hybridfree/eevblog-posts huggingface dataset:
Datasheet for this component.  - Page 1
Forum section: electronics / beginners

author: anda3243
author_rank: Contributor
timestamp: April 01, 2022, 03:14:50 pm
content: I have looked at 300+ different mosfets today in hope to find the datasheet.The component is desoldered from a electric bike controller. The controller was rated for 120 V battery voltage, but was butchered for a new project.The component is likely made in China. If not China, then Asia for sure.The text on the component has not yielded any results in Google or the mayor component pages.JP038N15P5CXX021904CThe component should be rated for at least 120 V. It was mounted next to capacitor rated for 130V.Help would be greatly appreciated.

author: anda3243
author_rank: Contributor
timestamp: April 01, 2022, 03:17:26 pm
content: I should add. It is most likely an N channel mosfet.

author: amyk
author_rank: Super Contributor
timestamp: April 02, 2022, 12:45:13 am
content: I don't recognise the logo but judging by the part numbering scheme it is likely to be a 38A 150V N-channel FET.I already looked here for some possible clues:https://alltransistors.com/search.php?search=jp0

author: MathWizard
author_rank: Super Contributor
timestamp: April 02, 2022, 03:07:34 am
content: What is it actually doing in circuit, was it a switch, or motor driver or SMPS type thing ?? I should watch a repair or teardown of new electric vehicles, I wonder how many PCBs there are and what it compares to.

author: anda3243
author_rank: Contributor
timestamp: April 02, 2022, 03:59:47 am
content: Thank you! I will look in this site and see if I can find something. Maybe I can go with something that has the same voltage and current rating.

author: anda3243
author_rank: Contributor
timestamp: April 02, 2022, 04:05:55 am
content: Quote from: MathWizard on April 02, 2022, 03:07:34 amIt is a drive for electric scooter/motorcycle. The drive is rated for 120V battery, and claimed that the power output to the motor is more sinus shaped. I assume thats why they have 12 of these mosfets, not only 6.I bought this thing 2 or 3 years ago, but the documentation was terrible and I could not get it to work.
datasheet for transistor? - Page 1
Forum section: electronics / beginners

author: anda
author_rank: Newbie
timestamp: May 25, 2016, 01:46:03 pm
content: I have this T78006AP and I cannot find any datasheet for it.Anybody have some data on this component?

author: PA0PBZ
author_rank: Super Contributor
timestamp: May 25, 2016, 02:19:02 pm
content: Search for TA78006AP
Datasheet for (Z)446 op amp (solved)  - Page 1
Forum section: electronics / beginners

author: wasting
author_rank: Newbie
timestamp: August 17, 2014, 10:19:10 pm
content: Hi there!Looking for info/datasheet about ST Z446 (see picture). I've tried google but with no luck :/Thanks in advance!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 17, 2014, 10:40:56 pm
content: pinout looks like a dual opamp.Z is probably not part of the part number

author: wasting
author_rank: Newbie
timestamp: August 18, 2014, 02:57:38 am
content: Quote from: mikeselectricstuff on August 17, 2014, 10:40:56 pmAn op amp is probably right as it's connected to an headphone output. I've tried searching for only 446 but no luck there as well.Can the 9521 be a date code?Cheers

author: mzzj
author_rank: Super Contributor
timestamp: August 18, 2014, 09:28:30 am
content: This was tricky one.952i == TS952ID

author: wasting
author_rank: Newbie
timestamp: August 18, 2014, 11:40:10 am
content: Quote from: mzzj on August 18, 2014, 09:28:30 amThanks!!

author: senso
author_rank: Frequent Contributor
timestamp: August 18, 2014, 01:23:20 pm
content: And its not ZT, but ST as in STMicroeletronics:http://www.st.com/web/en/home.html

author: David Hess
author_rank: Super Contributor
timestamp: August 20, 2014, 09:24:44 am
content: I thought that was the date code.It is not a very good operational amplifier based on the datasheet but I guess suitable for audio. Hopefully they were cheap.

author: GK
author_rank: Super Contributor
timestamp: August 21, 2014, 03:53:42 am
content: Quote from: senso on August 18, 2014, 01:23:20 pm“Life augmented”?? At first glance their home page looks more like a front for a company manufacturing air fresheners or feminine hygiene productsRather pretty girly whirly though........

author: wasting
author_rank: Newbie
timestamp: August 22, 2014, 07:21:30 pm
content: Quote from: David Hess on August 20, 2014, 09:24:44 amYeah, I'm pretty chocked that this is what's drives the headphones on a "professional" 500 euro sound card... (http://www.motu.com/products/motuaudio/ultralite-mk3)
Datasheet Formula Confusion - Page 1
Forum section: electronics / beginners

author: ruumoo
author_rank: Contributor
timestamp: December 06, 2018, 06:29:13 am
content: I'm designing a Li-Ion charge controller around the LT1513 ic. I want to use the given application circuit, but I want to use more charge current than in the example, but I can't figure out how to calculate IR5 for the charge current formula. IFBVOS is given as 2.5mV (It actually stands for Voltage Ofstet of IFB)
Datasheet  HOWTO - Page 1
Forum section: electronics / beginners

author: dds
author_rank: Contributor
timestamp: May 29, 2011, 07:49:08 pm
content: http://www.sparkfun.com/tutorials/223

author: Bored@Work
author_rank: Super Contributor
timestamp: May 29, 2011, 10:00:14 pm
content: I stopped reading atQuoteWhat do they want instead, marketing wank?
Datasheet interpretation for 74HC590 rise and fall times  - Page 1
Forum section: electronics / beginners

author: GreyArea
author_rank: Contributor
timestamp: August 30, 2019, 08:37:34 am
content: Hi, I'm reading the datasheet for the TI SN74HC690A counter. (https://www.ti.com/lit/gpn/sn74hc590a)Under the recommended operating conditions I can see that at Vin of 4.5 the max Input transition (rise and fall) time is 500ns. So this might be a silly question but the signal I'm trying to count has quite a slow Tr and Tf of about 600ns. Can I assume that I'm out of spec for a reliable count with this part and that I need to clean this up by adding schmitt trigger? If so, can anyone recommend a suitable jellybean schmitt trigger?

