hybridfree/eevblog-posts huggingface dataset:
How to test MOSFET's ( IRF740 ) PROPERLY ? - Page 1
Forum section: electronics / beginners

author: Mike Jung
author_rank: Contributor
timestamp: May 12, 2021, 09:25:54 pm
content: Can anybody please either explain or point me to some text on how to test MOSFETs properly ? I have a constant problem with a power supply using 4 IRF740. I also wonder if I could replace those with something better but without any other mods.

author: RichC
author_rank: Contributor
timestamp: May 12, 2021, 09:43:20 pm
content: You can certainly replace it, better depends on why it is failing currently.They're relatively high Rds for a power mosfet I assume because of the high voltage rating. If it didn't need that high voltage tolerance you could reduce the power dissipation by swapping to a lower resistance part.I would normally test by putting them in a circuit with an led as a low side switch and testing that they switch when the gate voltage is changed.

author: Jwillis
author_rank: Super Contributor
timestamp: May 12, 2021, 10:34:04 pm
content: This test won't tell you if the MOSFET is getting weak because the development of hot spots can slowly deteriorate the MOSFET die . This is caused by prolonged stress from over heating . This can reduce the current rating of the MOSFET because the die heats up faster and can no longer pass the rated amount of current. Excess heat can be slow death for a MOSFET .This test can tell you if the MOSFET has completely failed .Step 1 Diode checkSet DMM to diode and connect negative to drain and positive to source . Reading for a N-Channel should be around 0.3V to 0.9V . On a P-Channel it should have no reading . Diode is OKReverse the DMM test leds . N-channel should have no reading and a P-Channel should read around 0.3V to 0.9V . Diode is OK0V in either direction means diode is shortedStep 2 Resistance and continuity checkSet DMM to Ohms Drain to source should be very high resistance with test leds in either direction . Drain to source is OKVery low to 0the Drain to source is shorted . MOSFET is defectiveGate to Drain should read very high resistance . In fact you may even see the resistance climb fairly quickly to very high . The is means the gate is charging . Reverse the leds and you may see the gate discharge then charge again quickly . Gate to Drain is OK.Do the same from gate to source . If that checks the Gate to Source is OK . Don't worry you will not hurt the MOSFET .If the gate to drain and/or gate to source is shorted or very low resistance the MOSFET is defective.

author: james_s
author_rank: Super Contributor
timestamp: May 12, 2021, 10:35:08 pm
content: A better test might be to use a test load that requires a bit more power than an LED. It's trivial to wire up a mosfet to switch power to something like a 12V automotive light bulb, feed the gate through a resistor, anywhere from 100 ohms to a few k ought to be fine. The lamp should turn on when the gate is connected to 12V and off when the gate is grounded.
How to test negative power rail with electronic load - Page 1
Forum section: electronics / beginners

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 04, 2018, 09:20:31 am
content: Hi all,I've got a XHDZ-FZ-2D electronic load module from eBayhttps://www.ebay.com/itm/DC-1V-100V-Constant-Current-Source-Electronic-Load-Board-50W-Max-6A-Power-Tester-/232419643651and wondering if I can use it to with a negative voltage.The DUT is floating so can I just reverse the leads on the load input terminals?The schematic for the module are here:https://drive.google.com/file/d/0B4zALdueXAxdcm1jSWt6Tm9TZXc/view

author: Zero999
author_rank: Super Contributor
timestamp: August 04, 2018, 01:49:59 pm
content: Yes, it can be used to test a negative supply.No, don't reverse the terminals. Connect the positive to the 0V rail and the negative to the negative power rail.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 04, 2018, 04:13:07 pm
content: Thanks!

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 04, 2018, 05:36:48 pm
content: dont forget to add heatsink to the fleabay module, it can burn out pretty quick for higher load..

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 04, 2018, 05:42:42 pm
content: I have it for quite some time actually; it's in an enclosure with a big heatsink attached to it so no worries.
How to test old capacitors? - Page 1
Forum section: electronics / beginners

author: SylvainP
author_rank: Contributor
timestamp: August 29, 2015, 09:16:28 pm
content: Hello all.Due to putting the hobby aside for a few decades I have lots of old capacitors. I wonder how I should test them, is measuring their value with a cheap capacitance meter enough?I mostly have ceramics and electrolytics. I ordered an LCR meter recently if that helps (a DER EE DE-5000), I should receive it in a few weeks.

author: retrolefty
author_rank: Super Contributor
timestamp: August 29, 2015, 09:49:29 pm
content: Older larger electrolytic caps seem to have most trouble with old man time and heat aversion. People that restore the real old stuff (think vacuum tube equipment) will take time to 'reform' the old electrolytic at low voltage before applying full power to a piece of equipment.After that normal capacitance and ESR measurement should do a good job of checking their condition. Most small non-electrolytics caps are pretty reliable and should only require specific checking if higher level troubleshooting leads one to suspect one.

author: Fraser
author_rank: Super Contributor
timestamp: August 29, 2015, 10:02:17 pm
content: My personal view.... Bin the electrolytic if they are more than around 5 years old. No issues with ceramic, polyester, Mica or polyester capacitors as long as they have been kept dry.I don't waste time with poor quality or elderly electrolytic capacitors as the grit a dud could cause outweighs the cost of buying a selection of fresh stock values.Aurora

author: rdl
author_rank: Super Contributor
timestamp: August 29, 2015, 10:13:09 pm
content: I always thought that decent quality electrolytics would last quite a long time when stored somewhere near normal room temperature. I frequently use Panasonic electrolytics that were bought in the 80s and they seem to work as expected.

