STETZERiZER Filter - Page 1
Forum section: electronics / general

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 02, 2012, 08:39:38 am
content: i'd love to know whats in these things

author: vk6zgo
author_rank: Super Contributor
timestamp: May 02, 2012, 09:10:46 am
content: About equal parts Snake oil & bull faeces!

author: David Aurora
author_rank: Frequent Contributor
timestamp: May 02, 2012, 10:30:08 am
content: Quote from: vk6zgo on May 02, 2012, 09:10:46 amBased solely on the domain names that came up when I googled "Stetzerizer filter", I'd believe your BOM

author: vxp036000
author_rank: Regular Contributor
timestamp: May 05, 2012, 02:02:30 am
content: It's nothing but an over-priced AC line filter, if the box has anything in it at all. Any decent electronics guru could build his own for a fraction of the price. I never understood all the hype about power factor correction.The recent blog on the PFC chip really cracked me up. All that waste of circuitry to clean up the waveform a little. I think a couple well-chosen passive components would be more effective and way simpler.

author: Rerouter
author_rank: Super Contributor
timestamp: May 05, 2012, 02:14:17 am
content: power factor correction on some items can be a way to get around current limits on wires and fuses, obviously the more squewed your power factor the more current that flows in the wires, even if minimal,still the more genuine reason to try and aim for unity is, when you stat getting into higher levels of power, e.g. a 30KW (electrical) industrial aircon and a 0.2MW air compressor, crap loads of inductance, some resistance and rarely all that much capacitance on the non corrected units, you end up with a really horrible power factor, now for residencial the power companies could hardly give a f'k as you cant really shift it that much, but if your a business with a few of those running, they may start complaining to you to fix your shit, as while it rarely costs you anything extra, it can mess with there trasmission transformers, and effect other nearby users,i dont actually support the product at all, just saying PFC has a place, though you need to know when its really neccesary

author: vxp036000
author_rank: Regular Contributor
timestamp: May 05, 2012, 02:24:34 am
content: Power factor certainly is a real phenomena and, in some situations, it should be corrected for. But to correct for PF with a ridiculously complex circuit using ICs instead of a couple of passive components seems a little hard to justify.

author: T4P
author_rank: Super Contributor
timestamp: May 05, 2012, 12:21:55 pm
content: Quote from: vxp036000 on May 05, 2012, 02:24:34 amActive PFC can be give better PFC but as they say, really depends how good it is

author: vk6zgo
author_rank: Super Contributor
timestamp: May 05, 2012, 01:56:25 pm
content: From the "information" on the STETZERIZER sites,& the silly video,it doesn't seem like they are concerned with anything as real as Power Factor.They seem to spend all their time raving about "dirty electricity" & its alleged adverse affects upon our health,without specifying what it is.

author: G7PSK
author_rank: Super Contributor
timestamp: May 06, 2012, 09:41:45 am
content: If your electricity is dirty, you wash it! Right.

author: jahonen
author_rank: Super Contributor
timestamp: May 06, 2012, 02:52:21 pm
content: Quote from: vxp036000 on May 05, 2012, 02:24:34 amIt is not the complexity what matters, it is what is the cost and other factors. PFC chips are not generally very expensive, as the application is quite cost sensitive.Passive PFC implementation leads to very big and bulky passive components (which tend to be quite expensive), and result is not usually good enough to meet the requirements of harmonic currents (IEC61000-3-2). That is even more the case when power levels rise. Problem which is solved by PFC is not reactive linear load phase shift, but the insanely high current peak which flattens out the sinusoidal waveform due to finite grid impedance. Using a PFC makes peak current much lower as load is made look like a resistor.Regards,Janne

author: vxp036000
author_rank: Regular Contributor
timestamp: May 06, 2012, 03:12:12 pm
content: Umm, complexity = cost. At a lot of companies in my area, circuit design costs upwards of $100 / hr. So you see, the cost of passive components quickly becomes a non-issue compared to the labor cost. You also ignored the cost of assembly, which increases with complexity. And since when were large and bulky passive components required? There are 20 F or larger "super" caps that take up less room than that active PFC circuit.The whole concept of PFC is really no different than impedance matching in RF. We don't have any of these problems with harmonic currents with an RF source driving an impedance matched diode. In RF, there are well defined equations, based on physics, governing impedance matching and filtering. But when it comes to 60 Hz AC, all I see is a lot of hype and little to no science.Quote from: jahonen on May 06, 2012, 02:52:21 pm

author: SeanB
author_rank: Super Contributor
timestamp: May 06, 2012, 03:21:21 pm
content: A problem is the size of components at 56/60Hz, compared to those at even 10kHz. Yes, the passive PFC is simple to design, but it is generally big, heavy and not going to fit in the available space. Active PFC is smaller, lighter and will handle kW power levels whilst being under 1kg in mass, and dissipates less heat.I have a 1.5kVA isolation transformer, which does a pretty good secondary job of PFC. Big side issue is the 40kg mass, and the room heater effect it has.