author: StillTrying
author_rank: Super Contributor
timestamp: August 30, 2019, 11:44:27 pm
content: "the signal I'm trying to count has quite a slow Tr and Tf of about 600ns."Are they the 10% to 90% times. From the note underneath it looks to me that if you have fast 0.5V to 1.5V times and a good gnd you'd just about get away with your 600ns, it's a bit of a grey area.If this device is used in the threshold region (from VILmax = 0.5 V to VIHmin = 1.5 V), there is a potential to go into the wrong state from induced grounding, causing double clocking. Operating with the inputs at tt = 1000 ns and VCC = 2 V does not damage the device; however, functionally, the CCLK and RCLK inputs are not ensured while in the shift, count, or toggle operating modes.74HC14 or 74HC132 if nand is useful.
Datasheet needed UAA3000 - Page 1
Forum section: electronics / beginners

author: PinheadBE
author_rank: Regular Contributor
timestamp: October 20, 2021, 05:12:01 pm
content: Hi,I'm looking for the datasheet of the UAA3000 or µAA3000 IC.It is a timer chip in DIP-package that can be powered directly from mains and controls directly a triac.Elektor published in a summer edition several decades ago a very simple application circuit.(see a copy herehttp://electroniq.net/other-projects/uaa3000-timing-circuit-electronic-project.html)But I would like to have more specs on that chip since I have a bunch of them that I would be able to put to good useSo, should you have a copy of that datasheet, I would be delighted !Have a nice day

author: Jwillis
author_rank: Super Contributor
timestamp: October 21, 2021, 12:55:59 am
content: Obsolete 14DIP linear programmable timer . Don't want to create an accountHerefor possible datasheet .

author: amyk
author_rank: Super Contributor
timestamp: October 21, 2021, 02:48:35 am
content: Maybe some old Philips databooks may have the information, but I don't have any to look through. First appearance seems to be at least as early as 1982.
Datasheet or Manual for a "Gould 25 MHz (RTO) 325" - Page 1
Forum section: electronics / beginners

author: TheGenesis
author_rank: Contributor
timestamp: May 09, 2014, 06:37:53 pm
content: Just bought my first oscilloscope from eBay ... I couldn't find any information on the web.Does someone know anything about that thing?

author: HalfSpace
author_rank: Regular Contributor
timestamp: May 10, 2014, 11:24:44 pm
content: Hi TheGenesis,This scope was also sold as a Heath 4226 and Meguro MO-1252A (see pictures). You could try a manual search for these models.HalfSpace

author: Chris56000
author_rank: Frequent Contributor
timestamp: October 12, 2021, 04:41:47 pm
content: Hi!Manual with circuit diagrams & basic repair information now available on the Internet Archive – look under the Heathkit 4226 Model Number for it!Chris Williams
Datasheet question ChipCap 2; Vcore vs Vdd - Page 1
Forum section: electronics / beginners

author: PODF
author_rank: Contributor
timestamp: May 06, 2015, 08:05:57 am
content: Hi,i want to integrate a humidity sensor within a little Atmega project.I found the CC2D35 from GE. The datasheet says it can take between 2.7V to 5.5V.On Page 3 of this datasheethttp://pdf1.alldatasheet.com/datasheet-pdf/view/528939/GEC/CC2D35.htmlit says it has two voltage pins. One VDD and one VCORE.Now why is that? I found nothing on the datasheet itself so i assume it is clear for someone involved in electronics.Has this todo something with the chip can be powered by 3V (Vcore) and the i2c bus can be 5V (Vdd) or what is this for? why not just put only one V-Pad??Cheers PODF

author: tszaboo
author_rank: Super Contributor
timestamp: May 06, 2015, 10:31:33 am
content: You feed in on the VDD pin something between 2,7V and 5V. You bypass this with a ceramic cap. You bypass the VCORE pin with another capacitor. The device has an on-package regulator, probably 2,5V it needs an external capacitor for stability.This is just a guess.

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 06, 2015, 10:41:57 am
content: I haven't used that particular Atmel chip but if it's anything like the microchip PICs:- Its an internal regulated voltage for the processor- You need to bypass it with a low ESR cap close to the pins, the value may be critical so you must find the datasheet.- The pin may have configuration settings attached to it.You will need to find the detailed datasheet as this pin can be a real trap, if set up incorrectly it can cause spurious resets and increase current consumption.

author: PODF
author_rank: Contributor
timestamp: May 07, 2015, 08:02:00 am
content: Quote from: bookaboo on May 06, 2015, 10:41:57 amthanks for pointing that out, i searched and finally found the REAL datasheet. It has 45 pages instead of only 5!On Page 10 there it says how to connect these pins:QuoteQuote from: NANDBlog on May 06, 2015, 10:31:33 amyour guess was right with the capacitors. good i asked here and not just connected the Vcore and Vdd with just 5V...thankshere is the link to the big datasheethttp://www.ge-mcs.com/download/moisture-humidity/916-127B.pdf

author: lgbeno
author_rank: Frequent Contributor
timestamp: May 08, 2015, 02:08:31 am
content: Try one of thesehttps://www.tindie.com/products/ImpGuru/si7020-temperature-and-humidity-breakout/super easy to useSent from my iPhone using Tapatalk

author: tszaboo
author_rank: Super Contributor
timestamp: May 08, 2015, 12:21:35 pm
content: Quote from: PODF on May 07, 2015, 08:02:00 am
Datasheet Request MP6570 - Page 1
Forum section: electronics / beginners

author: maxpayne
author_rank: Regular Contributor
timestamp: January 19, 2017, 02:57:19 pm
content: Does anyone have the datasheet MP6570 ?http://www.monolithicpower.com/Products/Product-Detail/1167/MotorDrivers&PositionSensors/BrushlessDCPre-Drivers/MP6570

author: RogerRowland
author_rank: Regular Contributor
timestamp: January 19, 2017, 04:30:11 pm
content: There's a link to download it on that web page, you just need to register first. If you're reluctant to do that, you can use a throwaway email address for a one-off.

