hybridfree/eevblog-posts huggingface dataset:
Rigol DG1022U waveform was discontinued ? - Page 1
Forum section: electronics / general

author: stormbr
author_rank: Regular Contributor
timestamp: July 27, 2013, 04:18:18 pm
content: Hi all,I recently bought a dg1022u on the aliexpress, but just now looking in the rigol home page and i can't found this model in the list of products.What happened with this model of waveform DG1022U?Why this waveform was substituted by DG1022A?DG1022U is a model fake of rigol waveform ?Thanks for any help.

author: mcinque
author_rank: Unknown
timestamp: July 28, 2013, 08:46:51 am
content: Read thishttps://www.eevblog.com/forum/testgear/dg1022-vs-dg1022u-%28received-the-latter%29/

author: stormbr
author_rank: Regular Contributor
timestamp: July 28, 2013, 11:21:35 pm
content: If this model is sale on ebay and amazon, maybe to be a original brand of rigol.But not have specs in the home page is very bad for the rigol.Thanks by the help.

author: mickpah
author_rank: Regular Contributor
timestamp: July 29, 2013, 06:18:00 am
content: Quote from: stormbr on July 28, 2013, 11:21:35 pmnot bad for Rigol, is is a product they don't sell outside of China. These are grey market imports sold by people other than official dealers.if you buy out side of china you take your chances as I don't think there will be local dealer warrantythe offical ( Chinese ) data sheet is herehttp://www.rigol.com/download/China/DG/Datasheet/DG1000_DataSheet_CN.pdf

author: stormbr
author_rank: Regular Contributor
timestamp: July 30, 2013, 12:34:25 am
content: Thanks mickpah.
Pixsys ATR-171 teardown. - Page 1
Forum section: electronics / general

author: ResR
author_rank: Regular Contributor
timestamp: July 29, 2013, 02:39:46 pm
content: This unit broke just under 6 months and I took it apart to see why. I see a traces of magic smoke, but I can't find the source. No cracks, no burns, just some black stuff on some components. Main processor MC9S08 is a 8-bit MCU by Freescale, there is also AD7795 6-Channel, low noise low power, 24-/16-Bit ?-? ADC with on-chip in-amp and reference and other misc. ST, AD and TI components. The PSU driver chip is TOP 246 PN. It has custom LED display with pretty bright red, yellow and green LED's.I thought this supposed to withstand for years, because it controls industrial processes, but I guess I was wrong.

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 29, 2013, 02:50:22 pm
content: Hard to see how this thing folds up when assembled, but the cap in the top right of the picture (next to the transformer) has had a lot of the magic smoke looking at how it is discolored.Maybe have a look around there.

author: free_electron
author_rank: Super Contributor
timestamp: July 29, 2013, 02:54:50 pm
content: that chip is toast ...right hand side of picture just below the cap.the cap is discolored from the chip smoke.chip has a charred trail going downwards...

author: ResR
author_rank: Regular Contributor
timestamp: July 29, 2013, 04:00:52 pm
content: That's TOP 246. 132kHz switching regulator DIL-8, 3,11 euros from elfa distrelec. I was suspicious about that too, will test if I get enough to buy a soldering iron and a spare part mentioned above. I wonder, why those regulators burn out so easily, maybe the power fluxuation has something to do with?Edit: Sneaky little ... There is a hole at the bottom of the chip, top looked solid.

author: SeanB
author_rank: Super Contributor
timestamp: July 29, 2013, 07:08:06 pm
content: You are looking for trouble having a 1kV pulse on a tiny little chip with so little isolation. Slightest contamination on the die surface ( breath of the person doing a QC visual check on the wafer, or just on the die before encapsulation, or a spot of water trapped in a crack in the leadframe) and it becomes a time bomb. I prefer a separate power device and a switch die, even in the same TO package they work better.
Hakko FX888 vs 888D - Page 1
Forum section: electronics / general

author: echen1024
author_rank: Super Contributor
timestamp: July 27, 2013, 03:52:26 am
content: I am in the market, and looking for a new soldering station. I currently have a cruddy Velleman LAB1 3 in 1, and I would like to know if the digital is better, or should I buy an analog. Otherwise, is there another good soldering station for about the same price that can display the ACTUAL tip temperature.Thanks

author: PedroDaGr8
author_rank: Super Contributor
timestamp: July 27, 2013, 03:53:56 am
content: From what I understand they are more or less exactly identical internally. Just one uses a rotary knob the other a display. The fact of the mater is the display adds useless resolution that is really no improvement over the knob. So go with the cheaper of the two.

author: amyk
author_rank: Super Contributor
timestamp: July 27, 2013, 09:30:30 am
content: If you get the -D version, make sure you read the manual first.The controls are not particularly user-friendly.

author: Phroon
author_rank: Contributor
timestamp: July 27, 2013, 03:37:23 pm
content: One of Dave's biggest complaints about the plain 888 is the lack of a constant 'on' light. The -D model has the display as an on indicator, so at least that isn't an issue.

author: saturation
author_rank: Super Contributor
timestamp: July 27, 2013, 07:13:08 pm
content: Yes, but its simpler to replace the switch with a lit one.https://www.eevblog.com/forum/beginners/how-to-wire-mains-dpst-switch-lamp/msg249236/#msg249236

author: echen1024
author_rank: Super Contributor
timestamp: July 27, 2013, 08:22:15 pm
content: Ok. Thanks. That is one choice, but are there any other similar irons out there at around the same price that I can look at?

