hybridfree/eevblog-posts huggingface dataset:
How Do I Solder This - Page 1
Forum section: electronics / beginners

author: cortes
author_rank: Contributor
timestamp: September 03, 2022, 08:16:23 pm
content: My first project was on a breadboard. This is my second one. The board shown below is part of a kit to mount an ATOM lite. Other than the ones next to the pins at the top, none of the through holes are connected. I want to wire ground and one of the GPIO pins to the connector. Do I solder the orange connector to the board and then solder wires on to same pins? It seems like a logical way to do it. I'm asking in case there's a best practice to do these types of connections.

author: ataradov
author_rank: Super Contributor
timestamp: September 03, 2022, 08:36:45 pm
content: Yes, this is a typical way of doing it. Solder all the connectors first, so they are mechanically held in place, then use wires to make electrical connections.

author: jpanhalt
author_rank: Super Contributor
timestamp: September 03, 2022, 09:15:20 pm
content: Typical pin per hole. Stuff two wires (e.g., 24 awg or thinner) in a single hole.EDIT: Actually, with 0.1" pitch, 1206 and 1210 SDM's fit perfectly.
How do I suppress EMI from fan? - Page 1
Forum section: electronics / beginners

author: The Magic Rabbit
author_rank: Regular Contributor
timestamp: October 06, 2015, 04:22:34 pm
content: I've got a PIC at 48MHz processing data and using the PWM module to drive two fans via individual IRL520 FETs. The PWM module is running around 44kHz, with duty cycles between 20% and 100% I have a signal diode across the fan to protect the FET.When the duty cycle is below 100% the data on the I2C lines seems sporadic, so I'm convinced there must be some noise from the fan switching leaking back into the system.I have 0.33uF caps between Vcc and Gnd on the PIC, and also between +5V and Gnd on the I2C lines that feed the LCD and sensors. I have 470uF cap on the 12V input and also between 5V and Gnd after the 5V regulator.I'm sure I need to do something across the fans or around the FET to block electrical noise from the fans, but I don't know what. Sadly I don't have access to a scope to look at the signals.Can anyone advise?Sent from my XT1039 using Tapatalk

author: marshallh
author_rank: Unknown
timestamp: October 06, 2015, 04:32:50 pm
content: Sounds like something similar I had where a buck regulator was creating noise upstream. The solution was to put a 100uh coil in series with the supply of the smps (in your case, the motor that gets PWMd) as well as a diode to suppress back-emf.

author: tggzzz
author_rank: Super Contributor
timestamp: October 06, 2015, 05:04:40 pm
content: You will need to understand where the currents flow, and that cannot be done by looking at the schematic: you have to look at the actual construction.Remember there is no such thing as a wire, but there are long thin inductors and resistors which cause voltage drops when current flows through them. (Rule of thumb: 1nH/mm, and realise V = L di/dt and V = I R)Maybe threading the leads multiple times through a ferrite toroid might help - but it depends on the construction.
How do I tell if farnell stock is UK or USA based. - Page 1
Forum section: electronics / beginners

author: TheBrick
author_rank: Regular Contributor
timestamp: October 22, 2012, 09:15:47 pm
content: Stupid question I'm probably missing some stupid icon but I was just looking to order some stuff from farnell and according to the link below items held in the uk are free delivery (with in the UK)http://uk.farnell.com/jsp/bespoke/bespoke7.jsp?bespokepage=farnell/en_UK/support/webhelp/deliverytimesandcosts.jspmy list of items though must have something that has to be ordered in from the us as I have a £15.95 delivery charge added but I can't tell which item(s) are coming from the US so I can alter my order. Am I missing some filter? Or some icon I can't seem to find any details. As I said stupid question.

author: mariush
author_rank: Super Contributor
timestamp: October 22, 2012, 09:25:29 pm
content: in my basket, for products from US there's a note under the items. There's also a warning at the top of the page saying there's no returns or cancelling for themsee attached picture.If you can't figure it out ...Open each item you added to list in a new tab (click on scroll wheel or right click , T for "open in new tab") then look at the page... at availability it says "US stock" if it's sent from US.

author: AndreasF
author_rank: Frequent Contributor
timestamp: October 23, 2012, 07:31:41 am
content: and you can exclude US stock from appearing in your search by clicking "Exclude extended range" in the filter box on the left.

author: TheBrick
author_rank: Regular Contributor
timestamp: October 23, 2012, 07:44:10 pm
content: Thank guys I knew I must be looking straight through something obvious!
How do I test 2-pin hall affect sensor? - Page 1
Forum section: electronics / beginners

author: Mad Professor
author_rank: Regular Contributor
timestamp: February 15, 2015, 06:20:57 pm
content: Hi All.As per the topic title I would like to know how I can bench test a 2-pin hall affect sensor.The sensor in question is a Automotive ABS Active (Hall Affect) Sensor made by Bosch, Part Number: 0 265 007 527.So far I have been able to find out the following details, but I am unsure how I can bench test this sensor.http://rb-aa.bosch.com/boaasocs/index.jsp;jsessionid=1435E6E229F399ABC73665CD19815DDC.sundoro?ccat_id=340&prod_id=538QuoteThanks for your time.Best Regards.

author: SeanB
author_rank: Super Contributor
timestamp: February 15, 2015, 06:28:18 pm
content: Well, it would be a 3 wire sensor if the bolt hole is the ground, otherwise it is a sensor with a current output, delivering 6mA on one state and 16ma in the other state. Thus you use a 12V supply to pin 1 and a resistor from pin 2 to ground, detecting the voltage drop across the resistor. 16mA says it must drop 5V, so the value is around 300R, giving you a pretty close to TTL signal.

