hybridfree/eevblog-posts huggingface dataset:
Simulating vehicle electrical noise in a bench type setup - Page 1
Forum section: electronics / beginners

author: Bobertsawesome
author_rank: Regular Contributor
timestamp: March 27, 2020, 12:04:47 am
content: Hello there,My dad has a car audio amplifier that was acting up (intruding audible signal noise into the output stage), I recapped as a sort of standard protocol, but the noise remained, but even worse this time. I'm curious to as how I can inject noise into the 12v input, while the unit is powered from my bench supply. If I use my Waveform Generator directly across the + and - input, would it be protected against the 12v PSU source? Or would I need to place a diode in series with the output of the Generator to protect current from going into it? I plan to measure the voltage rail after the filtering caps to see if the problem is being introduced here.Thanks,Bobby.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: March 27, 2020, 12:32:32 am
content: DO NOT CONNECT YOUR WF GEN DIRECTLY TO 12V. It may be able to take but only MAYBE.A diode is not a bad idea...but...Two ways to inject noise into the power source:1 - With a switched load: Connect your WF gen through a resistor (say 1K) to the base of a fat NPN Darlington transistor on a heat sink. Connect the emitter to -ve (0V, or "ground") and the collector through a power resistor (say 10-15 Ohms, 25 Watt) to +12V. Turn the radio on. Dial up a sine/square wave on the WF gen at some few Hertz to few 100 Hertz to shake the 12V around at those frequencies.2 - connect the +12V input of the radio to the metal tang of a large metal Bastard file. The coarser the better. Have the wire from the power source stripped and handy. Turn the radio on and wipe the source wire up and down the file to create LOTS of sh!t, crap and corruption on the power to the radio. If it survives that it will survive anything from the 12V source.

author: Bobertsawesome
author_rank: Regular Contributor
timestamp: March 27, 2020, 01:21:41 am
content: Great idea, however, I do not have any single package Darlington pairs. I would assume building a basic paired circuit with the B817 and D1047 would work fine?

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: March 27, 2020, 02:10:26 am
content: Quote from: Bobertsawesome on March 27, 2020, 01:21:41 amNot the B817 as that is PNP but the D1047 could work. Pair it with cheap general purpose NPN signal or switching diode such as 2N2222 or 2N3904 or similar in your area. If your WG will drive 10 mA then maybe you can forget the 2n2222 and just connect it to the base of the D1047 through 1K. The signal at the WG should be 0V to 10V, not going negative.
Simulation of a blinking circuit (falstad) - Page 1
Forum section: electronics / beginners

author: maelh
author_rank: Regular Contributor
timestamp: January 13, 2021, 08:28:45 am
content: Hello,I have built a circuit from an electronics kit, which works as expected (blinking an LED).But thefalstad simulationof it, does not go into blinking mode. It lights up once, switches off, then gets "stuck".The manual has the circuit (which uses one center-tapped coil of the transformer, but not the other one -- so essentially it just uses two independent coils):https://www.robotshop.com/media/files/pdf/elenco-pk-101-manual.pdf(experiment #28, page 43).I am not sure what I could change to make it work. Any ideas?

author: Ian.M
author_rank: Super Contributor
timestamp: January 13, 2021, 09:01:21 am
content: Two coils do not equal a Transformer, as the simulator doesn't know about the magnetic coupling between them. Tryversion. It errors out after a few cycles but at least it oscillates.Falstad *sucks* for this compared to a real SPICE simulator running on your PC/Mac. The only thing going for it is its pretty animations! I strongly recommend learning how to use the freeLTspiceSPICE simulator. Its .asc simulation files are commonly used to share circuit ideas here and by other electronics communities.

author: maelh
author_rank: Regular Contributor
timestamp: January 13, 2021, 09:09:04 am
content: If you look at the schematic in the PDF, the secondary side of the transformer remains unconnected.The first simulation does oscillate, too, but it doesn't light the LED anymore.

author: Ian.M
author_rank: Super Contributor
timestamp: January 13, 2021, 09:21:07 am
content: What's the DC resistance of the transformer primary? Falstad *may* be better behaved if you add resistors in series with the transformer windings to match.However, the operation of aBlocking oscillatoris largely dependant on the transformer's core saturation characteristics, so Falstad is unlikely to give you realistic results. LTspice doesn't directly support saturating coupled inductors, but you can put a saturating inductor (Chan modelinductor core) in parallel with one of the coupled inductors to achieve the same effect.

author: maelh
author_rank: Regular Contributor
timestamp: January 13, 2021, 09:27:20 am
content: Thanks, knowing it's a blocking oscillator helps already a lot. I'll read and report back.
simulation of circuit - Page 1
Forum section: electronics / beginners

author: ishakderbak
author_rank: Newbie
timestamp: December 09, 2024, 01:10:16 pm
content: i need to simulate filters circuitthis is for my reportlabI would be glad if anyone could share simulation circuits with me since I struggle with them

author: themadhippy
author_rank: Super Contributor
timestamp: December 09, 2024, 01:33:22 pm
content: About the simplest and free simulation software out therehttps://www.falstad.com/afilter/circuitjs.html?startCircuit=filt-hipass.txt

author: ishakderbak
author_rank: Newbie
timestamp: December 09, 2024, 02:52:54 pm
content: what i will put in Ve and Vs

author: PGPG
author_rank: Frequent Contributor
timestamp: December 09, 2024, 05:21:27 pm
content: You have to drive Ve with AC voltage source and measure Vs (amplitude/phase). Spice should give you that.I can't be more specific. From Spices I used only PSPICE that I got demo at CEBIT messe around 1995 and used it last time about 15 years ago (since I moved from Windows 32 bit to Windows 64 bit it refuses to work). In 2023 I spend 2 days to check how Spice integrated in KiCad works.

