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Been playing with various chinese-originated latching relay solutions from Amazon. Most are 'overly optimistic' about capabilities. Very 'overly optimistic'. Otherwise the rest have issues operating in environment with heavy canbus, Bluetooth, pwm alternator, 2M xceiver, and brushed engine / HVAC fans. Reaching way back in my mind, I seem to remember JK flip flops toggling output when strobed if J&K are tied high. Maybe it wasn't JK, but another type? Important points being that outputs are low upon turn on, and stroking with momentary (debounced) switch (high input). I am thinking that can tie outputs to darlington driver array, like ULN2803 or similar. Up to 1/2A current, 50vdc max, designed for inductive loads. Haven't found any information on temperature control yet. Not sure if I am reinventing the wheel. I do know that relays / contractors that utilize magnets for latch hold are probitive physically and way overkill. Incidentally, relay outputs will be controlling multiple isolated power supplies. Need around 16ch of mixed outputs. Suggestions or alternatives if I am on wrong path? Tomorrow I will be trying to find 32/64 bit versions of LTSpice (or similar) as my 486DX4 based PC (500MB drive and 8MB Ram!) 16/32bit machine died during Hurricane Beryl. ~SD

Hello,I have the following old mixer called TXF-18075 which I want to test for saturation and power levels in down converting mode. I dont have any datasheet only this brief table I found.Unlike amplifier A mixer needs two input powers the RF and LO. How can I see In my lab two things: 1.What is the needed LO power? 2. How can I see mixer saturation using lab equipment? Thanks. /g/electronics101/photo/296358/3870599?p=Created%2C%2C%2C20%2C2%2C0%2C0

Hello: I am Ken Gordon, am now 82 years old, and have been involved in electronics since I was 13 years old in 1956. So, recently I have been involved in "Elmer-ing" a good friend who is not particularly adept at electronics. I have been helping him get his ham station operable on digital modes. He bought a new Acer laptop to use for these modes. While trying to get Fldigi installed, we discovered that his Acer laptop's USB ports' two data lines are reversed from all others we have dealt with up to this time: i.e. Data - (minus) and Data + (plus) are "reversed" in his new machine. This, apparenty, doesn't matter when those lines are used for USB devices such as a mouse or a USB powered CD drive, but that DOES matter when those data lines are used to pass audio to/from the computer to the digital interface (in this case either a SignaLink or a DRA device). I thought it might be easiest for me to make him a short jumper cable out of a short USB extension cable by cutting it, and "cross-wiring" those two data lines. However, upon opening the cable, I find not 4 (or 5) wires, but a total of 11, 3 of which are obviously grounds. I have not yet been able to "ohm-out" the wires vs connections since I must make a needle-point adapter for my VOM, but in the meantime, here are the wire colors. First, separate black, white, green and red. These should be the standard + and - 5 V and Data + and Data - But there are two "bundles" of other wires, These "bundles" contain a slim bare wire and two other thinner wires, pink and purple in one "bundle" and blue and yellow in the other. Might anyone here have a clue as to what these are, or how they are wired? Ken Gordon W7EKB Virus-free.www.avast.com

