hybridfree/eevblog-posts huggingface dataset:
Anybody use a Circuit Specialists CSIPPS33T power supply? - Page 1
Forum section: electronics / general

author: boltzmann
author_rank: Newbie
timestamp: March 13, 2012, 02:43:27 pm
content: Hi, I've been shopping for a bench power supply lately and thought the CSIPPS33T (http://www.circuitspecialists.com/programmable-bench-power-supply-csipps33t.html) looked interesting, but I haven't found any discussion on it (other than a somewhat tepid comment in their "compare the competitor" link). Has anybody here used one?Thanks!

author: T4P
author_rank: Super Contributor
timestamp: March 13, 2012, 03:10:19 pm
content: 3amps , hmm .Not enough to justify the 300$ tag .I know as a 32v x 2 , 6v x 1 , 5v 3amps x 1 programmable power supply might be worth it but really ,http://www.aliexpress.com/product-fm/428683956-MA009-30V-5A-mA-Display-Digital-Store-DC-Programmable-Power-Supply-DPS3305P-Programming-DC-Power-Supply-wholesalers.html2 of these would be ideal .

author: sotos
author_rank: Frequent Contributor
timestamp: March 13, 2012, 03:20:11 pm
content: Hello friend.Its the same as the ATTEN PPS3203T-3Shttp://www.attenelectronics.com/productBody.aspx?id=20&bid=25&sid=79Also their 5A model ATTEN PPS3205T-3Shttp://www.attenelectronics.com/productBody.aspx?id=92&bid=25&sid=79Look up for this model, to see whats going on.

author: David_AVD
author_rank: Super Contributor
timestamp: July 08, 2012, 12:42:59 pm
content: Has anyone here used one of these programmable power supplies? I realise they are not "top shelf" brands, but do they work as advertised?
Tek Current probe TCP312 and TCPA300 amplifier - Page 1
Forum section: electronics / general

author: Omicron
author_rank: Regular Contributor
timestamp: July 06, 2012, 08:18:57 pm
content: Some time ago I was able to obtain a second hand Tektronix TCP312 DC current probe and TCPA300 amplifier. I was experimenting with these to see if they are still in a working condition. I observed the following:This is a 40Hz square wave signal of 100mA amplitude. As you can see there is a peak at the leading and falling edges. This peak is not present in the actual signal but is an artifact of the current probe or the amplifier. I know these types of probes use a hall sensor for the LF part and a more conventional current transformer for the HF part. It seems almost like the HF and LF responses aren't matched. But there don't seem to be any adjustments inside or outside.Has anyone seen this kind of thing before? Would this indicate a bad amplifier or a bad probe? Neither the probe nor the amplifier offers any adjustments apart from some basic gain adjustments as far as I can see.Another thing I noticed is that the gain adjust on the probe doesn't seem to have enough range to properly correct a DC current measurement. It always reads a little low (about 5% and this probe in theory should be accurate to typically1%, worst case 3%).Any thoughts or ideas are most welcome.

author: free_electron
author_rank: Super Contributor
timestamp: July 06, 2012, 09:06:33 pm
content: is the clamp all the way closed ? ( there should be an led that tells you when it is. )it almost looks like the degauss circuitry is still running..

author: Omicron
author_rank: Regular Contributor
timestamp: July 07, 2012, 12:16:35 am
content: Yes, all the way closed. There is indeed an LED on the amplifier that lights when you forget to close it all the way. When I press the degauss button it seems to do it's thing.
Agilent E4438C ESG - rebranded Rohde6Schwarz? - Page 1
Forum section: electronics / general

author: Lukas
author_rank: Frequent Contributor
timestamp: July 04, 2012, 11:02:06 pm
content: Hi There,the GUI of the E4438Chttp://www.home.agilent.com/agilent/product.jspx?cc=DE&lc=ger&ckey=1000004297:epsg:pro&nid=-536902340.536880956.00&id=1000004297:epsg:pro&cmpid=92121looks somewhat similar to the one of Rohde & Schwarz equipment (http://www.mbmt.com/foto/RS_SMIQ03_Komm_300.jpg) Am I completely misguided, or does Agilent rebrand R&S gear?Lukas

author: poorchava
author_rank: Super Contributor
timestamp: July 06, 2012, 10:11:59 am
content: I don't think that these two are similar enough to say that Agilent rabrands R&S (or the other way around).Some photos of internals would have to be made, but personally I don't think that's the case.

author: free_electron
author_rank: Super Contributor
timestamp: July 06, 2012, 09:09:35 pm
content: the only rebrand they have is an older handheld spectrum analyzer from RS ( the rs FSH3 , which , weirdly has a big fat asic in it labeled with the 'Fluke' logo .... I replaced the battery on one of those for a friend of mine. the battery was also labeled Fluke and was the same pack as used in the scopemeters from fluke....talk about a chimera design ...

author: tnt
author_rank: Regular Contributor
timestamp: July 06, 2012, 09:19:20 pm
content: I don't quite see how they are "similar" ... I mean sure they display frequency amplitude and current status (RF on / modulation / ...) but that's pretty much what all RF siggen will display :pI have a previous model of agilent and it's already the same interface as the E4438C.Cheers,Sylvain

author: Lukas
author_rank: Frequent Contributor
timestamp: July 06, 2012, 10:00:50 pm
content: From the far the UIs appeared similar to me, but that's personal opinion. I couldn't find any further evidence. I would have been quite surprised if it was actually a rebadged instrument.
Teardown & Partial Review: Rigol DG1022 Arb. Function Generator - Page 1
Forum section: electronics / general

author: vl400
author_rank: Regular Contributor
timestamp: September 14, 2011, 10:03:44 am
content: Bought this the other day and after seeing some of the internal pics of the DG2041A that olsenn posted opened up my DG1022 to compare. I will be testing the performance of it later so will post the results.Here are some pics (click the thumbnail for higher res, the originals were hugh but photbucket automatically resizes them)...

