Surge Protector or Power Conditioner for Oscilloscope  - Page 1
Forum section: electronics / testgear

author: jram112
author_rank: Contributor
timestamp: August 15, 2013, 12:39:49 am
content: I'm setting up my workbench, and need more outlets. Then I started to wonder if I need a power conditioner for my scope or a simple surger protetor/power strip. I use Tripplite Isobars typically for a surge protector? Connected to the power strip I'll have the scope, bench power supply, printer, function generator, soldering iron, a few small dc power supplies, and possibly my laptop.Should I get a power-conditioning power strip, a UPS, or simply a good surge protector?

author: Unknown
author_rank: Unknown
timestamp: August 15, 2013, 12:48:40 am
content: No UPS, most are modified sine wave "almost square", useless for sensitive electronic equipment.Depends on the Budget...PS Audio Power Plant Premier or the New P5 or P10,are the best.FAil safe lightning strike protection...Leveler sentry RP2400A, "new vas2400."http://levelerllc.com/Catalog.htmlor Furman P-1800 PF R,http://www.furmansound.com/product.php?div=01&id=P-1800PFRVoltage Regulator the Furman P-1800 AR is nice.http://www.furmansound.com/product.php?div=01&id=P-1800ARor advanced UPS, like APC Surtra 1500XL or similar with true Sine Wave,or a Xantrex 2000 or 3000, inverters.http://www.xantrex.com/power-products/inverter-chargers/prosine-2.aspxthe New "very economic" ARTproaudio.com look very nice.http://artproaudio.com/art_products/power_solutions/look Furman Videos, very informative:http://www.furmansound.com/video.phphttp://www.furmansound.com/swf/furman_smp_plus.html

author: jram112
author_rank: Contributor
timestamp: August 15, 2013, 12:55:40 am
content: Some of those are too expensive for my setup. I'm looking for less than $150.Do I need power conditioning for a digital scope? Is the mains power noise typically a problem? I'm at a university lab.

author: Unknown
author_rank: Unknown
timestamp: August 15, 2013, 08:24:57 am
content: Generally I wouldn't bother, but it depends on the quality of your local mains electricity. Scopes are designed to deal with standard unfiltered mains power, though.

author: westom
author_rank: Contributor
timestamp: August 15, 2013, 12:33:36 pm
content: Quote from: jram112 on August 15, 2013, 12:55:40 amLearn what a switching power supply does. Any cleaning by a power conditioner is literally undone by a supply that converts power to a much higher voltage and radio wave spikes. Then superior filters and other circuits convert that 'dirtier' power into rock solid and stable, low voltage DC.What anomaly are you trying to solve? No power conditioner solves all anomalies. In fact, the term power conditioner is usually to confuse layman into spending big bucks on solutions that were unnecessary. To create fear among many who do not even know what a switching power supply does.

author: jram112
author_rank: Contributor
timestamp: August 15, 2013, 07:04:37 pm
content: Good points everyone. I'm not trying to solve any problems...yet. I'm just setting up a workbench and need a power strip. That's when I started to wonder about what kind of power strip. Think I'll just get a good quality power strip with surge protection to start.

author: Unknown
author_rank: Unknown
timestamp: August 15, 2013, 08:10:48 pm
content: Quote from: westom on August 15, 2013, 12:33:36 pmAdvanced Power Conditioners have Isolated-Zones, meaning each AC output pair is Isolated from the others,some even have outlets with filters designed for analog and others designed for digital equipment.when measuring low voltages & low jitter the diference is amazing.some equipment improoves amazing.http://levelerllc.com/Documents/Common%20Mode%20Protection%20-%20Leveler.pdf