author: jahonen
author_rank: Super Contributor
timestamp: May 06, 2012, 04:12:09 pm
content: Quote from: vxp036000 on May 06, 2012, 03:12:12 pmFor experienced power supply designer, designing a PFC pre-regulator should not take a long time. Neither the amount of components is usually significant issue since active PFC's are quite common. PFC controller chip and associated passives can be assembled in no time with SMD components. Every PC power supply should have one to comply with EMC harmonic current requirements. Of course, for very small power supplies, one may get away without one. Can you represent a simple passive circuit which filters out every other current harmonic other than just mains frequency current and can handle, say, 500 watts of power, which would be required for the power supply that dave showed in his blog?I'd like to see that 20 F capacitor which tolerates mains voltages (230 VAC, or if truely universal supply, up to 275 VAC), it surely is not very small, more likely it is equivalent to size of an refrigeratorHave you actually looked inside PC power supplies which have a passive PFC? PFC inductor is not small component. And like I said, complying to EN61000-3-2 will most likely require an active PFC, so whole thing is only for academic interest.What makes you think that there is no science and physics behind a PFC? I used to think that all things obey very same physics laws around here in this universe. Even RF does, although it is often thought to be somehow different kind of electricity. I think there are dozen papers published on the subject via IEEE etc. Are you actually familiar with the problem and why PFC is required? Your comment makes me think that might not be the case.RF impedance matching is a very different process. Just put in some passives or transmission line pieces to adjust the impedance around some frequency. Or put an appropriate filter to remove the unwanted harmonics. The whole process is usually simple for RF because the center frequency is usually very high compared to required bandwidth, so one can think just about the center frequency. Do you take any significant amounts of power via that impedance matched diode? Something like mixer or detector diode hardly does that. I bet that the RF amplitude is very small compared to diode V-I characteristic, especially for the mixer diode case.For mains applications, we want to pull significant amounts of power via the PFC (tens to hundreds or thousand watts). Main purpose of the PFC pre-regulator is to make AC into DC in such a way that current waveform remains sinusoidal. Yes, passive components can be used for power factor compensation if the load is linear but rectifier+filtering capacitor is a non-linear load. Even linear load is problematic to compensate passively if load varies greatly.Regards,Janne

author: Rufus
author_rank: Super Contributor
timestamp: May 06, 2012, 04:59:51 pm
content: Quote from: vxp036000 on May 06, 2012, 03:12:12 pmOn Semi, Fairchild, Analog Devices, LTC, TI, Cirrus Logic, NXP and others offer parts "to correct for PF with a ridiculously complex circuit using ICs" and engineers across the world are designing with them.You think "a couple well-chosen passive components would be more effective and way simpler" which makes you very ignorant.Ignorance can be forgiven and corrected. Failure to comprehend your own ignorance in the face of overwhelming evidence is the mark of a true idiot. Something which is much harder to put right.

author: vxp036000
author_rank: Regular Contributor
timestamp: May 06, 2012, 05:27:33 pm
content: I see you like to call people names without recognizing that what you see in industry is often a result of marketing and political environments, with very little scientific reason. Lead free solder and ethanol are a few examples.So let's talk about PFC. The power factor is the ratio of dissipated power to apparent power. With a resistive load, power factor is unity. Whenever there is a reactive load, the power factor is less than unity. The purpose of power factor correction is to maximize power delivered to the load. Power factor correction is performed by making the load look purely resistive. This is called an impedance transformation.We can transform the impedance with active circuitry or passive. In the RF world, active impedance matching is generally reserved for use on ICs where space is a consideration. A lot of common household appliances look like an inductive load, so to compensate, we add a shunt capacitance at the input. This maximizes the power transfer to your appliance. Instead of a shunt capacitance, yes, I could waste an entire circuit board full of active components. But I would need to see the math to be convinced that it actually works any better. In fact, it wouldn't surprise me in the least if circuits with active power factor correction were just as inefficient as circuits without any power factor correction, because of the additional power draw.

author: T4P
author_rank: Super Contributor
timestamp: May 06, 2012, 05:30:47 pm
content: Quote from: vxp036000 on May 06, 2012, 05:27:33 pmMeh. How much would an Active PFC actuallydraw?

author: jahonen
author_rank: Super Contributor
timestamp: May 06, 2012, 07:00:36 pm
content: Quote from: vxp036000 on May 06, 2012, 05:27:33 pmWhat you suggest has been used by power engineering people for several decades at least. Reactive power compensation by adding compensation capacitors is not a new thing, and synchronous motor can be used as a dynamic compensator which can act as an inductor or capacitor as required. But, matter of PFC is also to reduce the harmonic currents (or current distortion), i.e. to make the waveform more sinusoidal. As an example what it means as it seems not to be obvious, what kind of passive component could turn this example into linear load (seen by voltage source V1) as effectively as an active PFC:DC load is 200 watts, but loading from the voltage source is about 420 VA, so power factor is about 0.47. How would you compensate that?Regards,Janne

