X2 Filter Cap Recomendation - Page 1
Forum section: electronics / projects

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 13, 2013, 03:41:35 pm
content: Ok so to start with its been a while since i posted... sorry... have a full time job and stuff now so yah.My recomendation that I need is for what to do with damn Samsung laser printer I have....evertime it "warms up"(which is when I print, its asleep the rest of the time....lazy thing) it flickers my lights and causes all my UPS's to freak out due to noise on the line. At first I thought it was just my parents house... but now I have an apartment and it does it here as well. I don't have a scope to see what the lines actually look like at the time so my thought for a fairly cheap "fix" is to add some caps to it or replace the current one with a bigger one.The current cap has the following markings:680nK275V~X2Which the best I can decode is 275Volts, 10% and X2 rated but the cap rating it self has my scratching my head... per the marking it should be 68pf right? well the datasheet from the manufacturer list for the dimensions of it the only one with 68 in it is .68uF... so which is a more likley value? the dimensions are 15mm lead spacing, 10mm wide, 18mm long and about 18mm tall.The other question is what type of value should I look for in a new one? and should I just replace the existing one or try to add another in parallel either on the board or on the IEC socket? The board doesn't have a lot of space around it but I can go taller. The IEC socket doesn't have a lot of room around it...Thoughts? will it help at all without having a cap the size of my head? Is there a limit of how large of rating I can go before it might screw things up? Obviously i need at least 275Volts and X2 rating for safety. (In USA so 120V is the normal here)EDIT: Found a spot above the IEC socket that may be perfect.. was a cut out for if they have a (as Dave would say) "Big honking Mains switch"Oh and a bit of a rant... only had this issue with samsungs... I had a CLP300 color one before this that did the same thing... yet I've had Oki's and Brothers(a big honking MFP color laser) that didn't.... I don't know if its how samsung does their PSU or their general set up or if its lower quality parts causing it or what.Edit: Pic with areas marked

author: baljemmett
author_rank: Unknown
timestamp: August 13, 2013, 03:58:08 pm
content: Quote from: mitpatterson on August 13, 2013, 03:41:35 pmI would take the '680n' to mean 680nF, aka 0.68uF...

author: madires
author_rank: Super Contributor
timestamp: August 13, 2013, 04:31:36 pm
content: I see the X2 cap and a common mode choke but no Y2 caps. Doesn't the laser printer got a ground connection (PE) to mains? Anyway, you could check if the X2 cap is fine or failed open. Regarding the X2 cap's ratings I agree with baljemmett, i.e. 680nF.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 13, 2013, 04:51:01 pm
content: Quote from: madires on August 13, 2013, 04:31:36 pmThe Y2 Caps are tiny right next to the power input plug. There are 2 little blue ones with a bit of glue holding them to each other.(edit see attached)I don't think the cap is open......I think its poorley designed samsung PSU's.. this is the second Samsung Laser that has done this and they have both done it since they they were taken out of the box. And no.... I'm not trying to plug them into the UPS's Battery connections in case anyone was wondering... Right now the printer is plugged directly into the wall and still trips UPS's(and by trip i mean it causes them to sense the noise on the line and switch to battery. I have lessened how often it occurs by telling the UPS to allow a bit more noise before it kicks in but still 2 out of 3 times trips) other side of the room that is on a different breaker....

author: madires
author_rank: Super Contributor
timestamp: August 13, 2013, 05:12:18 pm
content: Quote from: mitpatterson on August 13, 2013, 04:51:01 pmThanks, found them. They're really tiny. El cheapos? High quality ones from Wima for example are much larger.QuoteBroken by design then? At first glance the mains filter looks reasonable besides the tiny Y2 caps. There are two pairs of wires, the top one is mains in, I assume, and the one at the right bottom might be for the fuser or something else. That means that the ground (PE) should be connected via the chassis.

