hybridfree/eevblog-posts huggingface dataset:
Estimating/Specing Power Requirements for System - Page 1
Forum section: electronics / beginners

author: MuhScopeBroke
author_rank: Contributor
timestamp: October 05, 2021, 03:47:25 pm
content: Hello, I am working on the electronics behind an autonomous sailboat and I have been stumped by how to estimate the power I need to draw from the batteries.I have specs for the larger loads in the system but there is still much ambiguity with the rest of the circuit. What does the process for estimating power consumption usually look like? How can I be sure that my BMS and circuit protection is specced correctly?Thanks for the help!

author: Jwillis
author_rank: Super Contributor
timestamp: October 06, 2021, 12:54:46 pm
content: Circuits only draw as much current in amps as they require for normal operation. The total amps is additive . So if circuit A draws 5 amps and circuit B draws 4 amps the total is 9 amps .Power is measured in watts . Watts is equal to Amps multiplied by the circuit Voltage . So if the 9 amps is on 12 V circuits then the total watts is 108 Watts .You can use a clamp meter or an in line ammeter to determine the current draw of each individual circuit.
Ethernet Card as Logic Analyzer? - Page 1
Forum section: electronics / beginners

author: Luu
author_rank: Newbie
timestamp: December 18, 2016, 02:59:59 pm
content: I was thinking, could a 1 Gbps Ethernet Card be used as a Logic Analyzer?I get that one might need to write a custom firmware for it to not discard non-ethernet data and you'd have to translate signals to -1V - +1V before handing it to the card. But just speed wise wouldn't the hardware on an Ethernet Card be able to process the incoming pixies really fast?I know some cards have a feature where they can detect cable problems. Like breakage in a cable, in what distance from the card the break occurred and in what wire. They would need to have some kind of raw access to do that I suppose?!Do you know of any obvious problems that would prevent such use?Do you know what kind of low level access Linux currently provides on ethernet cards? I.e. what's the lowest level exposed to userspace programs and what's the lowest a device driver typically sees? Is some decoding done on the card itself already or can you get true raw access to each individual wire state?

author: lapm
author_rank: Frequent Contributor
timestamp: December 18, 2016, 03:15:16 pm
content: What you want to logic analyzer is capture state of several signals in parallel. So etherned card would give you just one channel.Or do you intent to do parallel to serial conversion witch would drop our real capture speed way belove that 1Gbps...not to mention captur triggers implementations when using repurposed ethernet card...

author: stj
author_rank: Super Contributor
timestamp: December 18, 2016, 04:22:16 pm
content: i'm pretty sure the packet framing and error correction are in the hardware and you cant get raw aquisition.even if you could, they arent really gigabit because the pc side is not that fast.it's assumed that there is more than one pair of cards sharing the net, so the gigabit speed is split between them.

author: helius
author_rank: Super Contributor
timestamp: December 18, 2016, 05:23:32 pm
content: 1000baseT uses four balanced pairs in parallel with a symbol rate of 125 MHz, with deskewing and error correction in hardware. The coding is not binary; it uses five different voltage levels that are input to a descrambler before being stored. This is remarkably unlike a logic analyzer's acquisition section.The TDR feature uses the clock pulse hardware that is already required: such a feature would not be implemented if it required additional hardware. All it does is send a clock pulse over one pair and listen for an echo.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: December 18, 2016, 06:04:41 pm
content: Also, Ethernet is transformer coupled; the high pass effect makes LSA applications rather limited.

author: cdev
author_rank: Super Contributor
timestamp: December 20, 2016, 09:22:33 pm
content: You can use an Altera FX2 series dev board as a sigrok compatible logic analyzer. Some of them are extremely inexpensive. See sigrok.org
Ethernet Jack Transformer Question - Page 1
Forum section: electronics / beginners

author: RoadRunner
author_rank: Frequent Contributor
timestamp: August 21, 2017, 07:32:54 pm
content: i am currently in the market for a good quality Ethernet jack with Transformer. i know very very little about Ethernet Transformers.i have found two partshttp://www.mouser.de/ProductDetail/Amphenol-Commercial-Products/RJMG163128101NR/?qs=sGAEpiMZZMvlX3nhDDO4AMpc7KsfPAz1xfKNyIQRUBE=http://www.mouser.de/ProductDetail/Amphenol-Commercial-Products/RJMG1BD3B8K1ANR/?qs=sGAEpiMZZMvlX3nhDDO4AGM2u%252boEfEhzbp2mBVUa5oc%3dThey look same , but transformers in them drawn differently in datasheet.Are they really different or they are just drawn differently and functionality is same?

author: mrpackethead
author_rank: Super Contributor
timestamp: August 21, 2017, 07:46:21 pm
content: Yes, they both have a common mode choke, the one on the left is drawn a little oddly..

author: floobydust
author_rank: Super Contributor
timestamp: August 21, 2017, 07:51:07 pm
content: Those are extra common-mode chokes that some Ethernet jacks can contain, in addition to the transformers.If your product must pass EMC then it is easier to use that type of jack.The LED's are the other part to watch, how many LED's and colour etc.
Ethernet low power PHY  - Page 1
Forum section: electronics / beginners

author: rakeshm55
author_rank: Regular Contributor
timestamp: July 17, 2018, 04:51:31 pm
content: While searching for 10/100 Ethernet PHY I came across DP83822I(http://www.ti.com/product/DP83822I)When powered from 1,8V(Digital,Analog)On 100% Utilization consumes a power of about 130mWIs there any drawback for using such chipsets?? are they compromising link performance for power saving ??Any caveats
Ethernet MAC to MAC connection within a Board - Page 1
Forum section: electronics / beginners

