hybridfree/eevblog-posts huggingface dataset:
What is the best magazine for getting in to PCBs - Page 1
Forum section: electronics / beginners

author: Filand
author_rank: Newbie
timestamp: October 17, 2019, 10:59:07 am
content: Hi allWhat is the best magazine to get in to PCBs?Searching the web I have found these:Elector -https://www.elektormagazine.com/Nuts and Volts -https://www.nutsvolts.com/Circuit Cellarhttps://circuitcellar.com/Make -https://makezine.com/IEEE Spectrum -https://spectrum.ieee.org/Who would you recommend for a person that is just getting started (bought a Arduino starter kit, "Electronic Devices - Conventional Current Version" book and a multimeter)? And which do you prefer and why?Thanks!

author: DTJ
author_rank: Super Contributor
timestamp: October 17, 2019, 11:10:01 am
content: I'd say all of the ones you'd mentioned.Perhaps not get every issue but flick between them until you find one you like enough to subscribe. Some like circuit cellar may be too advanced but they often have a wide range of articles. CC seem to have the most interesting adverts.Maybe look at this one:https://diyodemag.com/

author: Filand
author_rank: Newbie
timestamp: October 18, 2019, 10:18:30 am
content: Thanks! Thats a pretty good idea. Will go down to my local magazine shop and see what they got!

author: DTJ
author_rank: Super Contributor
timestamp: October 18, 2019, 12:13:50 pm
content: You may find it cheaper to buy the digital version online & download it.
What is the best way to process this signal? - Page 1
Forum section: electronics / beginners

author: Deese
author_rank: Newbie
timestamp: October 19, 2016, 03:09:21 pm
content: The signal is a decaying positive dc voltage,there is a voltage limiter diode clamp in circuit so the max voltage of the signal is 600mv. So when the diode clamp turns off the dc voltage decays to zero in a curve. I want to measure/process that voltage close to zero,at a point in time,at the same point each cycle. The absolute value of the voltage is not really relevant,but the change in value from cycle to cycle is. If the voltage level increases we want to show the increase on an indicator/meter. So whatever the quiescent level happens to be we are going to null it/zero our meter etc.. Then read the change on the meter. The present way that is being used is a preamp amplifies the signal,then it is switched by a analog swith to an integrator. Supposedly there is alot of demand on the preamp in this method. It is said that it must have low noise,high speed,high BW,and must come out of saturation quickly. I was thinking that a sample and hold circuit,then a precision amplifier, would work better. Isn't the sample/hold ic optimized for high impedance/fast operation? Then a precision amplifier can amplify the voltage from the storage capacitor. The signal repeats at 1kHz frequency.

author: danadak
author_rank: Super Contributor
timestamp: October 19, 2016, 06:19:30 pm
content: Seems like if that voltage decays according to a known functional curve,like exponential decay, all you have to do is timeout fromn some start V,like your 600 mV as a starting point, and then some time, any time,measure V again and use the relationship to interprolate to the valueyou want at the low V point.If decay is not periodic then simply start a timer, and when it gets close to 1 mS,take a reading. Certainly a S/H where you go to hold at timeout is fine, of anA/D fast enough to meet your goals, like a SAR, A Cypress PSOC could handlethis quite easlily.You will have to do an end to end error budget to see if it meets your accuracy/precision requirements, taking into account T, Vref T & V, clock timing, offsets,etc....Regards, Dana.
What is the blue box of this Turn Signal Circuit? Solved - Page 1
Forum section: electronics / beginners

author: t1d
author_rank: Super Contributor
timestamp: December 27, 2018, 09:18:47 pm
content: A friend wants me to build this and I have the parts. But, the schematic is not traditional and I can't tell what is going on, in the blue box. An explanation, please and thank you.EDIT: The blue box is the relay. Solved.

author: Rerouter
author_rank: Super Contributor
timestamp: December 27, 2018, 09:22:27 pm
content: Its using an automotive relay, its using the capacitor to keep the relay closed for longer than the flash rate of the indicators,30 is common,87 is normally open contact87a is normally closed contact86 / 85 are the coil connections and dont care what polarity.

author: t1d
author_rank: Super Contributor
timestamp: December 27, 2018, 09:25:56 pm
content: Thank you!

author: glarsson
author_rank: Frequent Contributor
timestamp: December 27, 2018, 09:27:56 pm
content: The blue box has the same pinout as a automotive relay and the numbers (30, 85,...) are the standard numbers found on automotive relays, so perhaps the blue box is a relay with a diode in parallel with the coil? :-)

author: rbm
author_rank: Regular Contributor
timestamp: December 27, 2018, 11:53:49 pm
content: The diode illustrated is in parallel with the relay coil and is a snubber circuit (reverse-polarity) to reduce spikes that could hurt the upstream flasher.

author: Brumby
author_rank: Unknown
timestamp: December 28, 2018, 12:28:22 am
content: Quote from: rbm on December 27, 2018, 11:53:49 pmThe diode I see is not a snubber diode since it is not in parallel with the coil - unless you want to include the complete up-stream flasher circuit as being the path to chassis.What that diodedoesdo is prevent the capacitor from discharging back through the flasher circuit (including the flasher globes) when it is in the off state.

author: Rerouter
author_rank: Super Contributor
timestamp: December 28, 2018, 01:07:00 am
content: Brumby... there are 2 diodes in the diagram, so your both right.

author: Brumby
author_rank: Unknown
timestamp: December 28, 2018, 01:11:46 am
content: I didn't see the one inside the relay. It just looked like clutter.Need more caffeine.