This is only relevant for this group because we deal with science, or at least I assume the study and practice of electronics is scientific. A friend suggested this book and I just finished it....I'll avoid any rants about how the left needs to get a clue. Higher Superstition: The Academic Left and Its Quarrels with Science Read it and cringe..... To me a pound is a pound, a kilogram a kilogram, numerals go from 1 to as high as you want to count, social repression has nothing to do with any of the proceeding. Note, I don't especially like the metric system but I accept it is real and valid. It is worth noting the book was written in 1994, well before the current social conflict over woke, social justice, DEI, et al. To me a business exists to make money, Proctor and Gamble's Gillette's "We Believe" ad campaign credited with causing a $5 billion dollar loss. I'd be a little upset if I were a stockholder... [For those who require proof, do a net search or https://pguru12.medium.com/procter-gamble-three-year-after-gillettes-we-believe-ffa9c82d9772 "A major development was reported between late July and early August, when it was announced that Gillette had lost $5 billion in quarterly sales, resulting in P&G giving Gillette an $8 billion non-cash writedown in terms of valuation." Or look into Bud Lite....and what a debacle.] "Go woke, go broke." [I believe John Ringo, SF author, came up with that witicism.] A society that turns it's back on science or uses social criteria to decide scientific truths is in deep trouble. I'm reminded of the Indiana Pi Bill, look it up on wiki and laugh, then look at the current social situation. I bet it'd pass today. I actually heard an English professor in college complain that "Pi should be rational, it just isn't right....makes no sense." I kept my mouth shut because as an EE major I was alread on thin ice for studying something real. <you had to be there> Hum, reality isn't right or wrong, but it is real. [and yea Quantum Mechanics gives me a stomach ache, but it's real...for various versions of real.] If you can't remember 3.1415, maybe you shouldn't teach or vote. [If you only have a 4 banger calculator, a very close approximation to Pi can be found with 355/113. Give it a try...] [A friend used Pi to 25 places, backwards, as her master password to the Big Iron in college. Yea I know some odd people.] We have the most advanced civilization in the history of the planet, people in third world nations enjoy cell phones, computers and instant communication. One might expect this to lead to an appreciation of science. [When I see the ISIS or Starlink satellites I'm filled with wonder that we've come so far so fast. I remember John Glenn atop that rocket...poor BW TV in school.] I wonder how long before they start burning us at stake for being heretics in the current social structure because we believe 1 and 1 are 2, not the result of some inherent racial paradigm. [My wife read this, "Oh don't be silly, they won't burn you at the stake, they'll simply send you to a special camp to be reeducated.] I just heard a rant on the radio about the inherent racism in math which lead me to write this....I wanted to call in and as "so which numeral is an oppressed minority?" But decided against it as trying to convert a rock to life by lecturing it. Or get our cat to not twine between my legs as I try not to trip over her. Both tasks are futile.

I normally type in a special font for dyslexics, Dyslexie. I can go to character map and snag Greek letters and other symbols, like those used in math, but it is a royal pain while typing. For serious writing, I place {} around the normal ASCII English letter and then I'll go back and replace them after I finish, in TV we called it "We'll fix it in post." I find trying to engage number lock and press alt while trying to remember what key to press for what Greek letter I want to be a bit too confusing, of course I could make a cheat sheet, that I'd have to keep track of.

Hello,I have built a PI controller I have its time domain step responce and AC responce. PI controller is supposed to help with the DC part of the error signal of a PLL system. I cant undertnad how,Is there away i could see it? /g/electronics101/photo/296358/3866087?p=Created%2C%2C%2C20%2C2%2C0%2C0 /g/electronics101/photo/296358/3866088?p=Created%2C%2C%2C20%2C2%2C0%2C0 /g/electronics101/photo/296358/3865523?p=Created%2C%2C%2C20%2C2%2C0%2C0 /g/electronics101/photo/296358/3866089?p=Created%2C%2C%2C20%2C2%2C0%2C0 Thanks.

A company that offeres every RF connector in the universe, if they don't have it, it doesn't exist. I've been collecting RF adaptors since my first hamfest, 1966, and, we used an ungodly mess to adapt his odd equipment. He found Brache Manufacutring LLC Newport Beach California. Their catalog has connectors I've never seen! And that's saying something! Their prices are reasonable considering the oddity of some connectors and if the quality of the adaptor my friend received is any indication, they are a first class company. Note: I have nothing to do with Brache other then as an amazed neutral observer. Another company I have dealt with is Pasternak, they have a lot of microwave connectors and other components such as RF relays, but nothing near the number Brache has. Pasternak's products are also first class. Note: I have nothing to do with Pasternak other then as a satisfied customer.