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 06, 2018, 12:19:22 pm
content: Hi,I have read in some blogs that it is possible connect EMAC to EMAC (RMII interface) without having PHY chipsets within a board. Thus I can create a Standard high speed interface between two processors with lesser power consumption than having a full-fledged ethernet interface.Is there any application note specifying this scheme?? other than passive mention in blogs I cound not find solid information on this scheme. Is this technique commonly used.I have read (http://www.ti.com/lit/an/snla079d/snla079d.pdf) RMII to support a trace length of 6 inches.In Normal scenario Ethernet PHY acts as a passive device connection to MAC. In the new scheme PHY will be replaced by MAC. IN this case is there any specific configuration needed for MAC replacing PHY??Thanks in Advance

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 06, 2018, 12:36:05 pm
content: My primary aim is to have relatively low power high speed serial interface.

author: Cliff Matthews
author_rank: Unknown
timestamp: June 06, 2018, 02:09:18 pm
content: Full duplex 50Mbps costs about $6usd.. is that fast enough?https://www.mouser.ca/datasheet/2/408/TLP2367_datasheet_en_20171025-1075458.pdf

author: ejeffrey
author_rank: Super Contributor
timestamp: June 06, 2018, 05:19:21 pm
content: Yes, I have heard you can do this as well, but never done it myself.You will need to use an external clock, rather than allowing the MACs to produce their own clock since the receive and transmit clocks need to be shared.You may need to do something with the management interface. When I have used FPGA based RMII MACs we just ignored the management interface and used the default settings for duplex/speed/etc. But if you are using a CPU with a built in MAC it will likely try to send commands to the management interface. With no PHY to receive that, I am not sure what will happen.
Ethernet PHY LED - Page 1
Forum section: electronics / beginners

author: zero-ohm
author_rank: Newbie
timestamp: October 20, 2023, 10:47:30 am
content: I plan to use a KSZ8091RNDIA-TR together with a JX0011D21BNL which has two LEDs. I wanted to connect the RJ45 connector's LEDs similar to, as (at least) I think I know from other devices: the green one is on when there is an established link and the other one blinks on activity. Now, as it seems that the PHY has only one LED0 output and I am new to ethernet I am wondering how to do that. I see something about the configuration possibilities, but I am not able to understand what I have to do in order to get the behavior I explained earlier.

author: ataradov
author_rank: Super Contributor
timestamp: October 20, 2023, 03:35:47 pm
content: I just looked at surrounding network equipment and all of it uses combined Link/Act LED. The other LED is either absent or indicates connection speed.Some older Netgear equipment uses separate LEDs for 100M/10M, which behave like Link/Act, and what LED is on/blinking depends on the concoction speed. But this scheme only really works for 10M/100M devices and if both LEDs are of the same color.And in your case Link/Act LED is handled by the PHY. And for the connection speed you can drive the other LED from the MCU.

author: zero-ohm
author_rank: Newbie
timestamp: October 20, 2023, 03:47:11 pm
content: Interesting, all network equipment I found behaves as you described, but on all my computers I have a green light when the link is established and an orange(yellow) one blinking on activity. Yes, probably the right thing to do would be handle activity by the PHY and the link/speed by the MCU.

author: zero-ohm
author_rank: Newbie
timestamp: October 21, 2023, 12:40:19 pm
content: I searched a bit and found the source of my confusion, in the datasheet of the KSZ8091RND in the section 9.0 REFERENCE CIRCUITS — LED STRAP-IN PINS on page 53 the LED1/SPEED pin is mentioned, but I cannot find it anywhere else in the datasheet. Is this an error from the manufacturer? Or is there another pin which can also be used as LED1?

author: ataradov
author_rank: Super Contributor
timestamp: October 21, 2023, 02:36:11 pm
content: I think this is just a copy-paste error.
eTOMMENS power supply unit - Page 1
Forum section: electronics / beginners

author: Croby80
author_rank: Newbie
timestamp: November 30, 2020, 07:59:33 pm
content: Hello to everybody, I'm looking for a good (but not expensive) power supply unit for my personal laboratory and I'm observing the following model on aliexpress store:https://it.aliexpress.com/item/1005001615696493.html?spm=a2g0o.cart.0.0.5a3d3c00R6iaCI&mp=1it is a single channel 300W programmable power supply with a declared accurancy of 0,01mA for current and 0,1mV for voltage with capability to record and graphically visualize voltage current and power . It is possible to define 100groups of timed programmed steps and also to manage battery charge slopes. RS232, analog and USB interface are available (LAN optional) to be conneted to a PC to remotly control and to visualize V,I,P,R parameters. Sense compensation is another feature with a 4,3" rgb graphical display. Price = 511euros.Brand is AB-F but I suppose could be a rebrand for eTommens manufacturer:http://www.etommens.com/dgweb_content-847183.htmlAnyone has experience with these devices? Some expert could kindly give me his opinion?(I attached datasheet of previous 5 digit version =0,1mA, 1mV)Thank you

author: wraper
author_rank: Unknown
timestamp: November 30, 2020, 08:04:16 pm
content: It that F U song in their video about customer support?