author: vxp036000
author_rank: Regular Contributor
timestamp: May 07, 2012, 01:15:59 am
content: Maybe I'm missing something obvious, but it seems like a shunt capacitor would smooth out the current peaks. I don't doubt that it would take a relatively large value capacitor to clean it up. In fact, I know I've seen a compensation scheme like this for a diode bridge; I'll see if I can dig it up.Quote from: jahonen on May 06, 2012, 07:00:36 pm

author: SeanB
author_rank: Super Contributor
timestamp: May 07, 2012, 05:48:02 pm
content: Shunt capacitor will do nothing about the peaks. What you use is a LC tank in series with the one line, tuned to resonate ( but with low Q of course) at 3 times the mains frequency. This does a pretty good job of presenting a linear looking load to the supply, while increasing the conduction time of the diode considerably, lowering the power dissipated there.Active PFC generally will add around 5W of power dissipation, but the true power and the apparent power become nearly equal, lowering wiring losses and harmonics in the supply side.

author: Kremmen
author_rank: Super Contributor
timestamp: May 12, 2012, 07:27:24 pm
content: Quote from: SeanB on May 07, 2012, 05:48:02 pmTrue but once you have done the calculation and see what kind of components, esp. inductors you would need to do passive correction at 50/60 Hz and any appreciable power levels, the active PFC circuits start looking quite attractive alternatives. There are some passive schemes that avoid huge inductors, such as the valley filling cap/diode configuration but that will get you nowhere near the correction possible by an active corector. They of course have simplicity on their side.

author: free_electron
author_rank: Super Contributor
timestamp: May 12, 2012, 10:41:23 pm
content: Quote from: G7PSK on May 06, 2012, 09:41:45 amelectrons are extremely dirty ! they come from a power plant , travel through dirty lines and transformers , go through the washing machine motor of your neighbour , the dishwasher and other electrical appliances before they eventually run through your stuff. they are like money : the dirtiest thing on the planetand who knows where they have been before... bah ! they could be carrying all kinds of cooties !besides : why do we need to pay for electricity ? for every electron that comes in our house we deliver one back to power plant. we don't use them.the powerplants should be paying us since we give the electrons passage through our home wiring and equipment thus lowering the overall resistance the powerplant sees ! the less resistance there is in the network the fewer the losses are ....this is all a big hoax.

author: vxp036000
author_rank: Regular Contributor
timestamp: May 12, 2012, 11:04:40 pm
content: Thanks for the laugh! The scary part is, a lot of people would actually fall for this kind of nonsense. Kind of like a thread I saw on a different forum where someone was asking "why don't we all just run our houses off of gasoline or desiel generators?" Surely it would be cheaper than buying electricity. Uhuh, until you run the numbers, that is.Quote from: free_electron on May 12, 2012, 10:41:23 pm

author: vxp036000
author_rank: Regular Contributor
timestamp: May 12, 2012, 11:31:29 pm
content: That was kind of my point; only at relatively high power levels does any of this become problematic, at which point I would expect the large values of inductance to become almost a mute point. The whole idea of needing power factor correction for PCs, microwave ovens, and other home appliances is misguided, IMO. For lower power applications, the harmonics are nothing that an AC line filter can't take care of.True but once you have done the calculation and see what kind of components, esp. inductors you would need to do passive correction at 50/60 Hz and any appreciable power levels, the active PFC circuits start looking quite attractive alternatives. There are some passive schemes that avoid huge inductors, such as the valley filling cap/diode configuration but that will get you nowhere near the correction possible by an active corector. They of course have simplicity on their side.

author: free_electron
author_rank: Super Contributor
timestamp: May 13, 2012, 12:00:50 am
content: Quote from: vxp036000 on May 12, 2012, 11:04:40 pmLaugh ? I'm dead serious !Imagine having electrons that have gone through the neighbours washing machine motor at 1500rpm flow through your "double solid silver foil wrapped oxygen-free copper interconnects with 15 micron gold plated end connectors" And then they hit your hand wound counter earth-spin powertransformer of your audio installation ! you will hear that in the speakers ! these dirty electrons may permanently poison your primary transformer and damage your audiophile setup !Luckily you can buy little handpainted rosewood veneer MDF 'pucks' to put under the legs of the amplifier. They will compensate for the neighbours washing machine motor induced vibration of the electrons ... only 9.999$ a piece. To get even better performance you can stack mulitple on top of each other. (*)We also have pucks for microwave oven , dishwasher , dryer and many other household appliances. If you suspect an appliance we can custom make new pucks. Development cost is 15000$ and you will need to ship us the suspect appliance.we recommend buying a set for every appliance and making a stack out of those (*)(*) not responsable for toppling amplifiers if you would stack a whole bunch of them under each legi'm secretly hoping someone will ship me some appliances and a fat wad of money... i got some scrap wood to get rid of and i could use a new dishwasher

author: vxp036000
author_rank: Regular Contributor
timestamp: May 13, 2012, 12:06:43 am
content: This is going to be the next big thing after the retro encabulator. Where do I find a ding alarm?Quote from: free_electron on May 13, 2012, 12:00:50 am