author: HighVoltage
author_rank: Super Contributor
timestamp: February 15, 2015, 10:16:54 pm
content: Usually the Bosch Hall Sensors have a 3 wire connection and you need to use a 1kOhm resistor to source the output and then look at the voltage drop.In this case it seems to be different.It is very unlikely that the bolt hole is ground for the sensor, because of potential corrosion problems, this would probably not be allowed for a critical ABS sensor. But you can easily test it out and pretend the mounting hole is ground for the sensor and hook it up in a typical way.If the mounting hole is not the ground supply, then it is probably exactly like SeanB has explained it.Let us know your findings

author: Mad Professor
author_rank: Regular Contributor
timestamp: February 16, 2015, 07:12:40 pm
content: Thank you for your help and advice.With the details you have given, and the tests I have done, it seems that the sensor(s) in question are faulty, so new sensors have now been ordered.Thanks again for your time.Best Regards.

author: max_torque
author_rank: Super Contributor
timestamp: February 16, 2015, 11:23:41 pm
content: Pretty much from about the early 2000's onwards, most ABS systems from Bosch and Conti Teves moved to two wire 7-14mA sensors. This enables diagnostics as there is always currently flowing (wire break, short to vbatt etc) and because they are "powered" enables wheel tooth counting down to zero speed. The smarter sensors also encode rotation direction information into there output, via variable duty cycle proportions. This enables such technologies as hill hold, DSG gearboxes and electronic handbrake systems etc, where the car must be able to know if it is rolling forwards or backwards!

author: HighVoltage
author_rank: Super Contributor
timestamp: February 17, 2015, 10:12:28 am
content: Quote from: max_torque on February 16, 2015, 11:23:41 pmInteresting, thanks for this explanation.Is the 7 - 14mA a kind of standard on all automotive ABS sensors?
How do I turn on X-Y mode on analog scope ? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 17, 2019, 05:35:35 pm
content: I know how to do it my on DSO, but not my analog Tek2215https://www.tek.com/manual/2215-instruction-manualI don't see it in the manual either.Also do I hook up the common leads as well for in X-Y mode in general ?? I never played around with it. I have 2 little function generators, I should try them as X-Y

author: golden_labels
author_rank: Super Contributor
timestamp: June 17, 2019, 05:39:36 pm
content: The SEC/DIV knob. Page 2-5.

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 17, 2019, 05:47:49 pm
content: Oh I see it, thanks

author: Brumby
author_rank: Unknown
timestamp: June 18, 2019, 04:11:35 am
content: Quote from: lordvader88 on June 17, 2019, 05:35:35 pmJust treat the two inputs the same as you would for normal 2 trace operation - common ground for all channels.QuoteYou can have hours of fun with Lissajous figures checking out frequency and phase relationships - but there's a lot more you can do.

author: Gyro
author_rank: Super Contributor
timestamp: June 18, 2019, 09:19:37 am
content: Quote from: Brumby on June 18, 2019, 04:11:35 amYou can have some fun with chaotic circuits for a starthttps://docs.jeelabs.org/projects/chaos/
How do I use a multimeter to test a paint sprayer? - Page 1
Forum section: electronics / beginners

author: Kekeshi
author_rank: Newbie
timestamp: July 02, 2023, 11:16:14 am
content: I don't know if the mechanical swich under the trigger got stuck or the cables got fucked up but it's not working. Which cables should I test with a multimeter and what settings should I use on the multimeter? I'm kinda afraid to fuck around with it.

author: gjvdheiden
author_rank: Contributor
timestamp: July 02, 2023, 11:29:37 am
content: For safety I would be more concerned about all the _wet_ paint getting through the "isolated" plastic and making a nice short with the mains power, cheezz.Just unplug it and use it in ohms region. Check for continuity. beepie is short no beepie is no short.
How do i use an ADC with diffrent grounds? - Page 1
Forum section: electronics / beginners

author: FlimFlam89
author_rank: Newbie
timestamp: November 26, 2018, 08:15:32 am
content: I just wanted to start with thanks for the help in my other threads regarding this project, it’s much appreciated!I’m made a thread earlier about my school project loop powered sensors and this is the final piece in my puzzle to completing this!I’ve got the power supply, micro and all complementary electronics to work but there is still a problem with the measuring.The ground of the micro controller and OP-AMP are different witch prevents the micro from reading the voltage of the OP-AMP.Is there some way to get around this and still use next to no power?Is there some sort of dual supply OP-AMP or could I use some type of octocopter?I’m not really sure what to do here since I’ve never run into a problem like this...Below is an attached image of the working principle.The micro has to be in series with the load since this is a 4-20mA current loop.I want to use the power supply IC (LTC3255)OP-AMP is LT6106 (current sensing OP-AMP)The "load" is a temp sensor from the 90's

author: David Hess
author_rank: Super Contributor
timestamp: November 27, 2018, 08:23:45 pm
content: As shown the current shunt, operational amplifier, and microcontroller all share a "common" which is the negative power input to the microcontroller. Configure a standard single supply operational amplifier as an inverting amplifier, and the negative value from the current shunt will become a positive value referenced to the microcontroller's negative power input which is a common configuration for 4 to 20 milliamp sensors to measure their own output current.
How do I use MCSJK-6NC1 (Chrystal oscillator)? - Page 1
Forum section: electronics / beginners