author: stretchyman
author_rank: Regular Contributor
timestamp: December 09, 2024, 05:35:30 pm
content: LTSPICEIts free and everyone uses its coz its goodNo Brainer & no idea why its not already been recommended . Never heard of the other stuff mentioned?

author: PGPG
author_rank: Frequent Contributor
timestamp: December 09, 2024, 08:38:28 pm
content: Quote from: stretchyman on December 09, 2024, 05:35:30 pmAbout 2005, after 10 years of using PSpice demo version (limited to 30 nets, but it was even too much for my needs) when I practically simulated all what I needed I got info about LTSpice. I tried it, butI was lost in the fact that I had to write out some text commands in the schematic instead of setting the voltage/current source parameters after clicking on the source symbol and simply setting the simulation parameters in the dialog box opened from menu like I had it 'since always' in PSPICE. In the dialog box you see what you are setting while writing command you have to remember all symbols to be used.Do in LTSpice you still have to write text commands at schematic?I practically don't need Spice, but as KiCad (that I use to design PCB) have Spice in it (not very flexible yet, but each year better) than why not to have two tools with one schematic drawing interface...

author: Zero999
author_rank: Super Contributor
timestamp: December 09, 2024, 10:22:44 pm
content: Just use LTSpice.
Simulator of Piezoelectric Actuator - Page 1
Forum section: electronics / beginners

author: Freshman
author_rank: Regular Contributor
timestamp: December 16, 2024, 04:50:47 am
content: I was going through this Simetrix user manual (https://www.simetrix.co.uk/Files/manuals/9.0/SimulatorReference.pdf)to find out whether we can simulate actuators in Simetrix. Unfortunately, I couldn't find any.I am using this High Voltage Driver IC (https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/HV56264-Data-Sheet-DS20006477.pdf) to simulate this actuator (https://www.digikey.com/en/products/detail/epcos-tdk-electronics/B54102H1020A001/10257750).Should we create a model like this for an actuator? If some, any guidance on how to do it?

author: Terry Bites
author_rank: Super Contributor
timestamp: December 16, 2024, 04:38:40 pm
content: Have a readhttps://www.semanticscholar.org/paper/Modeling-an-Ultrasonic-Transducer-with-SPICE-Deventer/a85db298b8f63050d62f2d0fe598aa7bade1d078
Simulink Model for control of Full-Bridge DC-DC - Page 1
Forum section: electronics / beginners

author: Wrydog
author_rank: Contributor
timestamp: April 30, 2017, 02:18:02 am
content: Hello,I've some questions regarding my Simulink model shown below. This is primarily for controlling the output voltage of a full-bridge DC-DC converter.For the top model, I have a pulse generator (340V pulses) to represent the output of the two diodes on the secondary side of the transformer. For the plant, I have the transfer function of the inductor and the output capacitor which also has an 18 Ohm resistor b/c that's what was needed to get a good phase margin.The bottom model is mostly the same except for a step input that goes to 340V.I used Matlab's handy pidTuner to find values of kp and ki using the transfer function as the system. These values came to kp=1.022 and ki=4685.With the lower model, the output looks good, i.e. goes to 340V. However, the top model levels off a 666V. I assume that this is due to the pulsed input and that this top model is not correct. Is that right? Since the output node has a capacitor that can't change quickly can I assume that the step input is ok to use?What can I do to improve this? For instance, add a controller before the plant to vary the duty cycle based on output V? How would that work in the s-domain?Thanks.

author: Wrydog
author_rank: Contributor
timestamp: May 01, 2017, 07:23:01 am
content: Thanks Blue,Can you explain why it's 340+340? Doesn't subtracting the output from the reference voltage in this case work?
Simultaneous control of (PSU) outputs - Page 1
Forum section: electronics / beginners

author: christerb
author_rank: Newbie
timestamp: September 05, 2020, 04:59:21 pm
content: I need +/-15 VDC for the labs in Learning the Art of Electronics. I started out with a single channel PSU (TTi EL183) and a Digilent PowerBRICK (5 V to +/-12 V). It was sufficient most of the time, but I would have preferred +/-15 V. Now, after a long break, I want to continue (or maybe start over) with a 2-channel PSU. First I thought of TTi EL302RD (similar to what I have, but two channels). It has an on-off switch for each channel. Some PSUs can control both outputs simultaneously. When looking at TTi PL303QMD, I noticed in the manual that "Synchronous switching of the outputs is of increasing importance for circuitry which can be damaged if one voltage rail is present without the other." Is this feature important for opamps?

author: ledtester
author_rank: Super Contributor
timestamp: September 05, 2020, 05:54:29 pm
content: Here is a related eevblog forum thread:https://www.eevblog.com/forum/beginners/dual-power-supply-onoff-switch-for-opamp/

author: David Hess
author_rank: Super Contributor
timestamp: September 05, 2020, 08:03:06 pm
content: Quote from: christerb on September 05, 2020, 04:59:21 pmDual tracking power supplies are a common configuration going back decades; I like the old Tektronix PS503A but HP and others made them as well. Consider just making one out of an LM317 and LM337.QuoteIt can be important for operational amplifiers depending on the circuit. For instance in some operational amplifiers, powering up the positive supply before the negative supply while the common mode voltage is zero results in phase inversion which causes their output to go to the positive supply which may be really undesirable. In naive power supply designs, this results in a destructive positive glitch in the output voltage.
Sine oscillator - Page 1
Forum section: electronics / beginners