author: Croby80
author_rank: Newbie
timestamp: November 30, 2020, 08:12:00 pm
content: Sorry?

author: wraper
author_rank: Unknown
timestamp: November 30, 2020, 08:13:11 pm
content: Quote from: Croby80 on November 30, 2020, 08:12:00 pmPlay the video on aliexpress product page.

author: Croby80
author_rank: Newbie
timestamp: November 30, 2020, 08:32:44 pm
content: Maybe but I trust in datasheet performance expectations

author: Croby80
author_rank: Newbie
timestamp: December 01, 2020, 07:11:54 pm
content: Nobody else can give info or hints for a good and cheap single channel programmable power supply?

author: Electro Fan
author_rank: Super Contributor
timestamp: December 01, 2020, 07:17:34 pm
content: Quote from: Croby80 on December 01, 2020, 07:11:54 pmhttps://www.eevblog.com/forum/testgear/bench-power-supply-261782/
EV Charging Installation simpleSwitch EVEMS 240 --Estimate Seems High? - Page 1
Forum section: electronics / beginners

author: DW1961
author_rank: Frequent Contributor
timestamp: July 23, 2023, 02:26:29 am
content: California. This is the Chevrolet incentive program that allows $1200.00 plus $250 for documents, if needed, for an electrician to install the EV outlet in a garage:We have to have a SimpleSwitch EVEMS 240 installed so we can charge from 240.https://simpleswitch.io/This is a new install from the Chevrolet program using QMERIT. He's already getting 1200.0 for the EV 240 install, which means he would need to add a breaker and then run the wire to the 240 outlet.It's my understanding that the SimpleSwitch EVEMS goes inbetween the EV charging outlet and, in out case, the oven, since the EV 240 charger will be sharing the same breaker and wires from the over back to the panel breaker.It seems that he is charging 500.00 to hang the Simple Switch and connect the 240 charging outlet to the EVMS switch inbetween the oven. Since he is already getting paid to do any wiring between the panel and the garage 240 outlet, 500 bucks to connect the switch inbetween the oven and EV outlet and the oven seems like way too much.The oven outlet is on the same wall (inside) that the EV 240 outlet in going, outside in the garage. So, he isn't running any extra wire.
EV1HMC245AQS16 RF bidirectional capability - Page 1
Forum section: electronics / beginners

author: Sris2310
author_rank: Newbie
timestamp: October 22, 2022, 07:30:11 am
content: I want to use EV1HMC245AQS16 as a RF multiplexer. I have a IoT device that I need to test with 3 different antennae. The IoT module will be connected to 3 different antennae via the RF multiplexer. I will be using this RF multiplexer to test the reliability of the firmware running on the IoT device as the different antennae will provide different RSSI of GSM connection for the IoT module (Basically done by cutting antennae to simulate bad network areas). Basically I want to test the reliability of the firmware with different RSSI values of the network.Will this evaluation board be fine for this purpose?It should be able to handle bidirectional RF data transmission and also reception at the same time when one antennae is connected to IoT module.Can you tell me whether EV1HMC245AQS16 is suitable for this application?Product url:https://www.digikey.in/en/products/detail/analog-devices-inc/EV1HMC245AQS16/5403562?s=N4IgTCBcDaIKIDUCMAJAsgYTAFgKwEEBFAZSQDYQBdAXyAThanks.
Evaluating 9V PS - Page 1
Forum section: electronics / beginners

author: Anding
author_rank: Contributor
timestamp: December 15, 2024, 03:55:32 am
content: Hello,I have a new but inexpensive (a few $) 9V wall-wart power supply. Checking the voltage with a multimeter, I saw that it was fluctuating, and made another measurement with the scope (attached)May I ask, is the power supply performing adequately? Will the voltage fluctuations affect my projects?

author: Andy Chee
author_rank: Super Contributor
timestamp: December 15, 2024, 04:35:37 am
content: That fluctuation is concerning.What load did you have connected whilst measuring the waveform?

author: Anding
author_rank: Contributor
timestamp: December 15, 2024, 04:40:47 am
content: No load at all Andy. Open terminals.I actually bought two identical PS units and this observed performance is the same with both.I plan to use the PS in projects instead of a 9V battery, no my expectations are not too high

author: squadchannel
author_rank: Frequent Contributor
timestamp: December 15, 2024, 04:47:51 am
content: This is terrible; secondary side filter is missing.

author: BrianHG
author_rank: Super Contributor
timestamp: December 15, 2024, 04:54:13 am
content: This can happen with some switching power supplies which require a minimum load of something like 10% their rated power to get rid of that pulsing.Just add a load resistor and re-measure.More expensive or more sophisticated supplies will not pulse like that with a 0 load.

author: beatman
author_rank: Regular Contributor
timestamp: December 15, 2024, 05:36:28 am
content: Just connect some load on psu and measure again you see better waveform BUT all cheap psus use crap caps and ripple is high.I have a lot experiments with cheap and expensive psus.New 5 volt 1 A adapter for audio device shows 35 mv ripple under load i change the output filter caps with panasonic fr series (i have always in stock) and the ripple goes down to 12 mv.Lesson is a good cap is always a good cap for a reason.