Does anyone have any idea how difficult it is to arrange a circuit to apply power to a DUT (Device Under Test) only at peak voltage? On both halfs of the 60Hz waveform? It is an imperial PITA on steroids! I went with a NE555 triggered at the zero crossing point and timed half way from that point for peak voltage. Simple zero crossing pulse generator to start the NE555 cycle. https://sound-au.com/appnotes/an005-f1.gif I used a 4N27, the output transistor drove another transistor, Darlington configuration. This drove a 600V 6Amp Triac by Teccor Part# Q6006F52. I used a 300 ohm 100 watt resistor (I have all sorts of odd stuff) as the load to insure the TRIAC would turn on and off. The turn on and off was OK but the timing was anything but OK. The output drifted around the peak but never was remotely stable. I was ready to give up when a friend said "Terry just use a 2 wire light dimmer module, they'll let you set for peak and hold it. My friend brought over several Hubble dimmer and, after some rewiring, I have a peak current turn on power supply. Note: Use a dimmer with dual RC network for increased stability. Now tomorrow or Sunday or Monday or someday really soon now I'll check the peak current through a 0.5uF capacitor. Now the real question, will a Siglent SDS 1202X-E capture the transients as the capacitor charges from the rapid delta-V? [Damn I wish this font had Greek characters!]

There have been several comments on high voltage measurements and probes buried in various messages. While fixing my microwave, I needed to measure the high voltage output from the transformer. As many have mentioned, a regular DVM cannot be used at that high voltage. I have a 1000 to 1 high voltage oscilloscope probe, but it is designed for a 1MΩ load, not the 10MΩ of the DVM. Adding a 1.11MΩ resistor across the input to the DVM compensated for the input resistance. I double checked measuring the 120AC. The transformer output was 2,380VAC . As usual do not do it if you really do not know what to do. It was a bad high voltage capacitor. Surprisingly, the very detailed service manual had a surprising error: It described testing the high voltage diode in forward and reverse with a regular DMM using the diode test mode. It will read open both ways since the forward diode drop is typically 8V because of the stacked diodes. Bertho

The following items have been added to the Files area of the [email protected] group. /Bertho's Folder/Sync Pulse R0.pdf /Bertho's Folder/Sync Waveform.png By: Bertho <boman33@...> Description: Line sync pulse Generator

Been kicking around idea of getting a pc based o-scope to keep in my tool box. My first ever was one that connected to a SoundBlaster Pro sound card. Have had a few over the years (portable pc based). Came across this apparent jewel at Amazon. To my eye, looks like a winner. Amazon Share-Link, nothing nefarious beyond screwing up your looked at history. https://a.co/d/10yH0lr Thoughts? SD

My wife's an RN. I had to ask her "Whats a nebulizer," and, follow up, "Is that something people carry with them to use in a car?" I had imagined the 'inhalers' asthmatics employ to help them breathe. She recalled that a Nebulizer was a machine unlikely to be employed while driving about in a rental car. So I went online and found the instructions for use: How to Use a Nebulizer: Prepare the medication: Follow the instructions provided by your healthcare provider to mix the medication with saline solution. Assemble the nebulizer: Connect the medication cup, tubing, and mouthpiece or mask to the nebulizer unit. Plug in the power source: If the nebulizer is electric, connect it to a power outlet. Start the nebulizer: Turn on the device to create a mist. Inhale the mist: Sit comfortably and breathe deeply through the mouthpiece or mask. Continue until all medication is gone: The treatment typically takes 5-15 minutes. Clean and store: Disassemble the nebulizer, clean it thoroughly, and store it according to the manufacturer's instructions. Are you sure you weren't using s Hookah? -- G.T.