author: olsenn
author_rank: Frequent Contributor
timestamp: September 14, 2011, 01:43:41 pm
content: Nice! I was going to by this unit, but after noticing the limits to the non-sinusoidal waveforms and arb, I decided for the more expensive model. Let me know how it performs after you've broken it in

author: saturation
author_rank: Super Contributor
timestamp: September 14, 2011, 03:28:42 pm
content: The photos look like its made better.

author: SrS
author_rank: Contributor
timestamp: September 15, 2011, 08:55:49 am
content: The 2 DACs (below the big cyclone) with their number sanded off are AD9740 & AD9744

author: vl400
author_rank: Regular Contributor
timestamp: September 22, 2011, 09:43:11 am
content: I will do a proper test later using a spec an or VNA but for now I thought I would post some FFT screen grabs showing that Rigol still have not fixed the level change when using the sweep function. Manual sweeping over the same 0-20MHz range shows a flat response...

author: vl400
author_rank: Regular Contributor
timestamp: October 06, 2011, 02:07:42 pm
content: Here are some spec an screen shots of the sweep performance.Test cable freq response to confirm it does not skew the results. Its a quality SMA terminated coax...Auto sweep, not wonderful...Manual sweep using the dial, odd why the response is better compared to the auto sweep...And finally measuring the power output settings, the Agilent is not really suitable for low frequency testing but wanted to confirm the test setup is accurate...

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 06, 2011, 04:32:49 pm
content: excellent!

author: Unknown
author_rank: Unknown
timestamp: October 06, 2011, 05:45:14 pm
content: So it fails both its amplitude flatness spec (0.15dB <= 5MHz, 0.3dB <= 20MHz) and amplitude accuracy specs (1% + 1mVpp for 100kHz sine)?

author: vl400
author_rank: Regular Contributor
timestamp: October 06, 2011, 07:25:18 pm
content: Yeah some of the specs appear to be a little optimistic.Will retest the amplitude accuracy at 1KHz, was at 10MHz due to the available test gear (generally only deal with > 1GHz)

author: bingo600
author_rank: Super Contributor
timestamp: July 06, 2012, 07:09:14 am
content: I just did some ADEV measurements of my DG1022 herehttps://www.eevblog.com/forum/general-chat/rigol-dg1022-function-generator/msg126426/#msg126426/Bingo
EXtech EX430 questions - Page 1
Forum section: electronics / general

author: eevtony
author_rank: Newbie
timestamp: July 02, 2012, 07:36:59 am
content: Hi.I was wondering what experiences people have had with the above meter.Anything in particular wrong with it?Also, how is it for testing LEDs? Can it light them?I noticed on the $100 shootout that the EX505 wasn't able to.Thanks for any help people can offer.Tony
20V mod for Velleman/HQ Power PS1503SB - Page 1
Forum section: electronics / general

author: mightyzen
author_rank: Contributor
timestamp: June 30, 2012, 03:53:09 pm
content: As Balaur stated in his review of this unit, it is possible to increase the output voltage to more than 15V.By just turning the pot on the pcb I was able to go to 17.5V, which is less than the 18.5V Balaur was able to get.The pot is about 200R and in series with a 910R resistor to the positive rail. By putting a 4k7 resistor in parallel with the 910R, I was able to go beyond 20V. However, at 20V the build-in volt meter overflows. With the 4k7 resistor in place, you can use the pot to set the max voltage to just under 20V.See the photo's.If you want to, try this at you own risk, and remember the unit was designed to handle 45W max.BTW: the pcb is dated 2011.09.08 V3.0

author: Tube_Dude
author_rank: Regular Contributor
timestamp: June 30, 2012, 04:43:11 pm
content: HiInspect if at 20 Volts output and supplying the rated current, you don't have ripple at the output.Any regulated power supply need to have a minimal voltage difference between input and output, usually 3 to 5 Volts, to work properly, and usually the design team don't make that voltage too big, because it increase power dissipation and consequent increased expense in bigger heatsinks.Maybe you are lucky and this issue don't apply...

author: mightyzen
author_rank: Contributor
timestamp: June 30, 2012, 05:46:54 pm
content: The input stage (behind the rectifier) is 29.3V, so there is plenty of room. Applying approx 7 ohm load at 19.179V yields a 3.00A (rated) current, dropping the voltage to 19.141V. Will hook up the scope later.

author: Mint.
author_rank: Frequent Contributor
timestamp: July 01, 2012, 12:34:13 am
content: HA!Smart move!

author: mightyzen
author_rank: Contributor
timestamp: July 01, 2012, 12:14:48 pm
content: Ripple is worst when current limiting kicks in. At 19V, with current limited to 3.26A, ripple is about 6mV RMS with peaks not exceeding 13mV. Without current limiting these values more than halve. Which I think is pretty good for such a cheap unit.
Anybody using Agilent U3401A multimeter? - Page 1
Forum section: electronics / general

author: zaoka
author_rank: Frequent Contributor
timestamp: June 29, 2012, 08:43:04 pm
content: Does anybody is using Agilent U3401A multimeter, is it worth keeping or anything bad with this meter?Also is MINMAX capturing 1ms or 250uS max?Thank you!
LeCroy WaveAce 1000 / 2000 series - Page 1
Forum section: electronics / general

author: madworm
author_rank: Frequent Contributor
timestamp: July 07, 2012, 10:25:44 pm
content: By accident I came across the 'new' 1000 / 2000 series oscilloscopes.I've had a quick glance at the specs. Except for 'deep memory' and a wide-screen, they seem to be pretty much the same as the older WaveAce ones. The case looks a bit different. It's even got a rounded edge, much like the Agilent 2000/3000 ones. Buttons and UI look the same to me.I'd certainly like to find out if they still have the same deficiencies as their predecessors. On the other hand, I think I have had enough contact with products bearing that name.

