hybridfree/eevblog-posts huggingface dataset:
Expected average value of Vout - Page 1
Forum section: electronics / beginners

author: selotelefon
author_rank: Newbie
timestamp: October 23, 2023, 11:05:18 am
content: How can i calculate 5.b ?

author: Andy Watson
author_rank: Super Contributor
timestamp: October 23, 2023, 01:59:52 pm
content: I guess that you are expected to be able to identify a half-wave rectified signal and therefore know that \$V_{average} = \frac{1}{\pi} \times V_{peak}\$. You are told to use \$V_{in}\$ so \$V_{peak}\$ will be the peak value of \$V_{in}\$. This is provides an approximation of \$V_{ave}\$ and ignores the voltage dropped across D1.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 02:03:43 pm
content: Although the schematic drawing indicates a sine-wave generator, the problem is stated as using a square wave.The calculus is much easier with a square wave.

author: The Electrician
author_rank: Frequent Contributor
timestamp: October 23, 2023, 04:38:20 pm
content: Don't forget the voltage drop due to the diode.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 05:10:58 pm
content: Presumably, the (not shown) previous problem specifies if the square wave is positive-definite, or symmetric about zero volts.

author: MrAl
author_rank: Super Contributor
timestamp: October 23, 2023, 05:15:08 pm
content: Quote from: selotelefon on October 23, 2023, 11:05:18 amHello,A question comes up as to what model you are allowed to use for the diode. If it is an ideal diode (no voltage drop) then you can just use the regular formulas, but if the diode does in fact cause a voltage drop then you have to subtract that.I am assuming that you are at least allowed to use a constant voltage drop for the diode or none at all.Another formula if the diode has no drop is easy to remember if you use a sine wave. Since your meter probably shows volts RMS, for a full wave rectifier you can just multiply Vrms times 0.90, and for half wave (as your circuit) you can multiply by half that, 0.45, and that gives you the average voltage.For a square wave, I imagine you are assuming a square wave centered at zero volts DC. The average is then equal to the peak value.If your square wave is not centered at 0v DC, then you have to average the two peaks after taking the absolute values.A few examples:Square wave with 3v positive peak and -1v negative peak: (3+1)/2=2 Vavg (also see below)Square wave with 4v positive peak and 0v negative peak (no negative peak): (4+0)/2=2 VavgSquare wave with 3v positive peak and +1v negative peak (not really negative here): (3+1)2=2 VavgSquare wave with 5v positive peak and +1v negative peak (not really negative here): (5+1)2=3 VavgThere is another way to take the average though, which is the more usual case. This time you just add the two voltages without taking the absolute value of the two.Example:Square wave with 3v positive peak and -1v negative peak: (3-1)/2=1 Vavg.For your example you are going to end up with just a positive output with no negative part.

author: Benta
author_rank: Super Contributor
timestamp: October 23, 2023, 07:09:49 pm
content: Do your homework yourself.
Experience with 1.2mm FR-4? - Page 1
Forum section: electronics / beginners

author: Matir
author_rank: Contributor
timestamp: June 07, 2017, 10:57:27 pm
content: I'm working on a wearable for a special event (so very small quantity) where we want to keep weight down a bit, so it's been suggested that we use 1.2mm FR-4 instead of 1.6mm. I can't seem to find any information on how this compares with rigidity or durability to 1.6. It's going to have a hole for attachment to a lanyard set ~3mm from the edge, so my biggest concern is that this attachment point could break off. Anyone have experience with 1.2mm FR-4?

author: Buriedcode
author_rank: Super Contributor
timestamp: June 07, 2017, 11:08:03 pm
content: Never used 1.2mm but I have used 0.8mm and its still pretty strong.In terms of durability,I would use a plated through hole for the lanyard, and perhaps copper pour around it to increase rigidity. The hole is of course a weak point, but I wouldn't worry about it. As its something you've 'made' I'm sure people won't expect it to survive being stamped on or ripped off someones neck.Perhaps you could use a lanyard with a breakaway connector on it? Its a safety thing on many lanyards like for children's "medals". In that case it shouldn't have to cope with much strain anyway

author: Matir
author_rank: Contributor
timestamp: June 07, 2017, 11:17:13 pm
content: I probably will use a breakaway lanyard, and did plan to use a plated hole (tied to the ground plane on the back, just because...)Good to know it's still rigid at that thickness.
Experience with Cirrus Class 1 Sound Level Meter for Long-Term Outdoor Noise - Page 1
Forum section: electronics / beginners

author: sara.malik
author_rank: Newbie
timestamp: May 22, 2025, 08:34:49 am
content: Has anyone here used a Class 1 sound level meter for long-term outdoor noise monitoring? I'm researching options that meet environmental standards and came across this one from Cirrushttps://cirrusresearch.com/product/environmental-sound-level-meter/. Wondering if it's reliable for construction site perimeter measurements or if there are better alternatives?