author: Anding
author_rank: Contributor
timestamp: December 15, 2024, 08:04:20 am
content: Thank you all - "test under load" - I see!Here it is with a 330 Ohm supplying 27mA

author: PGPG
author_rank: Frequent Contributor
timestamp: December 15, 2024, 12:58:02 pm
content: Quote from: squadchannel on December 15, 2024, 04:47:51 amFilter for 1s pulses?

author: squadchannel
author_rank: Frequent Contributor
timestamp: December 15, 2024, 01:22:44 pm
content: Quote from: PGPG on December 15, 2024, 12:58:02 pmOuch, I thought it was more of a short pulse.
evaluating BJTs for a linear PSU: am I doing it right? - Page 1
Forum section: electronics / beginners

author: exe
author_rank: Unknown
timestamp: March 06, 2020, 09:54:29 am
content: Hello!When I was building a clone of blackdog's PSU I couldn't find exact pass transistor (2sa1943-something). So, I bought a clone from ST: 2sta1943. Latter I presumably found a Toshiba part, so I bough it too. I decided to compare them. So, I created a simple test rig (see pic for schematic). I apply a small stimulus between base and emmiter, and measure signal on emitter resistor. Here is what I found: transistors behave very different! It seems to me that the ST part is much better because 90 phase shift happens at much higher frequency. I'm also surprised that TIP2955G (with Ft of just 2.5MHz) in this setup performed even better than 2sta1943 with Ft of 30 MHz. In general, I found no correlation between Ft and performance in this test :/. May be some transistors don't like low Vce, or their Ft was calculated for lower currents when they perform much better.So, I want to choose "the best" transistor based on measurements.My question is: am I doing it correctly? I understand that due to self-heating it's not going to be very accurate, but as a figure of merit, can I use these data?Plot description: yellow line is stimulus, blue line -- response. Please ignore offset voltage on pictures, I set it to low values manually to remove stimulus, or shunt resistor would overheat.My bench PSU can only give 1A current, but it has two channels. So, I put two channels in parallel to get more current. The low-esr (0.05ohm as measured by transistor tester) cap of 220uF is put close to transistor because I use relatively long leads from the power supply.Because of drop on emmitter resistor R1, Vce is just 1V, the other two volts are dropped on the shunt.PS all parts are bought from presumably reputable sources: tme and mouser.

author: David Hess
author_rank: Super Contributor
timestamp: March 06, 2020, 11:57:44 pm
content: Quote from: exe on March 06, 2020, 09:54:29 amLike hfe, Ft is not well controlled and can vary over a considerable range for the same part number. If you need a tighter Ft to prevent oscillation or for performance reasons, then you may have to grade the transistors yourself.QuoteDatasheets specify the conditions for each measured characteristic.QuoteThe best test is in a circuit which is representative of the application circuit. But usually one of the three transistor configurations is close enough.
Evaluating residues below polycarbonate caps - Page 1
Forum section: electronics / beginners

author: Electrolitty
author_rank: Contributor
timestamp: July 28, 2023, 12:58:08 pm
content: Dears,I got a +30 years old function generator that still works fine but needs a bit of attention (potentiometer cleaning and stuff alike). I had a thorough look at the circuitry, especially the electrolytic caps which do not show any visible problems. However, I found some light brown residue under most of the WIMA MKC4 caps. It's rather powdery/solid than sticky, it does not seem to be glue. Should I be worried?Regardshttps://www.tawelectronics.com/wima/WIMA_MKC_4.pdf

author: Vovk_Z
author_rank: Super Contributor
timestamp: July 30, 2023, 11:41:25 pm
content: IDK, that possibly must be some glue to mechanically secure them to PCB.Wima MKC series are not noticed (yet) with bad things as I know.I would rather consider recapping electrolytic caps.AA501 Repair and Troubleshooting video for example

author: tooki
author_rank: Super Contributor
timestamp: July 31, 2023, 08:36:33 am
content: Is there any reason not to assume it’s simply excess flux?

author: Electrolitty
author_rank: Contributor
timestamp: August 07, 2023, 12:13:22 pm
content: Thanks for the hints.>Vovk_ZRecapping is a task that is on my agenda, for now I did not see anything suspicious, so I'm in no hurry.>tookiCould be flux, but I find this only in areas around the Wima capacitors, not near components that are farther away.For now, I suppose that it's not anything "dangerous".
EVBlog #262 Problem with power switch circuit variation - Page 1
Forum section: electronics / beginners

author: boanerxe
author_rank: Newbie
timestamp: September 12, 2016, 03:27:11 pm
content: Hello everybody!I'm currently working on a circuit which I'm trying to switch on using a button. The main idea is that when button is pressed, the power source gives power to a PIC microcontroller which writes '1' to PWR_CTL, causing the circuit to remain ON. I can use BTN_IN to detect when the button is pressed again for two seconds, and then, write '0' to PWR_CTL and power off the circuit.The problem is: When the circuit is off, I have about 1.7 V in V_IN, which means to have 1V in the regulator output. This is causing several problems in the rest of the circuit, since it is not completely powered off (in addition I have an undesiderable consumption).Can anybody suggest a simple soluition to keep the power source completely off?Thank you!!

author: klr5205
author_rank: Regular Contributor
timestamp: September 12, 2016, 04:53:13 pm
content: Stronger pull resistors all around perhaps?Could be that one or both of the bottom fets are leaking enough to drop ~500mV across R10 and turn it partially on.All of those fets have very low threshold voltages. What do you measure at each fet's gate when the circuit is "off" ?EDIT: You could also use your microcontroller to control the shutdown pin of the regulator, rather than having your own pass fet. The idea would be similar to how you use the PWR_CTL net now, where to mcu wakes up before the button is released and writes a "1" to the shutdown pin to latch power.