author: saturation
author_rank: Super Contributor
timestamp: July 27, 2013, 08:50:07 pm
content: Yes, see the archives of the forum for details.Weller WES51Xytronics, many choices under $100.http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&productId=2174733&catalogId=10001&CID=PDFhttp://www.xytronic-usa.com/shop/item.aspx?itemid=238
Anything worth harvesting from a plasma TV? - Page 1
Forum section: electronics / general

author: icon
author_rank: Regular Contributor
timestamp: July 23, 2013, 08:36:23 pm
content: HiI'm about to retire an ancient Hitachi plasma TV. It's so old it has two boxes - a 'base unit' with the inputs and switching, and the TV itself, which weighs an absolute ton.Is there likely to be anything interesting worth stripping out of it, do you think?CheersJohn

author: free_electron
author_rank: Super Contributor
timestamp: July 23, 2013, 09:01:21 pm
content: the plasma ! throw in a few dilitihum crystals, add a bussard collector and you can make a warpdrive ....

author: c4757p
author_rank: Super Contributor
timestamp: July 23, 2013, 09:03:26 pm
content: In my experience, televisions are made in too high a volume to be using generic, off-the-shelf parts. The only thing of use in the average TV is parts for repairing other TVs of the same model...Maybe the PSU board, I suppose.

author: Winston
author_rank: Regular Contributor
timestamp: July 23, 2013, 09:16:11 pm
content: Quote from: icon on July 23, 2013, 08:36:23 pmHigh voltage components after making sure any caps are fully discharged. I completely disassemble all consumer electronics before trashing them to remove big electrolytic caps, tantalum caps, inductors (sometimes just for their cores), power transistors, heatsinks and all hardware (sheet metal screws, nuts, bolts, washers, self-tapping screws), etc.

author: mariush
author_rank: Super Contributor
timestamp: July 23, 2013, 09:20:09 pm
content: speakers, audio amplifier, power supply , capacitors, inductors, maybe some fets , some diodes, some heatsinks for various projects etc etc

author: c4757p
author_rank: Super Contributor
timestamp: July 23, 2013, 09:21:27 pm
content: Well I stand corrected...

author: icon
author_rank: Regular Contributor
timestamp: July 24, 2013, 06:59:37 am
content: Quote from: c4757p on July 23, 2013, 09:21:27 pmYou'll have to make room for me; corrected is where I always stand.I think I'll leave the electrolytics alone. They must be over ten years old.CheersJohn
Help identifying unknown tft display - Page 1
Forum section: electronics / general

author: microbug
author_rank: Frequent Contributor
timestamp: July 19, 2013, 07:41:52 pm
content: I recently tore down an HP printer and got a nice little tft display. Unforturnately, I can't find any information / pinout for it. Does anyone have any ideas?http://www.anony.ws/image/kkCWhttp://www.anony.ws/image/kkCbhttp://www.anony.ws/image/kkChhttp://www.anony.ws/image/kkCv

author: Legit-Design
author_rank: Frequent Contributor
timestamp: July 19, 2013, 07:53:39 pm
content: What was actually driving it? I would start looking from the direction where that white cable went.

author: marshallh
author_rank: Unknown
timestamp: July 19, 2013, 10:42:51 pm
content: Here you go (it's an AUO optronics a024cn02)http://www.yslcd.com.tw/docs/product/A024CN02%20V.7.pdf8bit serial interface. Probably drivable with DMA and 8bit parallel slave port on a PIC or something similar.
Atten 936b - another Hakko clone - Page 1
Forum section: electronics / general

author: romovs
author_rank: Contributor
timestamp: July 16, 2013, 12:29:59 pm
content: Got an Atten 936b (another Hakko clone) from eBay last week for 40USD.Build quality is heinous, but frankly can't tell the difference with Hakko when soldering...Driver is similar to that inHuakko 936cclone, just different opamp (LM358N) and triac (BT137-600E).TopFuseDriver PCB frontDriver PCB back

author: saturation
author_rank: Super Contributor
timestamp: July 16, 2013, 12:45:52 pm
content: Thanks for the tear down, can you check how quickly it heats and regulate correct temperature?

author: romovs
author_rank: Contributor
timestamp: July 16, 2013, 02:27:07 pm
content: I tried measuring by attaching thermocouple with a piece of copper wire to the tip (conical that came with the station).It heated up to 350C in ~60 seconds..And recovered back to 350 from 240 in 43 seconds (average from 4 tests) when soldering 1/4W through-hole resistor to a protoboard.

author: amyk
author_rank: Super Contributor
timestamp: July 16, 2013, 06:52:55 pm
content: That sounds a bit on the slow side... the real 936 (60W) should take around 40s, so maybe yours is just 40W. Measure the power consumption to be sure.

author: saturation
author_rank: Super Contributor
timestamp: July 16, 2013, 08:08:19 pm
content: Thanks for the report. Yes, concur with amyk its a bit less power but adequate for your need, clearly; it shows the difference between the real Hakko and at least this copy; the original 936 does ~ 40 sec and is a good number to remember when comparing other irons; I think I checked that during the winter when room temp was 20oC, I recently rechecked it 24oC doing repairs this summer in an air con room, and its 23-25sec.You have to consider room temperature to since it requires more time, considering fixed power, to heat from ambient.It could also be the heating element in the clone, rather than the station itself.https://www.eevblog.com/forum/reviews/genuine-vs-fake-hakko-936-ceramic-heater-a1321/msg240453/#msg240453Quote from: romovs on July 16, 2013, 02:27:07 pm

author: ddavidebor
author_rank: Super Contributor
timestamp: July 16, 2013, 08:10:36 pm
content: Yeah difference from hakko is in the heating element and in the quality of the soldering iron (poo poor)

author: abyrvalg
author_rank: Frequent Contributor
timestamp: July 17, 2013, 09:15:27 am
content: Try touching some big solder surface. All 936 clones that we had behaved funny in such conditions - melting a small area around the tip for a moment, then sticking to it (thermal capacity of the tip is enough to melt, but thermal conductivity heater->tip is not enough to sustain melting).Or just check how easy the unscrewed tip slides on the heater - ours had a significant gap there so the tip was falling off with it's own weight
Making an RF/EMI Loop Probe yourself-For your Oscope - Page 1
Forum section: electronics / general

author: ACvolts
author_rank: Contributor
timestamp: July 15, 2013, 10:27:42 pm
content: I am trying to make my own RF/EMI Loop Probe. Here is what I am talking about with this Vid..In the above youtube vid, it costs 800.00 bucks for this RF/EMI Loop Probe he is holding.I've seen Dave the EEVBlog creator and mentor do this video on making an High Voltage Probe..Now can I use the same parts in this HV probe in Dave's vid with a Loop Probe I make myself?Dave if you see this, would you help? THanks a heap of Koala bear leaves!And if anyone wants to jump in this, the water is just nice and warm!

