hybridfree/eevblog-posts huggingface dataset:
DC load with mains as energy sink? - Page 1
Forum section: electronics / testgear

author: nctnico
author_rank: Super Contributor
timestamp: February 06, 2014, 01:30:04 pm
content: I'm wondering if anyone has ever seen a DC load which pushes the energy into the mains instead of dumping it as hot air? Such a device may be handy for an upcoming project which involves discharging batteries.

author: macboy
author_rank: Super Contributor
timestamp: February 06, 2014, 02:39:57 pm
content: You can obtain inverters designed to dump excess power from a solar panel installation directly back into mains. They are not cheap. You won't get enough energy savings to make it worth it. Think about it, even a large 100 AH battery has only 12*100 = 1.2 kWH of energy. Where I live, that's about $0.09 to $0.16 (CDN) depending on time of day. A small typical 7 AH gel cell battery holds literally one cent of energy.

author: ivan747
author_rank: Super Contributor
timestamp: February 06, 2014, 02:59:22 pm
content: I guess the main advantage is making it very small and make it run relatively cold. A solar installation is capable of delivering more than a kilowatt continuously during daytime. A solar inverter attached to the grid can discharge big batteries quickly.

author: TopLoser
author_rank: Unknown
timestamp: February 06, 2014, 03:29:22 pm
content: I've sold a couple of these in the last year...http://uk.farnell.com/ea-elektro-automatik/ea-elr-9080-170-3u0v-170a/electronic-load-80v-170a/dp/2300982The energy recovery function converts the supplied DC energy into a synchronous sine current and feeds it back into the local or public grid. This eliminates the usual heat dissipation to a minimum and saves energy costs at the same time.Not cheap though...

author: nctnico
author_rank: Super Contributor
timestamp: February 06, 2014, 04:25:33 pm
content: @Toploser: thanks! Those are probably larger then I'll need but at least they exist.Using a solar inverter is also an option although those probably need som extra circuitry to regulate the current draw from the battery. The project involves charging/discharging large batteries all day long for a long time. Even though a single battery doesn't contain a lot of energy the total amount of energy wasted will be huge.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 06, 2014, 04:35:51 pm
content: What happens when you are discharging a battery and suddenly the plug comes out? Do you get a zap?
Strange Build Date? - Page 1
Forum section: electronics / testgear

author: tony3d
author_rank: Frequent Contributor
timestamp: February 06, 2014, 12:55:19 pm
content: Hi All, really love my new 287, but noticed today that build date, and calibration dates are way off from one another. Is this unit I just bought really 4 years old? It's only been calibrated once. I don't get it. First Fluke product, so I'm not sure how to interpret this. Bought it brand new from an authorized dealer. Super cap seems to retain the clock settings fine.

author: taemun
author_rank: Regular Contributor
timestamp: February 06, 2014, 01:00:56 pm
content: The ARM Bootloader was 'built' (compiled) in 2010, not the DMM.

author: andtfoot
author_rank: Unknown
timestamp: February 06, 2014, 01:01:41 pm
content: I can't see any build date for the unit in the photos.Are you referring to the line below the ARM Bootloader version? If so, that build date is just the date the bootloader was compiled; not when it was programmed into the chip.

author: tony3d
author_rank: Frequent Contributor
timestamp: February 06, 2014, 01:05:11 pm
content: Oh, ok that explains it. Now I see. Just noticed the box says MFG Date Nov 2013! The serial on the box does match the number on the info screen. That was a bit confusing. Hopefully my super cap is still in good condition.

author: tony3d
author_rank: Frequent Contributor
timestamp: February 06, 2014, 01:14:29 pm
content: I also noticed that when I first bought the unit the recording memory was 99%, but now after deleting everything, I only get 98%. Is this normal, or am I doing something wrong?

author: BravoV
author_rank: Super Contributor
timestamp: February 06, 2014, 03:13:00 pm
content: Nothing to worry, yours actually is still very fresh from the factory imo (Nov 2013), also from your screen, its good to know that both mine are also using the latest bootloader.If the calibration counter is 1, then the cal date is the manufactured date, also make sure you don't loose that dmm verification data paper (sort of cal certificate), who knows someday it will be useful.Its weird that your dmm serial number doesn't match with the printed on the box, mine does.
UNI-T 71 fast continuity - Page 1
Forum section: electronics / testgear

author: Wytnucls
author_rank: Super Contributor
timestamp: February 05, 2014, 10:19:35 pm
content: This may interest the people who own a Uni-T UT71 meter.As you would have noticed, the normal continuity test is latched, but rather slow on these meters.I found a way to achieve a fast latched continuity test which doesn't involve any modifications.1. Turn the range switch toOhmand select thediodemode by pressing the blue button twice. You are now in the 4V range.2. Press theRANGE/SETUPbutton until the meter beeps and displays OFF in the 'low' setting.3. Press theHOLDbutton once to access the count display.4. press theHOLDbutton repeatedly to select each number in turn.5. Change each number with the+ and -buttons until your display reads27600and pressEXITto store it.6. You are now in a fast mode for your continuity testing, staying in the diode range.7. When you are done with the continuity testing, pressRANGE/SETUPuntil it beeps again, then pressSTOREto display OFF in the low mode.8. PressEXITto return the meter to its usual state.It is a bit of a convoluted procedure, but at least the function is available if you don't have another meter at hand.Happy testing!

author: sync
author_rank: Frequent Contributor
timestamp: February 05, 2014, 10:49:08 pm
content: I can confirm this. It's much faster now. But it needs at leased 75ms to reliable trigger. With smaller pulses it misses one sometimes. But much, much better than the standard continuity test. Good find!