author: SeanB
author_rank: Super Contributor
timestamp: August 13, 2013, 05:30:06 pm
content: I would be more inclined to think of poor sockets, poor cables and such on the UPS. Laser printers do draw around 1kW or so for a few seconds at start up to warm up the fuser, then tend to switch to a lower power heater ( so as to get a fast initial power up then low power to maintain during page print) so if that is causing a sag then there is a wiring problem, either marginal mains voltage, marginal power cabling to either the printer or UPS or a poor wall socket. The filter there will do a good job to attenuate mains noise from the printer, you could add an extra 680n in parallel with the mains input direct across the socket pins but I suspect it will not be very effective. That can be any value from 470nF to 1.5uF in an X2 capacitor, with the 275 VAC rating. Will help with noise from outside affecting the printer and items plugged into it, but not going to help with voltage drop during power on.Replace the cable from both the printer and the UPS to the wall, using cable sets of 1.5mm area or larger, and try again. I think if the cables are the ones that came in the box they will be 0.5mm cables or smaller, and are not good.As well if you have a meter with appropriate safety ratings ( cue the flame war hereabout this subject, enough pages already ) then measure the mains voltage at the socket outlets both normal and as the printer powers up.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 13, 2013, 05:31:45 pm
content: Quote from: madires on August 13, 2013, 05:12:18 pmGround is via the Chassis, the bottom right is actually the mains input. Top is out to Fuser. Far left connectors are smaller supplies. The fuser runs on Mains voltage so i think the only reason it goes to the PCB is for the relay on the board and for filtering.But yah...I think broken by design. Do you think the Y2 caps might need to be bigger or should I keep focusing on the X2 cap? What will do the most to filter the lines? I'm sure it would be so much better if i had a scope so we could see what it was actually doing to the line....... I don't have enough other uses for one right now so this would be the only reason for buying one...I was going to borrow a portable one(aka already isolated, no isolation transformer needed) from the school i went to about 2 years ago but that fell though....

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 13, 2013, 05:35:55 pm
content: Quote from: SeanB on August 13, 2013, 05:30:06 pmThe only thing is i've had BIGGER printers than this cause no issues so i don't think its the sag and the logs for the UPS show it being triggered by Noise not undervoltage. I've had different UPS's, different building(rents house and Apartment). The only common thing is the bloddy samsungs(this one and the old CLP-300)I will get my Extech EX330 out later and see... its CatII 1000V and CatIII 600V rated so I think i should be good on that front.

author: SeanB
author_rank: Super Contributor
timestamp: August 13, 2013, 07:34:41 pm
content: Noise will be the fast turning on and off of the fuser by the controller during warm up so as not to overshoot the set point. Likely not solvable by extra capacitors, but might work with a harmonic trap or a line choke on the supply. Take a long length of mains cable ( a 5m extension cord will do, and wind it into a tight coil and use it to power the printer, the extra inductance especially if you place a large ferrite block inside the coil might help.

author: edavid
author_rank: Super Contributor
timestamp: August 13, 2013, 08:47:51 pm
content: I agree, it's the fuser. You don't really know what the UPS considers noise and what it considers undervoltage.The simplest solution is to get a different printer.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 14, 2013, 07:07:54 am
content: Quote from: edavid on August 13, 2013, 08:47:51 pmI'm not disagreeing about the general cause being the printer. And we are on the EEVBlog forum not on a "tell me if my product is bad" forum. I'm trying to find a way to remedy this hopefully for the cost of just a few caps or similar.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 14, 2013, 07:12:24 am
content: And of course I know its not going to be super accurate measuring with the whole circuit in place but I used my Extech EX330 cap range to measure the X2 cap and was getting around .77 uF which is pretty close given the cap it self is only rated for 10% and other components on the board.I also measure and got close to 1M across the 2 hot lines(.98M). Not sure what its supposed to be but its at least not really low like a short.I fell in the shower earlier and hurt my back so i don't know if I'll be able to measure the voltage during power up today or not. I was just thinking this would be a good time for a TrueRMS meter with a min/max function.... too bad mine just has the silly hold button.

author: madires
author_rank: Super Contributor
timestamp: August 14, 2013, 01:35:59 pm
content: Since the mains filter is fine the next step is to check if the inrush current causes the problem. If you got a device with high power demand (1000W), like a heater for example, you could plug it in instead of the printer and turn it on and off several times and see what happens. If the lights flicker it's a problem with the mains wiring.