author: Fraser
author_rank: Super Contributor
timestamp: August 29, 2015, 11:04:41 pm
content: Electrolytic capacitors are sealed with a rubber membrane. It all comes down to how much you trust the membrane to hold up over time. I personally would not install a 1980's capacitor in a unit during repair or for important prototyping. Hobbyists can likely take a risk on non critical projects.If an old Electrolytic capacitor is installed in a piece of important equipment, how long will it last before the cap needs changing again ? Every time you change the capacitor, you thermally stress the PCB track adhesive. A PCB is always worth more than a decent capacitor. Why take the risk with such a low cost component ?Aurora
How to test the bq51050b? - Page 1
Forum section: electronics / beginners

author: Hellesvik
author_rank: Newbie
timestamp: July 21, 2024, 01:17:53 pm
content: I want to use the bq51050b to enable wireless charging in my project.So I am making a test-board for only the bq51050b first, to make sure I understand how it works.I have soldered up the test board now, and put it on a wireless charger, which works for phones.I tried to measure two things my multimeter:1. LiPo not connected, measuring amps.2. LiPo connected to GND and BATT, measuring amps.2. LiPo connected to GND and BATT, measuring voltage.Attatched image shows connection of PCB, battery and wireless charger.Kicad and gerber files found here if useful:https://gitlab.com/hellesvik/electronic_dice/-/tree/4_layer_test_gerbs/16mm0dice/kicad?ref_type=headsAll tests measure 0, so one of the following must be true:1. I am testing it wrong.2. My design is wrong.3. My soldering job went wrong.So I create this ticket to check 1: Am I testing it right?

author: m k
author_rank: Super Contributor
timestamp: July 28, 2024, 02:30:10 pm
content: Manual page 14 Functional Block DiagramFirst AC voltage must be between AC1 and AC2.Then it must appear as rectified in RECT.And finally outputted to BAT.

author: kevin.gibbs
author_rank: Regular Contributor
timestamp: April 02, 2025, 01:39:05 pm
content: If LiPo is connected and measured voltage = "0", maybe the battery is faulty?I didn't see how your coil (RX Coil) is made in the photo. Is there one at all?
How  to test this circuit pre installation - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 06, 2014, 12:36:39 am
content: Any tips on a test set up for this simple circuit? Whilst I am confident it should just work I am curious as to how I might check it out before installing it in the amp cabinet. It's a cathode bias circuit for a valve (tube) linear RF amplifier. Thanks.

author: Unknown
author_rank: Unknown
timestamp: January 06, 2014, 12:40:08 am
content: You know you can stick that screenshot in paint and trim all the black out (not racist) and save a lot of wasted bandwidth for anyone viewing it.

author: Dave
author_rank: Super Contributor
timestamp: January 06, 2014, 12:51:26 am
content: Quote from: Lurch on January 06, 2014, 12:40:08 amHate to break it to you, but if you need to point it out...How about building your circuit and testing it on a breadboard?

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 06, 2014, 01:13:46 am
content: I etched a pcb and built it this evening, just wondering what a bench test would entail, prior to testing it in the amp which has frightening HV levels and an expensive valve. Thanks.

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 06, 2014, 01:25:27 am
content: Quote from: Lurch on January 06, 2014, 12:40:08 amI am hopeless with image manipulation. I have done some (none racial) manipulation for you

author: Andy Watson
author_rank: Super Contributor
timestamp: January 06, 2014, 01:41:42 am
content: Light bulb, or light bulbs - the (now frowned upon) tungsten type. Pull-up the datasheet for the TIP147 and workout its Safe Operating Area and hence the maximum current at 40V. Then you need a D.C. power supply of more that 40V and whatever light bulb as appropriate to limit the current.I assume the TIP147 will be on a heatsink?You might also want to look at how you label the adjustment pot. As it is it appears to be labelled for the voltage present across this circuit, however, when you put this circuit into your final thing (transmitter cathode bias cct I assume), the sense of the pot is going to have the opposite effect on the bias current.
How to test TMO-4-2 - Page 1
Forum section: electronics / beginners

author: Crambone
author_rank: Frequent Contributor
timestamp: February 07, 2023, 09:48:32 pm
content: Guys, how can I test this?The one on the board is a TMO-4-2 can a TMO-4-2+ be used if original is shorted?ThanksTMO-4-2+.pdf(173.17 kB - downloaded 28 times.)

author: Kim Christensen
author_rank: Super Contributor
timestamp: February 08, 2023, 03:17:36 am
content: I believe that the + designation just means that it's RoHS compliant (Lead free). From their website FAQ:Quote
how to test TSOP 1738 - Page 1
Forum section: electronics / beginners

author: manjunath
author_rank: Contributor
timestamp: July 31, 2014, 11:57:34 am
content: Hi all,i tried to test TSOP 1738 using connection as shown in attachment but i didnt get output voltage. can anyone help me to solve this

author: VK5RC
author_rank: Unknown
timestamp: July 31, 2014, 12:07:14 pm
content: A quick look at the data sheet has a >10k resistor between 'Out' and Vs to pull it up, the data sheet comments 'out' should not be left 'low'.this may be a starting point, others I am sure will help.

author: Asim
author_rank: Regular Contributor
timestamp: July 31, 2014, 12:22:08 pm
content: The moment I read your post, I walked away of the PC, got a tsop1738, connected it as shown and tested the receiver with an oscilloscope to make sure it works, then tested it with a multimeter.first of all measure the output voltage WITHOUT pressing any button on your TV remote, it should be 5V.Secondly, when a button is pressed( keep holding the button), the receiver output will go down and up at 38KHz( you can see this if you have an oscilloscope), which will result in an output voltage drop at the output ( mine shows 4.4V)

author: amyk
author_rank: Super Contributor
timestamp: July 31, 2014, 10:07:19 pm
content: I can't be the only one who thought "a 1738-pin TSOP...? What?"
How to test various tools for ESD safety? - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: May 06, 2024, 08:56:57 pm
content: I've seen guides for testing bench and floor mats, but how are the various tools in a typical lab, for example brushes, screwdrivers, wipes, tweezers etc. tested for ESD safety? Is there an easy (and cheap) procedure I could follow in my own lab?