author: thefatmoop
author_rank: Contributor
timestamp: May 21, 2013, 09:54:59 pm
content: I'm making an LC meter and currently waiting on my DDS module. I wanted to free up my function gen, so i built a buffered phase shift oscillator.http://www.ti.com/lit/an/slyt164/slyt164.pdftop of phage 4.The yellow is the output of the oscillator, and the blue is the output of the RL voltage divider. Is the blue non sinusoidal because the oscillator has a lot of THD? Is this type of oscillator a parabolic oscillator?the op amps i'm using have 6mhz BW

author: Paul Price
author_rank: Super Contributor
timestamp: May 21, 2013, 11:49:09 pm
content: Looks to me like a quasi-quadrature elliptical transform oscillator. Definitely not a parabolic amplifier.
Sine to square. - Page 1
Forum section: electronics / beginners

author: neo
author_rank: Super Contributor
timestamp: May 25, 2017, 10:31:04 am
content: Not a question, just a useful circuit that i figure might be useful to someone. 60 HZ AC to a DC SQ wave, with variable voltage. It could probably be nit picked to death but this is what i came up with and it works for me, the resistor values are just what i had a bag of and they happen to work as for the transistors just about any npn and pnp will work. The zener diode exists only for two reasons, protection for the transistors and it keeps it from going negative. This took me a long time to figure out by just experimenting, longer than i care to admit.

author: danadak
author_rank: Super Contributor
timestamp: May 25, 2017, 11:20:48 am
content: I am not an expert in AC line interface but there may be safety issues youshould be concerned about. Hopefully other posters can comment on thisaspect of the design.One approach is to use an OptoCouper, lots of isolation, easy to implement.http://icecube.wisc.edu/~kitamura/NK/Datasheets/misc/5988-4082EN%20designers%20guid.pdfRegards, Dana.

author: neo
author_rank: Super Contributor
timestamp: May 25, 2017, 06:58:28 pm
content: Quote from: danadak on May 25, 2017, 11:20:48 amor just use a low voltage output transformer? As i said im sure its not perfect but it does work.

author: shteii01
author_rank: Frequent Contributor
timestamp: May 25, 2017, 11:29:01 pm
content: Timer-Generator Circuits Manual by R. M. Marston, Chapter 3, published in 1990 or 1991.
Sine Wave generator connecting rca audio - Page 1
Forum section: electronics / beginners

author: moutaindave
author_rank: Newbie
timestamp: January 09, 2025, 01:32:32 am
content: I need to connect a rca jack to my sine wave generator my options are gnd, 4-20ma, tri sin 2-10v pulse pwm I'm wanting to output 528hz.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 09, 2025, 05:43:45 am
content: Please attach a photo of your sine wave generator

author: moutaindave
author_rank: Newbie
timestamp: January 10, 2025, 04:17:27 pm
content: https://photos.app.goo.gl/i3MEy4yUFsuaQJa27

author: TimFox
author_rank: Super Contributor
timestamp: January 10, 2025, 04:56:54 pm
content: From that photo, the sine wave should be available between  and [TriSin2-10V].What does the manual say? I assume the front panel has a selection of Triangle or Sine, with the output at that terminal.
sine wave to square wave input about 14MHz 10Vpp and output 0/5V - Page 1
Forum section: electronics / beginners

author: juvann
author_rank: Contributor
timestamp: October 16, 2022, 05:48:36 pm
content: Hi,I have the attached signal about 14MHz and about 10VppI'd like to transform in square wave 0/5 V with a circuit single power 5V. I read some threads in this forum, but none support input voltage as in my case.Have you suggestions?

author: tggzzz
author_rank: Super Contributor
timestamp: October 16, 2022, 06:03:25 pm
content: That looks like an aliased signal to me; 14MHz and 30MS/s.What leads you to believe it is 14MHz and not a higher frequency?

author: juvann
author_rank: Contributor
timestamp: October 16, 2022, 06:08:16 pm
content: Quote from: tggzzz on October 16, 2022, 06:03:25 pmBecause the source which generate the signal is a NFC device which should trasmit at 13.56MHz, is not perfect 13.56MHz but can't be more than 14MHz

author: tggzzz
author_rank: Super Contributor
timestamp: October 16, 2022, 06:19:34 pm
content: OK.I would AC couple the input to 2.5V (i.e midway between power rails), a resistive divider to reduce the input swing to 5Vpp, diodes to prevent signal going >5V and <0V, and a comparator or schmitt trigger to square it up.If unsure, simulate your design with LTSpice or similar.

author: langwadt
author_rank: Super Contributor
timestamp: October 16, 2022, 06:27:39 pm
content: Quote from: tggzzz on October 16, 2022, 06:19:34 pmyeh, capacitor resistor into HC14 biased to ~2.5V

author: juvann
author_rank: Contributor
timestamp: October 16, 2022, 06:56:24 pm
content: So the circuit attached and which I foundhereis good for me. Correct?

author: tggzzz
author_rank: Super Contributor
timestamp: October 16, 2022, 07:09:32 pm
content: Thats the concept, but you will need to work out the details relevant to your application.

author: Benta
author_rank: Super Contributor
timestamp: October 16, 2022, 07:31:15 pm
content: Actually, this should be enough:

author: langwadt
author_rank: Super Contributor
timestamp: October 16, 2022, 07:44:51 pm
content: Quote from: Benta on October 16, 2022, 07:31:15 pmdepending on the size of the cap you might want a series resistor to limit the current through the ESD diodes

author: Benta
author_rank: Super Contributor
timestamp: October 16, 2022, 07:49:13 pm
content: Quote from: langwadt on October 16, 2022, 07:44:51 pmFor a 14 MHz input signal, I don't see a big issue...But you're right in another sense; the OP mentioned 10 VPP, which has to be reduced to 5 VPP, of course. A series resistor half the value of R1 or R2 is needed.Modified schematic:

author: juvann
author_rank: Contributor
timestamp: October 23, 2022, 07:21:10 am
content: The Benta's schema works very well.I used a capacitor 470nF, a resistor 1KOhm and 2 resistor 10KOhm for divisor, with a resistor 4.7KOhm doesn't work, the signal is very low about 100mVpp.