author: westom
author_rank: Contributor
timestamp: August 16, 2013, 01:23:52 am
content: Quote from: JuanPC on August 15, 2013, 08:10:48 pmYou are confusing most consumer products with something completely different that may sell on the order of a $thousand. Many power conditioners are only a direct connection to AC mains that is switched to a battery powered inverter during some anomalies.Even filters in many such devices is near zero.What each one might do must be defined specifically with manufacturer spec numbers. Any claim about filters or isolation, et al without spec numbers is often a rumor traceable to subjective advertising claims. Near zero filters or isolation can also be 100% in advertising brochures. Most, educated only by advertising, make recommendations without spec numbers.Best isolation is typically inside appliances. Often rated with isolation numbers approaching or exceeding 1000 volts.Best power strip for a bench is a $4 power strip from Walmart that must always have one critically important part - a 15 amp circuit breaker. Or spend a little more for one with a power switch.Greater concern is probably anti-static protection.

author: Unknown
author_rank: Unknown
timestamp: August 17, 2013, 02:35:14 am
content: Quote from: westom on August 16, 2013, 01:23:52 amhttp://en.wikipedia.org/wiki/Uninterruptible_power_supplyQuote from: westom on August 16, 2013, 01:23:52 am

author: vk6zgo
author_rank: Super Contributor
timestamp: August 17, 2013, 04:57:01 am
content: Quote from: jram112 on August 15, 2013, 12:55:40 amThe power to your lab may already be fed through a large high current Power Conditioner.Check with the people responsible for Mains power distribution in your University.

author: SeanB
author_rank: Super Contributor
timestamp: August 17, 2013, 06:54:43 am
content: I do have an isolating transformer, a ferroresonant unit. Do not use it often, mostly because it has a constant power draw of 1kVA. Makes a good room heater.

author: Unknown
author_rank: Unknown
timestamp: August 17, 2013, 12:35:28 pm
content: Quote from: JuanPC on August 17, 2013, 02:35:14 amWhich shows exactly what westom described, especially the cheap off-line UPS. Don't expect consumer UPSes to be double-conversion. And don't buy into the audiofool power conditioning nonsense that some companies try to sell.Quote from: JuanPC on August 17, 2013, 02:35:14 amA surge protector is useful, if you have moderate surges that they can deal with. How often do you get these types of surges? If this is what your mains power looks like, then I'd have a serious talk with your power company. A direct connection to overhead wiring in an area with many lightning strikes will make it more likely, but even then there is no more reason to protect a DSO than say a computer or TV. So if you have surge protectors on all your expensive electronics, then it makes sense to use it on the DSO. Otherwise I wouldn't bother, a DSO isn't more sensitive.

author: Unknown
author_rank: Unknown
timestamp: August 18, 2013, 06:39:27 am
content: Quote from: alm on August 17, 2013, 12:35:28 pmAgree, Cheap, brand X, UPS´s or Inverters are NoGO.Quote from: alm on August 17, 2013, 12:35:28 pmthere is equipment designed to answere that:http://www.gryphon-inc.com/Spec%20Sheets/Power%20Monitoring/960028C%20-%20ONEGraph.pdfQuote from: alm on August 17, 2013, 12:35:28 pmI can hear a Big difference, Big enough to spend more $$$, and start designing/modify my own equipment.Quote from: alm on August 17, 2013, 12:35:28 pmMy DSO was $3OOOusd.my TV is $300usd,.1Ox more reasons.

author: Carrington
author_rank: Super Contributor
timestamp: August 18, 2013, 03:51:37 pm
content: If you need a UPS then choose it with pure sine wave out.http://www.ablerex.com.twhttp://www.amazon.com/CyberPower-CP1500PFCLCD-Sinewave-Compatible-Mini-Tower/dp/B00429N19WBut I think that with the tripplite isobars is more than enough.http://dev.emcelettronica.com/ac-power-filter-and-phone-line-filter-homemade-circuit-breaker