author: fpliuzzi
author_rank: Regular Contributor
timestamp: July 15, 2013, 10:54:21 pm
content: Hello,Check out these other threads...www.eevblog.com/forum/projects/diy-magentic-field-probes/msg209554/#msg209554www.eevblog.com/forum/projects/idea-about-measure-emi-using-oscilloscope/msg240249/#msg240249These contains info about building low cost E-Field and H-Field probes for your scope (or spectrum analyzer).Regards,Frank

author: ACvolts
author_rank: Contributor
timestamp: July 15, 2013, 11:02:40 pm
content: Quote from: fpliuzzi on July 15, 2013, 10:54:21 pmTHanks!In that message I found a good link to Electro Magnetic Shielding:http://uniteng.com/index.php/2013/06/21/electromagnetic-shielding/
Variable Power Transformer 0-240v  500-1000watt purchase + 12v Transistor quest - Page 1
Forum section: electronics / general

author: ACvolts
author_rank: Contributor
timestamp: July 14, 2013, 08:18:56 pm
content: I am trying to buy a Var. Power Transformer and I found this one @ Jameco.com:POWER TRANSFORMER,VARIABLE,110/220VAC INPUT,0-240VAC OUTPUT,1000VAhttp://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_129008_-1They have a 500va for 139.00. Have any found another brand that they know of cheaper orbetter quality?Also interested to buy a quality made 12v Transistor. Something that will last. Any experienced Techheads out there know of a good high quality, industrial 12v Transistor? Link please.Thanks for replies.ACvolts

author: edpalmer42
author_rank: Super Contributor
timestamp: July 14, 2013, 10:48:01 pm
content: The name you want to look for is Variac. It's actually a brand name, but it's become a generic term for a variable transformer. ebay has lots of them. Make sure that you get one that's rated for 50/60 Hz. There are 400 Hz ones for aircraft systems that go really cheap.Ed

author: amyk
author_rank: Super Contributor
timestamp: July 15, 2013, 10:56:53 am
content: What do you mean by "12v transistor"? Do you need a FET, BJT, IGBT, ...? You can go to some of the manufacturer's sites likeIRF,Fairchild,ST, etc. and use the parametric search.

author: kripton2035
author_rank: Super Contributor
timestamp: July 15, 2013, 11:04:34 am
content: it would also be safer for you to get an ISOLATED version of the variac/transformer

author: madires
author_rank: Super Contributor
timestamp: July 15, 2013, 11:49:02 am
content: Quote from: kripton2035 on July 15, 2013, 11:04:34 amThat's a good advise! An isolation transformer and a variac (powered by the isolation transformer).

author: ACvolts
author_rank: Contributor
timestamp: July 15, 2013, 10:36:05 pm
content: Ah! Good to know. Thanks for the tips.ACvolts
Where can I buy a Digital Revolution (spin) Meter for like a motor? - Page 1
Forum section: electronics / general

author: ACvolts
author_rank: Contributor
timestamp: July 14, 2013, 08:34:34 pm
content: Ah, don't know where to find one! Or the right words to do a search.

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: July 14, 2013, 08:39:49 pm
content: You might look at tachometers.....

author: ACvolts
author_rank: Contributor
timestamp: July 14, 2013, 10:29:11 pm
content: Yeah I found a bunch of cheap ones and expensive ones on Amazon, thanks.2 in 1 Digital Laser Photo Contact Tachometer DT2236Bhttp://www.amazon.com/Digital-Laser-Contact-Tachometer-DT2236B/dp/B00CCZLSQ6/ref=sr_1_2?s=hi&ie=UTF8&qid=1373840686&sr=1-2-or-http://www.amazon.com/BestDealUSA-DT2236B-Digital-Contact-Tachometer/dp/B009DARQ0A/ref=pd_sim_sbs_hi_2Neiko 20713A Professional Digital Laser Photo Non-Contact Tachometer with Accuracy 99,999 RPM Measurementhttp://www.amazon.com/Neiko-20713A-Professional-Non-Contact-Measurement/dp/B000I5LDVC/ref=sr_1_66?s=hi&ie=UTF8&qid=1373837321&sr=1-66

author: mariush
author_rank: Super Contributor
timestamp: July 14, 2013, 10:44:49 pm
content: You mean something like this :http://www.digikey.com/product-detail/en/EMS22D51-B28-LS5/EMS22D51-B28-LS5-ND/3694109?
Cheap Chinese LED-lamp teardown and review. - Page 1
Forum section: electronics / general

author: ResR
author_rank: Regular Contributor
timestamp: July 20, 2013, 05:43:03 pm
content: First thing I noticed was the assembly complexity in this light bulb, for the cost of only 4 euros, it looked oddly complicated. There's a metal face plate hold with tiny screws, it hold three lenses in place, also the aluminium part of case was held to plastic base also tiny screws. One thing about screws is that the smaller it gets, the more time it takes to assemble with it. LED's were hand soldered. There was a lot of parts that could be press fitted and glued together. Small power supply has half bridge rectifier, no mains fuse, 13001 transistor, bottom of the pcb the pins are sanded almost against the pcb (sandpapered, not cut, with almost all the solder gone), it ain't gonna be plugged in. I like the use of thermal grease between LED PCB and aluminium case, at least that was made right. Maybe the manual labour is cheaper than pick and place machine? Now I have 3 1W power leds to play with.