author: Wytnucls
author_rank: Super Contributor
timestamp: February 05, 2014, 11:03:33 pm
content: The value that is entered controls the ohm beeper trigger.For a trigger below 150 Ohms only for instance, a figure of 2000 has to be entered, otherwise at 27600, the meter will trigger even on a very high resistance.Unfortunately, with a lower figure, the continuity test slows down, but is still faster than the original.

author: Wytnucls
author_rank: Super Contributor
timestamp: February 05, 2014, 11:17:01 pm
content: Be also aware that the voltage is slightly higher on the diode range, at 2.7V instead of -1.2V on the continuity position.

author: Wytnucls
author_rank: Super Contributor
timestamp: February 06, 2014, 10:06:04 am
content: Quote from: sync on February 05, 2014, 10:49:08 pmIt is possible to increase the sensitivity. One can experiment with the 'low' setting. 27690 is the maximum I can set on my 71D, before it starts beeping with floating probes. Note that when the trigger is very sensitive, the meter will register conductivity even for a resistance of several MOhms.

author: Wytnucls
author_rank: Super Contributor
timestamp: February 06, 2014, 12:43:39 pm
content: Here is a video I made of the continuity test on a sensitive setting (27600):(The most sensitive setting I have been able to achieve is with 27694 as the LOW trigger)
ECOM Ex-DM 1000 - A rebranded Fluke 87-III Ex - Page 1
Forum section: electronics / testgear

author: armandas
author_rank: Frequent Contributor
timestamp: February 05, 2014, 08:16:32 pm
content: Now here is something you don't see every day - a completely rebadged Fluke handgeld DMM. I scored this on an ebay auction that no one else was interested inJudging from the appearance, it is a rebranded Fluke 87-III Ex, although I was not able to find any references to an intrinsically safe version of the Series 3. This could be the first Fluke generation that had an Ex version. It looks like ECOM have been doing Ex modifications for Fluke for a long time (seehere), but no longer rebadge the DMMs.

author: armandas
author_rank: Frequent Contributor
timestamp: February 05, 2014, 08:17:33 pm
content: A couple of pictures from inside. Anyone knows what's that thing stuck to the front?

author: SeanB
author_rank: Super Contributor
timestamp: February 05, 2014, 08:22:29 pm
content: Probably a thermal shield to prevent bits of exploding fuse from burning a hole through the front panel.

author: Wytnucls
author_rank: Super Contributor
timestamp: February 05, 2014, 08:27:58 pm
content: I don't think it's a shield. It has wiring going to it.More like a sensor of some sort.Or perhaps the buzzer, as it looks like the whole PCB has been potted.

author: SeanB
author_rank: Super Contributor
timestamp: February 05, 2014, 08:33:50 pm
content: Likely then it is the MOV's for the EEx rating then under a blast shield so the arc as they fail will still not ignite vapour. Wiring looks in the right area for extra clamps.

author: Wytnucls
author_rank: Super Contributor
timestamp: February 05, 2014, 08:43:59 pm
content: MOV or a Gas Discharge Tube are good candidates.

author: armandas
author_rank: Frequent Contributor
timestamp: February 05, 2014, 08:52:19 pm
content: Ok, that kind of makes sense.

author: Napalm2002
author_rank: Regular Contributor
timestamp: February 06, 2014, 12:59:05 am
content: How much did u score it for?

author: EEVblog
author_rank: Unknown
timestamp: February 06, 2014, 01:02:34 am
content: Interesting!Certainly an approved custom job.

author: armandas
author_rank: Frequent Contributor
timestamp: February 06, 2014, 08:15:45 am
content: Quote from: Napalm2002 on February 06, 2014, 12:59:05 am£80Quote from: EEVblog on February 06, 2014, 01:02:34 amYes, even the manual is completely rebranded.

author: peter.mitchell
author_rank: Super Contributor
timestamp: February 06, 2014, 10:26:49 am
content: Quote from: armandas on February 06, 2014, 08:15:45 amBahhhhhginnn!Quote from: Wytnucls on February 05, 2014, 08:43:59 pmI think it is the MOVs, if you look at the board compared to a "normal 87 iii", there appears to be a "jumper" in a sheath under the compound, though it kinda looks like a MOV with the same coating fusible resistors get...
Siglent SDS-1102CML Just Died...    CHINA STRIKES AGAIN - Page 1
Forum section: electronics / testgear

author: hgg
author_rank: Frequent Contributor
timestamp: February 06, 2014, 04:56:51 pm
content: My Siglent 1102CML just died. I switched it on today and all I got was the initial Siglentlogo screen which is displayed forever and all the buttons are frozen.Any ideas before I send it to a low Earth orbit trajectory?Thanks.

author: echen1024
author_rank: Super Contributor
timestamp: February 06, 2014, 06:12:08 pm
content: May I ask how you get it to orbit?

author: electronics man
author_rank: Frequent Contributor
timestamp: February 06, 2014, 07:10:52 pm
content: Quote from: echen1024 on February 06, 2014, 06:12:08 pmrocket?

author: pickle9000
author_rank: Super Contributor
timestamp: February 06, 2014, 07:17:58 pm
content: So before you go ballistic,Is it under warranty?Is it too expensive to ship?Are you will to open the case and void your warranty?Any magic smoke smell?

author: Wytnucls
author_rank: Super Contributor
timestamp: February 06, 2014, 07:20:33 pm
content: You may have tried this already, but if not, unplug it from the wall socket for a day or so, before you try to switch it on again.

author: tautech
author_rank: Super Contributor
timestamp: February 06, 2014, 07:52:41 pm
content: Same problem in this thread:https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg277369/#msg277369https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg277526/#msg277526A couple of fixes there.

author: hgg
author_rank: Frequent Contributor
timestamp: February 06, 2014, 08:48:18 pm
content: tautechyou saved me! Thank you!I rapidly pressed the MATH function during initialization and that fixed it!Not sure why this happened though. It did not happen while it was on. It was offand it suddenly happened when I switched it on today.Maybe there is a firmware fix for that.Thank you guys for your suggestions!As for the low earth orbit, I will send it with a custom made rocket driven by thehacked 60hz Flir E4...