author: Brumby
author_rank: Unknown
timestamp: December 28, 2018, 01:14:18 am
content: I did say this!:Quote from: Brumby on December 28, 2018, 12:28:22 am

author: Rerouter
author_rank: Super Contributor
timestamp: December 28, 2018, 01:25:31 am
content: Welcome to the world of automotive wiring diagrams, trust me it gets far far worse.Its not uncommon for them to pull stuff like this, in flat image only PDF's
what is the cause of these oscillations and how I can prevent them - Page 1
Forum section: electronics / beginners

author: reinholdPL
author_rank: Newbie
timestamp: January 18, 2021, 03:11:23 pm
content: Hello, I made a simple DC motor control circuit. At maximum load, the motor consumes about 4A.Arduino provides a PWM signal with a frequency of 62.5 kHz.Everything works fine, nothing gets hot, the system does its job.However, on the oscilloscope I can see quite large oscillations on the drain.Interestingly, it changes quite significantly depending on duty of PWM signal fed to the gate.The ringing disappears completely when duty is over 70%.Circuit is powered from 12V car battery.How can I prevent such oscillations?Yellow signal is the drain voltage, purple is the gate voltage. Thank you for any help.

author: mvs
author_rank: Frequent Contributor
timestamp: January 18, 2021, 05:39:31 pm
content: Quote from: reinholdPL on January 18, 2021, 03:11:23 pmIt is back-EMF. You can add a 100n film or ceramic cap across motor terminals to mitigate ringing.Duty cycle plays a role, because there are two different modes of operation, if you look at motor winding (inductor) current.In continuous conduction mode (CCM) there are two phases in a cycle:1 Switch open, diode closed, motor winding current is flowing throught switch.2 Switch closed, diode open, motor winding current is flowing throght diode.In discontinuous conduction mode (DCM) there is aditional third phase in a cycle:3 Switch closed, diode closed, motor winding current is zero.In phases 1 and 2 the drain node is connected either to gnd or to +12V, so you can't see back-EMF on scope. In phase 3 this node is in high-Z (between rails) and you can see ringing on scope.

author: reinholdPL
author_rank: Newbie
timestamp: January 18, 2021, 06:13:42 pm
content: thank you for your answer. so if I understand correctly this aditional third phase starts when oscillations shows up on oscilloscope and ends when switch (mosfet) opens and first phase begins again, right?could this do any harm to my circuit?

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 18, 2021, 06:36:42 pm
content: why dont you utilize both IN A and B to get stronger driver? or make traces easily switched between both in case the first driver burnt?

author: Benta
author_rank: Super Contributor
timestamp: January 18, 2021, 06:45:54 pm
content: Quote from: reinholdPL on January 18, 2021, 06:13:42 pmThe oscillations start when no current is flowing in either switch or diode. The inductance is then in a high-impedance environment and together with the inter-winding capacitance forms a parallel resonant circuit.The oscillations are harmless and low power.

author: reinholdPL
author_rank: Newbie
timestamp: January 18, 2021, 06:46:27 pm
content: Quote from: Mechatrommer on January 18, 2021, 06:36:42 pmThanks for suggestions. This was just test circuit to see if everything will work like it supposed to do. I have another pcb where I have utilized both channels.
What is the CMRR definition exactly? - Page 1
Forum section: electronics / beginners

author: ilbs
author_rank: Contributor
timestamp: September 19, 2013, 05:49:27 pm
content: Hello,First and foremost I would like to introduce myself... I am ilbs, and I am new to this forum!I have seen many definitions in many articles throughout the Internet... here are some of the definitions I found:QuoteQuoteQuoteand so on....But my question is, for example, for a given differential op amp circuit, if we have a CMMR of:CMRR = Ad./AcmCMRR = 2/1Can we say that in this case the CMRR:"is the ability of rejecting 1 volt of common voltage for every 2 volts of differential voltage"I am looking for a definition of CMRR that involves a reference to its numbers in its ratio!Thanks all

author: mrflibble
author_rank: Super Contributor
timestamp: September 19, 2013, 05:56:45 pm
content: From thetutorial from AD:"The op amp common-mode rejection ratio (CMRR) is the ratio of the common-mode gain to differential-mode gain."Hopefully the tutorial clarifies things...

author: tszaboo
author_rank: Super Contributor
timestamp: September 19, 2013, 06:11:18 pm
content: I think your confusion comes from the two different definition of CMRR. If you speak from a system with two inputs (ie. Instrumentation amplifier) the definition is clear.If you speek of an opamp common mode rejection, the common mode voltage is (as it has only 1 input) the input voltage (which is referenced to ground) divided by two. So the number "two" comes from that.

author: ilbs
author_rank: Contributor
timestamp: September 19, 2013, 06:50:27 pm
content: Thank you both for your help!
What is the component used for the turn + push knobs? - Page 1
Forum section: electronics / beginners

author: jimjam
author_rank: Regular Contributor
timestamp: June 07, 2014, 02:38:02 pm
content: What is the component used for the turn + push knobs, like the ones they use on some of the oscilloscopes?

author: retrolefty
author_rank: Super Contributor
timestamp: June 07, 2014, 02:42:04 pm
content: You mean a quadrature encoder with built in push button? If so they are common.