author: tjoepar
author_rank: Newbie
timestamp: November 07, 2020, 04:27:24 am
content: Hi all,I'm trying to figure out how to use a Chrystal oscillator that has an "enable control" pin. The data sheet didn't help me at all and I can't seem to find any additional information on the device despite long google search. Any suggestions are very welcome! My question: how do I use the "enable control" pin? Would it be a logic pin, i.e. 5V means ON and 0V means OFF?This is what I'm trying to use in a function generator project (24MHz, 5V version):https://in.element14.com/multicomp/mcsjk-6nc1-24-00-25-b/oscillator-24mhz-7mm-x-5mm-cmos/dp/2854373http://www.farnell.com/datasheets/2864173.pdf

author: ataradov
author_rank: Super Contributor
timestamp: November 07, 2020, 04:39:20 am
content: Typically you just connect it to VDD. Oo just leave unconnected. It depends.And you are better finding a manufacturer that can actually put specifications into the datasheet. There are plenty of other oscillators that are way better documented.

author: tjoepar
author_rank: Newbie
timestamp: November 07, 2020, 06:06:10 am
content: Thanks for your reply Alex!That is sound advice, I guess I fell in a trap for young players

author: amyk
author_rank: Super Contributor
timestamp: November 07, 2020, 06:57:47 am
content: Funny to see one of the features being "Automatic mounting and reflow soldering" - sounds like they will automatically mount and solder themselves into place on the PCB.The actual company that makes them is SJK and the datasheet for the 6N series is here:https://www.maritex.com.pl/product/attachment/42231/QSDW48M00-SJK.pdf"Enable Voltage High 70%Vdd Disable Voltage Low 30%Vdd"Edit: even better, datasheet on the original manufacturer's sitehttp://sjk-crystal.com/upload/2640/download/1/pdf/17_6_smd_oscillator_3.pdf
How do I use the sense pins on an L293E - Page 1
Forum section: electronics / beginners

author: SlowBro
author_rank: Regular Contributor
timestamp: January 29, 2018, 11:49:14 pm
content: Here'sthe datasheet. "the L293E has external connection of sensing resistors, for switchmode control." But I couldn't find much online for how to use these.Could I connect them to an ADC and measure the current flowing through the motor?

author: SlowBro
author_rank: Regular Contributor
timestamp: January 29, 2018, 11:52:04 pm
content: Hmm.This pageseems to confirm. "You should put in a very small resistance, like 0.5 Ohm or 1 Ohm and then with an analogue input read the voltage, which will be proportional to the current."
How do I wire up this connector? - Page 1
Forum section: electronics / beginners

author: belaBartok
author_rank: Newbie
timestamp: August 28, 2012, 08:44:57 am
content: I am not so experienced yet with kinds of connectors and how to wire them together. I have been playing with molex stuff a little...so...I bought these 8pin connectors the other day from a surplus store. I got them home and realized I had no idea how to wire them up. I destroyed 1 of them trying various methods. They have "Panduit" embossed in the plastic. I went to the panduit site...couldn't really find anything to help me. Any thoughts? Thank you in advance.

author: amyk
author_rank: Super Contributor
timestamp: August 28, 2012, 09:25:09 am
content: There are special crimping tools for these but a blunt rod of suitable diameter should work for punching the wire into the metal prongs.

author: Psi
author_rank: Super Contributor
timestamp: August 28, 2012, 09:45:45 am
content: The wire should be pushed in with insulation still on. The metal forks will cut the insulation and make contact.You can try a general telecommunication punch-down tool, but i suspect its a special tool

author: David_AVD
author_rank: Super Contributor
timestamp: August 28, 2012, 10:27:35 am
content: I think I bought ours from Digikey. It's similar to this one from memory:http://www.digikey.com/product-detail/en/0638133504/WM5151-ND/2327986When you find the connectors on the Digikey site, they often list the matching tool on the product page.

author: SeanB
author_rank: Super Contributor
timestamp: August 28, 2012, 03:32:44 pm
content: I have had reasonable success using a thin bladed screwdriver ( Quante tooling is an arm and a leg, and I am not going to buy it for use once or twice a year) to push the wire between the blades. Otherwise a cheap Krone or clone network tool will probably do the job.

author: belaBartok
author_rank: Newbie
timestamp: August 28, 2012, 08:21:05 pm
content: Thanks for all the info. I will definitely order some from digi-key so I KNOW they match. I suppose I have a more general question would be; what are some good, reasonably priced connectors for standard pin headers one should have on hand for slapping something together? Thanks again.
how do mosfet drivers acheive a "dead time" ? - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: June 23, 2013, 06:51:13 am
content: I'm doing a push pull type power drive so need to drive my gates and effectively from the same output of a 555 but I need to make sure there is no shoot through. I tried the traditional driver with 2 BJT's but that has shoot through. So I will probably use a driver IC on this one but.... how do these IC's that usually have two drivers that are one the negation of the other so that they can drive pairs and bridges with no shoot through, but how do they create the dead time ? the only thing I can think of is a window comparator and maybe a low pass filter on the input to slow the signal down because the high speed switching will actually be produces by the output drivers.Thoughts ?

author: ejeffrey
author_rank: Super Contributor
timestamp: June 23, 2013, 07:05:00 am
content: If you mean a window comparator on the input, no. They have a single input threshold and a fixed or programmable dead time, independent of the speed of the rising edge.I am not sure how the delay is implemented in the real chips, but the way I would do it is to generate the complimentary outputs with standard logic. Then I would use an RC delay stage with a diode shunting the R. That would make a small delay for the on->off transition but a larger delay for off->on. Your window comparator idea would also work.