author: tautech
author_rank: Super Contributor
timestamp: February 06, 2014, 09:02:34 pm
content: Yes the problem is not unknown.Lets just hope Siglent see these posts and build a fix.Or at the least make mention of a boot up key stroke recovery in their manuals.Only too happy to be of help.

author: hgg
author_rank: Frequent Contributor
timestamp: February 06, 2014, 09:06:54 pm
content: Thanks again!
Anyone used a Fluke 6061A? - Page 1
Forum section: electronics / testgear

author: taemun
author_rank: Regular Contributor
timestamp: February 05, 2014, 04:12:48 pm
content: Have an option to pick up a Fluke 6061A with a dead display (hopefully to fix), was wondering if anyone here has used one, and has opinions on its relative merits versus, say, a HP 8644B. The specsheets read fairly similarly, although I prefer the big encoder on the HPThanks!

author: willb
author_rank: Regular Contributor
timestamp: February 05, 2014, 06:48:41 pm
content: I have a 6060A, it's ok, but nothing special. I find the user interface sucks. Performance wise it's ok. It can be a difficult instrument to work on if you run into any issues related to the generator portion. I frequently use a Marconi 2018A and HP 8640B at work and find both those units much more pleasant to use than my Fluke.I bought mine broken with no display as well. Mine came back to life easily. The power supply is a pain in the ass to take out because you have to unsolder all the LM series regulators (4 if I remember correctly), or unbolt them from the back panel, but then you risk damaging the insulators. The issue with mine in regards to the display were all on the power supply. I had a bad cap on the +37VDC rail, it was totally shorted, but didn't blow the main line fuse. The transformer actually got very very hot and started to smell hot too... Luckily I noticed the transformer getting hot quickly after apply power, so no damage was done. So I strongly advise to do a controlled initial power-up, or check caps right away. I also had an issue with one of the pins on the larger connector on the power supply PCB which supplied +6.2VDC to the VFD. At least it's fairly simple to work on (the power supply and display PCB). I did a complete re-cap of the power supply, and it's been problem free since. I also did a slight rejuvenation of the VFD, which gave me a crisp and bright display.Good luck.
Connectors/cables - Page 1
Forum section: electronics / testgear

author: JLM
author_rank: Contributor
timestamp: February 05, 2014, 04:32:14 pm
content: Is there a "go to" source for instrument cables and connectors -- good selection, quality and price? Or must I search through eBay, amazon etc. for individual sellers and deals?

author: Fsck
author_rank: Super Contributor
timestamp: February 05, 2014, 04:34:47 pm
content: I just go digikey or newark or allied electronics.

author: JLM
author_rank: Contributor
timestamp: February 05, 2014, 04:37:08 pm
content: Those guys are usually overpriced IMO

author: Fsck
author_rank: Super Contributor
timestamp: February 05, 2014, 04:46:28 pm
content: Quote from: JLM on February 05, 2014, 04:37:08 pmthere are some on ebay, but I've found the risk to be a bit high. and for connectors, you're very likely to get meh wun-hung-lo quality junk. I've seen vendors with one-offs of decent brand name connectors but not a continuous supply. (probably surplus-type)
Hacking the rigol dg4062 - Page 1
Forum section: electronics / testgear

author: JLM
author_rank: Contributor
timestamp: February 05, 2014, 04:30:14 pm
content: I thought I read that the dg4062 can be "upgraded" but despite a search on the forum can't seem to find the info. Help?

author: Gunb
author_rank: Regular Contributor
timestamp: February 05, 2014, 05:43:56 pm
content: Quote from: JLM on February 05, 2014, 04:30:14 pmhttps://www.eevblog.com/forum/testgear/dg4000-a-firmware-investigation/
DS2072 Auto Trigger Bug - Page 1
Forum section: electronics / testgear

author: m-joy
author_rank: Contributor
timestamp: January 22, 2014, 12:12:44 pm
content: Huhu,i am using the Rigol DS2072 with HW rev 2 and 200Mhz and newest firmware .Now i want to trigger a SPI signal. I connect CH1 to CLK and CH2 to DATA.The tutorial video on Rigol page says pressing AUTO will get the right axis scales .But when i press auto, the signal looks very weird and the trigger is somewhere at 90V or whatever (i remember i had an DS2072A for testing and i think this was working better, but not sure anymore).I can correct the waveform by myself, but isnt that weird?

author: Spikee
author_rank: Frequent Contributor
timestamp: February 05, 2014, 11:29:52 am
content: Yeah the auto button works shit when looking at (faster) SPI frames.When you do it manually and put the trigger on normal than it will work.
Velleman DVM860BL and DVM810 multimeters - Page 1
Forum section: electronics / testgear

author: edy
author_rank: Super Contributor
timestamp: February 09, 2014, 04:54:59 am
content: Hi folks,I blew out the fuse on my cheap-a$$ DVM810 multimeter (http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=350295) and when I took it apart, I noticed it was SOLDERED DIRECTLY to pads on the PCB! No holder, not an axial fuse... I mean a regular fuse that is supposed to go into fuse clips, but instead just soldered directly flat onto the PCB. It was a bitch to change, and I had to heat up both ends at the same time to pry out the old fuse, and had even more trouble trying to get a new fuse to stick as it was rolling around (or the solder wouldn't stick to it). Are they really trying to save a few fractions of a penny?What is interesting is I had a look on this site here:http://www.robotroom.com/Multimeter-Reviews.htmlTake a look at the Trisonic TS-F308, it is the same crap as DVM810 and shows the same soldered fuse:http://www.robotroom.com/Multimeter-Reviews/Trisonic-TS-F308-digital-multimeter.jpghttp://www.robotroom.com/Multimeter-Reviews/Fuse-holder-(Sinometer)-versus-soldered-fuse-(Trisonic).jpgSo while I was in the store buying a fuse to fix up the DVM810, I also picked up a Velleman DVM860BL as shown here:http://www.vellemanusa.com/products/view/?id=521480It cost a little more ($20) but looks to be better built. For one, the fuse is attached with clips. It takes 3 AAA batteries which makes it a lot easier to change (rather than the 23A 12V battery). The DVM860BL also came with a thermocouple and it has some extra features including auto-ranging, backlight, temp, diode testing and a few other modes.Internally I am sure it is still built down to a price. Anyone have any experience with it? Good, bad and the ugly? What do you think about the $20 price tag?