author: FrankenPC
author_rank: Unknown
timestamp: June 07, 2014, 04:00:43 pm
content: It's these if I understand you correctly:http://www.ebay.com.au/itm/1pcs-5-Pin-short-shaft-Digital-Push-Button-Switch-Rotary-Encoder-Switch-mah-/390651334723?pt=LH_DefaultDomain_2&hash=item5af4a25043Keep an eye on the operating lifetime. This one claims 30,000 "operations" or clicks.
What is the component with ref des DZ1? - Page 1
Forum section: electronics / beginners

author: nick42
author_rank: Newbie
timestamp: January 20, 2022, 12:45:15 am
content: Can anyone help me identify what the component is with ref des DZ1? I'm not an expert or anything like but more so a basic hobbyist when it comes to electronics, and I've never seen a component like this or even the ref des DZ. I searched a bit online but I didn't find anything. Maybe not searching with the right way?The board in the picture is the rear side of one of those flexible led strip

author: xrunner
author_rank: Super Contributor
timestamp: January 20, 2022, 01:37:19 am
content: Zener diode -https://www.globalsources.com/Zener-diode/smd-zener-diodes-1170842537p.htm
What is the correct name for wire wrapped around a post in vintage hifi - Page 1
Forum section: electronics / beginners

author: sel_199
author_rank: Contributor
timestamp: May 30, 2022, 10:49:44 pm
content: I was wondering if there is a tool for removing wire connections to the circuit board that are wrapped around a vertical metal post.I don't know what the correct term is for that type of connection so I can't really seach for a tool.Does anyone have any information on this thanks.

author: langwadt
author_rank: Super Contributor
timestamp: May 30, 2022, 10:52:06 pm
content: wirewrap ?

author: JDubU
author_rank: Frequent Contributor
timestamp: May 30, 2022, 10:54:22 pm
content: https://learn.sparkfun.com/tutorials/working-with-wire/how-to-use-a-wire-wrap-tool

author: sel_199
author_rank: Contributor
timestamp: May 30, 2022, 11:03:14 pm
content: Awesome thanks guys.

author: Ian.M
author_rank: Super Contributor
timestamp: May 30, 2022, 11:51:58 pm
content: Note that wirewrap used for consumer TV and audio off-board connections typically had a much larger square pin/post and wire diameter than wirewrap used for assembling prototype PCBs, which used thin 30 AWG silver plated Kynar insulated wire (aka: wirewrap wire) on 0.025" sharp cornered square posts, as shown at the Sparkfun link.The tool *MUST* match the wire and post size. You *MUST* use a fresh wire end to rewrap a joint - you cant use what ever you unwrapped as the post corners cut into the wire to make gas-tight contact.I suspect you may have some difficulty finding a manual wirewrap tool the right size for the wire and posts in your HiFi.If you don't have the correct tool or enough spare wire length, the standard practice in the repair trade was to re-wind any turns that were insulated + a turn and a half of the bare end and solder it, clipping off the rest, but leaving a slight nub so you can unwind from the end if you have to desolder it. Once soldered, a post can never be re-wirewrapped. To avoid this hassle, it may be worth desoldering the whole post from the PCB to avoid disturbing the wirewrap joint(s).

author: rsjsouza
author_rank: Super Contributor
timestamp: May 30, 2022, 11:57:02 pm
content: It is indeed named wire wrap and it was typical to be between 22 and 24 AWG.Such tools still exist for sale, typically more expensive than those ultra-fine wire wrapping tools mentioned by Ianhttps://www.amazon.com/Manual-Wire-Wrap-Unwrap-22-24/dp/B004IOQF4E

author: sel_199
author_rank: Contributor
timestamp: May 31, 2022, 09:10:24 am
content: Again thanks for the information guys, for the odd times I would need it wouldn't justify the expense of such tools.Looks like solder will have to be the way forward.Cheers.
What is the current leakage of MOVs  - Page 1
Forum section: electronics / beginners

author: Eraldo
author_rank: Regular Contributor
timestamp: August 30, 2023, 02:49:52 pm
content: I've been wondering lately as to what the current leakage of MOVs (metal oxide varistors) is. I don't think I've seen this measurement done and presented in the datasheets and nothing obvious showed up on google (like nothing on the main page with a concrete answer).My question came while thinking up a design about a multimeter and the high impedance mode (under 20 V for example) when the imput impedance goes over 10G ohm and i assumed the MOV would have very low leakage while being under it's rated voltage. But no component is ideal of course and their primary use is not in precision multimeters but ordinary power supplies. Maybe there are special ones designed for low leakage?My question is what is the typical value of it and is anyone has tried to measure it. If not it would be a very interesting topic to dwell in but unfortunately i lack the appropriate tools. Would be cool if someone did it though.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 30, 2023, 03:32:01 pm
content: Seach for "Varistor" and not for "MOVs" (Nocturnal Lepidoptera of London)See page 7

author: Eraldo
author_rank: Regular Contributor
timestamp: August 30, 2023, 04:12:03 pm
content: Quote from: Terry Bites on August 30, 2023, 03:32:01 pmVery interesting. But now i wonder why such info is not presented in the datasheet. They are pretty bare-bones.Also a resistance of 10⁹ is less than i thought but propably there are ones with higher resistance designed for multimeter use specifically.

author: bdunham7
author_rank: Super Contributor
timestamp: August 30, 2023, 04:26:51 pm
content: If you look at the data sheets you almost always see a chart of leakage/clamping currents, but the lower end might be 1µA or so and they don't characterize them below that. For a typical MOV used in a multimeter this might be 1µA @ several hundred volts. You can try to extrapolate by extending the curve off the lower end of the chart and I think you'll typically come up with leakage currents on the order of picoamperes at 10-20V.

author: Eraldo
author_rank: Regular Contributor
timestamp: August 30, 2023, 05:00:57 pm
content: Yeah funny thing is before i posted the original post i downloaded a generic mov datasheet to see what they include in it and after i double-checked now i totally missed it the first time (was buried behind pages and pages of product part numbers and dimensions)
What is the difference between the bandwidth of a scope and bandwidth limit? - Page 1
Forum section: electronics / beginners

author: Akj
author_rank: Newbie
timestamp: March 05, 2021, 05:51:55 am
content: Duh this hantek scope datasheet is confusing me!They've mentioned their scope bandwidth as 100mhz as you can see in the image attached but there is also a bandwidth limit parameter of 20mhz.Can anyone please explain me what does this mean?