author: boanerxe
author_rank: Newbie
timestamp: September 13, 2016, 06:18:25 am
content: Hi klr5205. That leak current you're talking about was one of my assumptions, but I could not get any changes by tunning the R10 values.Maybe changing N-channel MOSFETs by NPN could have some effect? Although I think that solution would be less energy efficient...The solution of controlling the shutdown pin of the source has the same problem I have know, since it is considering as "low" value less than 15% of the input voltage. If my reference is V_IN I'm having the same problem with those 1.7V.
Even-odd mode analysis - Page 1
Forum section: electronics / beginners

author: promach
author_rank: Frequent Contributor
timestamp: March 17, 2019, 03:18:52 pm
content: Could anyone show an actual circuit example using the even-odd mode analysis concept ?By the way, I am readingthis useful textronix TDR impedance measurement application note

author: rfeecs
author_rank: Frequent Contributor
timestamp: March 17, 2019, 04:22:15 pm
content: It is used all the time in analyzing differential pairs, like the inputs to op-amps. Same as differential mode / common mode. It is mentioned on the last page here:http://www.ittc.ku.edu/~jstiles/723/handouts/Odd%20Even%20Mode%20Analysis.pdfAlso used in analyzing coupled transmission lines:http://emlab.uiuc.edu/ece451/notes/coupled.pdfhttps://www.ewh.ieee.org/r5/denver/rockymountainemc/archive/2000/diffimp.pdfAnd coupled line structures like directional couplers:http://www.ittc.ku.edu/~jstiles/723/handouts/Analysis%20and%20Design%20of%20Coupled%20Line%20Couplers.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 17, 2019, 10:54:18 pm
content: An example would be a VNA with a single measured port and an open/short/terminated far port. A single port is just an impedance, but by seeing how that impedance changes due to the far port's impedance, you obtain the transfer characteristics (s21).Tim

author: rfeecs
author_rank: Frequent Contributor
timestamp: March 17, 2019, 11:30:03 pm
content: Quote from: T3sl4co1l on March 17, 2019, 10:54:18 pmThis would only work if you were measuring a reciprical network (S21 = S12). Then you have three measurements and three unknowns.For an amplifier or a network with isolators / circulators, it won't work.Also, I don't see how this is an example of even / odd mode analysis.

author: promach
author_rank: Frequent Contributor
timestamp: March 18, 2019, 12:39:24 am
content: I just found this nice article abouteven-odd mode analysis for Wilkinson Power DividerBefore reaching the even-odd mode analysis, I am bit confused with slides 10 and 11.For slide 10, why "250-ohm transmission line loads in parallel" ?For slide 11, why "quarter-wave transformer could convert RS to 2RS so we can match input ports" ?

author: rfeecs
author_rank: Frequent Contributor
timestamp: March 18, 2019, 02:23:57 am
content: Quote from: promach on March 18, 2019, 12:39:24 amAppears to be a typo. It should be "Two 50-ohm transmission line loads in parallel"QuoteConvert 50 ohm to 100 ohm on each arm, then in parallel they look like 50 ohms.
EveryCircuit simulator glitch - Page 1
Forum section: electronics / beginners

author: tobia
author_rank: Contributor
timestamp: May 23, 2015, 01:48:08 pm
content: Playing around with the free version ofEveryCircuit, I stumbled across some rather unusual behaviour.Take their Diode example, change the voltage source to an AC source (select it, then wrench button on the bottom toolbar, then ~ button), raise it to 1MV peak and raise the resistor accordingly to 5Mohm. Then plot the input voltage (select the piece of wire between voltage source and diode, then click on the eye button on the bottom toolbar), plot the current across the diode, and the voltage between diode and resistor.I expected to see either a traditional diode result, like the one you get with 1kV and 5kohm (see first picture) where the voltage drop is so tiny that it cannot be seen, or some kind of negative voltage breakdown.I certainly did not expect what I got (see second picture.) The positive voltages look all right (1), but there's some funny stuff going on at negative voltage (2) with some 100kV of voltage and 50mA of current across the resistor andbothseem to be leading the input voltage by 90°. That doesn't make any sense to me. And then there is a spike in current (3) at the beginning of the positive voltage cycle.All in all, I'm inclined to file this whole "app" as a piece of trash, aka. some fancy GUI trying to hide the underlying simulator's limits. But I'm a newbie, so I'd like to get some better opinion on what is going on.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 23, 2015, 02:02:34 pm
content: Those results look pretty good, honestly.You should expect the diode has some reverse capacitance. The spike seems to be on the wrong side, suggesting a poor model (it's not transitioning smoothly from "low conductance" to "high conductance"?), but it also handles it well (it recovers quickly, and doesn't oscillate between values after the spike).It's only a computational simulator. Expecting realistic results from a computational model reflects poorly on the one doing the modelling, not the computer.Tim
everyone designs super capacitor chargers like absolute uncoolness - Page 1
Forum section: electronics / beginners

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 22, 2021, 11:35:32 pm
content: how come super cap chargers are all rated below 2 amps, it doesn't make sense.What u need to make a decent one is a step up transformer, am I right?