author: maxpayne
author_rank: Regular Contributor
timestamp: January 19, 2017, 04:42:54 pm
content: Quote from: RogerRowland on January 19, 2017, 04:30:11 pmI tried that ... they are not allowing any GMail/Yahoo like address. Thats why I am looking if someone have already have it
Datasheet timing diagram questions... - Page 1
Forum section: electronics / beginners

author: MarkS
author_rank: Unknown
timestamp: April 14, 2023, 06:18:50 am
content: I chose a random figure from a datasheet. I'm trying to understand what the crosshatched waveforms mean. Is this standardized? It's not explained in this or other datasheets that I can see.

author: tggzzz
author_rank: Super Contributor
timestamp: April 14, 2023, 07:56:39 am
content: It means "not guaranteed" or "not important", "can change" or "might change".

author: Benta
author_rank: Super Contributor
timestamp: April 14, 2023, 09:23:02 am
content: In this case, I'd call it "don't care", meaning the address lines can change without anything happening.

author: MarkS
author_rank: Unknown
timestamp: April 14, 2023, 06:38:34 pm
content: That's what I took it to mean, but wasn't sure. Thank you!
Datasheet wanted - Page 1
Forum section: electronics / beginners

author: JeRo
author_rank: Newbie
timestamp: March 17, 2021, 03:16:24 pm
content: Hi there,I ordered some NE555p from Aliexpress, the writing on the DIP8 says NE555P JM AK36, but I cannot find the datasheet. I know, I can always just use the TI datasheet, but I am curious who manufactured this...Thanks in advance :-=

author: magic
author_rank: Super Contributor
timestamp: March 17, 2021, 05:55:34 pm
content: Nobody knows, I guess. There appears to exist a bunch of factories making generic chips like 555 and 358 in China and auction site vendors just send whatever they can get today. Sometimes with logo of a known manufacturer, most often TI, sometimes also "upgraded" to some better part.https://zeptobars.com/en/read/Ti-555-NE555-real-vs-face-china-chinese

author: JeRo
author_rank: Newbie
timestamp: March 17, 2021, 06:01:39 pm
content: But it works like a charm...I am not building high performabce medical stuff or whatever, does it make a difference for the hobbyist?

author: drussell
author_rank: Super Contributor
timestamp: March 17, 2021, 06:08:42 pm
content: If it works well enough for your purposes, then it really doesn't matter.If you were building a product you might be concerned with longer term reliability, I suppose, but a 555 isn't exactly a difficult chip to manufacture "properly enough" to make it work just fine for you, even if it is some no-name cheap Chinese "knock-off."

author: mvs
author_rank: Frequent Contributor
timestamp: March 17, 2021, 07:11:41 pm
content: Quote from: JeRo on March 17, 2021, 06:01:39 pmIt is not consistent. Some parts work, some don't.If you are so price sensitive, have a look at lcsc.com. It is a chinese distributor (sister company of JLCPCB) with quite low prices.They have a lot of domestic parts with datasheets (not always in english).
Date code for Analog Devices op-amp... - Page 1
Forum section: electronics / beginners

author: jimdeane
author_rank: Regular Contributor
timestamp: April 25, 2017, 10:15:35 pm
content: I'm trying to determine the date code for an op-amp in a piece of equipment that I think was purchased around 2000.The chip is an ADI (Analog Devices) OP496GP quad op-amp. I've checked the datasheet and did not find a code reference, and google was unhelpful (including checking links to the ADI website).Here's the totality of what's on the 14-pin plastic DIP:ADI S9542OP496GPM29604 0Center line is the chip ID, so either S9542 or M29604 is probably a date code. However, 95 and 96 seem awfully early for a near-2000 production date. Not impossible, perhaps it was old stock when sold. But I'm not sure, so I thought I'd ask here.

author: danadak
author_rank: Super Contributor
timestamp: April 26, 2017, 10:30:05 am
content: You might consider doing a post at ADI -https://ez.analog.com/community/amplifiersRegards, Dana.

author: amyk
author_rank: Super Contributor
timestamp: April 26, 2017, 10:54:42 am
content: The picture foundhere(attached for future reference) suggests it's the first line, as I doubt that is an IC from 1946(!)

author: MagicSmoker
author_rank: Super Contributor
timestamp: April 26, 2017, 11:55:01 am
content: Usually IC date codes are 4 digits, where the first pair of numbers specify the year and the second pair specifies the week. So without looking at any other references on the net, despite the ease of doing such, I would surmise that S9542 is the date code and that this IC was made in the 42nd week of 1995.The prefix S might be used to bin the part according to one of the critical parameters (say, offset voltage or current), or to indicate a specific fab or facility, etc.
dated (2000)  scope test report from CERN - Page 1
Forum section: electronics / beginners

author: apper
author_rank: Contributor
timestamp: June 10, 2014, 09:24:43 pm
content: • Agilent Infiniium HP54815A / 500MHz - 1GS/s• Tektronix TDS 3034 / 300MHz - 2.5GS/s• LeCroy Waverunner LT344L / 500MHz – 500MS/spdf.gz.pdf -> rename to pdf.gz and unzipEnjoy!