author: retiredcaps
author_rank: Super Contributor
timestamp: February 09, 2014, 07:51:46 am
content: Quote from: edy on February 09, 2014, 04:54:59 amThe ODM is Mastech. Mastech MS8221.The MSRP on Amazon.com is $150 (), but it is on sale for $20 USD.Take it apart and take clear focused pictures of the internal please.
Anybody have documentation for Hitachi V-353F? - Page 1
Forum section: electronics / testgear

author: scratch_monkey
author_rank: Contributor
timestamp: October 06, 2013, 02:29:22 am
content: LIke the title says, I would like docs for big old Hitachi scope. I found schematics for the 20MHz version, The horrizontal circuitry seems to be the same, but not the vertical.It is usable, but needs voodoo to operate. I think cleaning the pots would help, but don't want to make it less accurate than it is already.Also, the probe cal test point is non functional.

author: TerraHertz
author_rank: Super Contributor
timestamp: October 06, 2013, 06:38:09 am
content: I recently bought an original manual for a Hitachi V202, 352.Thought I'd scan it, but it's way down my todo list.Can you post pics of your scope, so we can compare?I'll post pics of my V0352 later, this evening probably.

author: scratch_monkey
author_rank: Contributor
timestamp: November 14, 2013, 02:04:55 am
content: Here is a truely hideous picture, that manages to capture every normaly invisble blemish. Should be enough for ID though.Apears very similar to Hitachi V-352.

author: Tray
author_rank: Newbie
timestamp: February 04, 2014, 07:08:00 pm
content: Hello ScratchMonkey,I have also just bought a V353F - did you ever find the right manual ? I found one for a V335 but the layout of the front panel is different. It seems that this model is less common and I can't find any info on it.I'd be interested in any info or scope timeline for Hitachi'sUpdate: the V-203F a 20 MHz version has the same front panel layout and the same functions. that user manual is available from several sites. the time base schematic on page 31 is listed as V-203F / V-353F.
Upgrade Rigol DS1052D with FW version 00.04.01 to DS1102D - Page 1
Forum section: electronics / testgear

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 07, 2014, 10:51:19 am
content: Hello,I wanted to double check if the upgrade procedure still works with the latest FW version?As I am about to order a DS1000D series scope, and have to decide between DS1052D and DS1102D.Is this the cheapest MSO option in a real oscilloscope? Or are there alternative brands besides Rigol for this MSO/Logic Analyzer combination?

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 10, 2014, 09:21:06 am
content: Is it still working, or did they increase the security?

author: johey
author_rank: Newbie
timestamp: February 04, 2014, 10:36:05 am
content: I have just ordered myself a DS1052D. Will soon be able to report, I hope.
20000 volt ohm meter - Page 1
Forum section: electronics / testgear

author: bhilly82
author_rank: Contributor
timestamp: February 03, 2014, 12:48:21 pm
content: I am going to be repairing a Atomics cdv-700 mod 6 geiger counter this weekend. My question is that the repair manual states i need a 20000 volt ohm multimeter and will my Fluke 17b suffice or do I need to buy a analog meter? The volt ohm on my meter looks to be 10 mega ohm. I do have a cheapy analog meter but i don't trust it for reading voltages in the kv range with it.

author: KJDS
author_rank: Super Contributor
timestamp: February 03, 2014, 12:53:46 pm
content: What voltage range do you need to measure? If it is 500V, then that would be usually measured on a 1000V range and so you would multiply the range by 20,000 to get 20Mohms which is about where your Fluke is.If it's 10V, then you could try adding a 200k resistor in parallel with your meter to see what effect it has.

author: edpalmer42
author_rank: Super Contributor
timestamp: February 03, 2014, 06:15:01 pm
content: The manual states "... a 20,000 ohm-volt meter....". Although the use of the dash isn't familiar to me, I think that they're referring to a 20,000 ohms per volt analog meter which means almost any decent analog meter. I'm always annoyed that they don't say "20,000 ohms per volt or more", which is the correct way to say it.In other words, use any DMM and you'll be fine.Ed

author: bhilly82
author_rank: Contributor
timestamp: February 04, 2014, 01:41:48 am
content: Quote from: KJDS on February 03, 2014, 12:53:46 pmThe voltages range from 1.5v to 900 volts +-10% for the Muller Geiger tube.

author: Macbeth
author_rank: Super Contributor
timestamp: February 04, 2014, 02:22:00 am
content: Quote from: bhilly82 on February 04, 2014, 01:41:48 amLook, back in the 1960's a meter that was as accurate as 20k/ohm per volt range was the top of the range. We are talking hand made and calibrated AVO-8's here. Most electricians meters were only something like 2 - 5k/ohm per volt. A 20k/volt then is like having a 5.5 digit true RMS bench meter now, and cost about the same.The service diagrams will have shown actual readings on the diagram that a 20k/volt meter would show rather than ACTUAL voltages.Basically, your DMM will show closer to the true voltage, and if it is over the ancient diagrams volts by a small margin, nothing to worry about. If it's less then something is out of kilter. If you really need to then just use ohms law to work out the differences.