author: m k
author_rank: Super Contributor
timestamp: May 12, 2024, 07:28:19 pm
content: Not easy.You must decide between good and bad without seeing bad.Problem today is that there are too many options.Insulating everything is not the way for home use.Back in the day you had a wrist wrap, mats and so on.But your hands were nekkid so "natural" discharge was always there.For special situations you have a special procedure.But then it's not ESD protection.And don't brush dry.
How to theoretical analyze the zener diode circuit? - Page 1
Forum section: electronics / beginners

author: electrowhiz
author_rank: Contributor
timestamp: March 24, 2019, 05:35:12 am
content: Hi all,Please find the circuit and the simulation result in the attachment the attachmentI am struggling to theoretically calculate the at which source voltage the zener diode will enter the breakdown region.The zener diode used is BZX84C15L. In the circuit, voltage applied is 17V. The voltage across the zener is around 14.6V and the current through the circuit is 80uA. Whether 80uA is the leakage current?How to theoretically determine the voltage across the zener for different supply voltage?Thanks

author: iMo
author_rank: Super Contributor
timestamp: March 24, 2019, 07:22:54 am
content: You cannot easily calculate where exactly comes to the zener/avalanche effect.It depends on many factors, from chemical's doses used during fabrication, size and shape of the n-p regions, temperature, etc.You would need the manufacturer's know-how to do that with still some percentage of precision error.Also the zener's diode "knee" is rather wide.

author: MrAl
author_rank: Super Contributor
timestamp: March 25, 2019, 07:23:25 am
content: Quote from: electrowhiz on March 24, 2019, 05:35:12 amHi,Zeners can usually be replaced by a voltage reference, which is far more stable over input and temperature.The standard way to analyze a zener circuit is to assume the zener voltage is constant. Then calculate the range of current that flows though the zener and make sure it stays within the operating range of the zener for decent regulation.To do this, you can replace the zener with a voltage source (battery) and calcualte the current into the battery as if to charge it. That's your zener current.To get a better approximation you have to have the zener curve. You would then do a similar thing except the zener voltage would change with the zener current.To get a first approximation you can assume a straight line curve, to get better you have to use the actual curve which may not be very straight line.

author: Ian.M
author_rank: Super Contributor
timestamp: March 25, 2019, 10:51:11 am
content: There's a paper on modelling Zener diodes in a SPICE simulator here:https://people.eecs.berkeley.edu/~hu/PUBLICATIONS/Hu_papers/Hu_Melvyl/Hu_Melvyl_91_01.pdfIf you absolutely had to, you could solve it manually using mesh or nodal analysis and the Shockley diode equation. Fitting the model to a specific part number Zener is a whole other problem - the datasheets are typically rather lite on accurate parameters so unless you put a specific diode on a curve tracer there's not a lot of data to work from.OTOH if you've put the Zener on a curve tracer, and aren't needing a model to sim it, you don't need to model it any more!
How to thermally connect a thermistor to a TO-220 component? - Page 1
Forum section: electronics / beginners

author: yelneerg
author_rank: Contributor
timestamp: March 30, 2016, 06:07:55 pm
content: I want to build a circuit which reacts to temperature (which will be the topic of a different post) and it seems like I should go with a thermistor as the sensor but I can't seem to find any examples of how to thermally bind the thermistor to an IC. Specifically I want to track the temperature of a LM317. Should I use some sort of thermal paste that could double as glue? Or maybe put the head of the thermistor in a blob of solder on the metal flange of the IC (although that seems like it would cause an unwanted electrical connection)? Attaching it with an alligator clip is what I've been doing so far as I'm prototyping.

author: Seekonk
author_rank: Super Contributor
timestamp: March 30, 2016, 06:37:52 pm
content: Epoxy thermistor into crimp lug and bolt it to the case.

author: dadler
author_rank: Unknown
timestamp: March 30, 2016, 07:47:14 pm
content: Could use something like this, in addition to a bracket or otherwise for bolting to the component:http://www.amazon.com/Arctic-Silver-Alumina-Adhesive-AATA-5G/dp/B0087X725S/ref=sr_1_2?ie=UTF8&qid=1459367137&sr=8-2&keywords=Thermal+adhesive

author: yelneerg
author_rank: Contributor
timestamp: March 31, 2016, 05:01:30 am
content: Do I not need to worry about keeping it electrically isolated?