author: apper
author_rank: Contributor
timestamp: June 10, 2014, 09:43:29 pm
content: another one, i just upload it, tell me when this is of no interest and i'll stop wasting space....A digital oscilloscope setup for the measurement of a transistor’s characteristics
Datron 1061 - Page 1
Forum section: electronics / beginners

author: rsedwards1
author_rank: Newbie
timestamp: March 24, 2024, 08:59:37 pm
content: I have a Datron 1061 , purchased in 2009 never used before , when powered up Error OL shows, pressing test goes through a routine t6he Error 5 .Pressing Man shows PASSUnit stuck on DCAC and kOhm buttons will not illuminate .Anyone have one of these or experienced the same fault

author: m k
author_rank: Super Contributor
timestamp: March 29, 2024, 02:03:01 pm
content: Is it the same with all ranges?https://www.eevblog.com/forum/testgear/datron-1071-shows-error-ol/25/
Solved Datron 4000A Fail 5 over 190 volts - Page 1
Forum section: electronics / beginners

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 20, 2024, 04:49:09 pm
content: I'm having a problem with my Datron 4000A.On High Voltage output anytime I try to go past 199 volts I get a Fail 5. OOPSNow I get to 100 V and I get Fail 5.When I run self test result is PASS.Any thoughts?I don't think I kept good notes when I worked on these Datron 4000s back in 2017.Seems my original thought that it was a relay problem was correct?After trying different methods of getting to 500-600 volts both positive and negative.I found that after sneaking up to that number without turning off the output, the relays were worked and it allowed me to continue without a FAIL.Several attempts at this and so far I can go to the higher voltages without a FAIL 5.It has been sitting for three four years now.
DAVE DAVE HELP A BRO OUT PLSSS - Page 1
Forum section: electronics / beginners

author: xxngo
author_rank: Contributor
timestamp: April 04, 2015, 02:10:24 am
content: Dear forum...I was watching the review video of Dave, reviewing of the Rhino Tools Desoldering Station. I thought that it would be handy to have one like so. But unfortunately, it turned out that Rhino Tools does not ship anywhere else beside Australia. What a bummer.I was just wondering, Dave if this ever get to you, would you do me the favour of purchasing the item and sent it too me please, If its not too much trouble. I will pay for shipment and anything else involve. Or perhalf you could have it in stock and I will purchase it from your website.If you're willing, please leave me msg at xxngo13@hotmail.com and I'll work out the payment with youThank you....

author: Sirius631
author_rank: Contributor
timestamp: April 04, 2015, 05:40:56 am
content: Where are you, xxngo? Someone closer to you might be able to offer an alternative/better solution. It's unlikely that the Rhino will meet your local power socket/voltage/frequency requirements, so you'll need an adaptor anyway.

author: xxngo
author_rank: Contributor
timestamp: April 04, 2015, 03:31:17 pm
content: Im in canada Sirius....getting an adapter is not a problem..the problem is finding a similiar product that is affordable.thanks Sirius, and if you or anyone can suggess a better option I would be very thankful. Cuz trying to desolder a board with one of them sucker pen is a waitse of time.thanks again

author: GreyWoolfe
author_rank: Unknown
timestamp: April 04, 2015, 07:12:07 pm
content: Here is the one I bought, basically the same thing.http://www.memotronics.com/vacuum-desoldering-rework-station-digital-temperature-controlled-dual-lcd-new/EDIT: double checked site, no longer available. Bummer.

author: Pillager
author_rank: Unknown
timestamp: April 04, 2015, 07:37:09 pm
content: Basically, I think, they are all produced by Zhongdi.Here's a link:http://www.china-zhongdi.com/products.asp?CataID=134&cataupper=&k=&Page=4They should be quite common, just search for "ZD 985", you should find something.Greets, Tom

author: xxngo
author_rank: Contributor
timestamp: April 05, 2015, 04:05:26 am
content: thank you very much for the suggestions, it looks good.
Dave Jones's brother - on the net  - Page 1
Forum section: electronics / beginners

author: Figaro
author_rank: Newbie
timestamp: October 24, 2020, 10:27:42 am
content: I have discovered dave's brother talking HF on the net - check for youself @

author: Microdoser
author_rank: Frequent Contributor
timestamp: October 24, 2020, 11:16:15 am
content: I watched his videos to get an initial handle on Altium. Took me a little while to get past his voice but the videos were informative.
Dave's negative feedback  - Page 1
Forum section: electronics / beginners

author: Cali-Sam
author_rank: Contributor
timestamp: May 30, 2013, 07:51:11 am
content: I bought one of Dave's negative feedback shirts during the 100 shirts goal. I'm not sure I got charged for one. When are they supposed to be ready to be shipped to people like myself?

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: May 30, 2013, 08:02:42 am
content: Quote from: Cali-Sam on May 30, 2013, 07:51:11 amI already received mine and I'm in Hong Kong.

author: Cali-Sam
author_rank: Contributor
timestamp: May 30, 2013, 08:05:48 am
content: Where the hell is mine then?

author: EEVblog
author_rank: Unknown
timestamp: May 30, 2013, 09:32:30 am
content: I've had mine here in oz for a week or more.

author: rkupka
author_rank: Regular Contributor
timestamp: May 30, 2013, 12:39:18 pm
content: arrived to Europe this wednesday too.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 30, 2013, 12:44:26 pm
content: What , we have to put in an order to get one , now I missed both , the notice to order and ordring

author: Cali-Sam
author_rank: Contributor
timestamp: May 30, 2013, 04:36:48 pm
content: Quote from: KD0CAC John on May 30, 2013, 12:44:26 pmYeah. A goal of 100 purchases had to be reached.. I was excited to see over 450 people punching in.. It is thrilling to realize how many people were willing to support!!Dave has got to do this more often....Anyway, back to me! I'm in California, how much longer would it take for the shirt to get here. I'm not in a rush or anything; I'm just excited to get mine!!Cheers!