author: bhilly82
author_rank: Contributor
timestamp: February 04, 2014, 03:45:25 am
content: Quote from: Macbeth on February 04, 2014, 02:22:00 amThe manual list all voltages as plus minus 10% so as long as everything is within that spec I am not going to get worked up. I just have to be careful about the gm tube. It can only handle 850-1000v with 900v being optimal.
Tenma 72-10500 / 72-10495 power supplies - Page 1
Forum section: electronics / testgear

author: Woodside
author_rank: Newbie
timestamp: February 03, 2014, 10:03:57 pm
content: I'm looking to upgrade my bench power supply and these two seemed good value.http://uk.farnell.com/tenma/72-10500/psu-bench-dual-3a-30v/dp/2251948http://uk.farnell.com/tenma/72-10495/psu-bench-dual-5a-30v/dp/2251947They are switched mode supplies but have stated ripple figures similar to linear (? 1mVrms and ? 1.5mVrms respectively).Has anyone got either of these, are they any good?Are the ripple figures as stated?Thanks

author: Monkeh
author_rank: Super Contributor
timestamp: February 03, 2014, 10:07:39 pm
content: Those are linear supplies..

author: Bored@Work
author_rank: Super Contributor
timestamp: February 03, 2014, 10:54:30 pm
content: Both are rebadged Korad Technology PSUs. Some people here like Korad PSUs very much. Not because they are good, but because they are cheap.

author: Monkeh
author_rank: Super Contributor
timestamp: February 03, 2014, 10:55:12 pm
content: Quote from: Bored@Work on February 03, 2014, 10:54:30 pmSome people here hate them very much. Because they are cheap.

author: Woodside
author_rank: Newbie
timestamp: February 03, 2014, 11:53:32 pm
content: Quote from: Monkeh on February 03, 2014, 10:07:39 pmI stated they were switched mode after this reply from Farnell technical supportQuote

author: Monkeh
author_rank: Super Contributor
timestamp: February 04, 2014, 12:34:50 am
content: A 180W SMPS does not weigh 7kg.

author: Woodside
author_rank: Newbie
timestamp: February 04, 2014, 12:54:30 am
content: I should have just asked on here rather than Farnell technical support
What do you expect to see across the output of an 'off' power supply? - Page 1
Forum section: electronics / testgear

author: icon
author_rank: Regular Contributor
timestamp: February 02, 2014, 10:27:56 pm
content: HiPossibly a really stupidly obvious question, but here goes; I was checking across the rails of something on the breadboard before I powered it up, like good boy. 10 Ohms. Oh dear. I ended up dismantling the whole thing before I realised that I was measuring the resistance between the outputs of the power supply in its 'powered up, but output off' state. Confirmed by pulling the power lead out of the breadboard - open circuit. Plugged in - 10 Ohms.Is this normal?ThanksJohn

author: ve7xen
author_rank: Super Contributor
timestamp: February 03, 2014, 01:23:06 am
content: Was the resistance slowly increasing? You may have been charging an output capacitor in your supply, or one you'd added for local decoupling.

author: icon
author_rank: Regular Contributor
timestamp: February 03, 2014, 07:33:37 pm
content: HiIt was even worse than that - when I looked again in daylight, it was actually reading -10Ohms (as in 'minus 10'). Whuh? Turns out that when off, there's -10mV (-0.010V) across the terminals. Hmm. Still would have expected it to be electrically 'disconnected'?John

author: ConKbot
author_rank: Super Contributor
timestamp: February 03, 2014, 07:39:22 pm
content: I'd expect a dead short, because that's what the agilents at work have. Which always makes it interesting when charging batteries, especially when interns or engineers are using it.

author: olsenn
author_rank: Frequent Contributor
timestamp: February 03, 2014, 07:59:05 pm
content: I've noticed that as well. A well designed power supply should always read "Overload" (be an open circuit) when in a powered off state. However, many (even decent) PSU's have a capacitor on the output which bleeds out slowly apon powering off the outputs.

author: robrenz
author_rank: Super Contributor
timestamp: February 03, 2014, 08:05:56 pm
content: What about the reverse voltage protection diode across many power supply outputs?
Mastech 5308, MA5308, capacitance scale question - Page 1
Forum section: electronics / testgear

author: ot1
author_rank: Contributor
timestamp: February 03, 2014, 04:59:13 am
content: I have seen many sellers of this LCR meter state the lowest range of the capacitance scale to be 2000 pf and only one store state the lowest scale to be 200pf. Which is correct? Has anyone measured caps in the range of 5 to 30pf and found the meter accurate/reliable?

author: BravoV
author_rank: Super Contributor
timestamp: February 03, 2014, 05:08:14 am
content: The lowest scale for capacitance measurement depends on the test frequency, at 100/120Hz the lowest only at 20nF (nano Farad) with 1 pF resolution, while for example at 10 or 100 KHz, the lowest range is 200 pF (pico Farad) with 0.01 pF (pico Fard) resolution.Regarding your question on 5 to 30 pF measurement, my MS5308 works quite well on this range.
Wavetek 5130A & PTS 620 not working at the lower band - Page 1
Forum section: electronics / testgear

author: nadona
author_rank: Regular Contributor
timestamp: February 02, 2014, 09:18:31 pm
content: I bought a Wavetek 5130A that doesn't work properly. While I was trying to fix 5130A and I spot a PTS 620 at a good price. But the 620 turned out to have bigger problems.Both units are synthesized frequency generators. Front knobs controls the frequency for 5130A. The PTS 620 is remotely controlled by a software.They share a common problem:1) Wavetek: If I adjust the knobs so that it points 123456789 and a Racal 1996 display exactly the same number (oh well a couple of Hz off maybe)But about 2KHz and down, 1996 display random number and I checked the 5130A's output. No output. So last decades not works alone.2) PTS 620: It has dead oscillator and works only 2MHz~~200MHz instead of 0.1MHz~~620MHz.Same problem with Wavetek: @MHz alone doesn't work. For example: 123,456,789 works fine but 1,234, 567 doesn't work at all.I have a few counter and they display all same. I checked with my DMM and oscilloscopes, also.Any idea? Need help.