author: Simon
author_rank: Unknown
timestamp: June 23, 2013, 07:13:16 am
content: point is by the time I put a window comparator in I might as well use a pucker driver IC

author: SeanB
author_rank: Super Contributor
timestamp: June 23, 2013, 09:31:13 am
content: Normally they implement the delay internally using a few cascaded weak gates, with a small capacitance on each node that creates the delay. Then it is used with an XOR to gate the drivers such that both are held off on a transition for a small period. Probably would be good to use the pukka driver instead if you are worried. Otherwise you have to implement this on separate pieces of silicon which will be a bit bigger.
How do Multimeters auto-range without blowing up their analog switch? - Page 1
Forum section: electronics / beginners

author: Felicitus
author_rank: Regular Contributor
timestamp: February 13, 2014, 12:29:30 am
content: Hi,I have studied quite many schematics recently, but none of them could answer my question so far: How do multimeters do auto-ranging without relais and without blowing up their analog switch?I have attached an example voltage divider as example. So if I apply 1kV at MEAS_IN, the divider would divide down to 1:20, which results in an input voltage of 50V at the 4051, which is certainly too much (and multimeters won't supply +.50V to Vcc/Vee).I then thought: "Hey, why not add clamping diodes to each divider?". In theory, this was a good idea, however, I didn't realize that they clamp all the time, so if the clamping diodes at the 1:20 node clamps, I get the clamped output voltage divided down, not my input voltage.I also have looked at several schematics for open source multimeters, including the OSHW Multimeter Project by stoney49 (which didn't show the input voltage divider at all) and the heise/c't Voltmeter for their lab (who use relais to switch inputs), so I couldn't answer this for now.Any pointers in the right direction are appreciated.Felicitus

author: free_electron
author_rank: Super Contributor
timestamp: February 13, 2014, 12:37:46 am
content: simple they use analog switches without protection. some of them use external jfets to perform the switching. others (like the agilent 34401) use asics with floating mosfets to do this work.

author: Felicitus
author_rank: Regular Contributor
timestamp: February 13, 2014, 12:44:23 am
content: Can you give me a pointer to such a part? Every analog multiplexer I have checked so far has a certain (low) value for their absolute maximum ratings for the input voltages, and often it's something like Vcc+2V/Vee-2V-I also might have lack in understanding analog switches. If I have a look at the CD4066 and place a clamping circuit at the outputs, would the CD4066 be damaged if e.g. 100V is applied to the input pin in the OFF state (hence no current is flowing)? Also, if the device is in the ON state, would the clamping circuit at the output be fast enough to turn on, and protect the CD4066?

author: Felicitus
author_rank: Regular Contributor
timestamp: February 13, 2014, 04:03:37 am
content: This has been answered by "accident" inthis thread. Big thanks to Jay_Diddy_B for giving me the pointer in the right direction!
How do reduce droop? - Page 1
Forum section: electronics / beginners

author: stafil
author_rank: Regular Contributor
timestamp: March 03, 2020, 07:29:17 am
content: I am using LTspice to simulate a circuit that has a PWM driving a pulled-up sensor using a NPN BJT.When the PWM truns off I see a droop of about .6Volt.What's the best way to get rid of it? Should I use a capacitor in parallel to the BJT?My circuit is:Code:+------/\/\/\/\------+| |PWM source ------NPN +--- PWM consumer| || 12v| |GND GND

author: Dave
author_rank: Super Contributor
timestamp: March 03, 2020, 07:59:57 am
content: Just because the circuit seems to work in simulation, doesn't mean that it works in reality. Check the current that is flowing through the base of the transistor when the PWM input is high. That amount of current would surely destroy a transistor in the real world.What you're seeing is the base-collector capacitance dragging the collector below ground when the base voltage starts dropping.First you need to add a resistor between the PWM source and base and calculate it so it doesn't saturate the transistor too much. You might try adding aBaker clampto further improve the result.

author: stafil
author_rank: Regular Contributor
timestamp: March 03, 2020, 08:42:32 am
content: Quote from: Dave on March 03, 2020, 07:59:57 amOh ok. In the datasheet 2N3904 was rated 200mA and according to LTSpice the current was from 120mA to -40mA(droop?) so I thought I would be ok. Good that I askedThe Baker Clamp however altered the PWM signal, but adding a 10k Ohm resistor helped a lot, thanks!
How do Solid State Refrigerant Leak Detectors work? - Page 1
Forum section: electronics / beginners

author: tigerstyle
author_rank: Contributor
timestamp: December 08, 2015, 06:36:23 pm
content: Sorry for the poor forum etiquette, but this seems like the best way to ask...I have done my research and have found that refrigerant leak detectors (sniffers) use a solid state sensor to detect gas leakage, and that other types are available:http://www.skateisi.com/site/_print.cfm?content=archive_gasleakdetectorultrasonic, dies, UV detection, flame detection etc.But the best seems solid state, the Javac model can detect down to 2 grams per year!http://www.javac.co.uk/automotivehandheld/705-202-g21-tek-mate-leak-detector/My question is really about the solid state sensors, is this priority technology that Javac and similar have developed? Or would it be off the shelf parts from DigiKey/Farnell? I can't get the right search term to google to read further on the sensor specs.Many thanks, love the show!