author: SeanB
author_rank: Super Contributor
timestamp: May 30, 2013, 06:08:44 pm
content: Got one of two, other must still be stuck in a negative feedback loop in customs, or some bastid is wearing it after nicking it from the parcel at the post orofice. Was promised to be delivered before 28 of this month........

author: Cali-Sam
author_rank: Contributor
timestamp: June 07, 2013, 05:48:11 am
content: It is june 6th and I Still haven't gotten mine. Man! I'm getting pissed !!

author: Barryg41
author_rank: Contributor
timestamp: June 07, 2013, 03:33:49 pm
content: I got both of my T-shirts two weeks ago.
Dave's u-Supply issue - Page 1
Forum section: electronics / beginners

author: ikrel
author_rank: Contributor
timestamp: January 04, 2013, 02:54:27 am
content: I've setup Dave's u-supply from the schematic and I'm having an issue with the voltage follower for the current sense resistor.I'm reading a constant 22.9v on the output of the follower (24v supply @ 0A) and only get a a few hundred millivolts difference as I adjust the current from the supply from 0-1.5A. if I probe across the resistor i get exactly what you'd expect(0-1.5v).I've change the op-amp(LM358) and nothing changed. What could be causing this?
DaveCAD: Representation for a MOSFET? - Page 1
Forum section: electronics / beginners

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 18, 2019, 09:09:34 am
content: When using DaveCAD how do you draw MOSFETs?(Context: Drawing all the bits of a MOSFET is a PIA)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 18, 2019, 09:49:41 am
content: TimCAD will sometimes draw an "insulated gate JFET" style symbol. Generally prefers the full version, since S/D matters.Can't speak for DaveCAD, obviously...Tim

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: October 18, 2019, 01:01:42 pm
content: KaiCAD usually draws the normal MOSFET symbol but with a straight line for the substrate/drain/source part and leaves out the double connection for the source and the body diode, instead just draws one connection and an arrow. basically likeCode:|| |----| |...| |<---|

author: Zero999
author_rank: Super Contributor
timestamp: October 18, 2019, 01:05:15 pm
content: ZCad normally draws the full MOSFET symbol, but only bothers with the body diode, if it's relevant to the circuit.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: October 18, 2019, 02:40:04 pm
content: I tend to go with the standard symbol used by analog IC communities - like a BJT (so arrow towards the 'gate' line for PMOS, away for NMOS), but the source and drain lines are perpendicular to the 'gate' line, instead of at an angle. So kinda like a JFET, but with the arrows like on a BJT.This is simply the way the community I work in has agreed to do it. I used to try the more 'correct' symbol as dictated by standards but the only thing it achieved was to confuse people looking at my work.Image of the symbols I use:

author: bjbb
author_rank: Contributor
timestamp: October 18, 2019, 04:02:49 pm
content: in order of precedence1. IEC 606172. ANSI Y323. your national standard harmonized with the IEC standard4. your employer's standard library.

author: mc172
author_rank: Frequent Contributor
timestamp: October 18, 2019, 04:09:52 pm
content: I draw a bipolar transistor and write an M next to it because I can't ever be arsed to draw or the bits nor remember where the bits all go.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 18, 2019, 04:20:58 pm
content: Quote from: mc172 on October 18, 2019, 04:09:52 pmThat in a nutshell was what motivated the question.

author: Kasper
author_rank: Frequent Contributor
timestamp: October 18, 2019, 05:08:56 pm
content: Quote from: mc172 on October 18, 2019, 04:09:52 pmHaha nice. I just put some right angles and write 'pmos' or 'nmos' and the body diode. Must have the body diode.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: October 18, 2019, 07:48:36 pm
content: I look it up. E.v.e.r.y.t.i.m.e.

author: TheHolyHorse
author_rank: Regular Contributor
timestamp: October 18, 2019, 08:12:19 pm
content: Quote from: SparkyFX on October 18, 2019, 07:48:36 pmThere's always something that you just can't remember if your life was depending on it.
Daves Dummy load, Question about the sense resistor in the circuit. - Page 1
Forum section: electronics / beginners

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: May 07, 2014, 11:37:41 pm
content: Ok so I built a digital version of daves dummy load and so far everything is working the way it should but I am confused about the current sense resistor. Originally I just thought it was there to sense current, but it has to be there in order for the circuit to work. I.e if you take it out and just through a DMM before the test load to measure the current nothing happens. So exactly does this resistor do besides sense current? Is there anyway to take it out and use a hi side sensor or even a hall sensor?

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: May 08, 2014, 06:25:28 am
content: Maybe im not really wording my question right, I guess what im asking is why does the circuit require the low side sense resistor to operate? Is it becuase the resistor is what is acually drawing the current from the attached load? I was under the impression the mosfet was drawing current based on its gate voltage?

author: lapm
author_rank: Frequent Contributor
timestamp: May 08, 2014, 06:40:37 am
content: Sense resistor is there to provide means to measure current flowing throw.Its dummy load - variable resistor with some smart to controll how much current it draws. This requires feedback mentioned above...Just becouse your resistor is able to consume 25 wats, docent mean you want to consume all that power - hence need to control current drawn...Take out sense resistor and you brake the feedback loop. Your multimeter probably will not have same value of shunt resistor inside it...

author: Nermash
author_rank: Frequent Contributor
timestamp: May 08, 2014, 06:50:41 am
content: Try searching among Mjlorton videos on Youtube, he did quite a lot experimentation and thinkering regarding the sense resistor in his dummy load build.