author: Vgkid
author_rank: Super Contributor
timestamp: February 02, 2014, 09:48:20 pm
content: Do you have a manual for the PTS, the company is still around.

author: nadona
author_rank: Regular Contributor
timestamp: February 02, 2014, 10:06:56 pm
content: I asked manuals and didn't get response.There is no manual for sale or posted for download. They go to website which offers the PTS manual and ask them to remove. At least that's what I found. For example KO4BB once had a PTS and now it is gone.I would appreciate if anyone who has 30, 500, or 620 manual PM me.

author: Vgkid
author_rank: Super Contributor
timestamp: February 02, 2014, 10:45:44 pm
content: Thats a shame, I was tempted to try to buy one(the manual was one of the reasons). Can you post pics of it?

author: nadona
author_rank: Regular Contributor
timestamp: February 03, 2014, 12:29:27 am
content: Somehow it now works to 619,999,999.9.To go 100MHz or 10MHz rage, have to go down 2MHz~~9.999,999MHz. And next I can go to any where up to 620MHz.Maybe that's how this works.Any one ever used PTS generator?
Pomona Minigrabber vs Minipincer - Page 1
Forum section: electronics / testgear

author: richfiles
author_rank: Regular Contributor
timestamp: February 02, 2014, 08:24:07 am
content: I have been looking to expand my home work bench, and wanted to get a good collection of test leads (BNC to banana, BNC to clips, banana to clips, double ended clips, etc). I had always preferred Pomona Minigrabbers at my old job, and was simply gonna buy the same, but could not help noticing that Pomona also makes a product called Minipincers. So, the big question... do any of you have any experience with both types, and specifically, what is your experience with the Minipincers. Do they "grab" as securely as the Minigrabbers do? My understanding is they are easier to attach and release, due to them NOT needing to be attached from the side of the lead. I can vouch for how easy it is to accidentally short two leads when dealing with a stubborn Minigrabber. Price difference between them is negligible to nonexistent, so does it pay to favor one over the other, or is it best to just have a couple of both?In the test bench ring, we have Minigrabber vs MinipincerDing, ding!Round 1!richfiles

author: Rerouter
author_rank: Super Contributor
timestamp: February 02, 2014, 09:24:32 am
content: seems there aimed more at smd components on board, where the mini grabbers are more aimed at dip pins and through-holeat my work we have only barely used the mini-grabbers, what would better suit us is a sharp insulation displacement grabber and a narrow pin probe, (were currently making due with multimeter probes in a 3rd hand thingy)

author: nanofrog
author_rank: Super Contributor
timestamp: February 02, 2014, 12:41:58 pm
content: Quote from: Rerouter on February 02, 2014, 09:24:32 amThis is how I see it as well, assuming the pitch is large enough to accommodate the pincer without creating shorts.Quote from: Rerouter on February 02, 2014, 09:24:32 amEver tried pogo pins/pogo test probes?The 3rd hand approach will work to hold them as well, so should be inexpensive to try.

author: robrenz
author_rank: Super Contributor
timestamp: February 02, 2014, 05:45:20 pm
content: I have lots of both but I really like the pinchers better. I find them more universally handy and quicker to attach and release. If you grab very fine wires you may need to tune the bend of the pinchers so they touch each other before they retract inside the nose.If you have a hour to waste you canwatch my videoof how I turned Pomona pincers into kelvin clips. If you watch it, the tip I made for these is more useful than the standard round nose.
Yokogawa Differential Probe Clips - Page 1
Forum section: electronics / testgear

author: skipjackrc4
author_rank: Regular Contributor
timestamp: February 03, 2014, 08:08:52 pm
content: I recently bought a 100 MHz, 1400V Yokogawa differential probe on eBay. However, the probe clips were not included in the auction. Does anybody recognize the name of these, or know of a source? They accept a shrouded banana plug.Attached is a picture of the clips I am talking about.Thanks!

author: PedroDaGr8
author_rank: Super Contributor
timestamp: February 03, 2014, 08:18:32 pm
content: They look a bit like the smt grabbers I have. Which are agilent U1163ASent from my EVO using Tapatalk

author: robrenz
author_rank: Super Contributor
timestamp: February 03, 2014, 08:26:25 pm
content: If you are going to use this for its intended purpose you better make sure you get clips that are rated for that high voltage. Your fingers holding those clips are going to be the shortest path to ground if the insulation is not up to par.

author: skipjackrc4
author_rank: Regular Contributor
timestamp: February 03, 2014, 09:45:07 pm
content: Quote from: robrenz on February 03, 2014, 08:26:25 pmThat's why I'm asking here. I found some rated for 1000V from Caltest, but that is not enough.

author: skipjackrc4
author_rank: Regular Contributor
timestamp: February 03, 2014, 10:14:11 pm
content: Well, according to this document:http://www.mouser.com/pdfdocs/HighVoltageDifferentialProbes.pdfThere are no pincer or hook clips that are rated for over 1kV. So I guess I will get these Flukes:http://www.amazon.com/Fluke-AC280-SureGrip-Hook-Clips/dp/B001WADEAK
My 287 Comes Monday! - Page 1
Forum section: electronics / testgear

author: tony3d
author_rank: Frequent Contributor
timestamp: February 01, 2014, 06:53:51 pm
content: So, Monday I should receive my new Fluke 287. I decided I'm going to keep it even thou this super cap problem seems to be an issue. The fact that the unit will be warrantied for the next 10 years makes me feel pretty good. Still I find it troubling that Fluke seems to be ignoring the issue. Have any of you guys sent in your 287/289 for repair of this problem? If so, how did that go? This will be my first Fluke product.