author: oPossum
author_rank: Super Contributor
timestamp: October 23, 2021, 12:11:18 am
content: Ideally you need a high efficiency constant current source.

author: langwadt
author_rank: Super Contributor
timestamp: October 23, 2021, 12:35:37 am
content: https://www.analog.com/en/parametricsearch/11413#/sort=5349,desc

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 23, 2021, 03:00:10 am
content: Quote from: langwadt on October 23, 2021, 12:35:37 amThat one would kick absolute bum.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2021, 03:51:42 am
content: Be careful about using the word “all” in your posts, since it is so easy to disprove.
Everything you EVER wanted to know about Soldering - Page 1
Forum section: electronics / beginners

author: watchmaker
author_rank: Unknown
timestamp: September 21, 2025, 02:41:06 pm
content: Came across this 1990 DOD document on soldering; Pretty damned inclusive and extensive.https://antiqueradios.com/forums/download/file.php?id=441586

author: tooki
author_rank: Super Contributor
timestamp: September 21, 2025, 03:01:45 pm
content: Here’s the official download from the military, as opposed to some random website hosting a copy watermarked from another random website:https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=71717
evv blog 81 finding components - Page 1
Forum section: electronics / beginners

author: johnmcgivern
author_rank: Newbie
timestamp: May 15, 2010, 08:02:33 pm
content: Hi Dave, do you know of any site to compare components ie srf10100 schootky rectifier.Do you think it would be possible to do a blog for beginners.Many thanks Dave its a pleasure to here someone talk about work in the real world.
EX300 Micro Amps - Page 1
Forum section: electronics / beginners

author: jyaan
author_rank: Contributor
timestamp: March 25, 2012, 04:41:25 am
content: I'm getting weird readings when I try to measure uA with my EX-330. When measuring with the mA mode I get 3.9, and when measuring across a shunt resistor I also get 3.9mA. But when the meter is in uA mode, I get around 1000uA. What's going on??? I recall Dave saying the closer you get to the limits of the meter, the more you're affected by burden voltage -- and the circuit also ran on 3.3v. But the mA mode was pretty close, so what's really happening here?

author: Unknown
author_rank: Unknown
timestamp: March 25, 2012, 10:01:17 am
content: I assume that the uA range goes up to 4mA. The uA mode probably has a much higher shunt resistance than the mA mode (see DMN manual). The higher burden voltage is screwing up your circuit, which you didn't mention, somehow.

author: jyaan
author_rank: Contributor
timestamp: March 28, 2012, 08:01:36 pm
content: The "circuit" is just an LED and resistor. I originally supplied 3.3v from a USB development board, and also tried two AAs and a 9v, but they all had similar results. Oh well, maybe I should consider getting a uCurrent.
Examples regarding SD cards - Page 1
Forum section: electronics / beginners

author: Dajgoro
author_rank: Frequent Contributor
timestamp: April 06, 2014, 10:02:45 pm
content: Hi.A while ago I posted a topic about SD cards with the Arduino, and I got that working.But I can't always use a Arduino everywhere, so today I was looking for some SD card examples for other platforms, but the problem is that a lot of those examples use some old compilers, or some odd tools, and some specific mcu-s, so I wasn't able to successfully compile any of the examples I found.So does anyone know any good examples that work with current development tools for any sort of simpler mcu like atmega, pic18f, LPC13xx series, etc... ?Edit:I already tried fatfs and petit fat, and all of the examples are a bit tricky to get working...

author: lapm
author_rank: Frequent Contributor
timestamp: April 07, 2014, 12:40:14 pm
content: Maybe you should take closer look how to talk to Sd cards.. Its not that difficult. Its much more difficult to write code needed to use it with some sensible file system so you can actually read that sd card on computer later easily.https://www.sdcard.org/downloads/pls/

author: Dajgoro
author_rank: Frequent Contributor
timestamp: April 07, 2014, 12:56:01 pm
content: Actually, the idea was to not have to deal with any low level stuff at all.For example the Arduino has a library for sd cards that just works out of the box, it takes a lot of memory, but it works. You initialize it, and you can use read write files just if it was a program running on a pc.The thing is that when developing a project, such libraries are kinda important, because you often just don't have the time to go deal with low level stuff, and if it is time critical, you would just pick a platform with that solved.So that is why I started this topic to see if there are such libraries for other platforms that are not arduinos.
Exceed 30 Khz - Page 1
Forum section: electronics / beginners

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: November 05, 2019, 02:25:54 pm
content: I need a speaker or other element that can reproduce in 30 Khz and 40 Khz, since the speakers I have do not exceed 21Khz ..Necesito un parlante o otro elemento que pueda reproducir en 30 Khz y 40 Khz, ya que los parlantes que tengo no superan los 21Khz..

author: oPossum
author_rank: Super Contributor
timestamp: November 05, 2019, 02:38:52 pm
content: Search for "ultrasonic transducer" and "ultrasonic distance sensor"

author: Gyro
author_rank: Super Contributor
timestamp: November 05, 2019, 07:02:27 pm
content: Piezoelectric and ribbon tweeters are often capable of significantly exceeding 20kHz - I don't think your ears can though!As oPossum says, ultrasonic transducers are available that run at 40kHz and, I think, some maybe 32kHz but these are very narrow band tuned and not suitable for any other purpose (apart from bat detectors).