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: June 01, 2025, 01:27:48 pm
content: If you need remote telemetry, solar power integration, etc, take a look at Svantek SV 307A or 01dB DUO.

author: Poroit
author_rank: Frequent Contributor
timestamp: June 02, 2025, 07:15:27 am
content: My former company distributed Cirrus Products 25 years ago.They were a bit rough around the edges mechanically but functioned OK.How are you planning to weatherproof and secure it?https://www.modalshop.com/rental/applications/noise-monitoring/construction-noiseRion was always a front runner.
Experiences with Rigol clearance gear? - Page 1
Forum section: electronics / beginners

author: wilheldp
author_rank: Regular Contributor
timestamp: November 11, 2013, 09:49:45 pm
content: I had my eye on a Rigol DM3068 and DG1022A in the clearance section of the RigolNA website just over a week ago. In fact, I had the DM in my cart and when I went to pull the trigger the next morning, they were all sold. I was hesitant and it cost me the opportunity. While I wait for new clearance stock, I had a few questions.The description on the clearance page says that all the gear is within spec, but may not have current calibration certificates. That's fine by me because I'm not doing any work that requires current cal certs, but it would be pointless to get a 6.5 digit DMM if it wasn't within spec. Has anybody purchased any Rigol clearance gear? If so, was it within spec and what was the physical shape of it? I can deal with minor dents and dings, but would prefer to not have operation issues like stuck buttons, etc.Also, does anybody have experience with turnover/replenishment of clearance stock? Is it a fool's errand to wait for another DM3068 to get listed?

author: derbenni
author_rank: Newbie
timestamp: November 12, 2013, 08:12:12 pm
content: I have actually bought a DS1052E from the Rigol Clearance section just a few days ago (EU one though).Now, I must note that I am in no way an expert in this field as I am just getting started. Therefore, I can unfortunately not really give you any information on how accurate the products are.I can however say that I am very happy with the overall experience. The product I received seemed like a new unit to me and the delivery was also very fast.I hope this at least helps you bit

author: wilheldp
author_rank: Regular Contributor
timestamp: November 12, 2013, 09:19:39 pm
content: Hey, hope it works out for you, and I appreciate the feedback. I'm getting concerned that they infrequently stock the clearance section (I'm thinking after a trade show or large demonstration event). It has been steadily clearing out for the last few days, and I haven't seen any new gear added to the list.
Explain result of circuit-analysis homework. - Page 1
Forum section: electronics / beginners

author: MarkusAnd
author_rank: Contributor
timestamp: October 05, 2020, 06:16:41 pm
content: Hello!Just got done with a circuit-analysis problem. I know I have the right answer. The problem is that I'm not sure if my way of doing the problem is correct. So can someone confirm that I've done it the right way. I would like to understand why things are the way they areSo the problem was to solve I2. I transformed the current-source to a voltage-source(and got that E3 = 4V) and used mesh analysis to calculate Ia.To my understanding, the current IA = I2 - J. I got 1amp for Ia and therefore I2 = 3A.My main question is if Ia really is I2-J?Regards, Markus

author: Ian.M
author_rank: Super Contributor
timestamp: October 05, 2020, 06:25:38 pm
content: Using the Principle of Superposition solves it more easily. Reduce J to zero. R1+R2 is then across a voltage source (E1+E2) so the rest of the circuit can be ignored. Similarly if you reduce E1 and E2 to zero, R1 and R2 become paralleled, and again the rest of the circuit drops out.

author: MarkusAnd
author_rank: Contributor
timestamp: October 05, 2020, 06:28:46 pm
content: Yes I know this isn't the easiest way to do it but the homework was to solve it with mesh analysis

author: Ian.M
author_rank: Super Contributor
timestamp: October 05, 2020, 06:30:20 pm
content: Quote from: MarkusAnd on October 05, 2020, 06:28:46 pmFair enough. However Superposition does make it easy for *YOU* to check your answer.

author: MarkusAnd
author_rank: Contributor
timestamp: October 05, 2020, 06:59:04 pm
content: Yup! got the right answer. But it still doesn't answer if I Ia = I2 - J. I would just like to know how someone who's a bit more experienced would solve I2 with Ia.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 05, 2020, 09:18:38 pm
content: It may help to note that the two voltage sources define a supernode across three nodes. A current source connected to one node of a supernode, can be moved to any other node in that supernode.The proof is like so:- Add an equal current source between the present and target nodes.- That current flows through a voltage source, so it has no effect on the circuit: this is an identity operation.- Now note the present node has two opposing currents into it, which can therefore be separated from it. This new floating node has an undefined voltage (it is two equal current sources in series) and no net current flow.- Combine the equal series current sources into one (this is also an identity operation).I don't think this really helps all that much, as you're still doing superposition, or nodal analysis, or the Norton-Thevenin transformation. You can just do it against R1 instead of R2. I suppose keeping R2's current "pure" (no transformation combining I2 and J) means one less thing you need to keep track of in the final steps.Tim

author: Benta
author_rank: Super Contributor
timestamp: October 05, 2020, 10:09:00 pm
content: Looking at the circuit, I'd prefer using node equations instead of mesh, but that's a question of taste.
Explanation how amplifier works - Page 1
Forum section: electronics / beginners

author: jimon
author_rank: Regular Contributor
timestamp: October 15, 2015, 10:03:55 pm
content: While watching some programming videos I found very nice and charismatic explanation how basic amplifier works by Gerald Jay SussmanJust check this out here :https://youtu.be/arMH5GjBwUQ?t=19m53s(at 19:53)I especially like concept of "wiggle it"

author: retrolefty
author_rank: Super Contributor
timestamp: October 15, 2015, 11:28:58 pm
content: An old grey beard once told me a amp is nothing more then a device that modulates it's power rail(s) based on it's input signal.
Explanation in digital MM specification - Page 1
Forum section: electronics / beginners

author: abdulbadii
author_rank: Frequent Contributor
timestamp: August 07, 2017, 01:55:38 pm
content: If a digital MM gives specification:Power supply rated voltage: 2x 1.5 VBut then in next lines it's also specifying:Regulated power supply range: 2.4 V +/-0.15 Vin its manual, what is this supposed to mean?