author: dr.diesel
author_rank: Super Contributor
timestamp: February 01, 2014, 07:09:33 pm
content: I wouldn't worry too much about the cap issue. Aside from the cap you're not likely to have any trouble with it, if the cap dies spend the $2 and fix it yourself. The repair takes < 5min vs the weeks it will take Fluke to turn it around.

author: tony3d
author_rank: Frequent Contributor
timestamp: February 01, 2014, 07:18:34 pm
content: Yes, but instantly void the warranty correct?

author: dr.diesel
author_rank: Super Contributor
timestamp: February 01, 2014, 07:26:54 pm
content: Quote from: tony3d on February 01, 2014, 07:18:34 pmPerhaps, but aside from operator error (and the stupid cap) you're never going to require use of the warranty.

author: Lightages
author_rank: Unknown
timestamp: February 01, 2014, 08:45:56 pm
content: I find that a bit amusing. Aside for a failure ( the cap) you will never need the warranty?The 87V needed a warranty fix too. The LCD displays of older models have failed over time. No company is without problems and Fluke has a warranty for a reason. Voiding the warranty to fix a problem they should fix just seems ridiculous.

author: dr.diesel
author_rank: Super Contributor
timestamp: February 01, 2014, 08:51:30 pm
content: I'm not saying anyone is perfect, but for the minimal chance I'd risk my $2 repair vs weeks without it any day of the week on a 287/289.The 287/289 has been out a long time pretty much without issue, note I'm not generalizing this thought throughout all of Fluke.

author: smoothtalker
author_rank: Regular Contributor
timestamp: February 01, 2014, 09:35:23 pm
content: Quote from: tony3d on February 01, 2014, 06:53:51 pmrelax dude. it's gonna be fine. IMO Fluke's warranty program is to provide end user the measurement confidence. i think it's gonna be a hassle claiming it when you need to.just enjoy the fluke. every product has hidden problems! at least you know the 287 is relatively very well designed. think about the TV you're watching, the oven and microwave in your house man. it might blow up anytime and who knows what hidden issues are there

author: BravoV
author_rank: Super Contributor
timestamp: February 02, 2014, 04:50:01 am
content: Although still not proven yet, I suspect at the heavily leaked cap or aged enough, it may actually the culprit of high battery drain problem that most 28x owners are complaining about.
GN Nettest CMA 4000 Teardown (Fiber optic testing equipment). - Page 1
Forum section: electronics / testgear

author: XOIIO
author_rank: Super Contributor
timestamp: January 31, 2014, 10:28:08 am
content: Alright, so finally got the tripod adapter to hold my phone, and made a cable to connect my Shure UC wireless mic to it, so I was happy enough with video quality to finally to a teardown of my Nettest CMA 4000, it's a fiber optic cable tester, also used to measure cable length and a bunch of other stuff, and I haven't seen a teardown of it before, or any fiber optic testing equipment that I can recall actually, so hopefully you guys enjoy it. Not too sure about how the mic sounds but it is definitely higher quality than the built in one on my old camera or my phone, and a couple people I know said it sounded more like "me", I guess I just need to get used to it.Anyways, two parts so far, the third video is just going to be a quick summary, showing that it works, and also showing how the visual fault locator actually looks on a broken cable, and how the cables are put together (I'm talking about the external ones, not the ones inside the laser section of course).If for some reason you want to buy it shoot me a PM or something, it's fun to muck around with, but it's not really that practical for me, though having a nice powerful red laser you can easily connect to the cables, and a couple adapters to join cables is fun for getting the laser from one side of the house to the other, though once again not really practical for anything. I tried placing the connector from the sensor on my Artic Spyder III but not much came out the end of the cable, it needs to be lined up super precisely.

author: XOIIO
author_rank: Super Contributor
timestamp: February 01, 2014, 07:02:17 pm
content: I'm gonna give this a quick bump since I posted it at a bad time for people to see it.edit: well guess this was a complete waste of time, no replies and a whopping 10 views on the videos, if any of those were even complete views.
AC/DC Clamp accessory for Fluke 233 - Page 1
Forum section: electronics / testgear

author: petrolhead
author_rank: Newbie
timestamp: February 01, 2014, 05:08:39 pm
content: After a AC/DC clamp to go with my Fluke 233 however over here, UK, they are too expensiveCan I use other makes ie Sealey
testing multimeters with a HP calibrator - Page 1
Forum section: electronics / testgear

author: KJDS
author_rank: Super Contributor
timestamp: January 31, 2014, 11:37:22 am
content: I've just done a quick video showing the testing of some bench multimeters using a HP calibrator

author: Vgkid
author_rank: Super Contributor
timestamp: January 31, 2014, 05:30:25 pm
content: Thanks for the upload, I remember finding a slightly older version of this calibrator in a storeroom at school(I was sneaking around). I found it interesting how it regulated its AC signal.

author: bingo600
author_rank: Super Contributor
timestamp: January 31, 2014, 06:40:07 pm
content: Nice calibrator Kev./Bingo

author: KJDS
author_rank: Super Contributor
timestamp: January 31, 2014, 09:11:18 pm
content: Quote from: bingo600 on January 31, 2014, 06:40:07 pmI had that and a Fluke 5100A. I kept the HP mostly because it's so much smaller. Given that I just want to make sure that things are working ok and I don't want to offer traceable calibration standards then I'm very happy with it.
HP3478a display interface? - Page 1
Forum section: electronics / testgear

author: cellularmitosis
author_rank: Unknown
timestamp: January 31, 2014, 10:55:34 pm
content: Hey all,Does anyone know what interface the HP3478a uses to talk to its display? Looking at the schematic, it looks like only a few lines connect to the microcontroller, so I'd assume it's a serial protocol?