author: N2IXK
author_rank: Frequent Contributor
timestamp: December 08, 2015, 11:14:15 pm
content: Here is the page of a manufacturer of such things, which contains links to datasheets and info on the different technologies used for various gases.http://www.figarosensor.com/For common refrigerant gases, look under "halocarbon" section...

author: tigerstyle
author_rank: Contributor
timestamp: December 09, 2015, 11:32:09 am
content: That's perfect, many thanks!
How do true RMS digital multi meters work? - Page 1
Forum section: electronics / beginners

author: alanb
author_rank: Frequent Contributor
timestamp: December 19, 2012, 12:34:57 pm
content: My guess would be that for each cycle there would be a series of measurements that would be squared, averaged and then square rooted. Am I correct?If so on a decent meter how many samples per cycle would be taken on say a 50Hz input?

author: ciccio
author_rank: Frequent Contributor
timestamp: December 19, 2012, 01:57:31 pm
content: Most meters use a dedicated IC such as Analog Devices' AD536A or AD736.Other use analog multipliers.If the instrument is DSP based, then the DSP can do the mathematics, and compute the RSM value directly starting from the A-D sampled values.

author: Wytnucls
author_rank: Super Contributor
timestamp: December 19, 2012, 02:34:18 pm
content: Here is the PDF datasheet for the AD636, with a fair amount of information about the principle of operation:

author: alanb
author_rank: Frequent Contributor
timestamp: December 19, 2012, 03:11:28 pm
content: Thank you ciccio and Wytnucls for the info.

author: blackdog
author_rank: Frequent Contributor
timestamp: December 19, 2012, 03:25:28 pm
content: Hi,Linear Technology app. note...www.linear.com/docs/24931www.linear.com/docs/4117Kind regarts,Blackdog

author: alanb
author_rank: Frequent Contributor
timestamp: December 19, 2012, 03:54:56 pm
content: QuoteThe last page of this application note, the good the bad and the ugly..... is fascinating.Thanks blackdog.
How do we simulate a real voltage (non-ideal) source with LTSpice? - Page 1
Forum section: electronics / beginners

author: AQUAMAN
author_rank: Regular Contributor
timestamp: November 18, 2014, 03:53:33 pm
content: For example if we buy a +5 to 12V DCDC converter with a regulated output, sure it is +12V source most of the timeBut when you ask to draw significant amounts of current from the source, even regulated voltage sources drop their value momentarily (perhaps for only several us), but this drop can be quite largeAfter all, this is why we add storage caps on our voltage sources right? To help the DCDC maintain the voltage under strong transient loadBut how do I simulate this drop under load in LTSpice? I have a simulation where in order to simulate correctly what happens in real life, I need to be able to view the drop of voltage on the source under load and how it recovers depending on how large the caps are to help it

author: tggzzz
author_rank: Super Contributor
timestamp: November 18, 2014, 04:15:10 pm
content: You will never have an accurate simulation of real life. But you can have a "good enough" simulationprovidedthat you can define what constitutes "good enough" or "what I don't care about".Question: why are you doing the simulation? If to see how your circuit will respond to voltage transients, then simply model transients using ideal voltage sources. If to see how the power supply will vary when your circuit is operating, then you will need a model of the specific PSU (good luck getting that) plus all the other non-ideal components such as wires (which are really inductors).Depending on what your circuit is, you might be able to simply insert a resistor in series with the ideal voltage. But you might also need to insert inductor(s) in the PSU lines. Or more complex inter-dependencies yet.

author: DanielS
author_rank: Frequent Contributor
timestamp: November 18, 2014, 04:23:27 pm
content: The easiest way to simulate a "non-ideal" source is simply to add the resistance and inductance in: the resistance provides droop proportional to current and the inductance provides some degree of sagging/surging from transients.Depending on exactly what you really want to achieve here, this may be good enough to simulate the regulation lag of a DC-DC converter for your purposes.If it is not, you can add a whole DC-DC converter to your simulations and put up with the increased simulation time.

author: tggzzz
author_rank: Super Contributor
timestamp: November 18, 2014, 11:53:17 pm
content: Another obvious point. IRL a significant part of your design+implementation will be to ensure that your circuit's performance is unaffected by whatever components happen to be between it and the power station.

author: liquibyte
author_rank: Frequent Contributor
timestamp: November 19, 2014, 12:31:07 am
content: I don't know if this is the kind of thing you're after but you can simulate noise with a behavioral voltage source with V=(white(2e6*time)/10) but beware, it takes forever to solve.Quick edit: I've been modelling a transient voltage spike at startup with a pulse voltage as well PULSE(0 18.3 0 5ms 5ms 100u 0 3).
How do you analyze a circuit with a short. Here is a simple circuit. - Page 1
Forum section: electronics / beginners

author: renzoms
author_rank: Regular Contributor
timestamp: January 05, 2020, 08:17:47 pm
content: I am familiar with kvl, kcl, thevenin, norton, nodal, mesh, supernode, supermesh, and using kramers rule. I’m getting back into it. So. What do you do when a circuit has a short?

author: renzoms
author_rank: Regular Contributor
timestamp: January 05, 2020, 08:27:13 pm
content: I've got answers. Thank you.

author: KMoffett
author_rank: Regular Contributor
timestamp: January 05, 2020, 08:30:42 pm
content: Please post the answer you arirved at. I may help others in the future. We are here to share solutions to problems.