author: saturation
author_rank: Super Contributor
timestamp: July 08, 2012, 01:03:33 pm
content: I am surprised you'd consider another WaveAce after what you've been through. If they lend you that model for evaluation before buying, that would be better, you could write the CEO and see what happens. You've done well so far. I think if it survives your scrutiny, it would speak highly for them, if they don't lend it to you, you've nothing to lose and they'll lose a potential customer.

author: Bored@Work
author_rank: Super Contributor
timestamp: July 08, 2012, 01:38:32 pm
content: Quote from: madworm on July 07, 2012, 10:25:44 pmThey look suspiciously like Atten/Siglent. I didn't search for the exact model, but the S icon in the scope's status bare gives it away. Looks like a cookie from PackMan, someone already took a few bites from.

author: madworm
author_rank: Frequent Contributor
timestamp: July 08, 2012, 02:22:52 pm
content: QuoteNo I don't! I just wanted to see if any new firmware for the 224 had been released and accidentally saw these. I wonder if they will discontinue or flog off the older ones pretty soon.I think I will go for the Hameg HMO2024. I've read a couple of very positive blog posts about it. The Rigol4000 looks interesting too (memory depth), but bus decoding costs too much for my liking.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: July 08, 2012, 03:13:46 pm
content: 4 hours left:http://www.ebay.de/itm/261057433987?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Tektronix 2336 YA -- service manual wanted - Page 1
Forum section: electronics / general

author: kfitch42
author_rank: Frequent Contributor
timestamp: July 07, 2012, 05:44:28 pm
content: Just bought a Tektronix 2336 YA off ebay. It does a wonderful job of displaying horizontal lines, but not much else. I popped it open, and it seems that the CH1 and CH2 BNC connectors don't actually connect to anything inside the scope. Does anyone have a service manual for this scope? Even a few pics of the insides showing where to connect things would be a big help.Kevin

author: chrome
author_rank: Regular Contributor
timestamp: July 07, 2012, 06:18:36 pm
content: http://www.ko4bb.com/Manuals/Tektronix/Tektronix_2336/Tek_2336_YA_Operators_Manual.pdfNot a service manual but might help you if you don't already have this.

author: kfitch42
author_rank: Frequent Contributor
timestamp: July 07, 2012, 06:49:01 pm
content: Quote from: chrome on July 07, 2012, 06:18:36 pmThanks for the link. But the scope actually came with a deadtree operators manual.

author: LEECH666
author_rank: Frequent Contributor
timestamp: July 07, 2012, 07:17:20 pm
content: A quick search of my usual resources didn't yield any free results, but someone on a forum suggested that you can buy a fully text searchable version of the service manual here:http://www.qservice.tv/vpasp/shopexd.asp?id=151&bc=noPricepoint is around 12$.They also link to a PDF containing a few sample pages of the SM here:http://www.qservice.tv/samples/2236_sample.pdfCheers,Florian

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 07, 2012, 08:06:17 pm
content: Found a 10MB zip with JPG's of the diagram.Not all that readable but better than nothing I guess.[edit: the link would help]https://www.box.com/shared/6eo83svohz

author: kfitch42
author_rank: Frequent Contributor
timestamp: July 08, 2012, 04:01:49 am
content: Quote from: PA0PBZ on July 07, 2012, 08:06:17 pmAwesome, looks like that might be enough to get me started! Not sure if I will have time to play with it tonight, perhaps tomorrow.Thanks,Kevin

author: kfitch42
author_rank: Frequent Contributor
timestamp: July 09, 2012, 04:06:34 am
content: Thanks everyone. I dug through the JPGs, then opened up the scope in order to find things like J915 on the silkscreen. In the process of studying the silkscreen I noticed two rather thick cables that were not connected to anything! I shoved them into the backs of the BNC connectors ... and now I can get real signals on the display!!! I will still probably break down and buy the service manual at some point. I am pretty sure the scope is WAY out of cal.Kevin
Agilent DSOX2002A - Page 1
Forum section: electronics / general

author: tcgoh
author_rank: Contributor
timestamp: June 27, 2012, 11:34:58 am
content: HiCan anyone help?I am wondering if this 2 Channel 70Mhz can be firmware upgraded by buying the appropriate Agilent option to 4 channel?Thanks.TC

author: EEVblog
author_rank: Unknown
timestamp: June 27, 2012, 11:54:23 am
content: No, not possible. It's only physically got the two channels on the front.Dave.

author: tcgoh
author_rank: Contributor
timestamp: June 27, 2012, 02:29:23 pm
content: DaveThanks. Looks like I will need to spring for the 4 channel to protect my investment.Keep up the great work, Dave. I really enjoy your reviews and occasional rants :-).Thanks again.TC

author: EEVblog
author_rank: Unknown
timestamp: June 27, 2012, 02:38:07 pm
content: Quote from: tcgoh on June 27, 2012, 02:29:23 pmYes, smart to but the most basic 4 channel you can get, then you can always software upgrade other stuff later.Dave.