author: digsys
author_rank: Unknown
timestamp: March 31, 2016, 05:20:01 am
content: Quote from: yelneergNormally no. From their specs - Layered composite of aluminum oxide and boron nitride , Pure electrical insulator, neither electrically conductive nor capacitiveOr you can use something like this (if it is a TO220 type package) - they have excellent fast temp tracking

author: yelneerg
author_rank: Contributor
timestamp: March 31, 2016, 06:21:05 pm
content: Oh nice, I didn't even know those existed.
How to translate compartmentalized liver to analog computer?  - Page 1
Forum section: electronics / beginners

author: shivajikobardan
author_rank: Contributor
timestamp: July 29, 2022, 12:57:54 pm
content: How to translate compartmentalized liver to analog computer? I Just want to learn to translate the figure to equations.Highly reputed source(International)-:The compartmental analysis figure is the diagram that I want to translate to differential equations and eventually analog computer.https://imgur.com/a/LrmXwN3This is fromhttps://imgur.com/a/TYMFWqJThis book. IDK about the author, but I bet that this is extremely reliable compared to the materials locally available and written by local authors. But it doesn't tell which equation it is modeling, so I am not 100% sure about it.It has problems as well-:It doesn't use negative for K12 And idk why is it using negative for K23.Less reputed source-:https://imgur.com/a/ms7QXsBThis is pretty ambiguous, their equation and figure don't even match.Highly reputed source(LOCAL RESOURCE)-:https://imgur.com/a/MsL07tPIf this source is correct, I don't understand how is it correct?My thoughts about sign what they should be-:If the arrows are coming towards the block in consideration, add + sign else add - sign.For eg-: consider x1 block, then we find x1', for that + will be what comes inside i.e K21*x2, and - will be what goes outside ie.K12*x1.My Teacher(He hasn't written any pdfs that I know of)-:He says "some books have written plus(in K21) while some minus I am not sure what it is actually." He is not the one who will check my final exam paper.We don't know who will check it or who checked it.

author: mag_therm
author_rank: Frequent Contributor
timestamp: July 29, 2022, 02:13:43 pm
content: 1. In your reputed source, the block diagram is preparedfromthe Ordinary Differential Equation (ODE)You can translate that block diagrambackto ODE.2. For ambiguous sign of K21, I suggest a hint (and did) to simplify the block diagram by isolating [ (-X2) *K21 ] as a separate branch,Then redraw and k21 will appear only once, and you will more easily see and apply the sign of it for X1.
How to Tune a PLL Based FM Demodulator? - Page 1
Forum section: electronics / beginners

author: explosifiy
author_rank: Newbie
timestamp: September 06, 2023, 09:46:46 pm
content: Hi, I am designing an FM receiver and I was planning on building a PLL to demodulate the signal. I think I understand the working principle of a PLL, correct me if I am wrong, but the raw input and the error signal is put into the phase comparator, the output is fed through the loop filter, and that goes into the VCO which produces the error signal which is also the output. But how would you tune it? For example: If the PLL locks on to a station at 90 MHz and I want to change to a station at 100 MHz how would I go about it?EDITTurns out I was a bit uninformed. Thanks for the clarification. I thought that the loop filter of the PLL somehow sorted out the frequencies. I now know that the tuning is done in the IF phase and that the audio signal is not the error signal, but the VCO control frequency.

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 06, 2023, 10:35:55 pm
content: You'd have 2 PLLs. One to generate the local oscillator for the first mixer. (This is the one that tunes in different stations)The 2nd PLL is tuned to the center frequency (fixed frequency)of the last IF stageand does the demodulation.

author: wasedadoc
author_rank: Super Contributor
timestamp: September 06, 2023, 10:45:29 pm
content: Quote from: explosifiy on September 06, 2023, 09:46:46 pmYou appear somewhat confused.The inputs to the phase detector are the signal to be demodulated (FMed IF frequency irrespective of transmitted frequency as pointed out above) and the VCO frequency (also FMed at IF frequency). The output of the phase detector is used to vary the VCO frequency. The VCO control voltage is the demodulated audio.

author: DimitriP
author_rank: Super Contributor
timestamp: September 06, 2023, 10:54:01 pm
content: QuoteWell...maybe ...eventually ...at some point in the future but certainly not right now.QuoteOne would go about it by either studying or asking about how receivers work ( or how doreceivers"tune" different stations?), instead of "designing a receiver".You could start here:https://en.wikipedia.org/wiki/Superheterodyne_receiverEnjoy the ride and welcome to the forum.

author: explosifiy
author_rank: Newbie
timestamp: September 07, 2023, 12:00:07 am
content: Quote from: wasedadoc on September 06, 2023, 10:45:29 pmThanks for the help! I knew something was wrong, but I couldn't find out what it was.
How to turn an RFID module to USB - Page 1
Forum section: electronics / beginners

author: Beeko
author_rank: Newbie
timestamp: June 12, 2014, 12:17:11 pm
content: Hello everyone,I am love embedded as a field, design and programming. I Ace'd my Embedded Systems course in university (the only one to Ace the project) and my project wasn't even workingBut it was designed properly, only thing that stopped it from working is lack of materials and time.But I never learned the basics properlyI barely know that AC and DC are two different things, no idea how to control and calculate amperes or voltsNow that we have set things clear, here is my question:I bought this RFID reader (http://store.fut-electronics.com/1RFR101A1M.html) a while back and now I am trying to connect it to the PC directly instead of an arduino. Anyone knows how to do that? If it's even possible?Thanks a lot!

author: jamesglanville
author_rank: Contributor
timestamp: June 12, 2014, 12:51:35 pm
content: You just need a USB-serial cable. The FTDI ones are nice, you can get dirt cheap prolific cables on ebay too. You could also use the USB-serial part of an arduino if you have one on hand. Just connect up the 5v, ground, tx and rx to the cable. You will need to switch the tx/rx pairs so the two can communicate.

author: Jeroen3
author_rank: Super Contributor
timestamp: June 12, 2014, 01:19:33 pm
content: The thing you try to build already exist for a price lower than the effort you'd be putting in.Find one USB RFID reader, either they have USB Serial or they are a generic hid.