author: renzoms
author_rank: Regular Contributor
timestamp: January 05, 2020, 08:37:56 pm
content: The compinents on the right can be ignored as the short bridges them. In technicalnterms, the potential on both sides of the components is the same (shorted), therefor the voltage across them is 0V, therefor the do nothingIn case of a short, both nodes at the ends of the short can be considered the same. Voltage at both ends must be equal. In the above schematic, that means no current into the capacitor and resistor on the right, because there is no voltage difference over them.The capacitor branch has no influence on the circuit because of the short you can just erase it from the schematic and it would be the same (in reality because of the wire resistance you would get a tiny bit of current on the capacitor but almost nothing)

author: andy3055
author_rank: Super Contributor
timestamp: January 06, 2020, 12:26:36 am
content: You explanation does not cover the 2 ohm resistor on the right side.

author: not1xor1
author_rank: Frequent Contributor
timestamp: January 06, 2020, 05:20:42 pm
content: Quote from: andy3055 on January 06, 2020, 12:26:36 amcome on... that is just a 5V voltage source with a 2 ohm loadwhat do you have to analyze?

author: andy3055
author_rank: Super Contributor
timestamp: January 06, 2020, 07:18:54 pm
content: Quote from: not1xor1 on January 06, 2020, 05:20:42 pmWith all due respect, my point was that he did not mention about it. He took a lot of time explaining what happens after the "short" but I wanted to encourage him to complete his train of thoughts/analysis. If you think it is a stupid question, that was not my intention. If he did not think about it, now you have given him the clue! He asked a question and he himself found the answer but partly. Or, at least he explained only partially. If this was a class room I am sure the teacher would ask him that. You need to think why I would pose that question rather than trying to be a smart ass trying to ridicule me. Please don't bother replying.
how do you calculate power output from a push pull tube amp? - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: February 02, 2020, 03:14:59 am
content: I want to calculate the output power from a 6V6GT, 6L6GB, and 6F6 ampsthey are all 2 tube push pull.also I know you can use a load and calculate by voltage drop but I want to calculate it without actually having the ampso can I calculate the power output by the tube specs or something?

author: gbaddeley
author_rank: Regular Contributor
timestamp: February 02, 2020, 05:44:11 am
content: Yes, it is a percentage of the combined max continuous dissipation of the output tubes. The % varies depending on the +HT, and how the tubes are driven and biased (the Class). The output transformer will deliver (nearly all) of this power into the load, provided the correct anode load impedance is matched to the speaker load impedance.
How do you call "Springy tabs" connectors? - Page 1
Forum section: electronics / beginners

author: fabiodl
author_rank: Frequent Contributor
timestamp: March 19, 2015, 11:52:57 am
content: What is the proper name for connectors with "springy tabs" like this one?http://www.gsm-support.net/en/connector-for-siemens-c55-12-pin-p1127I would need a connector like this with 1mm pitch, 16 contacts (and I do not know how to search for). Do you know any?If I cannot find any, I plan to use a Flexible flat cable, with some sponge behind, but I guess that individual springs like this will provide better contact.

author: tszaboo
author_rank: Super Contributor
timestamp: March 19, 2015, 03:08:01 pm
content: The proper name of these kind of connectors is SOAB stupid custom connector.

author: fabiodl
author_rank: Frequent Contributor
timestamp: March 20, 2015, 05:09:50 am
content: yes,actually I am trying to make a connector for the SOAP stupid dreamcast connectorhttp://www.gamesx.com/wiki/doku.php?id=av:dreamcastavout of a more standard one.I would go for an HDMI, but the pins on one side are not enough.
How do you call this type of connector - Page 1
Forum section: electronics / beginners

author: jimski
author_rank: Newbie
timestamp: November 11, 2023, 11:58:15 pm
content: How do you call this type of connector, what is its technical name?It looks like D-sub but it doesn't have pin contacts but instead has leaf-spring contacts around its perimeter.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2023, 12:08:45 am
content: edge connector?

author: Kim Christensen
author_rank: Super Contributor
timestamp: November 12, 2023, 12:14:27 am
content: Looks like a Centronics connector.

author: jimski
author_rank: Newbie
timestamp: November 12, 2023, 12:20:34 am
content: Kim, you were on the right track. Using your suggestion I found that it is called "Micro Centronics"https://www.cablestogo.com/learning/connector-guides/centronics

author: pqass
author_rank: Super Contributor
timestamp: November 12, 2023, 01:08:42 am
content: It looks like a 24 position (2 rows of 12 pins)GPIB receptaclebut different lock mechanism (similar to anAUIconnector).

author: jimski
author_rank: Newbie
timestamp: November 13, 2023, 08:03:08 am
content: While it is difficult to tell the connector dimmensions from the picture, it is narrower and shorter than GPIB. It is Micro Centronics and various companies make it in different pin configurations including 24, 26 and more contacs. After some digging I found DigiKey page that has all the Centronics connectors and Micro Centronics are included there but not easy to find without checking the specifications.https://www.digikey.com/en/products/filter/d-shaped-centronics-cables/466Here is a better picture of male version of this type of connector - except with more contacts - in comparison to D-sub connector.
How do you crimp your 1.25-3 spade connectors ?  Too small for normal crimpers. - Page 1
Forum section: electronics / beginners

author: ez24
author_rank: Super Contributor
timestamp: February 11, 2018, 02:34:25 am
content: These are too small for normal crimping tools so thus this questionhttps://www.aliexpress.com/item/SV1-25-3-100PCS-Pack-Red-Insulated-Spade-Terminal-Block-Connector-Electrical-Furcate-Lug-Crimp-Cable/32793552014.htmlI am running small wires through peg board. The holes are 1/4 inch diameter and these fit through. It just makes it easier for me to crimp first then run the wires.I have this and I am using the very tip but it does not cover the end of the connector completely:https://smile.amazon.com/gp/product/B017JX8W2I/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1Wondering if anyone knows a better way.thanks