author: Avacee
author_rank: Unknown
timestamp: August 07, 2017, 02:26:22 pm
content: What's the make and model? ... Got a link to a technical spec page or the manual?
Explanation needed for this electric scheme - Page 1
Forum section: electronics / beginners

author: aminfaka
author_rank: Newbie
timestamp: June 20, 2023, 03:08:13 pm
content: I dont really get the use of the components in this scheme, especially the adjustable resistor, the diac and the triac. Could anyone explain it to me? I've got an exam tomorrow so it's quite important. (see attachments)

author: wasedadoc
author_rank: Super Contributor
timestamp: June 20, 2023, 03:17:48 pm
content: If you understand the individual components then you should be able to work out for yourself waht the whole circuit is about.If you don't understand the components you don't merit an exam pass. You still have time to do your own bookwork or internet search and not rely on others to pull you out of a hole.

author: aminfaka
author_rank: Newbie
timestamp: June 20, 2023, 03:19:18 pm
content: Why did i even bother asking the internet, fucking hell

author: Benta
author_rank: Super Contributor
timestamp: June 20, 2023, 06:58:23 pm
content: It's a dimmer. Search for "triac phase angle control".And don't come back. Cursing people who help is bad strategy.
Explanation of hardware level bitstream process for FPGAs - Page 1
Forum section: electronics / beginners

author: eevguy2
author_rank: Newbie
timestamp: September 29, 2015, 02:09:17 pm
content: HI,I am looking for an explanation for what happens between the time the bitstream is loaded into an FPGA and the FPGA being ready to go.I know the bitstream is proprietary, but I am looking for a hardware level explanation. (Like the book "Code")I don't see how its possible to reconfigure physical logic gates.

author: DJohn
author_rank: Regular Contributor
timestamp: September 29, 2015, 03:21:19 pm
content: The simple version:Let's say you have a very simple FPGA with each cell containing a single 2-input gate, and an optional latch. The inputs can be driven by the outputs of any of the neighbouring cells, or by lines that stretch across the whole FPGA.The way you do this is to have multiplexers on each of the gate's inputs, selecting one out of all of the available sources for each input. The address inputs for these multiplexers are driven by registers that are loaded by the bitstream.Every cell contains a latch. The clock input is driven by another multiplexer (selecting either the global clock or a constant '0'). The output of the cell is another multiplexer, choosing either the output of the gate or the output of the latch. That makes the latch optional. All of these multiplexers are driven by more registers loaded from the bitstream.The gate itself is just a small 4x1 memory. Feed the inputs to the address lines, and load the truth table for whatever function you like into it.Real FPGAs have more inputs (which means a larger truth table) and a lot more optional features in their cells. But that's basically it. It's all multiplexers and small memories.

author: eevguy2
author_rank: Newbie
timestamp: September 29, 2015, 04:23:58 pm
content: Is there a way eevblog owner can make a video on this topic? I need to see it to get it.

author: SaabFAN
author_rank: Frequent Contributor
timestamp: September 29, 2015, 09:07:31 pm
content: I think, Dave has already made a vid.If I remember correctly, the video-number is in the 400-region - Just search for EEVBLOG FPGA on Youtube and you'll probably find it.

author: amyk
author_rank: Super Contributor
timestamp: September 30, 2015, 12:11:25 am
content: If you're curious about what the bitstream looks like:http://www.clifford.at/icestorm/The FPGA configuration process essentially involves a very long SIPO shift register whose outputs determine what each of the "tiles" do and how they connect.
Explanation schéma Delta Sigma Module - Page 1
Forum section: electronics / beginners

author: alex934
author_rank: Contributor
timestamp: August 04, 2016, 06:47:45 pm
content: Hi everyone, I'm using a capsense Delta Sigma Modulator but I don't fully understand how it works.The purpose is to measure a capacitance Cs. The datasheet gives (cf attachment)Firstly we assume that the capacitor is equivalent to a resistor. After that we got Iav = dmod*I If I understand dmod is just a value between 0 to 1 to modulate Iav.But how by substituting Ic = Iav we have dmod = Cs fs (vref/Idac)For me we have Ic = CsfsVCmodSo If we replace Ic = Iav we have CsfsVCmod=dmod*I do dmod=CsfsVCmod/IThank you very much
Exploring electronics - Page 1
Forum section: electronics / beginners

author: amrat.ch@gmail.com
author_rank: Newbie
timestamp: September 28, 2022, 12:11:06 pm
content: Hi There,I am retired n had set up electronics lab. My aim id to just explore various Electronics Electrical Magnetics. Currently I had explore magnetism and any waveform related.But sometime I am lost dont know what exciting to explore, so anyone can suggest idea to explore ?ThanksAmrat

author: MrAl
author_rank: Super Contributor
timestamp: September 28, 2022, 01:20:53 pm
content: Quote from: amrat.ch@gmail.com on September 28, 2022, 12:11:06 pmHow much math have you had?
export to pcb altium - Page 1
Forum section: electronics / beginners

author: alamwte
author_rank: Regular Contributor
timestamp: May 08, 2021, 07:51:49 am
content: Hi,I have a file that it will open in gerbv software. I want change it to PCBI don't know how to build its drill file?Would you help me?