author: idpromnut
author_rank: Unknown
timestamp: May 08, 2014, 01:26:54 pm
content: I have been having issues in my reproduction of Dave's DC load as well, but mine are of the flavour that the pass-mosfet bangs on or off with a very very small window of adjustment (2.5V into the feedback op-amp turns it on, and the mosfet saturates at 3-4V into the feedback op-amp). I thought that this might be a function of the type of mosfet I am using, and specifically the VGS threshold (I was initially using a logic-level mosfet). I swapped this out for a higher VGS mosfet and gt the same thing. I am using a LM358 in the same basic voltage follower -> feedback/control op-amp configuration as Dave.But to answer the question, the pass 'fet/transistor are there to absorb the power (voltage drop X current) that the sense resistor is not.Example: if you have a 1Ohm sense, and feed 10V into the load and want to set the load to 1A, the sense resistor should be dropping 1V across it (Ohms Law), and there for the remaining power of the 9V drop @1A must be dissipated somewhere, and this is in the pass 'fet/transistor.
Daves mailbag address please? - Page 1
Forum section: electronics / beginners

author: Mosaic
author_rank: Regular Contributor
timestamp: April 29, 2016, 02:11:27 am
content: Somehow I can't seem to find it anywhereand i'd like to send him a couple items.thxAncel

author: crispy_tofu
author_rank: Super Contributor
timestamp: April 29, 2016, 02:35:19 am
content: Dave can delete this if he doesn't want me to post it here, but:PO Box 7949Baulkham Hills BCBaulkham Hills NSW 2153AUSTRALIA

author: mariush
author_rank: Super Contributor
timestamp: April 29, 2016, 08:54:16 am
content: All the information you need is here:https://www.eevblog.com/about/contact/The address is publicly available.

author: Jeroen3
author_rank: Super Contributor
timestamp: April 30, 2016, 09:10:35 pm
content: EEVlabs is actually ongoogle maps. In the former Altium building.... As announced first of April this year....
Daves soft latch Video - Page 1
Forum section: electronics / beginners

author: rscott
author_rank: Newbie
timestamp: December 01, 2019, 04:10:38 pm
content: So i have been messing around with this circuit for the last 3 years off and on.I want to actually use it now. However, i noticed in his video, when power is applied, the circuit immediately comes on.Why is this? What do we do to fix it?Obviously we dont want the circuit to come on right awayThanks

author: rcbuck
author_rank: Frequent Contributor
timestamp: December 01, 2019, 09:16:20 pm
content: I built the circuit on a breadboard to use in testing a circuit I was building a couple of months ago. It more or less worked. The on-off latch seemed somewhat touchy depending on how long you held the button down. It also required a certain amount of time between button presses to function properly. For my use it did work and I learned how to get around the shortcomings.If I needed to build a soft latch circuit that had to be 100% reliable I would use a 50 cent PIC chip and software.

author: TomS_
author_rank: Frequent Contributor
timestamp: December 02, 2019, 01:42:01 pm
content: Maybe even one of those el cheapo Padauk 3 cent micros. I bet that thing costs less than all of the other components added together.Of course you do have a one off cost of the programmer... But then you can have soft latching circuits or button debouncers for years.

author: Peabody
author_rank: Super Contributor
timestamp: December 02, 2019, 06:10:57 pm
content: If a microcontroller is involved, then the circuit becomes simpler since you can use a GPIO pin to maintain power-on after the button is released, and then turn off power after the button has been pressed (and released) again. Attached are two versions of such a circuit. One uses two GPIO pins - one output to maintain power, and one input to sense the button press. The second circuit uses a single GPIO pin in INPUT_PULLUP mode for both functions.

author: Jwillis
author_rank: Super Contributor
timestamp: December 03, 2019, 07:27:13 am
content: In Daves circuit the gate of the mosfet is charged from the 100k resistor upon power up. Won't it be better to some way have the switch at the gate of the mosfet to isolate the gate until the capacitor charges . So when the switch is pressed the capacitor charges the gate there by turning on the mosfet which turns on the transistor to keeep the gate charged but prevents the capacitor from charging from the power source.So when the switch is pressed again the discharged capacitor shunts the gate charge to ground turning off the mosfet. which turns off the transistor which allows the capacitor to recharge for next turn on.
dB scale on spectrum analyzer - Page 1
Forum section: electronics / beginners

author: kumar
author_rank: Contributor
timestamp: December 29, 2013, 09:18:41 am
content: I am new to spectrum analyzer and want to know more about the dB scale displayed on spectrum analyzer.As I understand, the dB is the log of ratio of two similar values ( voltage,power etc.) On the spectrum analyzer the dBm scale is zero on the top of Y axis and becomes negative as we come down. Why is it so?

author: Bored@Work
author_rank: Super Contributor
timestamp: December 29, 2013, 09:24:00 am
content: Negative dB values indicate the actual value is smaller than the reference value. For dBm the reference is 1 mW. So, negative dBm values indicate the power is less than 1 mW.
dB    The exploration continues - Page 1
Forum section: electronics / beginners