author: Beeko
author_rank: Newbie
timestamp: June 12, 2014, 01:44:28 pm
content: Oh! So I can't just get a used USB cable and wire things together?Bummer!SO basically I need a Serial-USB Cable and connect the reader to the serial side?This is the cheapest RFID module in here

author: Jeroen3
author_rank: Super Contributor
timestamp: June 12, 2014, 06:07:36 pm
content: You can if you get an ftdi cable.
how to understand memory capacity in data-sheets? - Page 1
Forum section: electronics / beginners

author: m4rtin
author_rank: Regular Contributor
timestamp: September 25, 2015, 05:45:52 pm
content: I have a network device which has following physical chips on its PCB:Code:4x Samsung 719 K7N801801B-QC16 (SRAM, 9MiB according to data-sheet)4x Samsung 713 K7N801801B-QC16 (SRAM, 9MiB according to data-sheet)4x Samsung 710 K7N161831B-QC16 (SRAM, 18MiB according to data-sheet)12x 46V8M16 (DRAM, 128MiB according to data-sheet)How to understand this? Do I have 144MiB of SRAM? This seems to be unrealistic.. Or are those 9MiB and 18MiB in data-sheets meant to be for multiple physical chips? What about 46V8M16 DRAM? 128MiB doesn't divide with 12

author: Balaur
author_rank: Unknown
timestamp: September 25, 2015, 07:41:52 pm
content: Quote from: m4rtin on September 25, 2015, 05:45:52 pmNope, that one is a 512Kx18-Bit memory. It even says in the datasheet:QuoteIt's 9 megabit (Mb, not MiB).

author: m4rtin
author_rank: Regular Contributor
timestamp: September 26, 2015, 04:53:11 pm
content: Quote from: Balaur on September 25, 2015, 07:41:52 pmThanks! So actually I have 8x 9437184 bits and 4x 18874368 bit of SRAM? This means exactly 9MiB and 9MiB accordingly? And what about those 12x 46V8M16 chips? Those are 128MiB combined, i.e 12 physical chips together is 128MiB?

author: Balaur
author_rank: Unknown
timestamp: September 26, 2015, 06:32:38 pm
content: Quote from: m4rtin on September 26, 2015, 04:53:11 pmSeems so.Please note that the 2x18-bits or 36-bits configurations will most likely consists in a 32-bit word + 4 bits for the parity. The usable capacity is thus 8MB (Yes, MegaBytes, I'm JEDEC not IEC)Also, please note that depending on the context, you may like to use the notion of words instead of bytes. It makes more sense in the context of the application.As an example, if you have 2 512Kx18 bits memories, together will make a 512 Kwords memory, where a word means 32 bits (+4 parity bits).Quote from: m4rtin on September 26, 2015, 04:53:11 pmThose DRAMs are 128 Mb (datasheet dixit). The total capacity is 12x128Mb = 1546 Mb. If you like or need it to express-it as M(i)B, then it's 192 MB.

author: m4rtin
author_rank: Regular Contributor
timestamp: September 28, 2015, 08:15:04 am
content: Quote from: Balaur on September 26, 2015, 06:32:38 pmI see, thanks! So eachMT 46V8M16chip is 134217728(2*1024*1024*16*4) bits?
How to understand the functionality of analog Circuit - Page 1
Forum section: electronics / beginners

author: techguru
author_rank: Regular Contributor
timestamp: July 21, 2018, 04:20:38 pm
content: Dear all,How to interpret the functionality of circuit? for example if my analog circuit contain 10 operational amplifier, How should i start the analysis and find the functionality of the circuit?By seeing the circuit i should understand the purpose of circuit. I know this is surely out of Experience and intuition but how to get and start my analog journey?I request you all to share your experience, It could be books or case study, etc. Help me in this regard..

author: pelule
author_rank: Frequent Contributor
timestamp: July 21, 2018, 07:40:03 pm
content: I would start by interpreting the OpAmps in their basic circuit fucntion (buffer, non-inverting/inverting amplifier, integrator...)This gives at least at basic overview./PeLuLe

author: rstofer
author_rank: Super Contributor
timestamp: July 21, 2018, 07:53:08 pm
content: If the circuit is drawn properly, inputs will be on the left, outputs on the right. So, start on the left and think through to the right.It is helpful to know what the overall circuit is supposed to do. In my case, I use op amps for analog computing. The blocks will be inverters, summers or integrators. There are variations in the feedback capacitor size to speed up the simulation and some of the inputs use smaller resistors to provide a 10x gain at the summing junctions. This may not be the most common use of op amps!Do some research on the kinds of blocks that are built with op amps. Amplifiers, buffers and filters. The circuit design is usually just a collection of these basic blocks.
How to understand this data sheet (pressure sensor) - Page 1
Forum section: electronics / beginners

author: tigerstyle
author_rank: Contributor
timestamp: September 13, 2015, 02:01:08 pm
content: Hi!I'm looking to build a small arduino based (maybe mbed system) pressure sensor+LCD display, and am deciding on what pressure sensor to start the project with.I need to read a range of approx 0-30psi (0-200kpa) and these pressure sensors are cheap on RS.I want to keep the project simple, and understand this sensor needs a 0-10V power input, but I cannot understand what output range the sensor has?More expensive sensors are quite clear that they are 0-100mv output, so easy to build the rest of the design around.But I want it to be cheapSo looking to understand the cheap sensors first.Datasheet:http://docs-europe.electrocomponents.com/webdocs/0ef4/0900766b80ef4279.pdfRS link:http://uk.rs-online.com/web/p/pressure-sensors/7191156/Many thanks!

author: Andy Watson
author_rank: Super Contributor
timestamp: September 13, 2015, 02:11:35 pm
content: As the datasheet says: Full scale span 40mV. The full scale being 20 to 200 kPa for the 2202A sensor.