author: DTJ
author_rank: Super Contributor
timestamp: May 08, 2021, 08:31:51 am
content: Try asking in the Altium subforum.
Exporting data from Siglent SVA1032X - Page 1
Forum section: electronics / beginners

author: EBSDallas
author_rank: Newbie
timestamp: June 23, 2021, 08:10:23 pm
content: I've just taken delivery of a Siglent SVA1032X VNA. Can anyone tell me if it's possible to export measurement data for use by other software programs. I've been through the manual and haven't been able to find anything on it. It's entirely possible I just missed it as this is my first "real" VNA and I'm still getting used to it.Thanks.Everett

author: RoV
author_rank: Regular Contributor
timestamp: June 23, 2021, 10:07:38 pm
content: Yes, you can export with save, after inserting an USB stick.Default format is a .png dump of the screen, but you can select different formats with "File" key. Most useful is csv.For VNAs, touchstone format would be useful (.s1p, .s2p), but it's missing by now and you have to use csv

author: EBSDallas
author_rank: Newbie
timestamp: June 24, 2021, 03:39:28 am
content: RoV:Thanks so much!I completely missed it and it was right in front of me.EBS

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2021, 01:00:18 pm
content: Quote from: EBSDallas on June 24, 2021, 03:39:28 amYou can also bypass using a USB stick altogether with use of the SVA's webserver however you need select the filetype needed rather than the default PNG.You can do this from within the webserver UI (System>File) or from the instrument front panel (File).Setting the SVA/SSA Plus for webserver duties is very simple using System>Interface>LAN and let DCHP find a IP and use Apply to save it. Enter that IP into a PC browser for connection and control of SVA/SSA Plus.
Exposed copper on PCB edge? - Page 1
Forum section: electronics / beginners

author: Pack34
author_rank: Frequent Contributor
timestamp: February 07, 2017, 06:51:38 pm
content: I've seen this on some designs where there's an exposed copper guard ring along the board edge. I understand that guard rings can be used to reduce EMI, but would there be a reason for it to be exposed other than aesthetics?Example:http://www.baslerweb.com/en/products/cameras/area-scan-cameras/dart

author: suicidaleggroll
author_rank: Super Contributor
timestamp: February 07, 2017, 06:59:13 pm
content: A metal enclosure can make contact with an exposed ground like that and turn the entire box into an EMI shield.

author: Neilm
author_rank: Super Contributor
timestamp: February 07, 2017, 07:41:13 pm
content: 100% contatact to the box along the edge will offer better EMI than a box connected in just a few places. The rest of the gap appears as a slot antenna to EMI.Guard rings are also used to prevent current leakage across the suface of a PCB into sensitive electronics. (You find out how useful this is quickly if you are measuring a 10Gresistor at 9V)
EXT Trigger Rigol 1202Z-E - Page 1
Forum section: electronics / beginners

author: Matei
author_rank: Newbie
timestamp: March 10, 2023, 06:56:36 pm
content: Dear all,I am at my first post here and also at my first experiences using an oscilloscope.I finally pulled the trigger on a Rigol 1202Z-E scope (2 Channels, 200MHz) and quickly learned the hard way why people recommend the 4 channel versions.Unfortunately there was not enough budget available for the extra two channels.I am trying to measure two different signals in a circuit that are triggered by a clock. And it seems that this would be easily achieved by putting the clock on the EXT Trigger input of the scope and looking at the two signals on CH1 and CH2.I bought a third probe for the scope to connect the clock to the EXT. trigger input. It is also a PVP 2350 x1 and x10 probe just like the ones supplied with the scope.When tested, the probe displays the internal 1kHz calibration square wave correctly both on CH1 and on CH2. Both at x1 and at x10 attenuation.The 1 kHz square wave is 0 +3V.When moved to the EXT Trigger input it seems to have some troubles triggering:- At x1 Attenuation triggering starts at -0.53V and stops at 2.36V- At x10 Attenuation triggering starts at -0.54V and stops at -0.260VThis indeed corresponds to the 3V and 0.3V Pk Pk difference but I would somehow expected for both triggering to start at 0V and extend to 3V and 0.3V respectively.After noticing this and reading a bit more about this particular scope model in this posthttps://www.eevblog.com/forum/testgear/rigol-ds1202z-e-external-trigger-input-defective-or-general-problem/I performed a hardware reset. This did not fixed the problem.I watched a couple of videos on EEV blog about BNC 50 ohm terminations, transmission lines and so on, and assumed it might have something to do with some reflections in the cable.So I bought a 50 ohm passthroughhttps://www.amazon.de/dp/B07R7LJS67?psc=1&ref=ppx_yo2ov_dt_b_product_details.This also did not fix the problem.As mentioned at the beginning, I am a beginner with the oscilloscope measurements, and at the moment, I have no idea if I am doing something wrong, or if the device is either working as intended or is defective. Something smells fishy and I don't know where to start searching for information.Any help is highly appreciated.Kind regards,Matei
Extech 382-210 30V, 3A Regulated Digital Power Supply - Page 1
Forum section: electronics / beginners

author: obrien
author_rank: Contributor
timestamp: January 03, 2017, 04:50:09 am
content: Hi y'all,I am on the market for a basic power supply and I have a chance to get used but fully operational Extech 382-210 30V, 3A for about $40. Do you know if it's any good? I read the spec which meets all my needs but I did get burn with cheap tools before so I figured I better asked.I do not really know the marked and brands so well, I have a multimeter from Extech which seems fine but I have no clue how good power supply they make.Thanks for advice and if you have a tip for better tool I am happy to listen.
Extech EX430 DMM - Page 1
Forum section: electronics / beginners

author: NH-GrizzlyBear
author_rank: Contributor
timestamp: November 12, 2015, 01:47:29 am
content: What is the reason behind 'slow' auto-ranging? Can this device be hacked to speed it up?