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2022, 07:51:20 am
content: GoodThanks for reporting the results, too. Not everybody is so courteous.As I told my daughter, continue to "have fun, safely"!
Sine Wave - Page 1
Forum section: electronics / beginners

author: rekittag
author_rank: Newbie
timestamp: June 03, 2014, 09:51:25 pm
content: The "Step", "Line", and SinX/x button are grayed out. In most of the illustrations and photos, channel #1 is a sine wave. Step-bystep instructions star with "Set the HU to a sine wave..." Nothing that I do will get it to happen. I have tried and tried. I have read everything I can find. I have reloaded, re-downloaded, and reloaded the software.If no one can tell me what to do, I'll just return it.

author: c4757p
author_rank: Super Contributor
timestamp: June 03, 2014, 09:57:32 pm
content: Oh ffsWhat software?

author: rekittag
author_rank: Newbie
timestamp: June 03, 2014, 10:00:58 pm
content: It's a Hantek 6022be, the software came with it.

author: miguelvp
author_rank: Super Contributor
timestamp: June 04, 2014, 03:08:57 am
content: manual:http://www.electronicaestudio.com/docs/Hantek6022BE_Manual.pdfSeems to me that, the Step, Line and SinX/x are the interpolation settings (defaults to SinX/x) page 38 of the manual (40 of the pdf file)This won't generate a source or make a square wave into a sine wave. Not sure what you expect it to do.What those do, are to set how the data coming in will be interpolated and displayed.It's under the Utility/Interpolation menu

author: DJohn
author_rank: Regular Contributor
timestamp: June 04, 2014, 09:32:23 am
content: In pictures like the one on the bottom of page 36, the sine wave will be a signal that they're supplying externally. It's just a simple signal that they can use to illustrate the particular function they're talking about. The oscilloscope will not generate sine waves for you, as Migeulvp says. It's meant for looking at signals, not creating them.I don't have this particular scope myself, so I can't guarantee that I'm 100% accurate on this, but I would guess that the reason the Step / Line / SinX/x options are grayed out is because interpolation is not available on the timebase you've chosen. The scope has some maximum frequency that it can sample at. Interpolation will invent values for the times in between if you zoom right in. It doesn't make sense to use it at (say) 10us per division, because it has more than enough samples to display the signal accurately.There's a note just before the start of section 3.6.3, on page 38, which says "At the time base of 40ns/div or faster, user can use the 3 different interpolation modes to get waveforms of different smoothness". Set the timebase to 40ns or faster, and those options will probably be enabled.You might use Step or Line if you know that the signal is digital, and SinX/x if it's analogue. But there's no need to use this feature unless you've got a fairly high frequency signal.
Single (1 pos) 2.54mm 0.1" crimp housing - Page 1
Forum section: electronics / beginners

author: klmbk
author_rank: Contributor
timestamp: December 10, 2019, 10:44:48 pm
content: Suppose I'd like to make some jumper wires for the standard 2.54mm pitch rectangular pin header or socket.I must be missing something obvious, but so far I could only find two products for single crimp housing.Amphenol 65039-036LF ~ $1.20TE 7-87499-2 ~ $0.60I've a problem with their pricing. That makes up to $2+ for one jumper wire. That can't be it?

author: langwadt
author_rank: Super Contributor
timestamp: December 10, 2019, 10:52:24 pm
content: the keyword is dupont,random ebay hit,https://www.ebay.com/itm/254288790699

author: klmbk
author_rank: Contributor
timestamp: December 10, 2019, 11:05:14 pm
content: Forgot to say I was thinking of buying them from one of the usual big name distributors. As in adding them to an existing shopping list.But of course a bag of these on e.g. Ebay seems to be much cheaper, it seems like the way to go is to wait for the shipping and then be done with it.

author: chris_leyson
author_rank: Super Contributor
timestamp: December 10, 2019, 11:13:20 pm
content: Harwin M20-1060100 available from Farnell and Mouser

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: December 11, 2019, 12:49:21 am
content: Quote from: chris_leyson on December 10, 2019, 11:13:20 pmThe way I make test leads of this type is to solder insulated wire into a suitable crimp contact, e.g.https://www.harwin.com/products/M20-1160042/and then use heatshrink tubing for strain relief and insulation over the contact body. Every few years I buy a reel of 1000 contacts (usually a Molex part) for this purpose.For the wire, I typically use leftover ribbon cable, either conventional or twisted pair. PVC insulation on cheap ribbon cable means you have to be careful and quick when soldering it, but with practice it is not a problem.This makes for cheap test leads when prototyping.

author: klmbk
author_rank: Contributor
timestamp: December 12, 2019, 08:55:31 pm
content: Quote from: chris_leyson on December 10, 2019, 11:13:20 pmThanks, the price of this one makes much more sense, I think.I got a few Amphenol 47649-000LF and 48247-000LF female crimp terminals on hand. I suppose if the housing is described as 2.54mm pitch and looks similar enough then they're likely Dupont type and mostly compatible, including the noname ones, and with male pins as well. (It's all just for hobby use in this case.)