author: tcgoh
author_rank: Contributor
timestamp: June 27, 2012, 02:57:10 pm
content: My thoughts exactly.Agilent is offering a 100% discount (free upgrade) for the Wavegen and DVM modules till end August. So, seems like a good deal to get one before then.TC
Teardown STC-200(+) - Chinese PID Temp-Regulator - Page 1
Forum section: electronics / general

author: bingo600
author_rank: Super Contributor
timestamp: June 25, 2012, 05:59:54 pm
content: My brother needed a simple temperature regulator , for some "Cooking"I ended up getting this one.http://fzhanjing.en.alibaba.com/product/261917960-209562385/Digital_temperature_controller_STC_200_series.htmlThe seller sold me a PT-100 sensor also , but now i doubt i can use that one.As all the docs says it's for NTC (There was a NTC sendor in the box)I haven't even turned it on yet ....But i decided to see what it consisted off.The MCU is this one HT46F49Ehttp://www.holtek.com/english/docum/uc/46f4xe.htmThe manual is "lousy" as expected , but at least not "Super Chinglish".Maybe google xlate has improved.I'm not sure i'm happy about this one ...Well' see/Bingo

author: bingo600
author_rank: Super Contributor
timestamp: June 25, 2012, 06:03:35 pm
content: Had to zip the manual , to get it under 1MB

author: M. András
author_rank: Super Contributor
timestamp: June 25, 2012, 09:50:14 pm
content: i love that transformer

author: flolic
author_rank: Frequent Contributor
timestamp: June 26, 2012, 09:42:55 am
content: That's not a PID controller, it's just a plain digital thermostat with few extra functions.I have a similar one from ebay (http://tinyurl.com/7tjv2v7) and it works ok for what it is.

author: sorin
author_rank: Frequent Contributor
timestamp: June 26, 2012, 10:17:47 am
content: Quote from: flolic on June 26, 2012, 09:42:55 amyou cant say that,the only way to see if is a PID or no, is to see the source code of MCU.

author: flolic
author_rank: Frequent Contributor
timestamp: June 26, 2012, 10:34:39 am
content: Yes, but sellers always advertise PID functionality, plus that should be mentioned in a programming manual (which is not).
Automotive Electronics--The 24V Jump Start Condition - Page 1
Forum section: electronics / general

author: TerminalJack505
author_rank: Super Contributor
timestamp: June 28, 2012, 10:28:03 pm
content: Automotive circuits are expected to handle several transient over-voltage/under-voltage conditions. Most of these conditions are short-lived and can be handled with surge suppression components such as TVSs and MOVs.There are two particular over-voltage conditions, however, that are longer lived. The 24V jump start condition and the failed regulator condition.The 24V jump start condition is described inthisdocument as follows:QuoteThe failed regulator condition is a steady state condition (that is, it will potentially be very long-lived) and the voltage can reach +18V.A circuit that I am designing controls two 12V solenoid-operated valves. These valves each require about 1.5A at 12V. Naturally, the manufacturer says nothing about what happens when the solenoid is driven at 24V. It's probably fairly safe to assume this shouldn't be done, if it can be avoided.My question is, what is typically done in these cases? Ideally, I want to keep the solenoids energized during these conditions. What is the best, most cost effective way to protect the solenoids but keep them energized? Or is it even a problem? Would the solenoid coils survive these conditions?

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 29, 2012, 03:38:08 am
content: If you're willing to break one, just try connecting it to a 24V bench power supply.As for a solution, you could PWM the solenoids, maybe at 2-3kHz to also cause them to make an overvoltage warning sound.

author: TerminalJack505
author_rank: Super Contributor
timestamp: June 29, 2012, 04:47:28 am
content: The PWM idea sounds like it could be an inexpensive option.Unfortunately, I don't have any of the valves right now so I can't test either of your ideas. Right now a friend and I are just kicking around ideas.If it works then it would be better than some of the ideas I came up with. The cheapest solution I could come up with is the attached circuit.

author: poorchava
author_rank: Super Contributor
timestamp: June 29, 2012, 08:07:03 am
content: If I remember correctly ISO17650-2 standard specifies time of jumpstart condition test to 60s and regulator failure as 1 hour (for the sake of qualification).

author: TerminalJack505
author_rank: Super Contributor
timestamp: June 29, 2012, 08:44:58 am
content: Quote from: poorchava on June 29, 2012, 08:07:03 amThanks for the info. Its sounds like the coils might be fine without any extra protection in that case. I'll probably still add it, though.The PWM solution would likely require no extra components. The circuit will be MCU controlled so it would just need to detect the over-voltage condition and act accordingly.
Update for Hameg HMO 2524,3522 and 3524 available - Page 1
Forum section: electronics / general

author: Gunb
author_rank: Regular Contributor
timestamp: June 28, 2012, 11:48:05 am
content: FYI: now Hameg has released the update for the higher models of the HMO 2524, 3522 and 3524 officially.There are a few new features already known from the smaller HMOs. For the update older HMOs have tobe modified at Hameg site first before firmware can be flashed. Further details can be found in the release note includedin the zip-file.My scope was already modified at the beginning of 2012 for testing the beta. I would say it's worth toget the update ;-)PDF with changes of the beta is also included.Kind regardsGunb
35mm Cinema Film Projector teardown - Page 1
Forum section: electronics / general

author: tesla500
author_rank: Regular Contributor
timestamp: June 05, 2012, 07:43:50 pm
content: I know this isn't totally (or even mostly) electronics, but I think you'll find this one interesting. Here's a teardown of a 35mm film projector that I got from a local cinema after they converted to digital projectors.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 05, 2012, 11:19:47 pm
content: Super cool - my favorite kind of tech - originally very expensive but now completely obsolete!Do you have the Dolby digital decoder ? That would be interesting to see inside.