author: SeanB
author_rank: Super Contributor
timestamp: July 21, 2013, 06:14:16 am
content: The ones I buy here screw together, and have a lot better construction quality, though of course the heatsink is always going to be very much on the too small size so they fail fast. Quite a few I buy just for the LED puck and the driver, and install them with a better heatsink so that they work well. The drivers are pretty good.

author: ResR
author_rank: Regular Contributor
timestamp: July 21, 2013, 08:26:01 am
content: I buied this one to take apart and use the LED's for the solar rechargeable flashlight project using parts from old casette recorder and discarded burned out CFL. To power it I used Joule thief schematic and simple one transistor recharging controller is in progress on the same board. The battery is half empty, it has 5,5 volts of voltage with load.
PortaPow Dual USB PSU - Page 1
Forum section: electronics / general

author: andym8
author_rank: Newbie
timestamp: July 10, 2013, 03:33:56 pm
content: Hi all, any opinions out there on the construction/design of this power supply?Unless someone knows, I'll reveal the brand and cost after a few views are in.Full size images are available as attachments.

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 10, 2013, 04:06:43 pm
content: What's its rating? I mean it could be super if its rated for 12v@100ma... Also, is that 2 usb ports out? Seems like you could overload it pretty easily if so.Things I like;Fuse and MOV on input, full wave instead of half wave into main primary caps.Pretty good isolation slot, only Opto and cap crossingThings I am unsure about;Interwinding insulation on the transformerNo input/output chokes for noise suppressionThat blob o' solder on the diodes.

author: amyk
author_rank: Super Contributor
timestamp: July 11, 2013, 10:39:49 am
content: It looks like it's one of the more expensive ones.The transformer secondary coming out of the top is somewhat unusual. Probably triple-insulated wire too.

author: andym8
author_rank: Newbie
timestamp: July 12, 2013, 10:18:11 pm
content: It's aPortaPowDual USB Mains Charger. It cost £12 a couple of years ago and has now been superseded by the quad version, but the spec still looks very similar.It's rated 5.0V @ 2100ma, 1 socket up to 2.1A and the other limited to 0.5A.I don't have the equipment to test it, however, I have been happy with it charging my devices over the years. It's only now I'm looking for a bit more than ~10 Watts of power. The LEDs are too bright but it is nice to be able to 'see' current draw.
Teardown - Kodak Ektapro 4540 high speed camera head - Page 1
Forum section: electronics / general

author: tesla500
author_rank: Regular Contributor
timestamp: July 03, 2013, 05:32:45 pm
content: Teardown of a ~1993 Kodak Ektapro 4540 high speed camera head. This system could record 256x256 video at 4500fps, and lower resolutions at higher rates. I believe this was the world's fastest electronic camera at the time of release, and the system apparently sold for about $300k.Paper on the NMOS image sensor technology, which is a cross between modern CMOS sensors and CCDs.http://www.motionvideoproducts.com/MVP%20papers/Kodak%20HS%204540%20KEY%20TECHNOLOGIES.pdfThere's some evidence the sensor is made by Hitachi. A very similar sensor (with similar part number, Ektapro PN HE98256, Hitachi PN HE98268) was seen a Phillips camera teardown done by youtube user epattoAnd the following paper describes abandoned MOS sensor development by Hitach and Matsushitahttp://www.cse.yorku.ca/visor/resources/Canaan_Hong_PhD.pdf"In the late 1970s and early 1980s Hitachi and Matsushita continued the development of MOSimage sensors ,  for camcorder-type applications where high-speed operation withrelatively low resolutions were focused on. In 1982, NHK successfully integrated timingcontrol with passive pixel sensors. Temporal noise in MOS sensors started to lag behind thenoise achieved in CCDs. By 1985, Hitachi combined the MOS sensor with a CCD horizontalshift register . However, perhaps due to residual temporal noise, especially important inlow light conditions, Hitachi later abandoned its MOS approach to sensors."David

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 04, 2013, 09:21:35 am
content: I have watched all of your videos, yet I just surprised myself by finding that I haven't subscribed, so I remedied that.Great video!

author: amyk
author_rank: Super Contributor
timestamp: July 04, 2013, 10:27:28 am
content: Mike also has aslower model, anda much faster one.

author: Entropia
author_rank: Regular Contributor
timestamp: July 16, 2013, 06:34:47 am
content: Hi, epatto here.Here's more pics of the Philips camera's sensor in case tesla500 or others are interested:http://entropia.1g.fi/kuvat/Elektroniikka/Projektit/SSC/I also noticed that one of the Philips camera's sensor heads are up for sale on German eBay:http://www.ebay.de/itm/HE98268-SCK2173-01-A1B-Hitachi-JVC-CCD-Sensor-CCD-Modul-/200883349520It's identical to the one I have torn down (is that the right way to say it?).
Ascel AE20125 Function Generator Review - Page 1
Forum section: electronics / general

author: electronupdate
author_rank: Regular Contributor
timestamp: November 13, 2012, 03:58:06 pm
content: This is a small kit project from a company in Germany, sort of a alternative between designing-your-own and the very low end products from China in the $100.00 range.Not entirely awful, with bits of brilliance ... perhaps a good tag line for test equipment at the very bottom of the price range

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 14, 2012, 05:20:52 am
content: the USB noise spike at 8:02 probably from your "loose wire clip" cable? or long gnd clip probe pickup? try using proper probe or as short as possible gnd clip and see if its still exist, even better if you can directly solder a coax to the board and 50ohm terminate it at the scope end. nice featured FG kit though thanks for reviewing.