"Their cars monitor and record conversations, video, one company even claims the right to collect DNA." As responsible adults, given the current lack of 'Truthiness,' I think it is incumbent upon the author to include a link to the "reliable source(s)" for his assertion - esp the bit about DNA. As to the hacking comment "I wonder how long before someone hacks into a car and shuts it down . . . " I do believe that has been demonstrated some years ago - but a link wouldn't be out of the question. In the alternative, revise the claims by adding a couple of words - maybe a preface of "I believe" to the " one company even claims the right to collect DNA." As in "I don't believe immigrants in Ohio were "eating the cats, eating the dogs, eating the pets of the people that lived there." Further, it would be great if an Electronics Focused Group was able to divine and publish hacks that would allow owners to disable this feature or that much as 'the community' has discovered ways to disable (reprogram) this annoying key or that on my Windows Laptop. One of our vehicles had the ability to send location data to the dealer/company application whenever I pressed the "PANIC" button. Something I did a few times when I forgot what the aisle I'd left the thing in looked like from the perspective of the store I'd, just moments ago, gone into. Sometimes, after I park, the cars around mine move about while I'm in the store - maddening! There oughta be a law! -- G.T.

This is kinda interesting: https://phys.org/news/2024-02-altermagnetism-magnetism-broad-implications-technology.html#google_vignette Might kick tech up a notch or two... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

Andy, I may have missed a couple of other observations but I would like to mention: 1) In situations with a lot of old fashioned 1/2 wave rectifiers or SCR voltage controls (arc furnaces, electroplating controls, certain PCs and the like) or in particular, simple light dimmers, there is a DC unbalance reflected back to the line transformer source. Line power transformers are likely to be running near saturation (it's an economic design choice.) The transformer is now non-linear and harmonic mixing will take place. This effect even shows up in big substation links from ground currents such as Schumann resonances generating modulation side bands. Another example. I went to a customer site for a problem with our equipment. They had racks of PCs being turned and off for the start and finish of test sequences. The surge of too many adjacent test PCs simultaneously coming on coupled with too small wiring, led to PC power supply glitches affecting the test as each test start required the charging of the electrolytic capacitors in the step down power supplies. A couple of cycles, but more than enough to cause trouble. The turning-on PCs ignored the glitch as they have have delay circuits built in and ignore their own disruptive effect, but already ON PCs were not happy. Thinking back about the past, mercury vapor rectifiers were often in 1/2 wave configurations -- too expensive to wire up full wave rectifiers -- a 4:1 cost. Your linear accelerator may have had a similar problem, needs for a lot of power on a pulse basis. It may even have been synchronized to the line as I believe some are to minimize line noise from data capture, Regards, Charles Patton

OK upfront I'm an analog guy. I don't hate digital, far from it, but I prefer to solve my design problems with analog solutions. I have more computers then common sense, I can and do write code, bad code, overly complex code, but still code that works. I program in Ada [ick] or GW-Basic and compile it with a 198? MS compiler. I've avoided Raspberry, Ardunio, PIC, PIC-AXE etc because I have enough other problems. Although I did use some premade code to burn PICs to produce 60Hz, 440Hz, 1PPs real time and sidereal, and other useful frequencies from a 10MHz GPS disciplined oscillator. [I'd love to have premade PIC code for "D" and "C".] I understand RS-232 in and out, Ethernet from AX.25 (ham packet radio.) However I'm only aware of in car data networks because I had to deal with one. I learned enough about CAN to know I needed specialized, expensive, test gear to begin to unravel the CAN problems in our Volvo so I lobotomized it by replacing most functions with local relay control. I can look at the data streams with an oscilloscope but it might as well be High Martian. Until Goey's request for the pin out of a radio, I'd not looked into CAN since lobotomizing our Volvo. I was amazed to learn our Echo didn't have CAN. I assumed it did and prayed it would never give trouble. [Sometimes you luck out!] Though the current sensor in the battery lead creates some issues I'd prefer to avoid. Today I learned there is also a simpler car data network, LIN, that GM [and others] uses for controlling the radio et al in some models. Most cars made after 2003 will have CAN and, by federal law, all new cars and light trucks made after 2008 sold in the US must have CAN. I suggest anyone interested in CAN and LIN start with Wiki then dig as deep as they need. CAN/LIN will probably be part of your future. We were so "lucky" with our Volvo as they were an early adopter of CAN. I've learned some manufacturers require their "in car entertainment systems" receive authorization from the main computer before they will turn on. [Such joy.] I see how a cousin of my wife makes a comfortable living by rebuilding pre 1990 cars, his wife does the detail work (she can even replace the headliner!!!!). I can see why any sane person would want a pre-CAN car because it requires specialized equipment and knowledge to trouble shoot them. Imagine all the wiring interconnects in a modern car....now imagine trouble shooting them. CAN is being used for all sorts of non-automotive applications, the list is growing and bewildering. I suspect serious electronic hobbyists will have to deal with CAN/LIN sooner then later. This makes it look sooo simple... https://www.diagnosistips.com/automotiveacademy/can-bus/ That log cabin on 20 acres is looking more attractive every day.......