author: rfclown
author_rank: Frequent Contributor
timestamp: March 05, 2021, 05:56:07 am
content: Scopes will often have a Bandwith Limit function which inserts a low pass response. It is useful when trying to look at a signal which has high frequency noise on top of it.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 05, 2021, 12:03:29 pm
content: Quote from: Akj on March 05, 2021, 05:51:55 amThe specs for bandwidth limit at the top of the spec sheet represent what the particular oscilloscope model can support, typically at -3dB. You can think of this as the maximum signal bandwidth reliably tested and measured with the oscilloscope, although some models will exceed their specification.Depending on what you want to test/measure/observe you might want some headroom, for example if you are observing/measuring rise times.https://www.tek.com/support/faqs/how-bandwidth-related-rise-time-oscilloscopeshttps://blogs.keysight.com/blogs/tech/bench.entry.html/2019/08/16/supercharge_yourosc-pBDK.htmlThe reference to bandwidth limit further down the spec sheet is not the overall bandwidth limit of the oscilloscope but a feature (often invoked with a button) that enables a user to set a lower bandwidth, generally as a filter to help minimize noise.https://www.tek.com/blog/scope-tip-use-bandwidth-limiting-reduce-noise-captured-signalshttps://www.eevblog.com/forum/beginners/the-popular-oscilloscope_s-20-mhz-bw-limit/Note that these specs are in MHz (Mega for millions of Hz) rather than mHz (milli for thousandths of Hz), ie upper case M vs lower case m.edit - typo fixed

author: Akj
author_rank: Newbie
timestamp: March 05, 2021, 12:20:28 pm
content: Thank you for such a detailed explanation! I clearly understand this now

author: Vovk_Z
author_rank: Super Contributor
timestamp: March 05, 2021, 05:00:37 pm
content: We usually use scope with "20MHz BW limit" On, when there is no need in full bandwith.
What is the difference between TQFP48 and LQFP48 - Page 1
Forum section: electronics / beginners

author: Aztlanpz
author_rank: Regular Contributor
timestamp: January 14, 2018, 04:21:55 pm
content: What is the difference between TQFP48 and LQFP48 of there respected footprints.Aztlan

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 14, 2018, 04:51:51 pm
content: May vary by manufacturer, but T usually means Thin, so lower profile package
What is the difference in an AC capacitor over a DC capacitor? - Page 1
Forum section: electronics / beginners

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: February 15, 2017, 12:05:55 am
content: A lot of times I read that the capacitor needs to be DC or AC.And the rules of the game are that you never have the one you need... so can you use the one you have?In this case I have large AC caps but not DC.... and I need DC.....I play around and experiment a lot however I know my limitations and when to ask...I don't like things exploding in my face... I'm male.....Thanks in advance.

author: Seekonk
author_rank: Super Contributor
timestamp: February 15, 2017, 12:20:53 am
content: You can use AC caps on DC. AC caps have a much higher DC rating. All capacitors have microscopic air bubbles between the foil layers. Under a changing voltages, corona forms in these voids eventually destroying the insulation. AC capacitors are designed to deal with this. X2 capacitors actually have a layer of foil in between, making two capacitors in series and reducing corona effects in half..

author: ebclr
author_rank: Super Contributor
timestamp: February 15, 2017, 12:21:53 am
content: AC capacitor does not have polarity, but the constructions are generally based on films without any kind of electrolyte. The capacitor has a big volume/capacitance and is expensive also.Dc Capacitors are based on an electrolyte, that makes a very low capacitance/volume but works only on DC voltage because the electrolyte can't isolate on both direction

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 15, 2017, 12:30:19 am
content: In addition, AC capacitors have to deal with significant current flow in and out of the capacitor each cycle. Many DC capacitors do not, although those specified for switched mode power supplies and other similar applications will often have the most challenging specifications in this regard.

author: Brumby
author_rank: Unknown
timestamp: February 15, 2017, 04:59:52 am
content: This is the fundamental difference:Quote from: ebclr on February 15, 2017, 12:21:53 amDescribed as "non-polarized", they can handle a voltage of either polarity on the terminals and, thus a an alternating voltage. DC is just a special case where the polarity of the voltage does not change, so you can use AC capacitors - as is - in a DC application.NOW comes the big warning .... when it comes to capacitors used in MAINS circuits, you must be very careful to get properly rated capacitors. A prime example is the X and Y rated capacitors used for EMI suppression. DO NOT get this wrong.Just as an extra fun fact ... you can make a non-polarized capacitor by taking two polarized capacitors and connecting them in series - back to back. Whether that's a good idea or not is another thing.

author: David Hess
author_rank: Super Contributor
timestamp: February 16, 2017, 05:45:05 am
content: In the past when using non-polarized capacitors like ceramic, film, and paper, it was common to use DC rated capacitors in AC applications including X and Y line applications with a suitable derating.
What is the different between mpu6050 andLSM6DS3TR - Page 1
Forum section: electronics / beginners

author: abdelhaleem
author_rank: Newbie
timestamp: July 11, 2022, 02:32:18 pm
content: Hello,What is the different between mpu6050 andLSM6DS3TR?

author: tooki
author_rank: Super Contributor
timestamp: July 11, 2022, 03:18:48 pm
content: What questions are left unanswered for you after comparing the datasheets?
What is the different when a resistor is on the High or Low side in the circuit? - Page 1
Forum section: electronics / beginners

author: Chriss
author_rank: Frequent Contributor
timestamp: March 07, 2020, 11:15:56 pm
content: Hi!I'm curious about what is the difference when a resistor is put in series in a lets say 12vdc circuit where a motor is powered upin the high side or low side?I mean if the resistor is between the battery + and motor or when the resistor is put between the motor - and battery - ?I also saw sometime in circuit's where the current limiting resistor for the LED are put to LED and gnd but also the opposite.Thanks you for any explanation.