author: JustMeHere
author_rank: Frequent Contributor
timestamp: February 11, 2018, 03:16:05 am
content: See thishttps://www.youtube.com/watch?v=YLhpdgXzx28.Best tutorial I've seen.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: February 11, 2018, 03:27:19 am
content: Also I think you can do this with the crimper you show. If you look at the photos, that tool crimps the metal and plastic separately. Look at the photos in your link. Check out page 5-13 of this manual.http://www.ipc.org/committee/drafts/7-31F_d_620B-Feb2012.pdf

author: ez24
author_rank: Super Contributor
timestamp: February 11, 2018, 04:41:52 am
content: Quote from: JustMeHere on February 11, 2018, 03:27:19 amGreat manual - will add it to my listhttps://www.eevblog.com/forum/other-blog-specific/a/msg1341170/#msg1341170

author: ez24
author_rank: Super Contributor
timestamp: February 11, 2018, 05:20:29 am
content: From the manual, I came across "barrel" connectors. Thinking these might fit my 1/4 inch holes, I searched on Aliexprss. Then I came across thishttps://www.aliexpress.com/item/COLORS-DR-1-Crimping-Press-Plier-for-Opening-Barrel-Connector/32821038004.htmlThe description mentions :Capacity: 1.25 / 2.0 / 2.45 / 3.96 / 4.2 / 6.3 square millimeterThis is the first time I have seen the spec "1.25" mentioned, so I am going to order thisNow I have to wait until Chinese New Year is over.My crimp tool does not even touch the 1.25 spades.
how do you drive big power tubes like 4-250A's - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: April 22, 2020, 10:56:03 am
content: I've seen people use transformers to drive them, and big power tubes in cathode follower circuit.what would be a decently simple way to drive them, preferably without another transformer.also in a push-pull config, I intend to have a DC LTP PI driving any power tubes in cathode follower mode (if I use them and not a transformer)

author: TimFox
author_rank: Super Contributor
timestamp: April 22, 2020, 01:25:58 pm
content: Transformer or cathode-follower coupling is mandatory if you run the output tubes in class AB2, where there will be substantial grid-1 current as the grid-cathode voltage goes positive. This will cause huge problems with a coupling capacitor.With class AB1, where there should be no grid current, you only need sufficient voltage drive into a load which is essentially capacitive. What grid voltage swing do you need for your design?

author: TimFox
author_rank: Super Contributor
timestamp: April 22, 2020, 09:30:56 pm
content: Here is the Eimac data sheet for the 4-250A. There are two sections under "Class AB" for AB1 and AB2 operation. Note that two of these will require 145 watts of filament power (5 V at 2 x 14.5 A).http://tubedata.milbert.com/sheets/140/4/4-250A.pdf
How do you intepret percentage based value on ripple? - Page 1
Forum section: electronics / beginners

author: trumpet205
author_rank: Contributor
timestamp: February 09, 2015, 08:43:58 pm
content: I was looking at datasheets for various universal 12 VDC power supply with max output current between 4 to 5 A. Some datasheets, like this one:http://www.xppower.com/pdfs/SF_AFM30-60.pdfSpecifies ripple and noise to be 1% of max peak to peak. What does it mean to be 1%?

author: langwadt
author_rank: Super Contributor
timestamp: February 09, 2015, 09:03:54 pm
content: percent of nominal output voltage

author: trumpet205
author_rank: Contributor
timestamp: February 09, 2015, 09:06:27 pm
content: Quote from: langwadt on February 09, 2015, 09:03:54 pmSo in this case you mean max of 120 mVpk-pk?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 10, 2015, 02:53:48 am
content: Yes.Note also, that's in 20MHz bandwidth, with a capacitor bypass. It could be much worse than that in your actual application, especially if your circuit is sensitive to higher frequencies.Tim
How do you know where the load is? - Page 1
Forum section: electronics / beginners

author: Mattjd
author_rank: Regular Contributor
timestamp: January 22, 2018, 02:41:57 am
content: Embarrassing to say but I've never really understood Thevivin and Norton. Even following this guidehttps://www.allaboutcircuits.com/textbook/direct-current/chpt-10/thevenins-theorem/I've never understood how they determined what the "load" is. I'm currently in a Controls class and the textbook is going over some transfer functions for RLC circuits using impedence/admittanceshttps://imgur.com/a/a8zGyThe original circuit is the first, and the second is them applying Norton's theorem and I just have no idea how they determined to do that, at all.I'm sorry if this is vague. I know thevenin is a voltage source in series with load resistance and Nortons is a current source in parallel with the load resistance but as far as determining what the load is from the original circuit I just have no idea.If anyone could explain this to me once and for that would be AMAZING.

author: IanB
author_rank: Super Contributor
timestamp: January 22, 2018, 02:46:50 am
content: You get to choose. You "look into" the circuit between two points, and everything you are "looking into" (in front of you) is the source, everything behind you is the load.
How do you listen to the HD radio broadcast band on a SDR? - Page 1
Forum section: electronics / beginners

author: raspberrypi
author_rank: Frequent Contributor
timestamp: February 11, 2017, 11:11:58 pm
content: Has anyone here tried this? It would be cool to listen to my classical music in HD and then bluetooth it to my stereo system.