I made a mistake, in my description of a ultra simple current limited LED driver. Call the cyber police to take my PCs from me. [Me making a mistake ought to make at least one person in this group smile. I live to please.] I transposed the position of two components. The capacitor goes between the AC Hot and full wave bridge, not the other way around. The AC from the mains passes through the capacitor, the current is determined by the capacitor value (Xc) and mains frequency. Higher capacitance equals higher current. The now current limited AC passes through the full wave bridge producing 120Hz pulses of DC (100Hz pulses of DC in 50Hz nations] This safely (if the capacitor value isn't too large) provides current to power/drive a LED or LEDs. My fake florescent LED replacement tubes have a lot of small SMD LEDs. I quit counting at 50ish. I'd guess there are about 200. Note that is a guess and I won't pretend it is "mainly accurate," don't know, don't care. I laid it all out on my work bench, out of the protective plastic tube, and used a capacitor substitution box to pick the 'right' value capacitor. I kept feeling the LEDs and when they were just perceptible warm I backed down one step. Is the brightness optimal? Snort hardly. Is it efficient? Give me a break, nope, hardly. But 4 of them provide about 10% more light as 2 real florescent lamp tubes. Oh that 10% figure comes from a 50 or 60 year old professional light meter that, in 2008, agreed with a new, NIST traceable calibration, light meter, so I suspect it hasn't degraded in the 16 years....might well be wrong ...sort of "I hope it's mainly accurate." Best I could do on a moment's notice. I need to take it in to the lab for calibration....but then what does the odd spectra do to calibration.... And yea I had to rewire the fixture. Oh how sad. I dispensed with sockets because it was cheaper and easier, I'd have had to go to a real electrical supply house for sockets and they might not sell to a civilian they don't know, my EE diploma would get laughs, and EE can't change a light switch for hire in Kentucky. So I hardwired everything and used home made Lexan spacers. Looks more then OK, actually looks store bought if you don't look too close....but who cranes their neck to inspect a florescent light fixture? The LEDs face down so the reflector is sort of useless. So yea WN4ISX made a mistake. Yawn. I'll tell on my self.... during a graduation when we used rented professional 2M business band radios and I ID with my ham call instead of my name. That was a really big no no, but I was used to using my ham call on an HT and habbit won over the law. And there were negative consequences. The company monitored all comss with their radios and reported me to the FCC. The company owner was beyond upset. I have no idea why, it wasn't like anyone was going to waste time listening to 3 TV crews rush from staging area to staging areas and trying to set up with zero time. I was part of it and it was BORING! But the Freaky Candy Company has zero sense of humor. I still have the pink ticket framed on my wall in a place of pride, Paraphrased is says "Thou shalt not make this mistake again upon risk of forfiture of license." They get real twitchy over IDing the wrong license in the wrong radio service. [Again, damn sure wish I could spell.] Sorry I'm far from perfect but mainly accurate. At least I got the link to the graphic of the diagram right...

Not directly electronics but many in the electronics world use 900MHz devices for all sorts of applications. As a license free band, it's attractive for experimental remote control, remote monitoring (my remote Cosmic Ray monitoring project uses a one way 900MHz data link, our church uses 900MHz wireless microphones, my wife has a a pair of 900MHz headphones that blow the socks off any Bluetooth device) There is an ISM allocation used for industrial, scientific and manufacturing. If NextNav succeeds in convincing the FCC to either sell or simply assign large parts of the 900MHz band, a lot of users are going to lose. https://www.eff.org/deeplinks/2024/09/nextnavs-callous-band-grab-privatize-900-mhz I'd say write the FCC to complain but the FCC appears to have become the federal governments frequency sales store. Look at the UHF repack as an example. I posted this more out of frustration then expecting anything any of us do to have any effect on the FCC. I expect them to go after the 2M and 70cm ham allocations any day now.