author: edavid
author_rank: Super Contributor
timestamp: August 14, 2013, 03:39:08 pm
content: Quote from: mitpatterson on August 14, 2013, 07:07:54 amWell, caps are not going to do it. You would have to add a high power inrush current limiter... but then the printer wouldn't work, because it's expecting the fuser to heat up in a certain period of time, and if it takes longer, fail. The options that leaves are fixing your house wiring, or replacing the printer.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 15, 2013, 02:11:47 am
content: Quote from: madires on August 14, 2013, 01:35:59 pmI don't have a high demand device but I don't think its the mains wiring. This is the second building i've tried it in and at my parents i had tried it in different rooms. Now could they both have bad wiring? yes, but at this point the only thing is common is the printer... and I had a different samsung at my parents house as well at one time that did the same thing yet I have had a big Oki color printer and an even bigger Brother MFP that didn't cause the same issues. So the Samsungs have caused issues 100% of the time(2/2) but the other brands have not caused it (0/2). So by process of elimination I have to say its something in the way samsung designs their printers and/or power supplies.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 15, 2013, 02:13:27 am
content: Quote from: edavid on August 14, 2013, 03:39:08 pmSee my most recent reply, I don't think its the house wiring(2x different buildings same issue). I guess the question at this point is for this type of device what size of X2 and Y2 caps SHOULD they have put in? I'm really leaning towards either they didn't put big enough ones or they put complete crap ones in... hence why I though either adding more or replacing the current ones with name brand ones from digikey or similar might help(like an epcos brand or something)

author: WarSim
author_rank: Frequent Contributor
timestamp: August 15, 2013, 02:44:58 am
content: I really don't think anyone will be making a recommendation for X nor Y caps meant to fix a problem it is very unlikely it will fix.As stated in an earlier post replacing the suppression caps will not fix the problem.With the symptoms of flickering lights and cranky UPS that denotes excessive noise and mains power fluctuations.If it is as severe as the given symptoms make it seem, a new printer may cost less than the proper fix.If it is just a noise issue, then a fix would require data like required inrush current, startup power required, current induced noise and mains droop. It takes relatively allot to make an incandescent light flicker.If this printer was causing these problems when, new it would have been taken back, so I am assuming it is a new problem. In the cheeper printers the fuser and drum is one replaceable unit, which cost almost as much as a new printer. Because these items have a life rated in cycles and ages, without the cycle and page count data it is deemed likely that the fuser/drum is at end of life. Both a fuser and drum can cased your problems so both are suspected, because you do not state when during warmup the problem happens.

author: tld
author_rank: Regular Contributor
timestamp: August 15, 2013, 07:22:40 am
content: Quote from: mitpatterson on August 15, 2013, 02:13:27 amDude, wtf?!You ask for peoples advice, several people take time not not only give advice, but to explain the reasoning behind it. They all agree.Then you - without experience or explanation of reasoning - go "Naah, I'm just going to go ahead thinking this problem is the problem I want it to be".Not only that, but you do it without refuting the likely explanations you've been given.And you're more or less accusing Samsung of putting out a like with a crappy or otherwise deficient PSU, without this being a know major issue. Based on what?If you ask for advice, you don't have to take the advice, but you do owe the people your time to at least consider their responses (imho anyway).A to add a tad of my own thinking:Mains filters are not only for avoiding putting out noise on mains, but also for tolerating noise there. If this had been down to noise fixable by simply adding another 0.68uF cap to the printer PSU, don' you think the filters in the UPS would be able to handle that amount of input-noise?ffs, there's even an easy path to confirming or refuting what the others are telling you. Assuming the fuser runs for a few seconds or more, just check the input-voltage to and at the UPS when the printer fires up, and see if it sags.If you get (or can get) debug-output from the ups, it's quite possible that the information will be available there as well.tld

author: madires
author_rank: Super Contributor
timestamp: August 15, 2013, 11:55:37 am
content: Quote from: mitpatterson on August 15, 2013, 02:11:47 amVacuum cleaners are usualy around 1200-1400W.QuoteI agree that Samsung does something different than the others. After a bit of searching in the Internet I found that the inrush current of Samsung printers (the small inexpensive ones) is claimed to be around 11A (110V) for starting up and heating up the fuser. Just saying.