author: tesla500
author_rank: Regular Contributor
timestamp: June 06, 2012, 12:16:37 am
content: Quote from: mikeselectricstuff on June 05, 2012, 11:19:47 pmThanks Mike! I love this kind of stuff too.Unfortunately the Dolby digital decoders are still being used (as analog preamps for the main theater amps), I'd love to get one though. I'm eager to see how they do this rather intensive decoding job using 90s tech. Probably some high end (for the time) FPGAs. Gotta start checking ebay...David

author: BravoV
author_rank: Super Contributor
timestamp: June 06, 2012, 06:45:27 am
content: Thank you, really cool and thats is really an impressive machine, and its quite an effort just to drag it home, kudos to you & team.PS : Actually you've inspired me, I might approach our local cinema, who knows I could get one cheaply.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: June 06, 2012, 10:49:09 am
content: Great set of videos. Very interesting to see the internals of those big old projectors.So what's next? Teardown of the digital projector?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 06, 2012, 11:37:55 am
content: Quote from: DrGeoff on June 06, 2012, 10:49:09 amMight have to wait a while for that one - any chance of a quick video tour of the projection room to at least see the outside of all the gear??Meanwhile here's a teardown of a not-quite-cinema sized projector :

author: tesla500
author_rank: Regular Contributor
timestamp: June 22, 2012, 03:54:49 pm
content: Update: Ballast and Synchronous motor teardowns posted, check the first post.Edit: Looks like I've also got a Dolby Digital decoder for teardown too! One of the other theaters in the chain my friend works at is throwing some out.
U1272A: Nulling with dB measurements? - Page 1
Forum section: electronics / general

author: longview
author_rank: Contributor
timestamp: June 21, 2012, 10:23:54 am
content: Hi, I'm trying to do some relative measurements on my DMM and I want to do it in dB mode, but it's doing something a bit weird:If I set the output voltage to say +10dBm_600, then null it, if I go up 10 dBm on the output it'll read +10, as it should.But then if I go down 40 dBm to -30dBm, it should read -40, instead it reads 0.8 dBm.It's like it wraps around when it hits -20dB relative, it starts counting "up" again, like the null-point is shifting when it hits a certain limit.It's hard to put into words but basically if I null at +20 it'll read 0 at +20 and -20, it seems. Anyone have any idea what's happening here, am I missing something about the functionality?In the normal dBm mode it read everything like you'd expect, this only happens when nulled.

author: saturation
author_rank: Super Contributor
timestamp: June 21, 2012, 02:36:28 pm
content: I've never tried that, so I'll give it a whirl and report back.
Uni-T UTD2062CE DSO - Page 1
Forum section: electronics / general

author: Stephen Hill
author_rank: Regular Contributor
timestamp: June 22, 2012, 08:43:07 am
content: Hi,Has anyone used or owned this oscilloscope? If so, I would love to hear your opinion.http://www.uni-trend.com/UTD2062CE.htmlMany ThanksStephen

author: T4P
author_rank: Super Contributor
timestamp: June 22, 2012, 09:23:48 am
content: I suggest you stay away from anything UNI-T Bench ... pile of crap they are, the bench division is crapLikewise stay away from anything UNI-T except the UT10A, UT61x ( Might as well get E instead of D ), UT33x but yeahhttps://www.eevblog.com/forum/product-reviews-photos-and-discussion/uni-t-ut61e-multimeter-teardown-photos/msg81221/#msg81221

author: Stephen Hill
author_rank: Regular Contributor
timestamp: June 22, 2012, 09:27:36 am
content: Quote from: DaveXRQ on June 22, 2012, 09:23:48 amThanks for the warning. But I'm looking for specific feedback on this particular scope. If there is any...

author: Unknown
author_rank: Unknown
timestamp: June 22, 2012, 12:35:03 pm
content: There have been a few fairly negative reports on Uni-T scopes. I don't remember the exact models involved.

author: T4P
author_rank: Super Contributor
timestamp: June 22, 2012, 12:54:16 pm
content: Quote from: alm on June 22, 2012, 12:35:03 pm2000CEL and the 2000CE series they are fairly terribleThe biggest scam is the 2000cm

author: Stephen Hill
author_rank: Regular Contributor
timestamp: June 22, 2012, 12:59:28 pm
content: Quote from: alm on June 22, 2012, 12:35:03 pmBut most people only seems to speak out when something is bad. If something is good, they are happy and continue on with their life.I've seen good and bad reviews about their range of portable oscilloscopes, so this might suggest that there some good products by UNI-T...Anyway, if anyone actually owns this scope or any in this particular scope range, please let me know.

author: T4P
author_rank: Super Contributor
timestamp: June 22, 2012, 01:11:10 pm
content: Quote from: Stephen Hill on June 22, 2012, 12:59:28 pmI don't, but their portable division is a lil' bit good, the UT81B is a good and cheap scopemeterUT70 and UT71 is a flop, because of their glass fuses for something so priceyUT61x still their best series ever, but the highest grossing sales for them come from the UT61E and UT10A

author: Stephen Hill
author_rank: Regular Contributor
timestamp: June 22, 2012, 04:21:31 pm
content: Well I've found a supplier in my country (UK) who I've got in contact and I'm now just discussing this scope a bit more with him.So if I do decide to buy it then I post a review and teardown.I can buy this scope from the UK for 267GBP. This is compared to the DS1052E at around 310GBP.
Inductance meter on ebay? - Page 1
Forum section: electronics / general

author: trevwhite
author_rank: Frequent Contributor
timestamp: June 14, 2012, 10:26:02 am
content: Hi, has anyone used one of these? Are they any good?http://www.ebay.co.uk/itm/261036615580?ssPageName=STRK:MEBOFFX:IT&_trksid=p3984.m1427.l2649#ht_500wt_1156ThanksTrev

author: Mint.
author_rank: Frequent Contributor
timestamp: June 14, 2012, 10:30:06 am
content: Looks interesting, maybe ill buy. I had a look at the seller only 29 stars, but also 100% positive feedback from private sales.

author: Nermash
author_rank: Frequent Contributor
timestamp: June 14, 2012, 10:36:44 am
content: I think this is based on design that can be found online, with PIC 16F628.If the build quality is decent, I believe it should suffice for hobby usage.