author: FenderBender
author_rank: Super Contributor
timestamp: December 02, 2012, 09:47:37 pm
content: This looks not half bad...for the price.Might consider it, since I'm using like a 500kHz audio gen now.

author: nikodemus
author_rank: Newbie
timestamp: July 11, 2013, 12:30:10 am
content: I just built one of these.Haven't played with it much yet, so not adding anything of substance to the review -- nor would I be knowledgeable enough to, really... but wanted to say that the seller responded *very* quickly and was quite helpful with my snafus^Wlearning experiences. (My fault, not the kit's.)First time he provided me with specs to get a replacement for a part I had managed to damage, the second time he provided enough insight into the symptoms I was experiencing to allow me to zero in on bad joint that was causing trouble much faster than I otherwise would have. Class act!

author: saturation
author_rank: Super Contributor
timestamp: July 11, 2013, 11:47:03 am
content: Thanks! the Hantek 3x25 or its updated version can give you better performance for the money, $150 100 MHz, good stability to 40 MHz. See thread for details.
Nasty MAX3222 bug, surprise... or feature?  - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: July 11, 2013, 09:22:29 am
content: Hi guys,I noticed something nasty while using the popular Maxim series RS232 converters, namely with MAX3222.When you connect an RS232 connection (tested from a PC) to the device, while powered off (physically disconnected from anything else, except the RS232 connection with signals RxD, TxD, RTS,CTS) you get 0V on VCC - the main power rail for the logic of my device. That's OK.BUT! When you turn the system on (VCC -> 3.3V) and then back off (physically disconnect everything else except RS232) you get some small voltage (+1.2V) on the power rail. The MAX apparently remains somewhat opened, leaks something through somewhere and refuses to close. When you disconnect the RS232 connection and connect it again, 0V is on VCC, so the MAX3222 is apparently closed.So, I've eliminated all other sources of this - the RS232 connection goes through input protection that is grounded and directly onto the MAX3222. I wouldn't even have noticed this, if it weren't for an SD card that apparently doesn't have a Brown out circuit and doesn't handle half-powering down very well.Control signals of the MAX3222 are connected as follows: EN tied to GND, SHDN tied to VCC, the 3.3V IO is tied to a processors GPIO.So, beware! It was a nasty surprise for me. It should be noted that there are no serious power hogs on that rail, so maybe just adding a 1k resistor paralel could drop it down... dunno yet. I dunno if this happens with other members of the family, the specific model I'm using is MAX3222ECWN, date code 1106.David

author: Rerouter
author_rank: Super Contributor
timestamp: July 11, 2013, 09:38:26 am
content: that sounds a whole lot like its just the supply rail capacitance with whatever circuitry is in the chip only pulling current to that voltage then cutting out, (about 1 diode drop, or 2 schottkey drops)add something like a 100K pull-down and I'd be confident it would not hang around.

author: daqq
author_rank: Super Contributor
timestamp: July 11, 2013, 10:03:48 am
content: Actually, there are a few voltage dividers, when in parallel, it's about 5k in total connected between VCC and GND.

author: nctnico
author_rank: Super Contributor
timestamp: July 11, 2013, 10:07:15 am
content: Is this a real MAX3222 or a clone?

author: daqq
author_rank: Super Contributor
timestamp: July 11, 2013, 10:08:56 am
content: The package says it's from Maxim, and it came from a reasonably trusted source. So it's either a Maxim or a fake labeled Maxim.

author: amyk
author_rank: Super Contributor
timestamp: July 11, 2013, 10:57:24 am
content: Quote from: Rerouter on July 11, 2013, 09:38:26 amI'm guessing part of the circuitry powered by the charge pump lets the RS232 inputs back-power the device, which then keeps whatever transistor open to the supply rail, powering the charge pump (but maybe not enough to start it oscillating), etc.
Japanese side cutters? - Page 1
Forum section: electronics / general

author: komet
author_rank: Unknown
timestamp: July 10, 2013, 06:12:28 am
content: So I've seen a lot of discussion about European and American side cutters, but does anyone know about Japanese ones? I found the HOZAN N-55 on the Internet, which looks promising. Any experiences?

author: N TYPE
author_rank: Regular Contributor
timestamp: July 10, 2013, 12:49:03 pm
content: No experience with that particular product but Japanese tools do tend to be of very high quality, they use good quality metals and generally don't cut corners on forging/hardening etc..

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 10, 2013, 01:30:31 pm
content: http://www.marvelcorp.co.jp/
Experiences with Tenma soldering stations? - Page 1
Forum section: electronics / general

author: microbug
author_rank: Frequent Contributor
timestamp: July 30, 2013, 11:37:39 am
content: I'm saving up for a soldering station at the moment, and stumbled across this -http://uk.farnell.com/tenma/21-10130-uk-eu/rework-station-900w-220v-uk-eu/dp/2062633.While I am probably going to go for the trusted Hakko FX-888D, I wondered if anyone has ever seen 'Tenma' brand tools before. It looks reasonable value for money (although the soldering iron is only 50W), but I doubt the build quality.

author: Tita
author_rank: Contributor
timestamp: July 30, 2013, 11:55:10 am
content: If you are interested take a look at this homemade soldering station! O0It's not my design but i have made this soldering station and is working very good for my!

author: alanb
author_rank: Frequent Contributor
timestamp: July 30, 2013, 01:31:41 pm
content: I have purchased a Tenma soldering station from Farnell, it's not the one you are interested in but may be indicative of the brand quality.http://uk.farnell.com/tenma/21-10115-uk/soldering-station-60w-220v-uk/dp/2064549I am happy with it an consider it good value for money, the build quality is ok.In another thread on this forum someone has pointed out that Tenma is re-badged Atten.