author: cellularmitosis
author_rank: Unknown
timestamp: January 31, 2014, 10:59:10 pm
content: ah, this thread looks useful as a reference:https://www.eevblog.com/forum/projects/ressurecting-hp3478a/

author: grumpydoc
author_rank: Super Contributor
timestamp: January 31, 2014, 11:47:16 pm
content: QuoteOnly a little - I never got around to trying to decode what was happening, partly because I found a replacement display (still haven't fixed that 3478A though)
C-MAC STP 2390c 10MHz ocxo - Page 1
Forum section: electronics / testgear

author: npelov
author_rank: Frequent Contributor
timestamp: January 31, 2014, 06:20:12 pm
content: Hi,I recently ordered a 10MHz OCXO C-MAC STP 2390c. Can someone point me a datasheet for it for my datasheet collection. I'll probably forget pin out and it's always handy to have the datasheet offline. Does it have compensation?In case someone wants more details - I don't have a better oscillator to check how accurate this is, bus I made a snapshot with my new Rigol DS2072A - I've put the trigger at offset exactly one period at the lowest time base. The frequency counter shows 10.0000Mz, the trigger offset is exactly 100.000000ns. Yes, it's not accurate measure, but it's still a good thing that the oscilloscope's counter matches the oscillator frequency.P.S. I'm asking for compensation because I might find someone nearby with rubidium standard to check it/trim it.Edit: if someone is interested in exact link in ebay:http://www.ebay.com/itm/260871985838?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649I received it in about a week or two - pretty fast and it was sent with tracking number.
Agilent U1731C vs U1733C, anyone has teardown images of the U1731C? - Page 1
Forum section: electronics / testgear

author: mcinque
author_rank: Unknown
timestamp: February 01, 2014, 03:13:45 pm
content: I'm looking for a good LCR meter with ESR reading, and the 1731 fit my needs (I don't need 100KHz test frequency).I do not like buy expensive instruments with corrections on bad engineered pcb (like jumpers made with wire wrap cable or thru hole components soldered on the fly), I've seen Dave's excellent teardown video of 1733 and the nice internals of that model, and I was wondering if the 1731 model has the same internal engineering and construction quality of the 1733 but only a limited firmware.Any of you owns this 1733 model and can share a couple of teardown images?Thanks in advance!

author: PedroDaGr8
author_rank: Super Contributor
timestamp: February 01, 2014, 03:58:47 pm
content: Any reason why you are against the Der EE DE-5000? They OEM it for IET labs DE-5000. It's a great handheld real LCR, not just a toy.Sent from my EVO using Tapatalk

author: mcinque
author_rank: Unknown
timestamp: February 02, 2014, 10:06:37 am
content: Quote from: PedroDaGr8 on February 01, 2014, 03:58:47 pmnone, but I can't find one in my local distributors...I should buy overseas in Taiwan, and I don't like it very much: high customs taxes or lost shipment (both only in my country!) are the main reasons.
Software for Keithley 2000 - Page 1
Forum section: electronics / testgear

author: tjille
author_rank: Newbie
timestamp: January 31, 2014, 09:35:09 am
content: Hi,Some time ago I bought a used Keithley 2000 that I would like to connect to a laptop to make long-term analyzes. From Keithleys website I downloaded an old application that is DOS based. But it draws a lot of CPU resources and can not be customized. I would like to have a more modern software/solution. At the same time I do not want to put a lot of dollars on Labview or Matlab. I've been thinking about Excel VBA 2010 because I already have it in my laptop. Do you have any suggestions of free applications that work with a Keithley 2000 or know where to find ready VBA solutions?

author: TiN
author_rank: Super Contributor
timestamp: January 31, 2014, 10:12:27 am
content: 2000 have RS232, so should not be very difficult to write application which talks to it thru serial or USB to RS232 convertor.
[Rigol DS1000Z] Visualizing jitter between PPS signals - Page 1
Forum section: electronics / testgear

author: Mat
author_rank: Contributor
timestamp: January 29, 2014, 05:52:48 pm
content: Hey guys,I'm trying to setup a nice visual demo of a time synchronization protocol I've been working on.I've got three digital signals coming from different clock domains that simultaneously toggle once per second. I want to display some kind of statistical display of the jitter between them.The scope is in Normal triggering mode and I'm playing with persistence settings :1) Why does a sample older than 10 s not disappear when a 10 s persistence is set (seems to take much longer).2) Is there a way to have an infinite persistence but with statistical intensity grading, like a two-dimensional histogram? I know the scope is capable of that when trigger rate is fast, but it doesn't seem to be possible in this case...Thanks,Matedit : I have also tried it on the following scopes : GW-Instek GDS-2204, Tek TDS 2024, Tek TDS 744A, LeCroy LT344, but none of them fit the bill.
ELC - AL991S - PSU, BENCH, PROGRAMMABLE - Page 1
Forum section: electronics / testgear

author: R_G_B_
author_rank: Frequent Contributor
timestamp: January 30, 2014, 09:14:06 am
content: Is theELC - AL991S - PSU, BENCH, PROGRAMMABLE power supply any goodNeed + - voltage for opamp projectsCan please help our in choosing a decent bench power supply that does what it says on the tin the above price point. Your help will be appriated.R_G_B

author: TopLoser
author_rank: Unknown
timestamp: January 30, 2014, 09:23:35 am
content: I've got one of those in very good condition for £50 plus shipping if you want it. Don't know where you are though...

author: TopLoser
author_rank: Unknown
timestamp: January 30, 2014, 10:33:15 am
content: PSU is sold to the nice gentleman above.