author: Wendy_Preston
author_rank: Contributor
timestamp: December 13, 2019, 08:55:46 am
content: Quote from: chris_leyson on December 10, 2019, 11:13:20 pmJust for sake of completeness to this post (and tech drgs etc.) here's our website link to the housing mentioned:https://www.harwin.com/products/M20-1060100/This one will be properly compatible with thehttps://www.harwin.com/products/M20-1160042/contact you mention - just a push fit into the hosuing. You can also buy those M20-1160042 contacts as individual items, not on the reel:https://www.harwin.com/products/M20-1180042/Hope that's helpful!
Single Cell Li-ion to 3.3V - Page 1
Forum section: electronics / beginners

author: kissste
author_rank: Newbie
timestamp: January 18, 2017, 10:02:26 pm
content: Hi,I'm looking for a single cell li-ion (3.0-4.2v) to 3.3v step-down/step-up or just LDO tracking down to 3.0V and shutdown.peak @250mA, for max 20 seconds, then sleep for minuteThank you for any suggestionssomething like - ucc3954 - but, it's obsoletebut does not even have to be complicate, simply LDO to 3.3v when above 3.3v and then track down to 3.0v, and shut down there

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: January 19, 2017, 12:18:54 am
content: Here I have filtered for you the list of LDOs, your option to choose with shutdown or no shutdown , and use voltage divider for proper shutdown level.http://www.digikey.com/products/en/integrated-circuits-ics/pmic-voltage-regulators-linear/699?k=ldo&k=&pkeyword=ldo&pv129=76&FV=fff40027%2Cfff80182%2C10a40002%2C1f140000%2Cffe002bb%2C7ec0044%2C7ec0045%2C7ec0047%2C7ec004b&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500
Single Chip MW shortwave & FM Superheterodyne Receiver - Page 1
Forum section: electronics / beginners

author: jonovid
author_rank: Super Contributor
timestamp: March 28, 2018, 04:30:37 pm
content: BK1198 Single Chip Superheterodyne Radio Receiverhttps://www.jaycar.com.au/medias/sys_master/images/9071614492702/ZK8829-dataSheetMain.pdfBeginners Superheterodyne Receiverhas anyone used the BK1198? so is it any good or just a toy?listed in the new 2018 Jaycar electronics cataloguejust one resistor sets so many bands

author: MasterT
author_rank: Frequent Contributor
timestamp: March 28, 2018, 05:29:38 pm
content: Looks similar to digital radio receiver from SiLab, Si4825. Though, Si4825 has wider SW band, from 2.3 to 28.5 MHz.https://www.digikey.ca/product-detail/en/silicon-labs/SI4825-A10-CSR/336-4481-1-ND/8540653

author: BigAlTeh
author_rank: Newbie
timestamp: June 13, 2018, 06:03:48 am
content: Yes, I have build the radio using the chip BK1198. It is very sensitive and able to pick up distance stations. Well design by the Chinese engineers.I am very pleased with the performance. The performance is much better than the TD7000 chip.

author: Kevingo
author_rank: Newbie
timestamp: August 16, 2020, 08:14:56 pm
content: I built the radio using the jaycar spec and it is very good.It is amazing on shortwave and picks up many distant stations. Band selection works well via a simple pot too instead of the resistor chain.
Single Coil Latching Solenoid - Page 1
Forum section: electronics / beginners

author: djbunting
author_rank: Newbie
timestamp: November 07, 2014, 05:22:02 am
content: I have kludged together a system to control single coil latching solenoids for remote control and I am looking to further the project and roll my own solution.The specs for solenoids I am controlling are as follows:Voltage: 9 - 12 VDCResistance: 4.2Switching Time: 25-50 msecThe system runs on a 12v sla batteryThe mcu can source a maximum of 4mA at 3.3VCurrently I use this circuit to control the solenoids with a single mcu io using an onboard relay and a 4700uf capacitor.After a lot of browsing I have determined the below circuit to be the simplest I can find to do a similar operation without a relay. Note solenoid coil is the 100ohm resistor under capWhat I would like to know is what specs I need for the transistors to drive a solenoid of the above specsOr is there a simpler ? more elegant? more reliable solution?I appreciate any help you can give me thank you very much in advance.Long time amp hour / eevblog listener first time caller?

author: German_EE
author_rank: Super Contributor
timestamp: November 07, 2014, 09:14:17 am
content: Where is the relay coil in your schematic?

author: djbunting
author_rank: Newbie
timestamp: November 07, 2014, 09:45:09 am
content: Sorry should have mentioned that solenoid coil is the 100ohm coil under next to the 220uf capThank you
Single COM LCD with 1621 driver - Page 1
Forum section: electronics / beginners

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: May 25, 2020, 02:18:35 pm
content: Not sure if this is exactly "beginner" but I'm not sure where else it fits. For power reasons (and uC pin count) I would like to drive a single COM LCD display with a 1621 derivative LCD driver. The 1621 says that it can so 1/2 or 1/3 bias and 2 to 4 COMs. Does this mean I'm out of luck? Or can I hook up, say, 2 COM outputs to the same single COM on the display and just drive it twice? This is for custom glass that I am having built, but it was only after the drawings came back that I was able to test the setup and realized that I really need an LCD driver rather than relying on the uC. Anyone have any experience in this department?

author: ebclr
author_rank: Super Contributor
timestamp: May 25, 2020, 04:37:37 pm
content: You can use without problems, Juts maintain disconnected the other ones, Set the BIAS &COM to 2 COM.Make sure you really need only 1 com even small lcds use 2 3 4 , look more careful on your LCD specs, More coms makes the LCD cheaper and easy to makeHere a simple 4 digit LCD example