author: cliffyk
author_rank: Frequent Contributor
timestamp: November 05, 2019, 11:38:10 pm
content: Quote from: Gyro on November 05, 2019, 07:02:27 pmThe typical Arduino ultrasonic rangefinder module operates at 40 kHz.They can be had for< $5.00 on Amazon.

author: Brumby
author_rank: Unknown
timestamp: November 06, 2019, 01:47:55 am
content: The KEY question is whether you want a device to operate atone, specific frequencyin that band - or whether you want to operate overa range of frequencieswithin that band.Secondary question is one of curiosity (especially if wanting to operate over a range of frequencies) ... what is the application?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: November 06, 2019, 03:48:27 am
content: Depending on what you are doing, your existing speakers may work. The rating on speakers tells where their output drops below the in band value by some amount. Usually 3 or 6 dB. If you drive them hard there will still be output for quite a few kHz above that value. Electret microphones usually work somewhat to very high frequencies, though their response may vary by 10 dB or more over the ultrasonic range. You could try your speakers out and see if they are suitable for your application.

author: magic
author_rank: Super Contributor
timestamp: November 06, 2019, 06:59:20 am
content: Quote from: CatalinaWOW on November 06, 2019, 03:48:27 amMaybe if you buy them at MouserAFAIK, the ratings on speakers, and certainly on headphones, are completely devoid of any meaning whatsoever other than more usually means more within the same product line of the same manufacturer.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: November 06, 2019, 04:08:55 pm
content: Quote from: magic on November 06, 2019, 06:59:20 amWhat you say is true but it doesn't negate the point. Even the worst dreck will have some output at 30k. Whether it is enough to be useful will depend on the specific speaker and the OPs needs.
Exceeding attenuator max input voltage - Page 1
Forum section: electronics / beginners

author: ksat44
author_rank: Contributor
timestamp: May 04, 2022, 09:53:01 pm
content: Like the title says, I was just curious what could happen if the volts happen go above what's rated for the attenuator. I wanted to use the 20:1 Hantek and connect to an automotive primary ignition, which I've heard can sometimes exceed the stated 300V limit on the device.

author: bob91343
author_rank: Super Contributor
timestamp: May 05, 2022, 01:48:13 am
content: It could overheat and change in value or, worse, burn out.

author: bdunham7
author_rank: Super Contributor
timestamp: May 05, 2022, 02:10:45 am
content: The HT-201? It says it is designed for primary ignition, so it should be fine on any normal system (maybe not CDI) even if the peaks exceed 300V--which they often do. I don't see this 300V limitation--what exactly does it say?

author: Circlotron
author_rank: Super Contributor
timestamp: May 05, 2022, 03:10:41 am
content: The voltage rating will probably be frequency dependent. I've blown up two 400V rated probes with a 450V pulse that had a 1uS rise time.
Exceeding thermal camera temperature range - Page 1
Forum section: electronics / beginners

author: 4cx10000
author_rank: Regular Contributor
timestamp: October 25, 2019, 12:34:04 pm
content: Hi!What happens when the object temperature exceeds the object temperature range of a thermal camera? Tried to search but I could not find an answer or may be so that i did not fully understand what I read.I was looking at a FLIR C3 which has an object temperature range of -10°C to 150°C (14°F to 302°F and that will probably be just fine to most of my measurements, but what will the display show if the object I am pointing at has a temperature of 500°C?

author: Zero999
author_rank: Super Contributor
timestamp: October 29, 2019, 08:28:25 pm
content: It will most likely go off-scale

author: 4cx10000
author_rank: Regular Contributor
timestamp: October 29, 2019, 09:29:52 pm
content: Thank you Zero999!Well ... with other words then, if needed: better to buy a thermal camera with a wider object temperature range. I realize that I have to read up more on thermal cameras before I decide what to buy.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 30, 2019, 03:18:47 am
content: You might want to look at how to filter. Ex if you can find something that will filter out 400 C then anything that is 100 C through the camera will be 500 C

author: 4cx10000
author_rank: Regular Contributor
timestamp: October 30, 2019, 10:47:10 am
content: Hi JustMeHere!Thanks for your advice, but I am not sure how to practically deal with this. I was reading about different filtering and realized that it could be a not so easy task. However, it is of course possible, but with for example a FLIR C3 it feels a little scary. Have to read more about it or just simply pick another camera, but that would of course reveal in a not planed, extended budget.
Excel count no of words occurs in column - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: July 09, 2022, 06:37:16 am
content: 1. I have excel column as below:2. Need to show in excel how many times each individual word appears likeOne: 2Two: 2Three: 1Five: 23. How to do it?

author: Ian.M
author_rank: Super Contributor
timestamp: July 09, 2022, 09:30:58 am
content: *One* way of doing it is like this.How it works:In the columnuniquesapart from the first line (which is just the data value), there is a MATCH function that checks if thedatavalue is found anywhere above that line (note the slightly tricky array reference with the first row absolute). If not, it will return error value N/A. The IFNA function tests for that error value, and either returns thedataor an empty string.In the columncount, ifuniquesisnon-blanknot an empty string, it uses the COUNTIF function to count the number of occurrences of it within thedata

author: mariush
author_rank: Super Contributor
timestamp: July 09, 2022, 12:58:03 pm
content: If the number of words is very small, you could have a vertical column for each possible word somewhere far to the right where you put 1 or 0 if the cell has that wordex =IF(A2="One",1,0)Then you can have a summaryOne | =SUM(J1:K100)Two | = SUM(K1:K100)Three | = SUM(K1:L100).. and so on

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: July 10, 2022, 06:04:01 am
content: there are around 500 such words in a column, which may or may not be repeat.Checking for individual would be diffcult.Is there no such formula which can count each unique word?