author: westom
author_rank: Contributor
timestamp: August 20, 2013, 12:31:11 pm
content: Quote from: Seeagentory41 on August 20, 2013, 11:32:23 amMatters little how 'clean' or 'dirty' power is. Because a first thing electronics do is convert those spikes to high voltage DC. And then converts that to high voltage radio wave spikes. 'Dirtiest' power to electronics is created inside the power supply - regardless of how 'clean' AC power is. 'Sensitive electronics' is mostly urban fable since electronics even 40 years ago were required to withstand over 600 volts. Today's electronics are even more robust.Output from this 120 volt UPS is 200 volt square waves with a spike of up to 270 volts. Due to superior conditioning required inside all electronics, even that UPS is ideal power. BTW, it was promoted as a pure sine wave UPS. Because square waves and spikes are nothing more than a sum of pure sine waves. Others recite that advertising myth by ignoring the numbers.Most conditioning is recommended on hearsay, fear, and wild speculation. If needed, the recommendation came with specification numbers and numbers that define 'dirty' power. Then we learn that most spike removers (ie Tripplite) and other conditioners are inferior to what already exists inside electronics.First it converts 'clean' power into 'dirtiest' in the house. Then superior filters and other conditioners convert that 'dirtiest' power into rock solid and stable, low voltage DC. Matters little what adjacent and expensive magic boxes do. Best line conditioner is often inside electronics. But then conditioners were recommended to cure something that was not even defined by numbers. No numbers is typical of junk science reasoning.Some rare anomalies can overwhelm superior conditioning inside electronics. One might occur once every seven years. Those solutions do not work properly when adjacent to electronics. And are beyond what the OP asked for.

author: Unknown
author_rank: Unknown
timestamp: August 20, 2013, 08:59:23 pm
content: Quote from: westom on August 20, 2013, 12:31:11 pmdon´t know where you learned Electronics, but you should get a refound jajajajaja

author: Carrington
author_rank: Super Contributor
timestamp: August 20, 2013, 10:52:39 pm
content: Quote from: JuanPC on August 20, 2013, 08:59:23 pmjajaja = LOLIn a very basic:DC-> PWM-> Transformer-> "Pure sine wave"

author: eKretz
author_rank: Frequent Contributor
timestamp: August 21, 2013, 10:04:56 am
content: Quote from: Carrington on August 20, 2013, 10:52:39 pmThank you for that, I was wondering "What the..."

author: skipjackrc4
author_rank: Regular Contributor
timestamp: August 21, 2013, 03:15:29 pm
content: I use these Panamax units on my bench:http://www.amazon.com/Panamax-M8-EX-Outlet-Surge-Protector/dp/B0002V9INM/ref=sr_1_3?ie=UTF8&qid=1377097585&sr=8-3&keywords=panamax+8I use them for the automatic shutoff if the mains voltage strays too far from nominal (brown out, small over-voltage, etc). You definitely need surge protection, and I would only use units from known brands such as Panamax, ISOBAR, APC, etc... You don't have to spend a ton of money on it, but I would be hesitant to buy any cheap surge protector for expensive equipment.I have a lot of older stuff on my bench, which doesn't have any built in surge protection and is sensitive to over-voltage (hence the auto-shutoff feature of the Panamax units). With modern equipment with switching supplies, I don't think it would be as big of a deal.Any type of mains filtering won't hurt, but is probably not necessary, either. Unless you know you have a problem, I wouldn't pay the extra money for it. That said, the Panamax units have some filtering built in. They have published specs, though I don't know what they are off the top of my head. I don't really care--that's not why I bought them. Most gear has built in filtering anyway.

author: Carrington
author_rank: Super Contributor
timestamp: September 22, 2013, 10:52:45 pm
content: Anyone know where find something like this (see attachments), but full assembled.