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: May 26, 2020, 02:36:08 pm
content: Thanks! Like I said, I'm having these made for a project, so I know that it's only one COM for sure (it's only like 12 segments) but I got nervous when I decided to switch to a driver because all of the driver ICs that I can find only drive at multiple bias. I could probably have them retool for two COMs, but it's great to know that I probably won't have to.
Single connector Molex SL crimp housing? - Page 1
Forum section: electronics / beginners

author: dystopia
author_rank: Newbie
timestamp: May 20, 2021, 01:28:41 am
content: Hi,I've been using Molex SL series connectors for making custom PCB to PCB cables - pretty happy with them.I can't, for the life of me, find a single connector crimp housing either in the SL or KK series. I bought a "Dupot" connector set from Amazon - and the quality was, well, Amazon quality.Any recommendations for a .1" pitch single connector housing?

author: rdl
author_rank: Super Contributor
timestamp: May 20, 2021, 10:40:50 am
content: In the official Molex SL series, single position is not available. I've cut them down before but that's a bit wasteful. Pololu may have something that will work for you.https://www.pololu.com/category/39/cables-and-wire

author: dystopia
author_rank: Newbie
timestamp: May 21, 2021, 04:02:08 pm
content: Doh! How could I forget Pololu? Thanks for the ref - have ordered a bunch.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 21, 2021, 04:29:23 pm
content: "Any recommendations for a .1" pitch single connector housing?"How do you determine the pitch of a single conductor?Do you want a sliding connector, locking connector, etc? The "Berg-type" connector (now Amphenol?) will work with single conductors. Bullet and spade connectors are more robust, but are usually used for higher currents in such things as model airplanes and autos . There are also knife (aka jack knife) and locking wrist connectors (visualize shaking hands holding the other person's wrist). I have seen the latter two mostly in aircraft, but I use them when I want a reliable connection that is infrequently opened.Edit: Here's a link to Digikey Berg con connectors:https://www.digikey.com/en/products/filter/rectangular-connectors-headers-male-pins/314?s=N4IgjCBcoLQCxVAYygMwIYBsDOBTANCAPZQDaIArGAJwUgC6Avo4QExkgBGuATgOYACJEQB2I3EgAuRHg0ZA
Single DDR3 -> Processor line termination - Page 1
Forum section: electronics / beginners

author: subzero
author_rank: Newbie
timestamp: November 14, 2017, 02:13:07 am
content: Hi all,I've been working on microcontrollers for a little while, and I am just starting to make the transition into processors and external memories. I just have a few beginner questions about line termination between a single DDR3 and an A13 (Allwinner) processor.There has been a bit of conflicting information in appnotes and other sources that I have read. Some say that the line termination is only required for processor to multiple DDR3s, and some say that termination is required for a single DDR3. The Beaglebone Black schematic has no termination resistors on any lines (processor to single DDR3), yet the Olimex A13-512SOM (single DDR3) has 33 ohm termination resistors on all lines to the DDR3.A forum entry by a TI employee (on TI's forums) said to use the Beaglebone Black as a proven reference design (no terminating resistors), so presumably termination is not required in the case of a single DDR3, and only length tuning (and layer traversal) between the various byte lanes, control and address signals is the important part.What is the general consensus on line termination for a single DDR3? How important is line termination in this scenario?Thanks!

author: subzero
author_rank: Newbie
timestamp: November 14, 2017, 04:39:18 am
content: Thanks for the reply, blueskull.So it should be okay to leave the terminating resistors off the lines (as long as I maintain a 50 ohm transmission line), and tweak the ODT values as necessary?
Single ended signal on PCB - Page 1
Forum section: electronics / beginners

author: Vcky_electro
author_rank: Contributor
timestamp: June 13, 2019, 12:19:39 pm
content: Hi,I have designed board, in that due to board room limitation we cant achieve 50ohms impedance for single end signal. 60ohms is possible in that design, so what would happen if we use 60ohm impedance trace instead of 50ohm trace..Regards,Vicky

author: Raj
author_rank: Frequent Contributor
timestamp: June 14, 2019, 05:43:02 pm
content: you'll have to change your termination method, that's it
Single gauge and dual gauge TO-220 - Page 1
Forum section: electronics / beginners

author: mike_mike
author_rank: Super Contributor
timestamp: September 09, 2018, 11:36:04 am
content: Dear Forum,I recently bought a few LM317T in TO-220 case. I saw that the heatsink of those LM317 is very thin. I found that they are single gauge.I tried to install one of them on a heatsink, but I cannot install it properly because when I squeeze the M3 nut the lower part of the LM317T is rising from the heatsink and the heat generated by the LM317T is not absorbed by the heatsink, making LM317T to overheat.What should I do to install those LM317T properly on the heatsink ? I know that I can mount the LM317T using a clip, but sometimes I cannot use a clip due to the heatsink dimensions...Thanks in advance.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 09, 2018, 12:43:10 pm
content: The best way to solve this problem would be to buy some higher quality regulators that are made with correct thickness tabs and scrap the cheap ones. My fear would be if the people who made these knock-off cheap regulators cut corners on tab thickness, what else did they do internally to save money and will I find other problems over time if I use them.If you want to try using them (which I don't recommend) you could try using the largest size thick flat washer you can fit under the nut to hold the regulator on the heatsink without distorting the tab. If this works you're still going to be wondering when these cheap parts might fail.

author: james_s
author_rank: Super Contributor
timestamp: September 09, 2018, 04:26:16 pm
content: It sounds like what you bought are cheap counterfeit parts, they are probably deficient in other areas as well. I agree with the above poster, you should get some genuine parts.

author: floobydust
author_rank: Super Contributor
timestamp: September 09, 2018, 05:24:56 pm
content: This is cheap crappy Fairchild junk, who came up with "single gauge" TO-220Tab is 0.55mm thick verses 1.3mm(note F).It easily bends and doesn't fit insulator bushings. Absolute junk KA317.Buy another manufacturer's part.