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 10, 2022, 08:38:45 am
content: After applying the formula you can convert the formulas into values (In the example above right click column B, Copy, Paste as values) and then select column A and B and remove duplicates (on the Data menu). That will leave you with a single row for each value (word).

author: geggi1
author_rank: Frequent Contributor
timestamp: July 10, 2022, 11:15:45 am
content: the simplest way is to use the COUNTIF function.Here is a quick tutorial.https://www.w3schools.com/excel/excel_countif.phpI use this function a lot in my spreadsheets.

author: Ian.M
author_rank: Super Contributor
timestamp: July 10, 2022, 02:01:33 pm
content: Yes. That's what I did back in reply #1. The problem is to auto-populate the list of unique words, which I did by determining if the word did not appear on any line above it, which gave me the unique word next to its first occurrence, with its count next to that. If you need to eliminate the blank lines, you could try filtering on the unique word being not "".
Excellent article on Making a breadboard curve tracer - Page 1
Forum section: electronics / beginners

author: watchmaker
author_rank: Unknown
timestamp: October 01, 2023, 08:55:18 pm
content: This article does a great job of explaining Hfe and various instruments to measure it.The author then goes on to detail how to build a curve tracer and arbitrary wave form generator to run it. He includes SPice files and and such at the end.A biophysicist.https://www.biophysicslab.com/2021/04/27/testing_transistor_hfe/Regards,Dewey

author: liaifat85
author_rank: Regular Contributor
timestamp: October 02, 2023, 12:50:02 pm
content: Thank you. It is a resourceful article.
Exhaust Hood Fan Motor - Page 1
Forum section: electronics / beginners

author: Larsson55
author_rank: Regular Contributor
timestamp: June 16, 2021, 07:19:02 pm
content: Apologies if I’m in the wrong forum or section. We had to replace the old stove exhaust hood and looking at the fan motor I thought since it is a VS motor it may be suitable for my home made 5” mini table saw (currently it has a 48VDC motor and it straggles to cut anything above 1/8” ply).The motor is connected to a transformer type T57-0370, Class B 02414 and to a Capacitor 1200-020, 7.5 mF +/- 10%, type NS1PC, Non PCB, M07C10 made in UK. There is no indication about the motor RPM/ Amps.With the information provided is it possible to tell me what kind motor it is?Thank you

author: alpher
author_rank: Frequent Contributor
timestamp: June 16, 2021, 07:27:12 pm
content: Defitely not.

author: Manul
author_rank: Super Contributor
timestamp: June 16, 2021, 08:03:39 pm
content: AC single phase motor. Likely around 200W and not a torque monster too.

author: amyk
author_rank: Super Contributor
timestamp: June 17, 2021, 01:15:04 am
content: Posting some pictures of it would give a far better idea, but I'm almost certain it's going to be a multi-winding shaded-pole motor. Very low starting torque and power, definitely not suitable for a table saw.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 17, 2021, 11:51:24 pm
content: Here are 2 pictures of the motor. The motor is quite heavy for its size and use, I mean it only used to move air. Also I don’t know the purpose of the capacitor, perhaps it has to do with the variable speed? There is no specs written anywhere on the motor.BTW the table saw I mentioned in my first post is a MINI table saw with a 5” diameter blade, mostly used for hobby projects.From the motor picture do you have any idea of its approx. HP?Thank you

author: Manul
author_rank: Super Contributor
timestamp: June 18, 2021, 12:34:40 am
content: My guess would be somewhere between 0.1 - 0.2 HP maximum. That capacitor is probably a "run cpacitor". It shifts phase, to create a second phase for one of the windings.

author: amyk
author_rank: Super Contributor
timestamp: June 18, 2021, 04:17:59 am
content: Looks like an ebmpapst SR520132 / M4E068-DF63-80. Which according tohttps://datasheet.octopart.com/3214J/2H3F-191-EBM-Papst-datasheet-13189356.pdfis rated at only 42W of output power with 83W input, and has 30N.cm of torque - it's a PSC, so better than a shaded-pole, but not really what you'd want in a table saw.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 18, 2021, 07:42:53 am
content: Thank you folks, I have no experience with motors but I’m surprised for such a heavy motor to have almost no power. Not worth to keep it.

author: amyk
author_rank: Super Contributor
timestamp: June 18, 2021, 01:23:32 pm
content: That's because it's designed for reliability, not power density.
Expanding On Board Memory Hantek DSO5062b - Page 1
Forum section: electronics / beginners

author: tlu
author_rank: Regular Contributor
timestamp: October 16, 2012, 08:21:48 pm
content: To all Hantek DSO5062B owners, I would like to know if any of you had tried to expand the on board memory longer record time or perhaps allowing this dso to have deeper memory?Could this be done by unsoldering the one memory chip and replace it with a new one? Does the firmware need to be change to have the dso recognize this change?Just a thought, I don't know if it is even possible but seeing the BMV model having 2M of memory instead of 1M makes me think this is very well be possible since the Hantek DSO50262BM and BMV both have the extended memory.