author: Lightages
author_rank: Unknown
timestamp: November 12, 2015, 02:11:07 am
content: It is an old design with slow auto ranging. I don't think you can do anything to speed it up.

author: NH-GrizzlyBear
author_rank: Contributor
timestamp: November 12, 2015, 02:27:40 am
content: Quote from: NH-GrizzlyBear on November 12, 2015, 01:47:29 am...but why is slow? What technology drives the speed?

author: Lightages
author_rank: Unknown
timestamp: November 12, 2015, 02:32:45 am
content: The main chip inside and the clock speed set the auto ranging speed. There is nothing you can do to change the main chip.
Extech EX430 uA Current Measurement Problem - Page 1
Forum section: electronics / beginners

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: April 25, 2011, 03:41:16 am
content: Hi Everyone,Recently, I got myself an Extech EX430.After using for a month, I ran into some problem today when using it to measure uA current.I was measuring for few hours and it was fine showing some current like 22 uA. Then suddenly it only shows OL.I opened up the meter and checked the fuse, both are okay.I look for any possible burn components, but couldn't find any really.I thought of getting some opinions before sending them for warranty.Thank you.

author: gobblegobble
author_rank: Regular Contributor
timestamp: April 25, 2011, 04:48:19 am
content: This might sound a stupid question, but did you try mA range? Microamps range shows OL when your current exceeds 4mA so if the current is really above the scale for microamps you should get a sensible reading on milliamp range.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: April 25, 2011, 05:04:36 am
content: I was measuring very low power application which I already managed to push it down to ~22uA.Weird is, I didn't make any changes to the measured device that it suddenly when OL.Let me double check again.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 25, 2011, 05:43:42 am
content: whats with the "modern names" nowadays?! hardly can be pronounced
Extend logic board connection on DCDC converter - Page 1
Forum section: electronics / beginners

author: PeterFW
author_rank: Frequent Contributor
timestamp: April 10, 2016, 11:34:35 am
content: Hello!For a bit i have been working on some electric doohickey and the time will soon come were it has to be put in a neat box.I am using a Chinese DCDC converter, it seems to be manufactured by Minghe, sold as Dps-3806.The MingHe B3603 has been discussed at great lengh here on the forum and both converters (mine and the B3603) seem to use the same logic board.I have been thinking of extending the connection by 5 to 10cm so i can mount the logic board on the frontpanel and leave the rest tucked inside the enclosure.All the analog signals that are responsible for the accuracy run through the connectors, now i am thinking, will it be a problem if i add a few cm of wire in between?My plan is to simply etch two adapter boards and use a boxed headers, plugs and cable to extend it.Greetings,Peter

author: Alex Trofimov
author_rank: Contributor
timestamp: April 12, 2016, 11:18:47 am
content: Hi!I see a few possible issues with making a cable longer.1. Noise pick up. You should investigate how much are the signals succeptible to noise.2. Signal reflections. Shouldn't really be the case for a PSU (I guess it works under 1MHz) and 5 to 10 cm cable.3. Signal delay. For this length it is about under 1ns. Shouldn't be an issue, but it worth considering.If you plan to use the device by youself, and safety won't be compromised if it fails a bit, then burger all this, just test it and if it works, then Bob's your uncle. :-)

author: cowana
author_rank: Frequent Contributor
timestamp: April 12, 2016, 12:00:28 pm
content: Depending exactly which of the lines you're extending, the added inductance could cause issues if it's a high frequency signal.
Extended Systems Bridgeport ESI-2679 - Page 1
Forum section: electronics / beginners

author: carcanhol
author_rank: Regular Contributor
timestamp: March 07, 2015, 12:14:36 am
content: Hi, i wonder what is this thing i have and what it does.I need a box for a stepper motor controller but before i dismantle this thing, someone could tell me if this is worth something or its just trash.Thanks.

author: JoeAtl30319
author_rank: Contributor
timestamp: March 07, 2015, 12:34:59 am
content: "The ESI-2679B is basically an externally powered smart port. Itconnects to a PostScript printer via either a parallel or a serialconnection (with Macs, a serial connection is recommended), andrecieves data through its serial, parallel and AppleTalk ports." Sounds worthless in today's world.

author: carcanhol
author_rank: Regular Contributor
timestamp: March 07, 2015, 12:43:54 am
content: ok, thanks for the info, it is a really nice case for my controller.If anyone would be interested in the board as it has z80 cpu's i could trade it for anything. thanks.
Extender card design - Page 1
Forum section: electronics / beginners

author: johndon2000
author_rank: Contributor
timestamp: June 19, 2013, 09:17:35 am
content: I need a number of extender cards for tesing & repairing telecomms system cards... they can't be bought "off the shelf" and I think it would cost about $500/£500 to have someone design one for me... is it quite straight forward to design your own extender card?? (surely it's just case of designing a PCB with connectors on each end?!). Many thanks...

author: Kremmen
author_rank: Super Contributor
timestamp: June 19, 2013, 09:27:31 am
content: Provided you know the connector types yes, creating a design for an extender is straightforward. Whether it will work as intended depends. If there are high speed signals traversing the extension then you could get issues from signal propagation delays and trace inductances/capacitances. Real high speed signals see the tracing as transmission lines that need to be correctly terminated and the trace line impedance is also supposed to be close to the original. Meaning you need to pay attention to the PCB material, thickness, trace widths and spacing. Formulas for calculation can be found in inet.