author: trevwhite
author_rank: Frequent Contributor
timestamp: June 14, 2012, 11:08:22 am
content: Well I was wondering about it. It does state you have to be careful and discharge it between measurements else it could blow up. But if the accuracy is there then could be very interesting. No one actually used one?Trev

author: akis
author_rank: Frequent Contributor
timestamp: June 14, 2012, 01:51:36 pm
content: I boughthttp://www.ebay.co.uk/itm/320840062247?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648#ht_1112wt_1163and it's OK, a bit fiddly with the switches but OK in general.

author: RCMR
author_rank: Frequent Contributor
timestamp: June 17, 2012, 06:53:38 am
content: I've got one of these -- it seems to work okay when tested against a bunch of inductors I had laying around the workshop.

author: steve_w
author_rank: Regular Contributor
timestamp: June 18, 2012, 08:30:01 am
content: It claims .1pF resolution, just putting your finger near the probes, or having long leads could vary the measurement, could it be that accurate?steve w

author: notsob
author_rank: Frequent Contributor
timestamp: June 18, 2012, 09:33:47 am
content: AADE in Perth make an accurate Cx/LX unit, available in kit or assembled,price is probably not what you are looking for going by your ebay linkhttp://www.aade.com/lcmeter.htm

author: kripton2035
author_rank: Super Contributor
timestamp: June 18, 2012, 09:46:37 am
content: the original free design of this inductance meter is certainly near this web page :http://kripton2035.free.fr/lcr-repository.htmlregards,

author: Mint.
author_rank: Frequent Contributor
timestamp: June 18, 2012, 11:40:34 am
content: Quote from: notsob on June 18, 2012, 09:33:47 amI don't like the specs on this...

author: rr100
author_rank: Frequent Contributor
timestamp: June 18, 2012, 12:42:37 pm
content: There's a HP-6301 (Holdpeak) floating around ebay/amazon/etc. Quite cheap and seems to have better isolation and more "beef" compared to the others mentioned in this thread. Anyone has it?
Samsung Galaxy S III teardown. - Page 1
Forum section: electronics / general

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: June 16, 2012, 08:58:24 am
content: http://recombu.com/news/samsung-galaxy-s3-teardown-video-looks-painful_M17908.html

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: June 16, 2012, 09:21:38 am
content: And this too:http://www.eetimes.com/electronics-news/4375343/Teardown--Inside-the-Samsung-Galaxy-S3-smartphone?pageNumber=0

author: amyk
author_rank: Super Contributor
timestamp: June 16, 2012, 12:33:35 pm
content: Everything in mobiles these days is so highly integrated that a nondestructive teardown is not much more than separating the assembly into FRUs... although for now even with the lowest-end models we haven't reached the ultimate point of a single-die COB.

author: T4P
author_rank: Super Contributor
timestamp: June 16, 2012, 05:25:56 pm
content: What a idiot, the webpage says "Phone to beat"It's the One X Apple has to deal with, 32GB and only $898SGD Samsung is comparably $998SGD with only 16GB ( Expandable yes, but that's overpriced )

author: Chet T16
author_rank: Frequent Contributor
timestamp: June 16, 2012, 05:36:53 pm
content: The SIII is technically superior to the One-X, take a look at the benchmark scores. It's also interesting to note that the dual core One-X is posting better benchmark scores than the international quad core version and users are reporting it to be smoother in use.

author: T4P
author_rank: Super Contributor
timestamp: June 16, 2012, 05:51:05 pm
content: Quote from: Chet T16 on June 16, 2012, 05:36:53 pmWell it's "artificially boosted"Nvidia didn't do a very good job and those users were dual-core "fans"Trust me a 100$ difference is ALOT !

author: Chet T16
author_rank: Frequent Contributor
timestamp: June 16, 2012, 07:42:10 pm
content: The difference here is similar, ~€75. At launch the HTC was slightly more than the galaxy is now so there isn't anything in it really.

author: T4P
author_rank: Super Contributor
timestamp: June 17, 2012, 07:53:23 am
content: Quote from: Chet T16 on June 16, 2012, 07:42:10 pmAt launch the HTC here was already far cheaper then the samsung at launch
VTVM and TVM's - Page 1
Forum section: electronics / general

author: Dawn
author_rank: Regular Contributor
timestamp: June 16, 2012, 10:22:48 pm
content: With the recent threads on multimeters and voms, you just know that there had to be an equivalent on electronic analog voltmeters. Back in my early days during the mid 60's and early 70's when I first started in this hobby, a VTVM kit was among the 2nd or 3rd pieces of test equipment that would have been sought for a basic bench after initially acquiring a hobby grade VOM. The 70's brought in FET and transistor based VOM's at the kit/hobbly level. Many of them nightmares in the short run and unable to deliver the reliability of an 20 y/o second hand VTVM. There were many things a VOM just couldn't do and nor could a latter DMM with respect to a VTVM. To this day, a VTVM does have uses that are not duplicated in a DMM. It probably would be fair to say that they are irrelevant nowadays with the current crop of electronics and certainly no place in a development laboratory. Yet in service, there are still applications they are used for occasionally and not easily substituted and merit being kept on a shelf if needed. Some applications that they excelled in were:Most all could bias the movement for a zero center.High frequency response up to several meg ACCapable of reading very low ohm values right down to emitter resistors that regular DMM's cannot.Higher end volt ranges often to several thousand volts directly.Isolation resistor in the probe and tube amplifier gave a very high impedance that didn't disrupt circuit operation or detune it.Like 20k/ohm voltmeters, were standardized instruments that procedures and reference voltages were documented in older service literature.There are others, but suffice to say that if you're working in a service vocation, inevitably a VTVM would make your life easier at times.Regarding the TVM's that never seemed to succeed the VTVM's. One of their worst malady's was the presence of RF. Sometime even probing around and oscillator would drive the meter full scale. That forcible "thwack" any time a transmitter was energized or around powerful oscillator circuits made many of them undesirable for service. While there were many TVM's that were designed to be RF proof, most were service instruments designed by and unique to the trade. Alignment was touchy and could vary with battery or supply voltage and short time ageing. Thankfully, DMM's at hobby and service prices began to make their debut shortly afterwards.
Fluke 381 with IFlex - Page 1
Forum section: electronics / general