author: Nusa
author_rank: Super Contributor
timestamp: March 07, 2020, 11:19:57 pm
content: When the circuit is as simple as you describe, it doesn't make any difference functionally. Current is limited for the entire circuit, not just the side it's on.

author: Chriss
author_rank: Frequent Contributor
timestamp: March 07, 2020, 11:25:36 pm
content: Thanks for the fast replay.Actually yes, I mean the resistor is for current limiting, and nothing else.So that means there is no "right" or "wrong" way if the resistor is for current limiting only, like I described?Thanks.

author: greenpossum
author_rank: Frequent Contributor
timestamp: March 07, 2020, 11:29:47 pm
content: Electrically there is no difference but sometimes there is an advantage elsewhere due to the location. For example when I had an array of LEDs where the drivers were sinking current, putting the limiting resistors on the high side allowed me to use a resistor network to save space as the common pin of the network went to the postive supply..

author: digsys
author_rank: Unknown
timestamp: March 07, 2020, 11:47:46 pm
content: It is "traditionally" put in the high side - especially if there are several devices powered from that supply eg vehicles etc In many cases, you want to keep the 0V REFCLEAN.The main "old" reason that resistors were put in the "low" side was for current sensing, but these days there are heaps of high side current sense ICs that can go up to quite high voltages, so even that is not necessary any more.
what is the easiest way to open all options on real DS2202? - Page 1
Forum section: electronics / beginners

author: Aido4ever
author_rank: Contributor
timestamp: March 24, 2014, 12:24:15 am
content: Hello everyone.I just found out the ds2072 was hacked to be upgraded to DS2202.I'm one of those unlucky ones who bought the original DS2202 and my trail period was out and left without bus decoding...I was reading a bit about the upgrade process which all where referring to upgrading ds2072 to ds2202.All i want is to open all options on my DS2202, can you help me with it?Thank you very much.

author: true
author_rank: Frequent Contributor
timestamp: March 24, 2014, 12:47:23 am
content: To respond to the topic: if you buy the options, that's the easiest way.To respond to the body: the same exact mechanism is used as is on a 2072. Read the "sniffing" thread.

author: Aido4ever
author_rank: Contributor
timestamp: March 24, 2014, 08:45:35 am
content: I found a web script that does generate a key just as the linux software does is it legit?I understand that for the non A series there is no need to extract the private key is that correct?I also understand that I have to upgrade to the latest firmware even though it's not a firmware hack jusy a serial key to input is that correct?Can you direct me to the windows keygen? Or a way to extract the keys on the non A series? The manual I found instruct how to do it on the A series.Sorry for the confusion.

author: BravoV
author_rank: Super Contributor
timestamp: March 24, 2014, 09:52:59 am
content: Read it "throughly" ->here.

author: Aido4ever
author_rank: Contributor
timestamp: March 24, 2014, 11:14:04 am
content: Ok, i've successfully opened all the options on my scope.I've upgraded to the FW03 and then entered the serial number.Now, how do i check to see that all options are really opened? and how do i know if my scope now is 300mhz?thanks

author: Aido4ever
author_rank: Contributor
timestamp: March 24, 2014, 11:42:32 am
content: Ok, i found out how to check and everything is great!!!Thank you guys...(Now i feel ripped of since i bought the expensive ds2202 )-:)
What is the function of this resistor? - Page 1
Forum section: electronics / beginners

author: tohtorizorro
author_rank: Contributor
timestamp: November 09, 2023, 04:24:14 pm
content: The classic dj turntable Technics SL1200 mk2 has a popup style lamp. A spring mechanism pushes a micro switch so that the lamp turns on when it bounces up from its hiding place. It has a small incandescent bulb that draws around 50-60mA when connected to the ~20V rail. There is a 1.5k resistor in parallel with the switch so that basically a tiny current flows through the lamp even when it is in the off position. What might be the reason for such implementation? Why not just keep the lamp completely disconnected when off?image of the switch/lamp circuit as well as the whole schematic attached below.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: November 09, 2023, 05:16:31 pm
content: Hi tohtorizorro,...it's to preheat the lamp so it lasts longer.It's a PITA to change them (Next time i'll replace it with a LED).Best regards

author: BrokenYugo
author_rank: Super Contributor
timestamp: November 09, 2023, 05:22:53 pm
content: It may also reduce RFI/click and switch contact wear. Incandescent lamps have a positive temperature coefficient and are nearly a dead short cold, very high inrush, preheating will help that.

author: tohtorizorro
author_rank: Contributor
timestamp: November 09, 2023, 07:47:23 pm
content: Thanks, guys!I'm servicing couple of the mentioned devices and about to replace the lamp with leds and can now carry on and discard the resistor without worries.
What is the functional difference between parallel flash and parallel EEPROM? - Page 1
Forum section: electronics / beginners

author: alank2
author_rank: Super Contributor
timestamp: October 31, 2019, 09:10:54 pm
content: What is the functional difference between parallel flash and parallel EEPROM?

author: langwadt
author_rank: Super Contributor
timestamp: October 31, 2019, 09:54:15 pm
content: usually if you need to change a byte in flash you need to erase a whole sector, in eeprom you can change a single byte

author: jackthomson41
author_rank: Regular Contributor
timestamp: November 01, 2019, 12:51:16 am
content: Flash memory, also known as flash storage, is a type of nonvolatile memory that erases data in units called blocks and rewrites data at the byte level. Normally used for storing code.EEPROM is also a non-volatile memory, data will remain intact even it's powered off. Normally routine data is saved in EEPROM. Btw I am talking aboutMicrocontrollers.