author: djnz
author_rank: Regular Contributor
timestamp: March 22, 2019, 06:34:12 pm
content: I was bitten by this issue today, and the parts were of known provenance, bought from authorized distributors. Upon investigation, it was clear that this is not a case of counterfeit parts etc; many (all?) manufacturers are supplying TO-220 parts with thinner tabs now, by default, and have re-designated the old thicker tabbed parts to other order codes. For example, ST's version of the thicker tabbed 7805 is now L7805CV-DG, and if you just order L7805CV, you get the one with a thin tab.

author: Jwillis
author_rank: Super Contributor
timestamp: March 22, 2019, 09:50:18 pm
content: Shoulder washers.
Single Non Inverting Buffer With Open-Collector High-Voltage Output - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: May 17, 2018, 01:52:54 am
content: Hello,does anyone knows if there is asinglenon inverting buffer with open drain/collector on chip that will takes 5V as input and with a pull up resistor will have 12V on the output? I found the SN7407 but it has 6 buffers inside the chip. I found many sinlge buffers but not with "High-Voltage Output". Thanks in advance.SN7407 datasheet:http://www.ti.com/lit/ds/symlink/sn7407.pdf

author: Wimberleytech
author_rank: Super Contributor
timestamp: May 17, 2018, 02:16:12 am
content: Are you constrained by space?

author: 2X
author_rank: Frequent Contributor
timestamp: May 17, 2018, 11:23:49 am
content: Yes, space is an issue.

author: Peabody
author_rank: Super Contributor
timestamp: May 17, 2018, 02:04:35 pm
content: I'm not aware of of a single-gate part that will handle 12V on the output. If you don't find one, you could combine a single inverting buffer such as the MC74VHC1GT04 with an NPN transistor. You would need a base resistor and the collector resistor to 12V.

author: David Hess
author_rank: Super Contributor
timestamp: May 17, 2018, 07:04:37 pm
content: Do you need current gain?If not, then a single NPN transistor operating in common-base mode with the base biased from the logic supply can operate as a high voltage buffer with an open collector output. A single part like apre-biased transistorcan work this way. Any logic level n-channel MOSFET will also work.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 17, 2018, 10:10:17 pm
content: Yes, a dual BJT or MOSFET, with pull-up resistor [and base limiting resistor -- or use the "prebiased" kind].Alas, sad that 7406/7 is the only 30V part (and there were some oddballs for driving nixie tubes at 100V+), IIRC. When they made 74HC, they didn't try to make a 30V version. Nor the 74HC1Gxx and TinyLogic families. (Incidentally, 74LVC (and the respective TL family) is "high voltage tolerant", but that means 5V for a chip intended for 2-3V operation, not 30V.)Tim

author: Wimberleytech
author_rank: Super Contributor
timestamp: May 17, 2018, 11:13:48 pm
content: For dual MOSFET, here is an option: TD9944

author: 2X
author_rank: Frequent Contributor
timestamp: May 18, 2018, 12:27:52 pm
content: Thanks all of you for the replies.
Single, or few, transistor inverter or buffer with semi-precision threshold - Page 1
Forum section: electronics / beginners

author: Infraviolet
author_rank: Super Contributor
timestamp: June 11, 2024, 12:41:18 am
content: Is there an easy way with a small parts count, something like one or two transistors and a very few resistors to make either a NOT gate or a buffer gate with a reasonably precise threshold at whatever voltage one desires? Hysteresis not required, but ok if it can be added with no increase in part count.A typical logic gate IC will, depending on the logic family, have either a wide or narrow input range where the state changes, may or may not have hysteresis, and will always have this range where the change occurs centred either on a fixed voltage or a fixed proportion of Vcc. But if one wants to create pre-gate inputs to systems of standard logic gates, is there a way to do it?Say you want a logical inverter which takes Vcc=5V, and then has it's output stay high (at 5V or close) while the input is under 4V (+/-0.3V, semi-precision as I said, doesn't need a perfect threshold +/-0.01V or anything like that), and the output go low (<0.5V, hopefully very near Gnd) when the input gets above this fairly high threshold. Or 4/5ths Vcc if this is a better way to think of it than 4V. Is there a circuit design which will behave like this for any given threshold you select, perhaps subject to the constraint that the threshold selected must be > Gnd+1*(diode or transistor drop) and < Vcc-1*(diode or transistor drop)?I'm interested in ways to do this with generic parts, not special specific ICs designed as custom threshold logic inputs. Comparators don't seem so great an option either, as they don't seem to have standardised pin positions the way op amps often do (atleast for quad op amp packages).Thanks

author: David Hess
author_rank: Super Contributor
timestamp: June 11, 2024, 12:56:43 am
content: A differential pair does exactly that. Emitter coupled logic (ECL) works exactly like this and relies on a hidden reference voltage applied to the other side of the differential pair to precisely control the threshold voltage of the gate input.The simplest implementation is a comparator, which will work fine as either a logic buffer or logic inverter with a precision threshold.
Single phase rectifier with 1 thyristor in LTspice - Page 1
Forum section: electronics / beginners

author: Michelemmike
author_rank: Newbie
timestamp: April 28, 2022, 03:27:30 pm
content: Hi,I'm having trouble simulating this simple circuit in LTspice, since all I get is a bunch of random spikes. The .asc file is attached. The thyristor I used is a real component.Here's the datasheet:https://www.vishay.com/docs/94391/vs-70tpspbf.pdfHere's the Spice model:https://www.vishay.com/docs/96761/vs-70tps16.pdfCan anyone help me?