author: tigerstyle
author_rank: Contributor
timestamp: September 13, 2015, 02:54:52 pm
content: Oh thanks,I got confused by the Min38.5 Avg40 Max 41.5 part, but I see how that fits in now, margin of error/accuracy.0.2mV/kPa sweet
How to understand/read this schematic  - Page 1
Forum section: electronics / beginners

author: eevfan007
author_rank: Contributor
timestamp: June 29, 2014, 12:55:43 pm
content: I want to create this circuit, but I need to be sure I understand i correctly. Is the top part of the schematic (the charger IC) supposed to connect to the booster part (lower part of the schematic ) of the circuit like how I've drawn it in? I've added a LiPo battary in between those two circuits. Hope that is the correct placement.Image of the board is here:

author: senso
author_rank: Frequent Contributor
timestamp: June 29, 2014, 02:36:18 pm
content: Click on the high-line tool(looks like an eye) and click on that VBAT symbol and see for yourself.

author: eevfan007
author_rank: Contributor
timestamp: June 29, 2014, 02:43:50 pm
content: Click on what? its a picture....

author: c4757p
author_rank: Super Contributor
timestamp: June 29, 2014, 02:47:42 pm
content: So download the original. By the way, we can'tseethat picture.

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 29, 2014, 02:57:59 pm
content: @senso and @c4757p, it appears that the schematic file is NOT available, so eevfan007 can not use the features in the EDA software (Eagle CAD).We have only a PNG bitmap rendering of the schematic diagram available.The simple answer to your question is: Yes.Actually the battery is already shown on the original diagram at the far left of the page, so your addition seems redundant.

author: c4757p
author_rank: Super Contributor
timestamp: June 29, 2014, 03:04:36 pm
content: Well that's a shame. I thought Adafruit generally tried to be friendly to OSHW. I guess providing a graphic of the schematictechnicallycounts, but it's not really in the spirit of things, is it?Anyway, here's abigger version.

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 29, 2014, 03:05:28 pm
content: That circuit would be difficult to "create" even for people with years of experience and who knew how to understand schematic diagrams.Note that all of the components are flea-size, surface mount which is difficult enough to design, produce, and assemble.But further, note that some of the board layout and some of the components are very critical to the proper operation of a switch-mode power supply (SMPS).SMPS are among the more difficult circuits to work on, and I would NOT recommend even a thru-hole version of this SMPS as a beginner project.
How to unlock a Rigol DS 2072a - Page 1
Forum section: electronics / beginners

author: from_the_north
author_rank: Newbie
timestamp: March 05, 2020, 02:21:07 am
content: Hi everyone.I`m new to the electronics arena, but I`m a motivated hobbyist. I`m a big RC plane fan and wanted to delve into electronics side of thingsI bought a used DS 2072a and was wondering if the hack still works and is available to unlock this unit.If anyone has a link or advice much appreciated.Thanks

author: MarkF
author_rank: Super Contributor
timestamp: March 05, 2020, 03:32:18 am
content: You can start here:https://www.eevblog.com/forum/testgear/sniffing-the-rigol_s-internal-i2c-bus/msg486238/#msg486238andhttps://www.eevblog.com/forum/testgear/unlockinghacking-the-rigol-ds2000a-series-scope-the-short-post/
How to use a CRS8675 Aptx Module - Page 1
Forum section: electronics / beginners

author: 450nick
author_rank: Newbie
timestamp: February 04, 2021, 01:05:29 am
content: Hi there!I'm currently trying to work out whether or not I could build my own simple bluetooth receiver for a classic car project that I'm currently undertaking. I have a simple goal; to build a neat little bluetooth receiver using a CSR8765 (with AptX enabled), with optical SPDIF output to feed an amplifier directly. I'm hoping to add an IDC connector to allow me to add an off board play/pause button and track skip forward and backward and a pair of 3.5mm mic inputs and that really is it. I'll control the volume from the amp directly and then all I need to do is design some sort of 3d printed housing. I am armed with Autodesk Eagle and have built a few PCBs using some Chinese PCB suppliers before but nothing related to audio or bluetooth. My problem is that I'm struggling to find any reliable information to design a circuit schematic. I've managed to find some reference designs from herehttps://www.tinyosshop.com/datasheet/TS8670_reference_design.pdfbut they don't cover the play controls so I'm a little stuck. Does anyone have any experience here or help they could offer? I have made a start at an Autodesk Eagle Schematic but I'm a little stuck.
How to use a vacuum pickup tool? - Page 1
Forum section: electronics / beginners

author: alank2
author_rank: Super Contributor
timestamp: July 22, 2015, 03:15:03 pm
content: Do you just center the part over where you want it and release/drop the part into place? Or do you put it in place and then release the vacuum?

author: zapta
author_rank: Super Contributor
timestamp: July 22, 2015, 03:41:48 pm
content: Quote from: alank2 on July 22, 2015, 03:15:03 pmI put it in place, sticking the part into the paste.What tool do you use? I tried a few passive ones but they worked poorly.

author: alank2
author_rank: Super Contributor
timestamp: July 22, 2015, 03:50:52 pm
content: I've made one out of a pneumatic dispensing station and a manual pickup tool. I just turn up the vacuum until I can pickup parts and use the foot pedal to release them with just enough air. How do you keep from smudging the paste when you press it into the paste? Maybe my hands just aren't steady enough.