author: MosherIV
author_rank: Super Contributor
timestamp: November 01, 2019, 07:42:53 am
content: Another difference is the memory size of flash and eeprom.Flash will generally be larger than eeprom.Fash is available in Mega Bytes (MB)Eeprom is available in KiloBytes (KB)
what is the ic name for this chip. - Page 1
Forum section: electronics / beginners

author: prodarkness
author_rank: Contributor
timestamp: March 22, 2018, 09:09:14 am
content: i'm having problem finding the identical ic's online can someone help .. appreciate much, thank you.

author: Zero999
author_rank: Super Contributor
timestamp: March 22, 2018, 09:17:43 am
content: It isn't an IC or semiconductor. It's a common mode choke: a passive component.

author: prodarkness
author_rank: Contributor
timestamp: March 22, 2018, 09:26:34 am
content: @hero999 does this common mode choke have values to look out for ? because i am repairing a board but this component does not have a values stated and i believe its spoiled.

author: Zero999
author_rank: Super Contributor
timestamp: March 22, 2018, 11:17:32 am
content: Quote from: prodarkness on March 22, 2018, 09:26:34 amWhat makes you think that?It has two coils on the same core, which should be isolated from one another, like a transformer, except it isn't used in that manner. It should be fairly easy to verify there's no insulation failure or melting of the wire, with a continuity test.A common mode choke is used for EMI filtering, quite often to comply with EMC regulations. It's possible the circuit may work without it, just no longer comply with the relevant regulations and risk causing interference.See links below for more information:https://www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/26to30.ashxhttp://www.we-online.com/web/en/passive_components_custom_magnetics/blog_pbcm/blog_detail_electronics_in_action_61439.phpIf the common mode choke is bad, it's highly likely due to something else in the circuit going wrong. I think it's highly likely the fault lies somewhere else in the circuit.

author: prodarkness
author_rank: Contributor
timestamp: March 23, 2018, 06:30:51 am
content: @hero999 thank you so much will search for other faulty parts in the circuit board
What is the max voltage rating of a typical 1/4W E24 resistor? - Page 1
Forum section: electronics / beginners

author: dog80
author_rank: Regular Contributor
timestamp: December 18, 2013, 01:03:24 pm
content: I want to use a resistor for a very tiny current at mains voltage. The power doesn't exceed 0,25 Watts, but are these mains rated?What is the max voltage rating?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 18, 2013, 01:18:32 pm
content: Take a look at a few datasheets - ISTR around 200V is typical. For mains I'd suggest using 2 or 3 in series to spread it out. Bear in mind you may have transients,

author: Neilm
author_rank: Super Contributor
timestamp: December 18, 2013, 04:58:24 pm
content: Quote from: mikeselectricstuff on December 18, 2013, 01:18:32 pmAlso bear in mind that resistors can (and do) fail short circuit. I would go for 3.

author: qno
author_rank: Frequent Contributor
timestamp: December 18, 2013, 06:21:13 pm
content: There are special Hi voltage resistors.Jus take a look at Farnell or RS and search for resistors with a 500 or 1000V spec.

author: olsenn
author_rank: Frequent Contributor
timestamp: December 18, 2013, 08:05:56 pm
content: You can also get transient voltage supressors if you're worried about transients. A decent quality HV resistor should be perfectly fine for 220V though
what is the maximum voltage for this part - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: January 16, 2019, 01:07:41 am
content: This is a great inexpensive boost chiphttps://datasheet.lcsc.com/szlcsc/1811201211_hengjiaxing-HX3608_C296278.pdfbut im not sure if it will accept up to Vin max for VEn pin. It says the minimum is 3.6v for VEn but it doesn't say maximum for the pin. Typically for swhiching ICs its up to Vin max but Im not sure about this part.

author: amyk
author_rank: Super Contributor
timestamp: January 16, 2019, 01:24:41 am
content: Given the sample application schematic I would certainly hope so.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: January 16, 2019, 02:11:15 am
content: It seems like the package is far too small for the power handling of this device or is it typical of this package?

author: spec
author_rank: Frequent Contributor
timestamp: January 16, 2019, 09:05:44 pm
content: Quote from: LaserTazerPhaser on January 16, 2019, 01:07:41 amHi LaserTazerPhaserPage 3 of the datasheet say Vin is 2 to 20V, but being a boost switcher, Vin can never be more than Vout.

author: Zero999
author_rank: Super Contributor
timestamp: January 17, 2019, 11:59:15 am
content: Quote from: LaserTazerPhaser on January 16, 2019, 01:07:41 amThe application schematic shows EN connected to Vin, which implies En is rated up to the supply voltage.The minimum voltage for EN isn't 3.6V, but the voltage at IC's GND pin.The thresholds for EN are only specified for a 3.6V supply.In reality, EN can probably be slightly higher than VIN and slightly lower than GND without causing any issues: +0.3V above VIN and -0.3V below GND is probably acceptable.
What is the meaning of USB DM? - Page 1
Forum section: electronics / beginners

author: ssashton
author_rank: Frequent Contributor
timestamp: January 11, 2023, 12:14:59 am
content: Simple question but I couldn't find it in google.In USB schematics D+ Data Positive is called DP. Why is D- Data negative called DM and not DN?While I'm asking, can anyone help explain what the other USB OTG connections do? Such as OTG_HS_ULPI_NXT and OTG_HS_ULPI_DIR?Thanks!