author: Audioguru
author_rank: Super Contributor
timestamp: February 12, 2017, 12:55:04 am
content: What is HD radio broadcast band? The FM broadcast band sounds pretty good, except when they play RAP noise.What is SDR? They are simply three letters that mean nothing. Please talk in words, not letters.

author: tkuhmone
author_rank: Regular Contributor
timestamp: February 12, 2017, 12:58:04 am
content: is it this ?https://en.wikipedia.org/wiki/HD_RadioHave not yet studied it, but I guess I need to go article through...

author: james_s
author_rank: Super Contributor
timestamp: February 12, 2017, 06:51:38 am
content: HD Radio in the US is a closed proprietary system, you cannot decrypt it without a chipset licensed from Ibiquity. The whole thing is a scam, private corporation managed to push it through and make it a standard.Short answer, at the moment you can't, although I'd love to see someone crack it just on principal.

author: raspberrypi
author_rank: Frequent Contributor
timestamp: February 12, 2017, 10:00:57 am
content: Quote from: Audioguru on February 12, 2017, 12:55:04 amWhat is HD? What is FM? What is a RAP noise?SoftwareDefinedRadio. Very fun, cheap hobby. The uses are endless. I would like to get more into it.So if you wanted to do so could you buy the chip? After reading about how its controlled by one company I want it to fail. Although it could have been awesome we had to make sure it was privatized.
How do you organize learning/research and document your projects? - Page 1
Forum section: electronics / beginners

author: beatle
author_rank: Contributor
timestamp: May 12, 2013, 11:42:29 pm
content: Hi, guys!As a long time lurker here I know that the members of this forum have great knowledge and have built great projects, so I hope you can share your habits on this matter as I have been pondering the right approach for a long time now.I have had this hobby for some years now, but I am not knowledgeable yet so I have a lot to learn and explore, but as I have a terrible memory I seem to forget most of it quite fast. I do enjoy learning new things about electronics and I spend a lot of time reading various resources, but I sometimes find myself rereading, say, a book on power supply design and rediscovering much of it anew. How do you organize your learning process to avoid it? Do you keep a note book where you jot down cool circuit tricks and facts on components and such and just make general notes just as if for an university course?I imagine that some of it is just a symptom of not only my bad memory, but also my lack of practical circuit building and experimenting to cement the experience, that leads to the question about documenting project design process. Do you find that describing what you are doing, your decisions and discoveries in a web blog, for example, helps you to learn more from a project? Or do you keep your design notes and write down discoveries you researched for your own future reference in some form?Please share your methods! (And forgive my clumsy English!)

author: Dave
author_rank: Super Contributor
timestamp: May 13, 2013, 02:57:18 am
content: When it comes to general electronics knowledge, I am able to memorize most of it just after reading it once and taking the time to think about the circuit operation. If I read something useful and can't remember it exactly when needed, I often remember, where I found the info in the first place, and look it up.As for project ideas, I have a folder in which I store my research, drawings, calculations, schematics, and everything else. I have these papers bunched together for each individual project idea. For these projects I also have files scattered all over my computer. Haven't yet found the determination to organize them.

author: beatle
author_rank: Contributor
timestamp: May 13, 2013, 12:34:31 pm
content: Folders for projects sound like a very good practice! It has always bothered me that info exists concurrently in paper notes and computer files (CAD schematics and quickly jotted notes from some web page mostly).Thank you for sharing!
How do you read the date code on this part? - Page 1
Forum section: electronics / beginners

author: alank2
author_rank: Super Contributor
timestamp: June 22, 2015, 05:25:00 pm
content: http://www.epsondevice.com/docs/qd/en/DownloadServlet?id=ID000639I've got some marked "1102A" and another marked "3382B" and "3472B"...Thanks,Alan

author: TimFox
author_rank: Super Contributor
timestamp: June 22, 2015, 05:35:46 pm
content: 1102 should be the 11th week of 2002.3382 should be the 33rd week of 1982.3472 should be the 34th week of 1972, which doesn't seem reasonable.

author: alank2
author_rank: Super Contributor
timestamp: June 22, 2015, 06:38:15 pm
content: Quote from: TimFox on June 22, 2015, 05:35:46 pmI agree. I don't see a doc on their website that covers date codes either and how it is decoded isn't mentioned in the datasheet...

author: w2aew
author_rank: Super Contributor
timestamp: June 22, 2015, 08:57:04 pm
content: There really is no standard on date coding. A common convention is WWYY, but it is certainly not a standard. Companies are free to choose any system they desire for date or lot code marking (including none at all).

author: Shock
author_rank: Super Contributor
timestamp: June 24, 2015, 07:10:19 am
content: Could be Y/WW/XX (XX being batch/run/machine etc).

author: amyk
author_rank: Super Contributor
timestamp: June 24, 2015, 11:20:56 am
content: Have you tried asking Epson?The Japanese are known for using some different calendars like the one based on the date of the emperor, but Y/WW/XX or WW/Y/XX seems like a good guess.

author: alank2
author_rank: Super Contributor
timestamp: June 25, 2015, 03:58:23 pm
content: Quote from: amyk on June 24, 2015, 11:20:56 amI emailed them.A new one to add to the mix:F162BF172BDate also found on reel 2006.05.04So the "16" and "17" would be the week.That leaves the "F" and the "2B"...

author: amyk
author_rank: Super Contributor
timestamp: June 25, 2015, 09:29:48 pm
content: Probably this:1 = 19912 = 1992...8 = 19989 = 19990 = 2000A = 2001B = 2002C = 2003D = 2004E = 2005F = 20062A/2B could be the location it was made.