AC.

Paul

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This discussion is now over. If you are going to resort to insults in place of facts, I don't see any reason to continue.