author: daedalus
author_rank: Regular Contributor
timestamp: June 19, 2013, 01:16:47 pm
content: if you post a photo of one of the daughter boards connectors, ideally showing the tracing up to the connector we can probably advise how much of a pain its likely to be.

author: johndon2000
author_rank: Contributor
timestamp: June 19, 2013, 01:34:59 pm
content: Hi, I've attempted to attach a pic but it won't let me!!If you google "NT9X35BA" it brings up a pic...Thanks

author: dfmischler
author_rank: Frequent Contributor
timestamp: June 19, 2013, 02:07:03 pm
content: Isthisthe extender card you need? Or maybethis one? This was from a quick search for "nortel extender card" on ebay. There are more choices.

author: daedalus
author_rank: Regular Contributor
timestamp: June 19, 2013, 02:15:19 pm
content: Hi, I just came across one of your earlier posts about this card when googling. Are you refurbishing these cards commercially, or do you just have a couple of dead boards and want to get the system up and running? From your previous thread it sounded like the latter. These guys have 7 of the same module on ebay for $80 each, which have been tested as good and come with warranty.http://www.ebay.com/itm/Nortel-NT9X35BA-DMS-100-EN-NET-X-PT-CARD-/300575313492At that price you would need to have quite a few broken modules to be worth the time/effort reverse engineering a schematic for something this complex.The connectors may well be proprietary (cant see from picture), if so that means scrapping a backplane and a module to make your extender. Even with your breakout, you will need some serious kit to sniff the traffic across the bus, and some serious time investment to decode what is happening. This really isn't worth it for a $80 swap-out.
Extending a short pulse - Page 1
Forum section: electronics / beginners

author: elki
author_rank: Regular Contributor
timestamp: January 05, 2024, 10:24:59 pm
content: Does anyone know the best way to extend a very short positive pulse, of let's say 10 ns to something like 1 us, coming out of a comparator? Thanks!

author: elki
author_rank: Regular Contributor
timestamp: January 05, 2024, 10:42:29 pm
content: I was thinking one could do it with Schmitt inverters (please see below attached), but had limited luck with it.

author: TerminalJack505
author_rank: Super Contributor
timestamp: January 06, 2024, 02:39:15 am
content: Extending pulses is the sort of thing that a one-shot multivibrator is made for. The 74HC123 and the 555 timer can do that.

author: MarkT
author_rank: Frequent Contributor
timestamp: January 06, 2024, 01:56:29 pm
content: Quote from: TerminalJack505 on January 06, 2024, 02:39:15 am10ns is short for a 555 - even a CMOS 555 such as the 7555, go with the 74HC part if the voltage allows (upto 6V)

author: elki
author_rank: Regular Contributor
timestamp: January 06, 2024, 07:05:26 pm
content: Yes, I managed to make it work with 74HC123 - a powerful IC!
Extending camera cable for mobile application - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 30, 2017, 06:17:38 am
content: 1. Have to extend mobile camera by around 15cm to outer custom body.Attached is camera pic & its mating connector pic on PCB where camera needs to be connected.2. Is there any off the shelf 15cm long camera cable extender available? or custom parts available to make so like connectors separately & wire separately which can be then connected or soldered?

author: Mjolinor
author_rank: Frequent Contributor
timestamp: October 30, 2017, 10:34:28 am
content: There is a high probability of it not working with an extension cable of that length. The capacitance of the cable is probably more than the driver circuitry can handle.

author: RoadRunner
author_rank: Frequent Contributor
timestamp: October 30, 2017, 11:11:46 am
content: extending a high speed bus without taking drivers into consideration going to cause issue.you can have external USB camera which plug into phone's OTG port.if you still want to try , you can get your own flex made and mount appropriate connector onto it .

author: Raj
author_rank: Frequent Contributor
timestamp: October 30, 2017, 02:41:48 pm
content: Will buying a snake camera, be a solution for you?
Extending phone camera's flat flex cable - Page 1
Forum section: electronics / beginners

author: plutoni5
author_rank: Newbie
timestamp: February 20, 2017, 11:34:48 am
content: Hi. I want to move the camera module from my phone (Nexus 5) to the outside of the case and have it like ~10cm on the wire. Now I think this lenghts shouldn't drop the voltage to the point it doesnt work or something, but the main thing is getting flat flex cable extender that would fit good. How do I get the model or the socket information for that phone? Where do i look to buy flat flex cables? Or maybe I should solder some thin wires? But that would be a problem since Im not so good with soldering and its very miniscule. Thanks

author: testian
author_rank: Regular Contributor
timestamp: February 28, 2017, 10:47:15 pm
content: I guess the only thing you can do is opening you phone and take measurements/pictures of the cable/connector.If you just want an external, flexible camera. There are android OTG endoscope cameras you could use.