A safety hint. If you decide you've just got to look at the AC Mains with a battery powered oscilloscope, reconsider, if you still decide 'I just have to do this...' then consider using a AC mains to 12 to 30V step down transformer. The transformer will isolate you and pass the 50/60Hz. It will show you the turn on of a SCR/Triac light dimmer. If you believe you need higher accuracy, reconsider why? What are you looking for? High frequency noise on the AC mains? OK you've decided to play Russian Roulette. Obtain a 9K 10W resistor, obtain a 1K 10W resistor, wire in series. I like the Dale aluminum body units because you can mount them on a heatsink that you can connect to the safety/protective ground. Wire one end of the 9k to the AC Mains hot, wire the other end to the 1K, wire the other end of the 1K to neutral. Monitor the voltage across the 1K, it will be 1/10 the incoming voltage. Touching it and ground probably won't hurt or kill you. Just tested mine while sitting on a chair in a 1/4" sheet of Lexan. Used my right finger and thumb. As expected I felt nothing. This is still stupid silly but the safest way to actually directly monitor the AC mains. However, I doubt your scope will see any HF trash on the AC mains. I live to fight EMI/RFI, interference on the AC Mains created by all the switch mode power supplies. I have an intrinsically safe AC Mains to communication receiver, spectrum analyzer interface that has been hi-pot tested over night with 10kV on the AC mains side. In addition to extreme isolation from the AC Mains voltage, either 120V US, 240V the rest of the world, the output is clamped at +/- 2.1V. It was an extremely non trivial project, the actual schematic is bog simple, obtaining components that could withstand 10kV for ~10 hours was the royal PITA. Capacitors large enough to pass 50kHz with "no loss" and withstand 10kV are rare. And pricey. There are commercial units https://www.reliantemc.com/laplace-voltage-probe-plip/ https://www.onfilter.com/test-and-measurements These are serious scientific instruments not "magic hocus pocus dirty power will harm your health or kill you." If you can't afford either, and if you don't have the skill set and access to a certified hi-pot tester, to roll your own, don't. Again, before monitoring the AC Mains for anything but voltage with a meter and current with a clamp on, really think "Do I need to do this?" With "Why do I need to look at the AC Mains." Death is for keeps. [The afterlife doesn't count because we won't be bothering with such trivial things in heaven or hell of Valhalla or Fólkvangr. <sorry for the font change there, had to look it up> I'd cover more religions but can't think of their afterlife policies off the top of my head right now, but I'm pretty sure none of them suggest we'll much care about earthly problems.] I lost a friend in college who was trying to look at the AC Mains with a scope and isolation transformer. He was alone so I don't know how he screwed up. Smart guy, not prone to foolishness, yet he died. So yea I'm a bit too focused on the safety issues with scopes and AC Mains. Going to the funeral for a good friend sucked bilge water.

Surprised all the CAN complainants here are not Card Carrying EFF Members! https://en.wikipedia.org/wiki/Electronic_Frontier_Foundation The Electronic Frontier Foundation (EFF) is an international non-profit digital rights group based in San Francisco, California. It was founded in 1990 to promote Internet civil liberties. It provides funds for legal defense in court, presents amicus curiae briefs, defends individuals and new technologies from what it considers abusive legal threats, works to expose government malfeasance, provides guidance to the government and courts, organizes political action and mass mailings, supports some new technologies which it believes preserve personal freedoms and online civil liberties, maintains a database and web sites of related news and information, monitors and challenges potential legislation that it believes would infringe on personal liberties and fair use, and solicits a list of what it considers are abusive patents with intentions to defeat those that it considers are without merit. -- G.T.