author: KM4FER
author_rank: Regular Contributor
timestamp: November 14, 2014, 03:42:35 am
content: About 1km from my house there is an AM broadcast station transmitting on 1.49Mhz. Their signal gets into everything I try to do on a breadboard. So, just for fun I hooked up about 2m of antenna wire to one end of a 1k resistor and then attached my scope across the resistor with the probe on the wire/resistor connection and the ground clip on the opposite side of the resistor. I get a beautiful eye pattern on the scope with a 35mV peak-to-peak voltage for the unmodulated carrier. From this I can calculate the RMS voltage to be:RMS = P2P/(2 X sqrt2) = 0.035/(2 X sqrt2) = 0.0124V = 12.4mVThe power dissipated in the resistor by this signal is:P = E^2 / R = 0.0124^2 / 1000 = 154nWTherefore the power loss in the resistor is:dBm = 10 log P/1mW = 10 log( 154 x 10^-9 / 1 x 10^-3) = -38dBmThis makes sense since the power dissipated in the resistor is much smaller than the 1mW reference.Now lets look at the voltage of the signal on the antenna:dBmV = 20 log V/1mV = 20 log 0.0124 / 0.001 = 22dBmVThis also makes sense since the signal is a little over 10 times larger than the 1mV reference.But if I reference the signal to 1V instead of 1mV then:dBV = 20 log V/1V = 20 log 0.0124 / 1 = -38dBVAgain this makes sense since the signal is only about 1/100 the value of the reference voltage.Fun stuff.earl...
dB to percentages - Page 1
Forum section: electronics / beginners

author: edba
author_rank: Contributor
timestamp: October 17, 2024, 11:24:33 am
content: HiI have a bit of basic question which is just confusing completely this morning. I have a spec stating the voltage gain of an amplifier is x10 +/-0.9 dB. Don't ask me why the limits are in dB they just are!So I convert 0.9 dB to a percentage which is 10^(0.9/20) = 1.1092, whilst 10^(-0.9/20) = 0.9016, so the gain could be 11.092 to 9.016 or 10 +1.092 / -0.984. Why are the limits not symmetrical anymore, as with +/-0.6 dB? I am forgetting some of my mathematics rules from 40 years ago! It maybe a senior moment!BrEdba

author: PGPG
author_rank: Frequent Contributor
timestamp: October 17, 2024, 12:02:47 pm
content: Quote from: edba on October 17, 2024, 11:24:33 amBecause dB expresses deviation as exact value being changed by the factor and not by value.It is like saying that gain is 10 but can be 2 times higher or 2 times lover giving you 10 +10/-5.Such information is closer to real live. If gain of 10 is very not accurate it is more normal to expect it being 2 times smaller or 2 times higher than being ±10 giving you 0 at one and. What with gain being 10 ±15 where with + we don't have a big problem but having the phase reversed by inaccuracy is rather not expected.There are many values that are very not accurate. For example transistor beta varying from 100 to 600.

author: radiolistener
author_rank: Super Contributor
timestamp: October 17, 2024, 12:03:01 pm
content: dB for voltage and current is 20*log(ratio).dB for power is 10*log(ratio)since your specification is voltage gain 10x ±0.9 dB, it's more easy to convert 10x to dB: 20*log(10) = 20 dB.So, your specification is voltage gain +20 dB ± 0.9 dB = 19.1 ... 20.9 dB range.Now you can convert back to linear ratio:10^(19.1/20) = 9.0210^(20.9/20) = 11.09As result your voltage gain should be within 9.02 ... 11.09 range.It is not symmetrical because your error specification is in dB which is logarithmic scale.

author: edba
author_rank: Contributor
timestamp: October 17, 2024, 12:46:17 pm
content: Ok thanks for the answers. Yes the easiest way is to convert the gain to dB, so expressed in the same units, then convert the + and - limits back to linear gain.

author: TimFox
author_rank: Super Contributor
timestamp: October 17, 2024, 01:38:42 pm
content: dB are a ratio, percentages are an increment.For quantities like gain, you should use dB: if you increase something by 20%, and then decrease it by 20% you do not get back to the start.1.200 x 0.800 = 0.960, not 1.000If you increase something by 3 dB, and then decrease it by 3 dB, you get 0 dB which is back to the start.
DB9 Connector Alternative  - Page 1
Forum section: electronics / beginners

author: Larsson55
author_rank: Regular Contributor
timestamp: January 06, 2025, 01:46:31 am
content: The attached picture is for a DB9 connector sold in Amazon. I'm looking for a similar connector but the bottom part should be like the top part (it should not have the 9 pins male connector), in other words I will use it as a cable splicer. I will insert one cable at the top and another cable at the bottom to splice them together.Perhaps you know something similar?The control cabinet of my cnc sits about 6 feet away from the cnc and I need good quality connectors to splice all cables from the cnc to the control cabinet.Thanks

author: brucehoult
author_rank: Super Contributor
timestamp: January 06, 2025, 02:45:43 am
content: That looks like an E shell to me ... so DE-9. DB shell is much bigger, with room for 25 pins at that same pitch. Note for example the same size DE-15 used for VGA with finer pin pitch in three rows.So you just want a 10 wire terminal block with a cover?It might be simpler to just find the same item as in your picture, but female, and screw them together.

author: Larsson55
author_rank: Regular Contributor
timestamp: January 06, 2025, 03:09:52 am
content: Quote from: brucehoult on January 06, 2025, 02:45:43 amActually my larger cable has 5 conductors and your idea to get male/female sound excellent, but more costly which is not a big deal.Many thanks

author: jpanhalt
author_rank: Super Contributor
timestamp: January 06, 2025, 03:48:58 am
content: I am not sure what you are looking for. Some possibiities:1) Euro screw type connector between two cables (green connector in what you show) and no DB9 involved.2) A typical gender changer/connector depending whether the ends are same gender or not.3) Something like this , again with a choice of gender:https://www.amazon.com/gp/product/B07N3B34LT/

author: Larsson55
author_rank: Regular Contributor
timestamp: January 06, 2025, 04:19:58 am
content: Quote from: jpanhalt on January 06, 2025, 03:48:58 amBasically I want to splice all cables from my tabletop cnc to the controls cabinet which sits about 6 feet away from the cnc. There are about 10 cables with different number of conductors per cable. The splice must be removable so soldering the cable ends from the cnc to the controls cabinet is not good. What was mentioned before to get a male/female DB9 connectors and screw them together sound a good choiceThanks
dbi loss of 15-20m rg58 cable - Page 1
Forum section: electronics / beginners

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: April 26, 2015, 02:53:08 am
content: hi everyone!i am getting a uhf radio antenna installed (at home not in a car, hence why i need 15-20m) and i need about 15-20 meters of 50 ohm rg58/u cable (jay car product wb-2010) and i have a uniden at870 antenna which is 6.5 dbi. the absolute length of the cable would be 25m. if it was 25 meters what would be the dbi loss of the cable.thanks and please don't be to harsh because i am 14 and don't know everythingthanks again!