author: Glocal
author_rank: Contributor
timestamp: June 14, 2012, 04:52:04 pm
content: Hi.I have gotten Fluke 381 with Flex , bought on Ebay .The meter is amazing and very accurate and the option of the remote display is more than great to make an easy job specially working with ( db boards) the only thing i found strange was that the continuity test : didnt really sound clean and sharp as it used to be with Fluke meters. i thought was maybe because of the radio signal ? and when i removed the remote Display from the meter and get it close to my ear I heard something like scratching : it stops when you remove the batteries . Honestly i never had a meter with a remote display before so maybe all that is normal .If any one has the meter I`d be more than thankful to hear from them.

author: retiredcaps
author_rank: Super Contributor
timestamp: June 14, 2012, 07:34:58 pm
content: Martin did a review on it. He did the continuity test around the 28 min mark.

author: Glocal
author_rank: Contributor
timestamp: June 15, 2012, 04:11:48 am
content: Thanx : i had already seen it...it seems like no one got this meter.
OWON SDS7102V just arrived - Page 1
Forum section: electronics / general

author: akis
author_rank: Frequent Contributor
timestamp: June 13, 2012, 10:06:04 am
content: I have received my first DSO and have played with it a little bit.Nice large screen and much smaller package overall than I had expected it to be. I have learned quickly what most of the buttons do.Some great points:Horz and Vertical auto-centre in a simple button push, auto-"50%" trigger, "autoset" and "autoscale" buttons so you can at least get a wave on the screen again, if you have messed up lots of other settings. I also like the "measure" button which allows you to display on the bottom of the screen up to 4 types of measurements on each channel, eg frequency, RMS, mean etc. Much better than trying to count rectangles and do mental math.You can also set a limit of 20MHz on the channels so that you get less spurious noise.It makes calculations easier because it understands the probe setting (1x 10x 100x etc) and marks the divisions accordingly, whereas on the analog scope I had to remember to multiply everything by 10.There are many more functions of course, these are just first impressions.Some criticisms:When I "add" channel 1 to inverse channel 2 to make a differential measurement, it shows me all 3 curves, ch1, ch2 and the combined "M" (M for "math"). Unfortunately there no way to hide ch1 and ch2, and in this mode I really only want to see M, not 1 or 2. This is very annoying straight away.The trigger function area should have another real button or two for very common things, eg "trigger source on channel 1 or 2", "trigger coupling" etc - currently you need 3 or 4 button presses to change triggering from ch1 to ch2.When I want to zoom in and view a captured wave I only have one knob to move left or right, and it takes dozens of turns to move into the captured wave. There should be a "smart" move, like on my kitchen oven, where turning the knob quickly increases the step. Having said that, if you rotate the time base button, it zooms in and out centred on the middle of the screen so that way you can move to a specific area quickly.

author: akis
author_rank: Frequent Contributor
timestamp: June 14, 2012, 01:17:35 pm
content: Another omission: you can not take auto-measurements on the Math curve. The Math curve is a "Ch1 operation Ch2" curve.For example when I am taking differential measurements not only do I have 3 curves cluttering the screen, but I cannot even see the measurements on the combined curve. Very annoying having to do mental maths again.
Cool Tiny USB Li-Ion chargers. - Page 1
Forum section: electronics / general

author: samgab
author_rank: Frequent Contributor
timestamp: June 12, 2012, 10:53:00 pm
content: by Cottonpickers.I like their new design, that has a 3D printed case, and multiple current selections, also the option to turn the screen on and off.Here is a review of the new one:http://www.candlepowerforums.com/vb/showthread.php?336422-Cottonpickers-Nona-Charger-ReviewHere is the page where the maker discusses them:http://www.cpfmarketplace.com/mp/showthread.php?240304-gt-FS-Cottonpickers-Chargers-incl-Worlds-smallest-Li-ion-charger-with-displayAnd here is a review of one of the simpler models with display and only 4 current settings:http://www.lygte-info.dk/review/Review%20Charger%20CottonPickers%20DM+4Settings%20UK.htmlThey use (almost) proper CC/CV method. The almost is because the current starts to drop just before full 4.2V has been achieved, probably due to the algorithm of the microchip controller, or possibly due to the power output limitations of USB.But it's a pretty cool little solution, for charging individual Li-ion cells such as 18650's or 10440's etc, I think.

author: samgab
author_rank: Frequent Contributor
timestamp: June 12, 2012, 11:03:38 pm
content: Oh, and they use as a microcontroller, Linear Technology's LTC4054:http://www.linear.com/product/LTC4054-4.2http://cds.linear.com/docs/Datasheet/405442xf.pdfPretty neat little IC.

author: T4P
author_rank: Super Contributor
timestamp: June 13, 2012, 09:21:34 am
content: Fact of matter is, a Li-Ion cell will slowly complete charge near 4.2V because of rising internal resistance towards charging, and the microprocessor is there to detect the rising impedance
Rigol DP1116A - ground loop question - Page 1
Forum section: electronics / general

author: EmpireJones
author_rank: Newbie
timestamp: June 16, 2012, 04:54:44 am
content: In the following video:http://youtu.be/L1M29SOLXm4?t=11m24s, the DP1116A is connected directly to an oscilloscope. I'm still learning about this stuff, but shouldn't that configuration create a ground loop? Or is 1. the DP1116A not grounded unless the grounding port is used or 2. it assumed that an isolation transformer is being used?Thanks!