author: krivx
author_rank: Frequent Contributor
timestamp: July 30, 2013, 02:20:58 pm
content: Tenma is a house brand owned by Farnell, they buy in cheap gear and re-brand it. I don't think it's re-badged Atten, it's more likely that they use several suppliers. I have bought some cheap Tenma DMMs that didn't match any Atten models I've seen.

author: Kevin.D
author_rank: Frequent Contributor
timestamp: July 30, 2013, 02:47:03 pm
content: As has already been said I think Tenma might be various brands that have been rebadged .I Just repaired a Tenma 72-8700 power supply , it's actually a rebadged UNI-T UTP3705 .It's very iffy build quality/design really ,it comes with free things like 300mV voltage spikes during relay changovers, live mains input wire that runs with the low voltage wires and rubs up against low voltage connectors on it's way to the mains switch and a few other design flaws I could mention. I wouldn't recommend it unless you are getting it really really cheap.
BK Precision 864 programmer find - Page 1
Forum section: electronics / general

author: AmirTheGreat
author_rank: Unknown
timestamp: July 05, 2013, 07:05:27 pm
content: So recently I got my hands on an 864 programmer and I don't know what to do with it.does anyone know how much it would go for on eBay? (I couldn't find any info)Or should I just send it to Dave for Mailbag/ possible teardown
Reworking dual-loaded boards? - Page 1
Forum section: electronics / general

author: Eliminateur
author_rank: Regular Contributor
timestamp: July 12, 2013, 05:48:49 pm
content: Hello chaps,i've encountered a "dumb" problem when trying to rework/reflow a board with BGA components: it's dual loaded!with chips on exact opposite sides(RAM chips)So if i heat the board using our regular rework station, the underside component will fall off!.And since they occupy the exact same place i can't "isolate" the underside component with alu tape either (or it won't heat the underside of the component as it shouldhow do you people rework these kind of board?, how are they manufactured in the first place???, do they use some kind of "glue" that sticks the component to the board whilst both of them are heat-soldered in place?

author: ElektroQuark
author_rank: Unknown
timestamp: July 12, 2013, 08:19:21 pm
content: Quote from: Eliminateur on July 12, 2013, 05:48:49 pmNo, they will not. Solder will maintain them in place, they will no fall off if you don't move the PCB abruptly.

author: ablacon64
author_rank: Frequent Contributor
timestamp: July 12, 2013, 08:31:24 pm
content: Surface tension magic,.They won't fall. err... Unless you heat the board too much and make it bend, I guess.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 13, 2013, 12:52:45 am
content: As long as you don't go crazy jolting the board around by bumping it or lifting it at odd angles while the solder is liquified, it should be fine, just like the other guys already said.
Hakko FX-951 super bargain - Page 1
Forum section: electronics / general

author: aruna1
author_rank: Regular Contributor
timestamp: July 04, 2013, 12:39:18 am
content: hijust came upon this super bargain while i was looking for a soldering station.http://www.aliexpress.com/store/product/Free-shipping-ESD-lead-free-220V-digital-HAKKO-FX-951-Soldering-Station-hakko-fx-951-rework/806914_874421666.htmlI was looking for a digital soldering station below $100 and this seller sells Hakko FX-951 for $90 including shipping price.as I heard hakko 951 cost above $200 and this is super cheap, because this product *seems* genuine.image shows hakko logo and markings,(I compared the image posted by the seller with fx-951 image from hakko site, and they seems identical). As far as I know, clones cannot have same markings as the original product though their form factor and shape is identical, which leads me to beleive this is a genuine hakko unit.differences I noted are,this product has no sleep mode.(original hakko does have sleep mode)this product does not come with copper wool and holder.kindly share your wisdom please and tell me should I buy this.Thank you

author: nanofrog
author_rank: Super Contributor
timestamp: July 04, 2013, 02:32:17 am
content: It's NOT a genuine Hakko.Take a much closer look at the iron (no quick release grip section <how it changes tips>, and the strain relief looks to have just about been an afterthought). Might work OK, but I wouldn't assume this is the case.To see what I'm talking about, look closer at the FM-2028 (iron for the FX-951):http://www.hakko.com/english/products/hakko_fm2027_2028.html. No where near the same as the iron included with that unit you linked.

author: aruna1
author_rank: Regular Contributor
timestamp: July 04, 2013, 02:45:00 am
content: actually seller offers FM-2028 iron instead for iron shown in descriptionQuote
Rigol DS1052E Crashing?? - Page 1
Forum section: electronics / general

author: olsenn
author_rank: Frequent Contributor
timestamp: December 31, 2011, 06:38:09 pm
content: Hi everyone,I recently discovered that my DS1052E (hacked to DS1102E) firmware version 00.02.05 SP1 crashes everytime I change the slope in the trigger menu from Rising or Falling edge to bidirectional (the up and down arrows). Does anyone else have this problem or know of a fix for this?

author: Fraser
author_rank: Super Contributor
timestamp: December 31, 2011, 06:46:30 pm
content: I recommend reverting to firmware 2.04 as the 2.05 versions seem to be a tad flaky !This forum has a whole thread on Rigol 1052E firmware upgrading/downgrading. FW2.04 is king in my opinion.

author: dickydom
author_rank: Newbie
timestamp: July 04, 2013, 08:30:15 am
content: Yes, this happened to me just last night. Screen is now frozen on vertical lines. Can anyone give advice. Firmware up/down grade ?
Voice filter - Page 1
Forum section: electronics / general

author: SPRX
author_rank: Regular Contributor
timestamp: July 10, 2013, 04:22:31 am
content: I found some of my recorded voice files are hard to listen with high noice ratio and faded voice on them.I wonder if there is a tool to filter out the the noice and improve the voice of the naration.Thanks

author: marshallh
author_rank: Unknown
timestamp: July 10, 2013, 04:30:35 am
content: Download AudacityRemove noise - select a silent portion containing the noise profile. Use the Noise removal plugin and hit the "Get noise profile" button.Then select the entire duration and remove all noise.Then Effects > NormalizeNext you should run it through a dynamic range compression to even out the volume of your voice. Use the Compressor effect.Lower the threshold and increase the gain. Play around until you get it where you want.