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: April 26, 2015, 03:06:11 am
content: sorry forgot the frequency is 476-477 mhz. (aussie uhf cb)thanks

author: TSL
author_rank: Regular Contributor
timestamp: April 26, 2015, 03:43:43 am
content: You dont want to use RG58 above 50Mhz the losses are too great.At 477 Mhz and 5 watts out of your CB and 25M of RG58 the loss is around 8.2dB.The means that only about 0.7 watt is reaching the antenna. Most of your power is being lost in the coax.At UHF frequencies you need to use much better coax, you won't get that from JayCar.Most home CB installations use LMR-400, it has much lower loss.Using the example above the loss would only be around 2.2 dB which means that just under 3 watts will be getting to your antenna.For an online calculator, go here...http://www.arrg.us/pages/Loss-Calc.htmGoogle "coax loss" for more information.regardsTim

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: April 26, 2015, 09:37:16 am
content: Quote from: TSL on April 26, 2015, 03:43:43 amhi, thanks for your quick response. it was very helpful!what about lmr-900? that looks even better that the lmr-400. it has a lower loss. could i still use that for cb?thanks!

author: Dago
author_rank: Frequent Contributor
timestamp: April 26, 2015, 12:22:23 pm
content: Quote from: rickselectricalprojects on April 26, 2015, 09:37:16 amSure you can use it, do notice that it is about 22mm in diameter (almost an inch) though.

author: German_EE
author_rank: Super Contributor
timestamp: April 26, 2015, 04:49:22 pm
content: One more thing, 6,5dBi is the gain of your antenna compared to what's called an isotropic radiator, something that radiates equally in all directions (think of a bare light bulb hanging down from the ceiling). But, when talking of gain or loss in coax it's just dB. So:dB Used to compare levels of powerdBi Gain of an antenna compared to an isotropic radiatordBm Gain or loss compared to one milliwatt (which is 0dBm)There's also dBV and dBuV but let's not complicate the issue as you have just startedThe following calculator will help you convert between units.http://www.temcom.com/pages/dBCalc_en.html
dBm calculating - Page 1
Forum section: electronics / beginners

author: Mepakos
author_rank: Contributor
timestamp: August 02, 2019, 08:49:52 am
content: How do i calculate dBm with these Values.R= 50Ω and 40dB

author: richard.cs
author_rank: Super Contributor
timestamp: August 02, 2019, 09:50:21 am
content: dBm is a measure of power, dB referenced to 1 mW. Your starting information doesn't include a way to calculate power so you can't get to dBm.

author: radiolistener
author_rank: Super Contributor
timestamp: August 02, 2019, 08:00:40 pm
content: dBm means "decibel milliwatt", this is more convenient to represent power.If you have power in Watts - Pwatt, you can convert it to power in dBm:dBm = 10 * log10( Pwatt * 1000 ) = 30 + 10 * log10( Pwatt )If you want to get power in Watts from power in dBm:Pwatt = 10^( (dBm-30)/10 )dB is just a ratio in logarithmic scale. dBm means power ratio to 1 mW, represented in logarithmic scale.

author: radiolistener
author_rank: Super Contributor
timestamp: August 02, 2019, 08:11:36 pm
content: If you have 40 Vrms (Volts RMS) on a load with R= 50Ω, then there is a power:Pwatt = Vrms^2 / R = 40^2 / 50 = 1600 / 50 = 32 WattdBm = 30 + 10 * log10( 32 Watt ) = 45 dBmDon't confuse RMS voltage with peak voltage, because for peak voltage power will be different. If you have 40 Vpk on a load with R= 50Ω, then there is a power:Pwatt = Vpk^2 / (2*R) = 40^2 / (2*50) = 1600 / 100 = 16 WattdBm = 30 + 10 * log10( 16 Watt ) = 42 dBmThis calculation for peak voltage is valid for a sine waveform only. This is why RMS voltage is more proper way for AC measurements.

author: Bud
author_rank: Super Contributor
timestamp: August 02, 2019, 08:40:05 pm
content: Quote from: Mepakos on August 02, 2019, 08:49:52 amYou cant calculate that from your data. dB is a measure of ratio, not an absolute value. I have two sticks in my hands, one stick is twice as long as the other. Can you tell how long my sticks are in inches ?

author: fourfathom
author_rank: Super Contributor
timestamp: August 02, 2019, 09:58:06 pm
content: Quote from: Mepakos on August 02, 2019, 08:49:52 amAs others have pointed out, that "40dB" is at best ambiguous. If you mean "40dBW" that equals 10kW. To convert dBW to dBm, just add 30: 40dBW = 70dBm (adding 30dB is the same thing as multiplying by 1000.)
DBM01 - Page 1
Forum section: electronics / beginners

author: shruthi
author_rank: Newbie
timestamp: January 22, 2015, 06:50:29 am
content: Hello everyone ,I hav purchased DBM01 ble module with TI CC2540 in it. I am using a android development boardI am trying to interface DBM01 to the development board via UART .Wat I m having doubt is how to flash a prog to CC2540 which is in DBM01 ?Guys plz help me out