author: senso
author_rank: Frequent Contributor
timestamp: February 28, 2017, 10:49:06 pm
content: Its a custom made flex with a connector in the end, you wont get extensions for that off the shelf, and 10cm is enough to degrade the MIPI signals..
Extension Board Design - Page 1
Forum section: electronics / beginners

author: Kegsworth
author_rank: Newbie
timestamp: May 15, 2023, 03:25:11 pm
content: Hi all,Newbie here, found you guys through a google search. I have a question for a project I am working on and am hoping you guys can help me out.A little about me, I am currently a Mechanical Design Engineer that has recently moved into a hybrid Elec/Mech role. I accepted the role because it is about 10% Elec and 90% Mech and I graduated in 2020 with an BSEET with a focus in Mechatronics. However, I immediately took Mech roles due to job scarcity (Covid) so my Elec has gotten weak over time and I've forgotten a lot of basic design principles. Luckily, the Elec portion so far has just been creating wiring diagrams for existing components and vetting new technology for our systems.Anyway, I recently had a project dropped into my lap where I need to design a simple PCB for a controller of ours. The controller has too many wires running to our terminal block so I need to create an extension board so we can distribute them more evenly... there are several terminals that have 6+ wires assigned and it is making it difficult for Techs to install and troubleshoot the system.My question is (and bear with me), can I just design a board with two terminal blocks, one heading back to the main board, and one for new components to attach to? I feel like the design is too basic, like I'm missing a few components... I would think I needed some resistors but I'm not sure, again, I have forgotten a lot.Thanks in advance!

author: barshatriplee
author_rank: Regular Contributor
timestamp: May 15, 2023, 05:33:11 pm
content: Would you share some more details? Such as the schematic, purpose of the PCB etc. I think it will be easier for the people of this forum to answer if you do.

author: Kegsworth
author_rank: Newbie
timestamp: May 15, 2023, 06:05:15 pm
content: Quote from: barshatriplee on May 15, 2023, 05:33:11 pmOf course! Makes sense. I will add them shortly.

author: Kegsworth
author_rank: Newbie
timestamp: May 22, 2023, 11:50:00 pm
content: So looking at the pictures, I have too many connections to terminals 1, 4, and 7 on the main control unit. I would like to create an extension board that will allow me to spread the connections out but meet at the same point.Thoughts?
External DC voltage when supply is off? - Page 1
Forum section: electronics / beginners

author: JDtOSU
author_rank: Newbie
timestamp: April 27, 2020, 04:58:07 am
content: I have a lithium polymer battery charging setup that has the charger in a box with 2 dc power supplies wired in series to create 24V. The power supplies are Meanwell LRS-12-350. Currently there is an ac socket that I connect to power up the supplies.In the future, I would like to have the option to connect the charger to an external DC source (either my Prius at 14.5V, a solar setup at 24V, or simply an external battery) for charging in locations without AC power.I am trying to understand if I am able to apply DC voltage to the output of the internal DC power supplies when they are powered off such that I can use a simple external connection wired in parallel to my internal supply. I do not need to have redundant or parallel operation, just either/or.One solution I have found is to use a diode on the output on the power supply. A diode is not required on the external side as that will simply be disconnected when the internal supplies are used.Is this diode necessary or are there other options? I do not prefer to use a switch as the currents could reach 50A on the external supply, although the current internal supplies are more like 30A.

author: Manul
author_rank: Super Contributor
timestamp: April 27, 2020, 02:09:54 pm
content: Most likely it will be ok for a flyback converter like this. For testing you may try to apply voltage with current limiting. Use a lab power supply, set current limit to lets say 50mA and slowly rise voltage. Or use resistors, like 1K, 470 ohms in series to limit current. Observe how voltage rises on power supply output and how much current it draws. If it easily rises to nominal voltage and current draw is small (like 0-10mA), then it will be another confirmation, that it is probably ok. If voltage is not rising and starts to draw noticable current, stop.
External EMI filter for MIG welder? - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: December 19, 2016, 04:51:40 pm
content: I have a MIG inverter welder, and when it is in use, the fluorescent tube lights will flicker and one of the computer UPS goes rapidly into and out of overvoltage protection, making its relays chatter.I suppose this is due to insufficient EMI filtering on the welder. So far I haven't noticed any other problem, but I don't feel comfortable with all that noise on my wiring.Is there some type of external EMI filter that I could use on the welder? Like something that goes between the wall socket and the welder power cord?

author: SeanB
author_rank: Super Contributor
timestamp: December 19, 2016, 06:11:22 pm
content: More likely the supply is on the same outlet, and this has poor connections. Use the welder on a different circuit, and if this does not cause interference then you need to check the circuit the lights and UPS is plugged into. There likely is a poor socket ( very likely with the Attic socket system, it easily loses tension in the sockets from age, use and overloads) on the supply, or the supply itself has high impedance connections there. As you do live in a complex it likely is they skimped on cable size, and it might be poorly sized to run the 16A load of the MIG welder or the connections to the breakers might be loose or arcing. time to call an electrician to inspect the system, and verify it is still compliant with regulations.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 19, 2016, 06:19:14 pm
content: Arc welding is notorious for poor EMI. If you choose EMI filtering, take into account that they often stretch the limit of the fuses up to the limits, so even if meant to be used on a 16 A fuse, they might well use up to 20 or 25 A, because the fused will tolerate it for 1 minute or so. So prefer filters made for 20-25 A or so. For the same reason make sure the outlet is connected with good size wiring (e.g. 2.5 mm², not 1,5 mm²).Sometimes with a longer distance to the distribution transformer, the grid voltage might just drop to much because resistance is to high. Here a filter can not help as the problem is at 50Hz not in the kHz range.
External Power Supply for USB3 devices - Page 1
Forum section: electronics / beginners

author: Heisen
author_rank: Contributor
timestamp: August 15, 2023, 02:21:01 pm
content: Hi everyone,I want to supply external power to four USB3 ports, I just want to know is this board design okay? Since tracks are very short do this need control impedance stuff of differential pairs?There are four male type A and four female type A connectors and a DC barrel Jack.Its a four layer PCB with TopLayer and BottonLayer as signal and the middle two are solid GND plains.Will this support USB3, USB3.1 and USB3.2 speeds?Thanks.
External Power Supply Load Instability - Page 1
Forum section: electronics / beginners

author: wardenclyffe
author_rank: Contributor
timestamp: April 10, 2013, 06:03:06 pm
content: Hey guys, I was running some tests for work on a power supply the other day and I noticed the input power started fluctuating a lot at certain loading conditions. From about 15-30% load the input power would swing by as much as 5 watts, but it was almost perfectly flat at loading conditions above and below that range. Anyone have any idea why that might be happening?