author: BillyO
author_rank: Super Contributor
timestamp: January 11, 2023, 12:50:45 am
content: The data pair in USB is differential. It is just normal practice to call the (-) side Data Minus (DM) and the (+) side Data Plus (DP).For OTG see:https://en.wikipedia.org/wiki/USB_On-The-Go

author: tooki
author_rank: Super Contributor
timestamp: January 11, 2023, 07:01:12 pm
content: I have mostly seen it called DN in schematics I’ve seen.

author: Rick Law
author_rank: Super Contributor
timestamp: January 11, 2023, 10:22:44 pm
content: Interesting how minds work:Opposite of Positive is Negative (DN)Opposite of Plus is Minus (DM)DNis probably more natural to those more comfortable with English. Non frequent speaker of English see the + on electricals and in their minds translates it to their native language to whatever means electrically positive. The opposite of "electrically +" in their native language could be rather different than the word "negative" when translated back to English.The + and - is less language dependent and just a math symbol. Personally, I think D+ and D- is probably more suitable for international.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 11, 2023, 10:48:13 pm
content: FWIW:- theUSB 2.0 specuses D+ and D-- theUSB 3.0 specuses Dp1 and Dn1 (and Dp2/Dn2 for the doppelgangers on the USB-C "flippable" connector)So even they couldn't make up their minds. Though the change is understandable; I think "D+1", "D-1" (etc.) would have been asking for confusion.

author: tooki
author_rank: Super Contributor
timestamp: January 12, 2023, 07:50:02 am
content: Quote from: Rick Law on January 11, 2023, 10:22:44 pmAnd it is analogous to the inputs on an op-amp.One problem is that in some PCB layout programs, you can’t use + and - in net names (or not in the differential pair function). For example, in Altium, a differential pair’s nets must be named, for an example pair called “D”, exactly D_P and D_N. Anything else and you break the pair apart. (IIRC, this limitation may have been remedied in a recent update.)

author: ssashton
author_rank: Frequent Contributor
timestamp: January 17, 2023, 11:21:10 pm
content: Thanks for all the replies!
What is the meaning of Vceo, Vcbo and Vebo in Transistor? - Page 1
Forum section: electronics / beginners

author: Walt Peter
author_rank: Newbie
timestamp: March 18, 2016, 12:24:31 pm
content: In transistor, does Vceo means the total voltage of Collector and Emitter? And Vcbo means the total voltage of Collector and Base? And Vebo means the total voltage of Emitter and Base? Thank you.

author: Ian.M
author_rank: Super Contributor
timestamp: March 18, 2016, 12:31:40 pm
content: No. All voltages are measured as voltage differences. The transistor's leads are b,c and e. o means open circuit. Voltages given in the V--o form are usually maximum ratings.Therefore Vceo is the maximum voltage the transistor can withstand on its collector measured relative to its emitter with the base open circuit. It is likely to be less than Vcbo because leakage across the reverse biassed collector base junction provides base current that starts to turn the transistor on. With the emitter open circuit there is no transistor action and the collector base junction acts as a simple diode.

author: Walt Peter
author_rank: Newbie
timestamp: March 18, 2016, 12:40:51 pm
content: How can I calculate the V__o? Thank you.

author: Ian.M
author_rank: Super Contributor
timestamp: March 18, 2016, 12:54:40 pm
content: No such thing. I was using V--o as a generic description of the parameters Vceo, Vcbo and Vebo. None of them are calculable, they have to be looked up in the datasheet.

author: Brumby
author_rank: Unknown
timestamp: March 18, 2016, 02:11:44 pm
content: Quote from: Ian.M on March 18, 2016, 12:31:40 pmLikewise:Vcbo is the maximumVoltage the transistor can withstand on itscollector measured relative to itsbase with the emitteropen circuit.Vbeo is the maximumVoltage the transistor can withstand on itsbase measured relative to itsemitter with the collectoropen circuit.Quote from: Walt Peter on March 18, 2016, 12:40:51 pmAsIan.Mhas said - you don't calculate these. The manufacturer designs and tests the device toprovideyou with the information via datasheets. They GIVE you these numbers (and a whole lot more) for you to use in designing your own circuits.

author: Shock
author_rank: Super Contributor
timestamp: March 19, 2016, 05:47:21 am
content: Read this:http://www.onsemi.com/pub_link/Collateral/AND9129-D.PDF

author: Walt Peter
author_rank: Newbie
timestamp: March 19, 2016, 06:25:43 am
content: How can I know does my circuit exceeded or lower than the "limit"? Thank you very much once again.On my case, I used 9 volts at Base and Collector respectively. Why the transistor S2013 will dead? Thank you.

author: Cicada
author_rank: Regular Contributor
timestamp: May 18, 2022, 10:10:22 am
content: Apologies for bumping this topic up in the queue just to add this file but I thought this might be very relevant to this thread.https://toshiba.semicon-storage.com/info/docget.jsp?did=63509I have also attached the file.Cicada.Edit: I was looking for info on Vcex
What is the most effecient way to practicing PCB-design? - Page 1
Forum section: electronics / beginners

author: siyar
author_rank: Contributor
timestamp: March 18, 2025, 11:08:35 am
content: Hi,I'm new to PCB-design. I know the basics which means that i am able to produce a PCB from schematic to gerber. My last project was a 4-layer stm32 board with a few peripherals + a buck converter.Im looking for an effective strategy to accelerate my skills. Fx an issue i have is that i feel like i waste to much time on assigning footprints. Is there a effecient workflow to do this faster or is there some common footprints i should memorise?Also i was considering mastering one type of circuit at a time. Fx first ill do 10 PCB's for power circuits, then ill focus on high-speed digital circuits etc.Is this a good approach?Any tips will be appreciatied. Thanks in advance.