author: zapta
author_rank: Super Contributor
timestamp: July 22, 2015, 04:20:42 pm
content: Quote from: alank2 on July 22, 2015, 03:50:52 pmI keep the pump on until the release. My previous setup had a solenoid valve but I simplify it by controlling the pump directly with the foot pedal. I don't know if I smudge more or less than you but in general it works well once I reflow it. One thing I made sure is to use the right needle size for the part. I used to needed sizes, a very narrow one for small parts down to 0402 and a wider one for MCUs, USB connectors, etc.I am pretty happy with my current setup, the most important aspects of it are 1) having an active pump and 2) using a foot pedal for a stable release with no residual vacuum 3) having an ergonomic hand piece (it's a 3D printed handle with the shape of a Metcal handle).

author: jwm_
author_rank: Frequent Contributor
timestamp: July 23, 2015, 03:26:29 am
content: If you have some scrap laying around that has nice rails the you can make a manual pick b place machine that keeps your parts parallel to the surface.http://hackaday.com/2014/03/13/manual-pick-and-place/Various other linkages work too of course, any parallel motion will do.
How to use GPIO2,14 & 12 of ESP8266 as input? - Page 1
Forum section: electronics / beginners

author: mrnams
author_rank: Newbie
timestamp: October 24, 2023, 05:45:23 pm
content: I have ESP8266 NodeMCU V3 board, I defined GPIO2, GPIO14, GPIO12 as input and set to LOW in setup function, but when I read state of these GPIO they always give HIGH, I read that these are set to HIGH by board after bootup.Please not I have used all other GPIO, and they are working, so only these two are available.My question is what to do to use these GPIO as input?

author: m k
author_rank: Super Contributor
timestamp: October 30, 2023, 08:02:52 pm
content: Input pins are externally defined.

author: liaifat85
author_rank: Regular Contributor
timestamp: November 01, 2023, 11:07:48 pm
content: I think you have to use a board with a higher number of GPIO pins.
how to use interruptions for rotary encoder on pic16f886 for C language - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: January 23, 2017, 08:34:39 pm
content: Hello, i need to use a rotary encoder to control pwm output on pic16f886 on C language (mikroC), why i need interruptions? because the pic has to manage 2 analog readings and 1 lcd displaying data at the same time, so reading the encoder without interruptions just doesnt work. the problem i have is that i dont know how to manage to read the encoder using interrupts, can you give me any idea of what instruction should use to have proper readings? the encoder is one of those "digital potentiometers" or pot-like encoders, has 2 outputs. Thanks for your time

author: android
author_rank: Regular Contributor
timestamp: January 23, 2017, 08:47:34 pm
content: Have a look at pub.c inhttps://sourceforge.net/projects/pub-usb/
How to use NTAG216 in place of NTAG215? - Page 1
Forum section: electronics / beginners

author: DivineChaos
author_rank: Regular Contributor
timestamp: February 29, 2016, 06:45:44 am
content: Hey guys, been working on a project that clones NTAG215 data onto new blank NTAG215 cards.However, out of necessity I am wondering if anyone here knows pretty much exactly what to do in order to use the NTAG215 data and place it onto a NTAG216 card.The only difference that I see is available memory, perhaps fill the 215 data with 0's?Any thoughts?

author: Fred27
author_rank: Unknown
timestamp: February 29, 2016, 10:45:36 am
content: I'd have thought that it would work without any changes. Quickest and easiest way to find out would be to just get a NTAG216 and just try it.

author: DivineChaos
author_rank: Regular Contributor
timestamp: March 01, 2016, 04:11:55 am
content: Try 1: Copy the data directly, no modificationResult: Failure to readTry 2: Open tag in hex editor fill remaining space with 0's to 924 bytesResult: Failure to readI have 8 more tags and therefore 8 more attempts. Any ideas?
How to use RTCC with PIC32MM0064GPM028? - Page 1
Forum section: electronics / beginners

author: Pariston
author_rank: Contributor
timestamp: July 16, 2020, 11:10:11 am
content: Could anybody explain or send me a tutorial link on how to use RTCC with PIC32MM0064GPM028? I believe it is possible to do this internally with external crystal (without DS1307), but I have never done RTC programming before and datasheet instructions seem unclear to me...
How to use TCRT5000 Infrared Sensor module with digital output (Arduino)?? - Page 1
Forum section: electronics / beginners

author: MrOmnos
author_rank: Frequent Contributor
timestamp: December 14, 2015, 07:39:11 pm
content: Hi guys!! I bought these TCRT5000 Infrared Sensor module for my line follower bot.It has two output pins, digital and analog. I am familiar with analog pin and I have used it several times. But I don't know how to use the digital pin in these things. I tried digital read but it didn't help. If anyone knows about these sensors or has worked with them before, some help will be appreciated.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 14, 2015, 10:01:20 pm
content: The DO pin appears to be the output of the LM393 comparator circuit. Have you tried adjusting the potentiometer, which apparently sets the comparator setpoint?I've used the raw sensor itself but not this module. I expect that digitalRead() would do the trick if the setpoint pot is set properly.
how to use this pir sensor? - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: January 16, 2022, 02:56:12 pm
content: hey.i very much like to know where all these 4 wires go?its a mains pir sensor with blue+blue+yellow+brown wires.its adjustable,just what i need!the best would be a 12v adjustable pir switch but havent found one.thanks,guys.https://www.ebay.com/itm/313812705872?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818142055%26meid%3D2fe89be975cf4fcca6e2c449f1ce378b%26pid%3D101113%26rk%3D2%26rkt%3D12%26sd%3D265474583436%26itm%3D313812705872%26pmt%3D1%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWeb%26brand%3DUnbranded&_trksid=p2563228.c101113.m2108

author: rpiloverbd
author_rank: Regular Contributor
timestamp: January 16, 2022, 03:49:28 pm
content: Hello, you may find this video helpful. It shows how to connect a 4-wire PIR motion sensor to a load.
How to use TLE2425 for Virtual ground - Page 1
Forum section: electronics / beginners