author: MikeK
author_rank: Super Contributor
timestamp: June 16, 2012, 02:16:37 pm
content: It has a floating ground output, which is not connected to earth ground. Notice the separate green "earth" terminal.

author: EmpireJones
author_rank: Newbie
timestamp: June 17, 2012, 01:37:17 am
content: Perfect, that's what I was looking for. Thanks!
Original Fluke 83 dataloging capabilities - Page 1
Forum section: electronics / general

author: Elektrongeek
author_rank: Contributor
timestamp: June 07, 2012, 05:07:04 pm
content: I ve recently buyed on eBay an fluke 83 in remplacement for my fluke 73.I have looked at the back of the multimeter and it says / (HOLD) ULTRASONIC DATA OUTPUT.So i ve wonder if we can use that to transfer measures written on the multimeter to a PC .And Ive search on goggle and I've found that projecthttp://www.circuitmaestro.com/Projects/DataHolster/DataHolster.htmlDoes anyone know if it is working or not .Sorry for My English mistakes I'm french
Ratelco PS 8/9 Power Supplies - Page 1
Forum section: electronics / general

author: Dawn
author_rank: Regular Contributor
timestamp: May 31, 2012, 12:45:18 pm
content: I'm curious how many of you are familiar with the Ratelco PS 8/9 series power supplies? I've never known them be found outside the communications sector where they were as common as a Simpson 260 VOM or a Bird 43 wattmeter. These power supplies were overbuilt beasts and rarely if ever failed they were so dependable. They were an early PWM supply that originally dated back to the mid 60's and continued well into the early 2000's when the company was sold and fragmented. The supply was capable of 0-15 or up to 40V in two ranges on the PS9 and up to 40 amps continuous duty. They had a detachable head that allowed the controls to be placed at bench level while the monster sat on the floor or bottom shelf. It had a current preset control and full analog metering of both V/A. The head was pretty flexible in it's design that over the years there were a few companies that made an accessory head. One of note that was very small one like a mobile radio control head that had a DVM for the volts and edgewise meter for the current and a switch with voltage presets in addition to the variable voltage control. Motorola sort of copied the supply in a bench top version that took up a lot of bench space and I think is still made today with some minor improvements. The high current outputs were giant banana jacks. Ratelco made a lot of different power supplies, power conditioning systems, and UPS systems for various specific industries. To my knowledge, only these two supplies were sold strictly to communications manufacturers and shops and for a while re-branded by Motorola until they copied it. They made 220/240V versions, so these must have been exported. I'm wondering how many of you seen these outside the states as well.Here's an image on one on the 'bayhttp://www.ebay.com/itm/Ratelco-2079B-DC-Power-Supply-Untested-/190524756020?pt=LH_DefaultDomain_0&hash=item2c5c291034
Gossen METRAHIT 2A - Page 1
Forum section: electronics / general

author: kcs
author_rank: Regular Contributor
timestamp: May 21, 2012, 04:07:06 pm
content: I miss Dave's DMM reviews, so I have decided to do my own review of Gossen METRAHIT 2A multimeter. Actually it is not a proper review, but...I have bought it from eBay, it is used but looks like new. This multimeter isn't cheap. I am very happy with it, I like its built quality, the only thing that is not right is that when I adjust its ohm range for 10x, 100x or 1000x and then switch to 1x, I need to readjust it (look at the second set of photos). Comparision was made with Fluke 87 V. Everything seems all rightexcept VAC.

author: kcs
author_rank: Regular Contributor
timestamp: May 28, 2012, 12:14:12 pm
content: I want to fix this issue with ohms range. I suspect that one or some resistors could be out of range and that they need to be replaced. Is it possible to get schematics for this meter anywhere? I was out of luck trying to find it on the internet.

author: grenert
author_rank: Frequent Contributor
timestamp: May 28, 2012, 01:08:19 pm
content: Do you mean that you have to zero the meter each time you change ohms range? If so, that is normal for an analog meter.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 28, 2012, 01:11:53 pm
content: Quote from: kcs on May 28, 2012, 12:14:12 pmWhile I also think there is nothing to fix you could ask Gossen for a schematic. They do help people out, even with older models, if they have the information and if it isn't proprietary information.

author: kcs
author_rank: Regular Contributor
timestamp: May 28, 2012, 01:28:07 pm
content: Quote from: grenert on May 28, 2012, 01:08:19 pmYes, exactly. It is strange that you say it is normal, as my old cheap Sanwa multimeters have not had that problem.

author: Fox
author_rank: Regular Contributor
timestamp: May 28, 2012, 01:38:34 pm
content: For Ohms measurement in the user manual Gossen says:- choose your settings x1..x1000- short the leads- adjust the scale too fullscale- measure your resistanceSo with this meter you practically have to adjust your meter every time you change ranges.If you don't have a user manual here is the link to the english one:http://www.gossenmetrawatt.com/english/produkte/metrahit2a.htmAbout the AC Volts.The Metrahit is a averaging Meter, the Fluke has True RMS capability, maybe that's the reason for the discrepancy.But 28V difference seems a bit much, assuming you measureing mains.

author: grenert
author_rank: Frequent Contributor
timestamp: May 28, 2012, 01:41:42 pm
content: Quote from: Fox on May 28, 2012, 01:38:34 pmFox, I think you're reading off the wrong scale.

author: Fox
author_rank: Regular Contributor
timestamp: May 28, 2012, 01:50:16 pm
content: Quote from: grenert on May 28, 2012, 01:41:42 pmIndeed i did, not used to read analog meters any more

author: kcs
author_rank: Regular Contributor
timestamp: May 28, 2012, 02:04:49 pm
content: Thank you all.1. Ohms. If it supposed to work this way, let it be, but I would prefer to make no adjustments.2. VAC. Yeah, I have made the same mistake reading the wrong scale.