author: Terry Bites
author_rank: Super Contributor
timestamp: April 28, 2022, 05:15:31 pm
content: Is your trigger pulse delay triggered off of the zero crossing point of the AC?Are your gate drive pulse width, current and polarity correct? Gate drive is essentially current and not voltage driven.Your pulse source must be able to supply the required current. If you dont meet the min pulse with firing will be erratic or non existentCheck your datasheet for appropriate gate current.https://electricalbaba.com/single-phase-half-wave-controlled-rectifier/

author: Michelemmike
author_rank: Newbie
timestamp: April 28, 2022, 08:02:38 pm
content: Quote from: Terry Bites on April 28, 2022, 05:15:31 pm- Yes. The delay is 3ms. The period of the AC source is 20ms.- I'm driving the gate with an indipendent current source.- The pulse width is set to 1ms, is it ok? I don't see any info about that on the datasheet.- I set the gate current to 80mA, since the Maximum DC gate current not to trigger is 6mA and the Maximum required DC gate current to trigger ranges between 80-150mA depending on temperature.- The polarity is correct, I think. Thake a look at the attachment. I'll insert also a png.The thing is, that the circuit works with the default SCRs. I'm having trouble with this one, which is a manufacturer's one.
Single pulse circuit to ON relay once - Page 1
Forum section: electronics / beginners

author: afsar
author_rank: Newbie
timestamp: November 19, 2021, 03:07:04 pm
content: I am looking for a circuit to ON relay once using a single pulse when power on. I can achieve this easily using microcontroller such as arduino. But I am looking for passive components to achieve this objective. I have used different combinations with 555 timer bus nothing worked for me. My standard problem is "When power on, the circuit will wait for 20 seconds and after that 500 msec square pulse will on the relay and after that relay will be off. Please help!

author: ledtester
author_rank: Super Contributor
timestamp: November 19, 2021, 04:01:54 pm
content: A little microcontroller would be the simplest approach.Are you familiar with the Digispark boards? You can use the Arduino IDE to program them.https://www.google.com/amp/s/www.instructables.com/How-to-Setup-DigiSprak-Attiny85-Board/%3famp_page=true

author: IDEngineer
author_rank: Super Contributor
timestamp: November 19, 2021, 04:11:32 pm
content: Cascade a pair of oneshots. Done!

author: afsar
author_rank: Newbie
timestamp: November 19, 2021, 05:07:46 pm
content: Please read my post again! Thanks

author: afsar
author_rank: Newbie
timestamp: November 19, 2021, 05:09:31 pm
content: Thanks! Please elaborate I will be very thankful to you. How can I add initial time laps of 20 sec?

author: IDEngineer
author_rank: Super Contributor
timestamp: November 19, 2021, 05:32:26 pm
content: Look up "monostable multivibrator". A very standard component available in a wide variety of logic families. Use the first one to get your initial delay, which triggers the second one to give you the output pulse you desire. Both completely configurable with R and C values using standard, off the shelf parts.Or, as user ledtester pointed out, you could use a little microcontroller. Use its internal clock generator if absolute timing tolerance isn't critical and this approach would have fewer total parts and PCB real estate than the oneshots.There you go - two options. Have fun!

author: afsar
author_rank: Newbie
timestamp: November 19, 2021, 05:42:12 pm
content: Thank you so much for giving importance to my newbie question. It finally solve my problem.

author: steve65
author_rank: Newbie
timestamp: May 19, 2023, 03:15:51 am
content: Quote from: afsar on November 19, 2021, 05:42:12 pmI know this is an old post, but if you managed to solve the problem could you describe your solution? I'm trying to do something similar
single pulse every morning from solar panel - Page 1
Forum section: electronics / beginners

author: djacobow
author_rank: Super Contributor
timestamp: August 26, 2017, 02:50:06 am
content: I'm a bit embarrassed to be asking this in the beginners forum, but my analog fu is pretty weak.I have an RPi that I am powering from solar + battery remotely. The unit does not need to run at night. To reduce cycling of the battery (and to allow it to be smaller), I'd like to shut down the pi at night.I need a circuit that can do two things:1. generate a signal that I can send to the gpio when the voltage from the panel (it's a 6V panel) goes below a certain value. I'll use this signal to initiate a clean shutdown2. generate a pulse when the panel goes above a certain volate. Preferably, it would only do so if the panel was above that voltage for a certain amount of time, and it would not do so repeatedly within a short period, say 10 minutes. Ideally, one pulse in the morning. This pulse would reset the pi and cause it to boot.I can do this with another micro, but thought it would be nice to see if I could pull it off with a few transistors, maybe a 555 or two. Is there an obvious, simple solution?

author: tautech
author_rank: Super Contributor
timestamp: August 26, 2017, 02:59:47 am
content: Something like a CMOS Micropower Over/Under Voltage Detector like Intersil's ICL7665 is what I've stocked up on for H/L voltages monitoring use. 2 monitoring circuits in the package and logic level outputs. Available in DIP 8 and SOIC 8.

author: tautech
author_rank: Super Contributor
timestamp: August 26, 2017, 03:31:07 am
content: Thinking about it some more you might only need one part of the package if you get the user definable hysteresis as you want it. Get both the Intersil and Maxim datasheets.....Maxim attached FYI, use Fig 5.

author: djacobow
author_rank: Super Contributor
timestamp: August 27, 2017, 05:40:58 pm
content: This was a one-off for a quick hack project, so I was hoping to use stuff I had around rather than a special purpose chip. In the end I used an attiny 84 because I had a tube of them laying about.With the adc's I could implement whatever hysteresis function I wanted.One more opportunity to improve my analog skills passed up....

author: Zero999
author_rank: Super Contributor
timestamp: August 28, 2017, 08:42:17 am
content: Quote from: djacobow on August 27, 2017, 05:40:58 pmThat's the best solution. You also can modify the software to compensate for things such as clouds and a solar eclipse.Analogue skills are still very important these days but not for this sort of thing.