author: SPRX
author_rank: Regular Contributor
timestamp: July 11, 2013, 06:50:26 am
content: Awesome, It worked really well !!!Thanks Marshallh !!
Teardown: Auditek ER-740 - Page 1
Forum section: electronics / general

author: ResR
author_rank: Regular Contributor
timestamp: June 30, 2013, 04:45:27 pm
content: Look what I found. It's a Auditek ER-740. Anyone knows any specs for this thing? Is this worth to keep in one piece or only to use as parts source?

author: SeanB
author_rank: Super Contributor
timestamp: June 30, 2013, 05:32:15 pm
content: Pretty standard 1970's to 1980's tech tape deck ,and with belts still in good condition. Probably meant to be built into a console as a tape source or tape recorder for PA systems or other announcing duties or area background. Not stereo, but if you want to keep it get some cassette tapes and play them, and see how it performs.Worst case keep it to copy tapes to your PC from things like telephone recorders.

author: ResR
author_rank: Regular Contributor
timestamp: July 03, 2013, 03:35:13 pm
content: I took one apart (I had 2 of them), most parts are made 1987-1989, if the Dave method is correct with transistors and electrolytics. Elna caps everywhere (is it good brand?), the construction is solid, lot of sheet steel, resembling soviet construction style, magnetically shielded 27VA transformer is handy, there was also omron switches and two small bayonet sockets with 3V bulbs. And huge resistors, like modern 1W size carbon film ones. I'm keeping other intact and look how to use it someday.
0 to 99,999,999 ohm resistor substitution with 1 ohm step - Page 1
Forum section: electronics / general

author: Winston
author_rank: Regular Contributor
timestamp: July 01, 2013, 02:05:32 pm
content: This just showed up at Tindie. Looks easy to set and is a good price. I have no association with the seller.https://www.tindie.com/products/redrocketlabs/resistance-decade-box-resistor-substitution-box/

author: kripton2035
author_rank: Super Contributor
timestamp: July 01, 2013, 02:41:40 pm
content: eh the original is here :http://www.digitalunderpants.com/diy-resistor-substitution-decade-box/not sure the original maker authorizes the selling of his making...and sure it's not worth $75 !!!

author: Winston
author_rank: Regular Contributor
timestamp: July 01, 2013, 05:59:32 pm
content: Knowing the specifics of its internals, it sure isn't worth $75, I was just comparing it to eBay units and their prices, all of which are higher. I was wondering if a DIY version was on-line somewhere, sothanksfor posting it! I shall now make one of my own for much less than $75.

author: alank2
author_rank: Super Contributor
timestamp: July 01, 2013, 07:19:22 pm
content: I ordered one of these:http://www.ebay.com/itm/151073472738?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649I think the guy is a member here, I saw a thread about it here a day or two ago...

author: Winston
author_rank: Regular Contributor
timestamp: July 01, 2013, 08:11:45 pm
content: Quote from: alank2 on July 01, 2013, 07:19:22 pmThat's a very clever design, 1/2W instead of 1/4W, much cheaper, probably much quicker and easier to select values, and all I really need. Thanks! I'm buying one and putting banana jacks on it.Video about its creation:Seven Decade Programmable Resistor - A Low Cost Solution

author: alank2
author_rank: Super Contributor
timestamp: July 01, 2013, 08:59:39 pm
content: Quote from: Winston on July 01, 2013, 08:11:45 pmI thought it was pretty cool too - I really appreciate that he put the 500mW resistors on there...

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: July 03, 2013, 11:12:11 pm
content: I made one if these fir less than £18 with a 1% tollerance on all values and they can all handel 0.6WGranted the case looks a bit beaten up but it works nicely and it works from 0-99,999,999ohms +- 1% 0.6WI quite like itconsidering its one of the first pieces of equipment that i built in my very small but growing labIn total i got 10 dials for about £10 anand the resistors (10 of each decade except i got 25 of the 10M) for about £8the case i had laying around in my parts draws and the same with the banana plugs ( which would have added £5 to the cost in total.i know it can be made for cheaper and to a lower tolerance too
Teardown: 1979 vintage temperature controller - Page 1
Forum section: electronics / general

author: ResR
author_rank: Regular Contributor
timestamp: June 28, 2013, 03:31:07 pm
content: Temperature controller PTR-P from 1979 (34 years old) used to control the temperature in a pig farm using various ventilators and air valves (by the look of the cabling, most parts was missing). Of course for the time period, there is no paint on a pcb, no silkscreen, but the traces are hand drawn and tin plated.