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 02:30:04 am
content: What problem are you trying to solve? Something very similar will probably be already in your scope, if it was found to be necessary during EMC compliance testing. The filters will probably contain a common-mode choke and some caps to filter out the high-frequency interference that an SMPS might produce. It won't do anything about distortion, whatever that document might claim. Neither will it do anything about surges, too high or too low line voltages, unlike the UPSes or surge protectors mentioned previously.Some UPSes and surge protectors claiming to contain a filter against interference might contain something similar.

author: peter.mitchell
author_rank: Super Contributor
timestamp: September 23, 2013, 08:01:28 am
content: Bah, want to surge protect your scope? If it has a voltage rating on it of 100~265v and no voltage selector switch, just run it off batteries. 100+ VDC should be A OK

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 09:18:50 am
content: Will that make the active PFC circuit that is likely to be present in any 100-265V power supply happy, though?

author: AndrejaKo
author_rank: Frequent Contributor
timestamp: September 23, 2013, 12:44:00 pm
content: It would be best if Carrington replayed to this, but in his absence, I'll mention a few things explained in another thread:He has a Owon SDS series scope and they have pretty bad power supply units which can generate large amounts of noise. I can clearly pick up its noise on my unit by placing probe on the power cable insulation even with extra ferrites on the cable near the scope.I'm attaching a schematic made by TomC of one of the PSU types used by that scope series. It does have X and Y capacitors and a common mode choke for filtering, but that's it. There is no power factor correction of any kind as far as I can see.Also attached is the datasheet for the main voltage regulator on the board.

author: Carrington
author_rank: Super Contributor
timestamp: September 23, 2013, 02:41:33 pm
content: Quote from: alm on September 23, 2013, 02:30:04 amYou know what is a PLC?Yes, something very similar is already in my scope, and in others equipments.Quote from: alm on September 23, 2013, 09:18:50 amPlease explain to me what is the problem if I add another filter. Power supply happy maybe?Only is it necessary for EMC comliance, are you sure?Quote from: peter.mitchell on September 23, 2013, 08:01:28 amThese filters are not for surge protection, and in my case 265V is not a surge or overvoltage.AndrejaKo, thanks.

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 03:19:54 pm
content: Quote from: AndrejaKo on September 23, 2013, 12:44:00 pmI wonder if that thing passed compliance testing, or if they just print those FCC/CE labels without even testing.If it is indeed high frequency noise that's being conducted via the power cable, then filtering or ferrites might help. A filter will likely just contain another common mode choke and some X/Y caps, similar to what's already in the scope. What makes you think this will be sufficient? It sounds like it would be best to add filtering as close to the scope as possible. A ~1.8 meter mains lead to the magic filter box may act as antenna.Quote from: AndrejaKo on September 23, 2013, 12:44:00 pmThe power switch probably won't be happy with 100 V+ DC. It's probably only rated for ~40 VDC, since arcing is much worse with DC than with AC. The rest would probably work fine with DC, although 100V would probably be a bit low, since even a 100 Vrms mains voltage would still result in ~140 VDC after rectification.

author: Carrington
author_rank: Super Contributor
timestamp: September 23, 2013, 04:22:09 pm
content: Quote from: alm on September 23, 2013, 03:19:54 pmLOL... If that thing (OWON SDS) pass these tests, then anything can passes.Quote from: alm on September 23, 2013, 03:19:54 pmLong time ago that I had placed the ferrite to the cable."A ~1.8 meter mains lead to the magic filter box may act as antenna."Correct."What makes you think this will be sufficient?" Well, but sure that it will not get worse. They are effective up to 30MHz.If you know of a better solution, then tell it.

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 05:13:01 pm
content: Use a different power supply to power it from the DC input (this scope has a battery option, doesn't it)?

author: Carrington
author_rank: Super Contributor
timestamp: September 23, 2013, 05:36:58 pm
content: Quote from: alm on September 23, 2013, 05:13:01 pmWait wait..."power supply happy""magic filter box"

author: westom
author_rank: Contributor
timestamp: September 24, 2013, 02:23:54 am
content: Quote from: Carrington on September 22, 2013, 10:52:45 pmAs stated previously:QuoteSuperior conditioning inside electronics includes that same line filter (ie Schurter, Corcom, Interpower) or something equivalent. And is enhanced by additional layers of filters (conditioning). Existing conditioning circuits are why 'dirty' power even from a UPS is ideal power for electronics; including the OP's scope, bench power supply, printer, function generator, and laptop.