author: mitpatterson
author_rank: Regular Contributor
timestamp: August 15, 2013, 03:49:04 pm
content: Quote from: madires on August 15, 2013, 11:55:37 amWell my Vacuum cleaner doesn't cause me any issues.... My printer's "sticker" rating is 8.5 Amps. I just did some testing with my Meter wiring in parrelle to the printer measuring the voltage and the lowest my eye saw on multiple test was 109V (121V is about "Average" for my apartment) Most of the test it only dropped to 112V. My UPS is set for its "low voltage" threshold to be 88 Volts(thats the highest it goes) but that is for it to be completely "out" so when it interrupts other times it logs it as Electrical noise.tld: i'm sorry I've been listening to what others have said but it feels like they aren't listening to me saying its not just the one printer and one house type thing. This exact printer has caused issues in 2 houses, another similar color one did in the other house. Yet my Brother printer never caused issues, my Oki never caused issues. So I'm left seeing that the ONE thing in common is the samsung brand.I honestly love this samsung other than the bit of flickering it gives my CFL's and it tripping my UPS's.

author: tld
author_rank: Regular Contributor
timestamp: August 15, 2013, 09:34:35 pm
content: First off, I was probably a bit harsh in my choice of words, sorry about that.I'm not saying there's no difference between samsungs and other printers. It seems quite possible that there is one, but I'm not following the leap over to the caps, and not to it being a f'up with them on Samsungs part.The bigger printers might not cause the issue, but that doesn't mean it's not a fuser-draw issue. Chassis-size isn't a reliable indicator of current-draw.Let me just make some stuff up to illustrate how all of this could be connected...Larger priters are often workgroup-printers. They often stay on all day, and doesn't need the same speedy warmups that smaller single-user printers need. That alone could explain higher draws on a smaller printer.Also, there's the issue of ramp-up. How fast is the fuser-heater drawing current? Does it ramp up slowly? Or go instantly from 0 to 8A?I wouldn't bet anything significant on it, but that difference could explain the UPS triggering on one, and not the other.If you imagine a near instant draw of 8A, and a 0.68uF cap trying to dampen that, I' thinking it's just not going to do a lot.(On an unrelated note, part of me is tempted to suggest the printer is defective, identifiable by the missing Xerox-logo... Can you buy something like the Phaser 6600/DN?)tld

author: WarSim
author_rank: Frequent Contributor
timestamp: August 16, 2013, 02:33:29 am
content: Quote from: mitpatterson on August 15, 2013, 03:49:04 pmThe sticker rating is the circuit load rating and doesn't not mean max current draw. With a laser printer the startup for the fuser can be considerably more. A sag of 12v due to one appliance is not great either, but should be tolerable, if there isn't any induced noise.With your latest information it looks more likely you have a failing drum or fuser heater breaking down. But until you test inrush current draw and noise levels I can not be sure.I agree with the previous post. The personal printers are competing on the first print benchmarks. The result of the fast warmup is lower fuser/drum like and higher startup current and higher inrush current.Yes you could compensate for the problem with a multi stage high current filter networks. Each stage costs about $60 - $180 and if your UPS is not giving false alarms you will most likely need two additional stages. You are looking at over 40vpp noise that has a sustained pulse long enough for a UPS to complain. Even if the caps are defective it still would not account for the problem. Because you need to chain the filters they will need to complete filters, not a few caps. One choke, 2 inductors, 3 caps, 5 beads min each stage. The built in filter seemed to be enough to be the final third stage. I certainly do not recommend this approach.Lastly if you must try the caps first. Do not change the values very much, unless you run the new numbers for the new values. Caps too large could starve the printer and cause other damage. Extremely large could cause external damage. Then again if you do cause more damage this cap discussion will become moot.