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2013, 06:36:07 pm
content: Just lovely transistor spacers and those electrolytics are incredible.
Manual Pick n Place - Parts & PCB organisation - Page 1
Forum section: electronics / general

author: Pat Pending
author_rank: Regular Contributor
timestamp: June 30, 2013, 03:09:08 am
content: This design is a neat time saver.Here the PCB conveniently sits atop the acrylic sheet as to limit hand travel.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 30, 2013, 09:12:39 am
content: Fine until you need 12mm or wider tape, or tape with deeper components.You probably want something less slippery than acrylic.You need a longer exposed length of tape so you don't have to keep pulling through & peeling back the cover all the time.

author: miceuz
author_rank: Frequent Contributor
timestamp: June 30, 2013, 09:22:43 am
content: What do you use to pick components from the tape?

author: Andy Watson
author_rank: Super Contributor
timestamp: June 30, 2013, 09:34:09 am
content: Quote from: mikeselectricstuff on June 30, 2013, 09:12:39 amAnd possibly more conductive if you're handling static sensitive components.

author: nctnico
author_rank: Super Contributor
timestamp: June 30, 2013, 11:53:29 am
content: I bought a couple of hundred of these boxes to store SMD components:http://www.ebay.com/itm/160548130026They are very convenient for hand assembly.

author: free_electron
author_rank: Super Contributor
timestamp: June 30, 2013, 01:57:06 pm
content: Quote from: Pat Pending on June 30, 2013, 03:09:08 amhmm. that's a neat idea.. but i see some oints of improvement . i'll cook up a more advanceddesign that can be lasercut and can handle different tape widths and has a wind-up mechanism... ii'll post the design files here.

author: Pat Pending
author_rank: Regular Contributor
timestamp: June 30, 2013, 07:13:05 pm
content: Quote from: free_electron on June 30, 2013, 01:57:06 pmDon't forget the coffee cup holder.
Dearborn CANBUS Diagnostics devices teardown - Page 1
Forum section: electronics / general

author: Stonent
author_rank: Super Contributor
timestamp: June 28, 2013, 07:32:48 am
content: These are devices used for car, and heavy duty machinery engine programming and diagnostics. I have a photo teardown of a 3 Plus and a 4 which are consecutive products. I was interested to see that they kept the labeling of the boards very similar even though they went from RS-232 to USB and also changed the brains.In order to use these devices, you need diagnostic software provided by the manufacturer of the vehicle, construction equipment, truck, engine, etc.We'll start with the 3 Plus and then go to the 4.Boards Removed and Separated:Component Side:Back Side:Board 1 Back Closeup:Code:U12Philips74HC04DHex InverterU11Philips74HC241D3 State Octal Buffer / Line DriverBoard 1 Front Closeup:Code:U9FreescaleXC68HC58SAEJ1850 to MCU Data Link ControllerU7MaximMAX3237CA11Mbit/s RS232 Line TranceiverU17On Semi74HC32AQuad 2-Input OR GateU14On Semi74HC86AQuad 2-Input XOR GateU6Analog DevicesADP3050Current-mode monolithic buck converterU1Philips74HC04DHex InverterU4TI75176BRS-422/RS485 TranceiverU5PhilipsA82C5218051/8052 MCUBoard 2 Back Closeup:(No components)Board 2 Front Closeup:Code:U5Intel87C19616-Bit MC96 MCU 32KBU6On Semi74HC573AOctal 3-State Noninverting Transparent LatchU7On Semi74HC573AOctal 3-State Noninverting Transparent LatchU1AllianceAS7C10261Mbit SRAMU6On Semi74HC08Quad 2-Input AND GateU11Philips74HC241D3 State Octal Buffer / Line DriverU8AtmelATF22V10CHigh Perf Electronically Erasable PLDU3National16550Standard 16550 UARTIn the next post I'll do the 4.

author: Stonent
author_rank: Super Contributor
timestamp: June 28, 2013, 07:45:17 am
content: 4 TeardownBoth Boards Separated:Board 1 Back:Code:U11Philips74HC241D3 State Octal Buffer / Line DriverU12Fairchild74HC04Hex InverterBoard 1 Front:Code:U9FreescaleXC68HC58SAEJ1850 to MCU Data Link ControllerU14On Semi74HC86AQuad 2-Input XOR GateU1Fairchild74HC04Hex InverterU4TI75176BRS-422/RS485 TranceiverU5PhilipsA82C5218051/8052 MCUU16PhilipsAU5790DSingle Wire CAN tranceiverU17On Semi74HC32AQuad 2-Input OR GateU6Analog DevicesADP3050Current-mode monolithic buck converterBoard 2 Back:No interesting components.Board 2 Front:Code:U1FreescaleMC68376BACFI25Toucan 68000 Series CANBUS MCUU6On Semi74HC08Quad 2-Input AND GateU5On Semi74HC04High Speed Hex InverterU2AMDAM29F400B4Mbit FlashU4ToshibaTC55NEM216AF4Mbit SRAMU7NetChipNET2270USB 2.0 controllerWell hopefully you found these interesting.
PCB Drill bit sizes and kits. - Page 1
Forum section: electronics / general

author: expertmax1
author_rank: Contributor
timestamp: June 25, 2013, 11:52:44 pm
content: Hey fellow members !I'm currently etching my own PCB (with success, hooray!) but now I have to drill the holes. I can borrow my friends drill press but I have no idea what size of drill bit I need to use. Is there a kit ? If someone asks for hole size, I have no clue. I'll drill the standard size so, whatever the standard size is.Thanks !

author: sleemanj
author_rank: Super Contributor
timestamp: June 26, 2013, 12:12:18 am
content: 0.8mm, 1.1mm and 1.4mm0.8 does most things (header pins are a tight fit but they do go in, which helps keep them there while you solder)1.1 for the thicker legged stuff1.4 for really big thingsUnless your friends press is a micro drill press, well you probably won't hold a 0.8mm bit in a normal chuck. Use a dremel, or something like -http://www.ebay.com/itm/12V-Small-PCB-Drill-Press-Drilling-With-0-8mm-Drill-Diameter-28mm-Motor-Diameter-/290717399541?pt=LH_DefaultDomain_0&hash=item43b01b79f5- these work quite well (I sell the same style chucks locally here in NZ for people to slap onto their own DC motor from the parts drawer).I wouldn't bother with carbide drills, just use good old HSS.

author: expertmax1
author_rank: Contributor
timestamp: June 26, 2013, 02:53:21 am
content: Just bought one ! 3$ + Free shipping is just too good to be true ! Thanks !