author: CarlG
author_rank: Regular Contributor
timestamp: April 10, 2013, 07:39:11 pm
content: What type of load do you use? Constant P, constant R, constant I? Is the output voltage fluctuating as well?

author: SeanB
author_rank: Super Contributor
timestamp: April 10, 2013, 08:01:20 pm
content: Tap changing points will show that as the supply changes the dissipation in the pass element with the varying output voltage. As the output gets to the set point the power supply will change to a different tapping on the transformer, and this increases the power the pass device has to dissipate by a large amount.

author: wardenclyffe
author_rank: Contributor
timestamp: April 10, 2013, 08:40:00 pm
content: I am using an electronic DC load with a constant power setting.

author: CarlG
author_rank: Regular Contributor
timestamp: April 11, 2013, 07:36:13 am
content: Constant power is seen as a negative resistive load by the supply, and may cause instabilities in a SMPS, which I (for some reason) just assume you have.
External power switch - What am I doing wrong ?  - Page 1
Forum section: electronics / beginners

author: usahin
author_rank: Newbie
timestamp: October 07, 2019, 09:13:41 am
content: Hello,I am trying to add a controlled external power supply to a battery powered device. You can see the schematic in the attachment.When i turn on the EXT_IN power, Q1 automagically turns on and Q3 latches the gate of Q1, I removed the C2 cap and D1, changed the value of R1,R2 and R7 couldn't find any solution.In my opinion, during power up R1 should keep Q1 closed. After first power on / power off sequence every thing works fine. Should I use a fet with smaller gate charge instead of Q1? What am I doing wrong ?Thanks in advance for your replies.

author: Zero999
author_rank: Super Contributor
timestamp: October 07, 2019, 12:57:05 pm
content: Perhaps the drain to source capacitance of Q1 is causing Q3 to turn on, when the power is applied. Try a 1nF capacitor between Q3's base and emitter.
Extra diodes in Boost Circuit  - Page 1
Forum section: electronics / beginners

author: yashrk
author_rank: Frequent Contributor
timestamp: January 31, 2023, 08:20:40 am
content: Hey all,I was looking at this eInk display module fromWaveshareThey are using a boost converter on the module shown below1. I'm not sure what two diodes D1 & D2 after capacitor are doing.2. I am guessing 3Ohm resistor in series with the mosfet is to limit the current, is that correct and why is it needed?Link to moduleLink to datasheet (Refer page no:8 )Thanx in advance!Edit: Also, how to add an image inline?

author: Ian.M
author_rank: Super Contributor
timestamp: January 31, 2023, 09:29:22 am
content: It makes a *lot* more sense if you don't chop off half the circuit!The diodes and capacitor form a charge pump to generate a negative rail 'PREVGL' which will be slightly less voltage than the positive rail 'PREVH' as its got an extra diode drop, and the charge pump has significant output impedance.The 3 ohm resistor is to sense the current through the MOSFET. The voltage across the current sense resistor is node 'RESE' which goes to the CoG or CoF Eink driver's switching controller as current feedback.I've drawn in the connections implied by matching netlabels to help you understand it.P.S. In-lining attached images is the bane of this forum - it *CAN* be done by going back and editing the page's BBCODE after posting the attachment (so its URL is known and stable), but is generally undesirable except in complex posts with many images you are commenting on individually, as many of our users don't have 1st world 'unlimited' bandwidth, and resent the increased page load times, and having to pay for images they didn't need to study closely.For %DEITY%'s sake, *PLEASE* *DON'T* go there, unless you are willing to use a photo editor *EVERY* *TIME* to shrink your images to web-friendly resolutions and sizes.

author: MathWizard
author_rank: Super Contributor
timestamp: January 31, 2023, 10:10:17 am
content: Charge pumps, I've heard of them but never studied them or made 1. I bet I've seen them in digital circuits I worked on, with SMD parts. Trying to figure out unknown SMD circuits, with sot-23 parts, I can see I'd miss a charge pump, and think it was some dual protection diode, or dual zener, or BJT.

author: MrAl
author_rank: Super Contributor
timestamp: January 31, 2023, 12:42:32 pm
content: Quote from: yashrk on January 31, 2023, 08:20:40 amHi,3 Ohm wow, that is kinda high for this kind of application, unless the output current is not very high.This can sense current and also limit current to about 1 amp or so. If the mosfet blows short, the max input current would be about 1 amp or so.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 31, 2023, 12:47:32 pm
content: Quote from: MrAl on January 31, 2023, 12:42:32 pmIt is an e-ink display so, yes, low current.

author: yashrk
author_rank: Frequent Contributor
timestamp: February 01, 2023, 08:44:21 am
content: Quote from: Ian.M on January 31, 2023, 09:29:22 amThanx Ian, as always you were very helpful. As it was negative charge pump I didn't noticed it until you pointed it out.