author: RoadRunner
author_rank: Frequent Contributor
timestamp: December 23, 2011, 10:49:44 pm
content: hii want to make a virtual ground circuit with TLE2425http://www.ti.com/product/tle2425i have a op-amp based virtual ground , (a 10k-10k voltage devider and op-amp as voltage follower)but i want to know to used TLE2425 to do the same

author: grenert
author_rank: Frequent Contributor
timestamp: December 23, 2011, 11:37:31 pm
content: This site covers the TLE2426. Not sure how much it differs from the TLE2425, but the principles should be the same.http://tangentsoft.net/elec/vgrounds.html

author: RoadRunner
author_rank: Frequent Contributor
timestamp: December 24, 2011, 09:06:02 am
content: @grenertthank you for your information ,, that is quite enough for methe main diffrence between TLE2425 and TLE2426 is that :- 2425 will work only 5v power so 5v/2 ==2.5v virtual groundand TLE2526 is Vin upto about 40v so 2526 is quite better solution
How to Wire 2 Pots and 1 Switch to Alternate them (Steering Joysticks) - Page 1
Forum section: electronics / beginners

author: Profanity
author_rank: Newbie
timestamp: May 06, 2020, 03:22:59 am
content: I have an asphalt paver with 2 joysticks that are both controlled with Pots for both left and right tracks, I have to change out the pots because I'm losing neutral position and the machine will crawl unexpectedly when in the center position.So I have to desolder the old pots and just ordered the new ones.My question is.If I buy 4 pots is there a way to wire them in such a way to keep the original joysticks(with the replacement pots) and another set of pots with knobs that I can toggle between the two. Can it Be Done with one switch with the left and right tracks simultaneously? Or one switch per left and right tracks individually.The reason for this is while traveling the machine doesn't have to be extremely precise, but while paving driving straight is key and precise movements are crucial to the asphalt to be laid correctly.I'm expecting that a knob being closer to the pot and more of a pinch movement would be more accurate than a lever (joystick).I've attached a picture of the pot, and the pot in the machine wired to the circuit board.The pot in the circuit board will have to remain, but the other mounted to the frame of the machine's control box and knob inserted on the exterior.Keep in mind I'm not an electrical engineer, most I've done is fiddled with an Arduino.I also have a 3d printer so links to any knobs that you know about that I can manipulate to fit would be appreciated.If I left out any information let me know ill try to elaborate to the best of my abilities. Or can provide more photos.
How to wire a amp meter to monitor 3 DC motors? - Page 1
Forum section: electronics / beginners

author: golash
author_rank: Contributor
timestamp: November 21, 2014, 04:07:20 am
content: HiI need help wiring a dc amp meter to monitor the total amperes of three motors. I have the circuitworking for one motor. But am uncertain what the correct wiring is to monitor 3 motors runningsimultaneously. Is it as simple as running the + wire from each motor to the amp meter. I`ve beenlooking for circuit diagrams but haven`t found anything.The current test has the – going direct to the motor and the + goes to the amp meter and then continueson to the motor.

author: Paul Price
author_rank: Super Contributor
timestamp: November 21, 2014, 04:18:42 am
content: Yes.

author: golash
author_rank: Contributor
timestamp: November 21, 2014, 04:22:41 am
content: Thanks...that was fast
How to wire a Current Transformer - Page 1
Forum section: electronics / beginners

author: anishkgt
author_rank: Frequent Contributor
timestamp: August 13, 2018, 05:22:04 am
content: Hi All,Is there anything else that i would need when using a Current Transformer ? I will be using this with an arduino to measure AC current of a Spot welder. The current schematic of the Current Transformer is from its data sheet (http://www.tamuracorp.com/clientuploads/pdfs/engineeringdocs/L06PXXXS05.pdf)The optocoupler is to sense when the electrodes are shorted for a spot weld.

author: Dave
author_rank: Super Contributor
timestamp: August 13, 2018, 06:20:27 pm
content: That is not a current transformer, but rather a hall effect current sensor. Yes, your connection method is correct.

author: anishkgt
author_rank: Frequent Contributor
timestamp: August 16, 2018, 09:13:08 am
content: Thank you appreciate it.
How to wire an analog 5A AC panel ammeter? - Page 1
Forum section: electronics / beginners

author: Frankentronics
author_rank: Regular Contributor
timestamp: May 04, 2020, 03:08:19 am
content: Greetings,I was wondering if I need a coil or a shunt to wire one of those cheap analog AC panel ammeters. Or does it have a built-in shunt?I need to monitor a variable transformer rated at 2.5A max and the meter is 5A AC.https://www.ebay.com/itm/AC-5A-Analog-Ammeter-Panel-Pointer-AMP-Current-Meter-Gauge-85L1-0-5A-AC/130908745105?hash=item1e7ac4ed91:g:fksAAMXQuu9RkmSdThanks...

author: rdl
author_rank: Super Contributor
timestamp: May 04, 2020, 03:18:39 am
content: For that range, and considering what's printed on the scale, it probably has internal shunt. You could always test it first, if in doubt.

author: WattsThat
author_rank: Frequent Contributor
timestamp: May 04, 2020, 03:21:50 am
content: According to the auction description:“This meter doesn't need extra shunt,it can be connected directly“

author: Frankentronics
author_rank: Regular Contributor
timestamp: May 04, 2020, 03:24:06 am
content: Oh, thanks... I didn't see that.

author: jackthomson43
author_rank: Contributor
timestamp: May 04, 2020, 04:54:28 am
content: Yeah I have worked on a similar one during myBachelor’s degree in Engineeringand they have builtin shunt so there's no need to attach an external one.