author: Whuffo
author_rank: Regular Contributor
timestamp: September 24, 2013, 09:48:15 pm
content: Quote from: SeanB on August 17, 2013, 06:54:43 amIt's either a HUGE unit or it's defective. If the tuning capacitor is leaky they'll burn up a lot of power; this is probably your problem.I was just getting ready to recommend a Sola ferroresonant transformer for those concerned about their mains power. You can usually find them on eBay or other buy / sell / trade venues; they're very heavy and expensive to ship so find one close to home. They'll regulate the voltage, strip off the noise, and do it reliably day in and day out. Before buying one, calculate the load you're going to apply and get one just a little bit bigger; there's a small magnetizing current that's always drawn and this is proportional to the size of the transformer. They're MUCH more efficient than the solid state units, and incredibly reliable. Put some spark gaps and big MOVs at the power panel and you'll keep the lightning bolts out and the Sola will regulate and filter the power.

author: madsci
author_rank: Regular Contributor
timestamp: September 25, 2013, 06:52:51 am
content: APC SmartUPSes are everywhere and decommissioned ones are dirt cheap. Laypeople even give them away because they appear to be totally non functional if the batteries go completely flat. Truly dead ones are extremely rare and its generally worth a gamble to purchase one of these "dead" units because chances are, it will come alive 100% with a change of batteries.My lab is equipped with several SmartUPSes that I got for little or nothing due to dead batteries. The batteries aren't cheap but for the price of a crap UPS, you can have a good one if you're willing to get a used UPS. The things last forever, so age really isnt too much of an issue. I've seen plenty of them so old that they have the old APC logo on them (early 90s) and they run just fine. The soldering and design are what you'd expect in telecom grade gear.Oh and Dave liked the design. It really is cool how they work. All of them, from the little 450VA to the 5kVA units work the same with the inverter run backwards to charge the batteries.Anyway...about my units and what I got them for:There is a floor standing SmartUPS 1500 for the main PC and a rackmount SmartUPS 1500 for the mini bench when I'm in school. The tower model 1500 was $75 with half good batteries, the rack unit was free and appeared to be dead due to a lack of batteries.At home, there is a SmartUPS 3000XL that runs the entertainment system and hackspace and a SmartUPS 700 to keep core network infrastructure alive. (modem and router stay up for ~2hrs) The 700 was free, the 3000XL cost me $100 with an extra battery pack that I of course had to rebuild.All of these have pretty substantial mains filtering. They eat small spikes and common mode noise like a fat kid eats candy.These UPSes kicked in about 10 times during the summer....Texas gets some nasty weather and our squirrels are suicidal. Let's just say squirrels die in vain when they decide to try to black out my shop....they blow up on the 7.2kV primary and I keep computing, measuring, fixing and jamming out without a pause.

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2013, 07:56:04 pm
content: The filter in an APC smart UPS (which is an offline UPS BTW) isn't any better than the filter already present in the equipment. Equipment manufacturers generally do put good filters in their equipment otherwise they keep getting it back for repairs under warranty. Then again nothing will withstand a direct impact from a lightning strike.

author: peter.mitchell
author_rank: Super Contributor
timestamp: September 26, 2013, 04:54:00 am
content: Quote from: Carrington on September 23, 2013, 02:41:33 pmMy point was though, if it is an SMPS powered and it is that vital you have a clean input/no risk with input, you could just run it off a bunch of batteries, completely isolating it AND giving it an incredibly clean input, and not injecting any noise back into the line.

author: madsci
author_rank: Regular Contributor
timestamp: September 26, 2013, 06:49:30 am
content: Quote from: nctnico on September 25, 2013, 07:56:04 pmIt's a line interactive UPS. It contains a buck/boost transformer.It also has one thing my scope, PC and such do not have: Several large MOVs.Direct lightning hit? I'm more worried about *me* at that point. The building is probably on fire too.