author: tszaboo
author_rank: Super Contributor
timestamp: March 18, 2025, 01:03:06 pm
content: You learn it by doing it. So make more designs, even if you wouldn't order it.Yes libraries and footprints take time. So build up a library of components that you can use on future projects.

author: PGPG
author_rank: Frequent Contributor
timestamp: March 18, 2025, 02:05:56 pm
content: Quote from: siyar on March 18, 2025, 11:08:35 amI started to use KiCad in 2017 (V4.0.7 was first I have installed). Before designing my first KiCad PCB I made my libraries (initial set of symbols and footprints needed for first PCB).I use only my libraries, and with all symbols having footprint assigned. I have never even tried how footprint assigning in KiCad looks like. I waste time on footprint assigning only when adding new symbol to my library. During PCB design I spend exactly 0 time on footprint assigning.Using only my own libraries have one, not expected by me, 'side effect'. When changing main KiCad version number V4-V5-V6-V7-V8 (I don't use V9 yet - too new, too many bugs) I didn't needed to mix once more my own libraries lists with KiCad libraries lists. Whenever new KiCad version is released I see people asking how to have everything with library in order. As my library lists does't change I just have to show KiCad at first run my lists and done. As I have read recently with V9 they still have not solved this library lists problem.To better know how to design PCBs I suggest to read pdfs I have found about 2002..2004. I have linked them at KiCad forum (hope links are still valid):https://forum.kicad.info/t/decoupling-capacitor-via-placement/25132/14https://forum.kicad.info/t/decoupling-capacitor-via-placement/25132/19
What is the most important IRC channel about electronic issues  ? - Page 1
Forum section: electronics / beginners

author: OpenglMan
author_rank: Newbie
timestamp: May 23, 2014, 12:20:38 am
content: Well , According to the subjet, does anybody know any interesting IRC channel ?I have seen #hackaday in freenode, but with very few people.Regards

author: kc9qvl
author_rank: Regular Contributor
timestamp: May 23, 2014, 12:23:58 am
content: #eevblog gets some actionirc://irc.afternet.org/#eevblog

author: OpenglMan
author_rank: Newbie
timestamp: May 23, 2014, 12:50:10 am
content: thanks kc9qvl,I have used qwebirc.afternet.org to connect to that channel, but I obtain the following message:ERROR: Closing Link: by London.UK.AfterNET.Org (Sorry! Your connection to AfterNET has been rejected because of your internet address's poor reputation. You may try an authenticated login using Login-On-Connect (LOC) instead. Seehttp://afternet.org/rblfor more information.)[02:45] == Disconnected from server: Connection to IRC server lost.What is wrong ?

author: kizzap
author_rank: Unknown
timestamp: May 23, 2014, 01:14:20 am
content: Someone was obviously banned from using that address to access the afternet servers, due to being dodgy.As for *BIG* electronics chat IRC channels, Freenode also has the ##electronics channel, which at this current moment in time is filled with 582 people...

author: OpenglMan
author_rank: Newbie
timestamp: May 23, 2014, 03:05:49 am
content: Thank you very much kizzap, it seems very interesting and useful
What is the Mysterious Device? - Page 1
Forum section: electronics / beginners

author: GDuncan
author_rank: Newbie
timestamp: November 11, 2018, 08:25:11 pm
content: Hi Guys,I bought this thing for the enclosure but thought, before tearing it to bits, it might be worth asking you guys what it actually is.Any ideas?

author: Rx7man
author_rank: Regular Contributor
timestamp: November 12, 2018, 06:35:53 pm
content: something that was very specific and expensive at one time.. I have no idea what exactly it is, but it could be anything from railway or pulp mill controls to who knows what.

author: GDuncan
author_rank: Newbie
timestamp: November 12, 2018, 08:12:28 pm
content: Wow, thanks blueskull for your analysis! Much appreciated!It'll feel somewhat sacrilegious tearing this thing apart, a thing that clearly so many hours of manual labor have gone into. But there's nothing else for it. Kinda like an old beautiful piano that's pointless to repair.
What is the name of manufacturer of inductors and transformers, marked as "SAE"? - Page 1
Forum section: electronics / beginners

author: LinuxHata
author_rank: Frequent Contributor
timestamp: February 23, 2025, 07:29:39 am
content: Hello.Quite often I experience a lot of pulse transformers and inductors in various devices, marked with that logo.These are mostly elder devices, so most likely, brand no longer exists, but it would be nice to know the name anyways.Attaching photo of the logo.

author: inse
author_rank: Super Contributor
timestamp: February 23, 2025, 07:33:12 am
content: Interesting, I thought they were only making motor oil.😆

author: wasedadoc
author_rank: Super Contributor
timestamp: February 23, 2025, 08:37:34 am
content: Quote from: inse on February 23, 2025, 07:33:12 amSAE is not a maker of motor oil. Society of Automotive Engineers, IIRC. You often see SAE rating on oil containers as indicating the oil's specification

author: Smokey
author_rank: Super Contributor
timestamp: February 23, 2025, 08:44:46 am
content: The logo kind of looks like a play on E-Cores.Just a wild guess:https://www.sae.tdk.com/

author: SteveThackery
author_rank: Super Contributor
timestamp: February 23, 2025, 12:01:23 pm
content: Quote from: wasedadoc on February 23, 2025, 08:37:34 amI think it was meant as a little joke.....

author: ME
author_rank: Frequent Contributor
timestamp: February 23, 2025, 12:41:15 pm
content: Self addressed envelope or stamped addressed envelope?

author: LinuxHata
author_rank: Frequent Contributor
timestamp: February 23, 2025, 01:47:21 pm
content: Yes, it is SAE Magnetics, now part of TDK, and sadly, not datasheets/info....