hybridfree/eevblog-posts huggingface dataset:
Manual Pick and Place - Page 1
Forum section: electronics / projects

author: JohnSL
author_rank: Regular Contributor
timestamp: May 23, 2014, 05:19:04 am
content: Hi,After assembling some SMD PCBs with a solder paste stencil and hand-placing the 0603 components, I started to look around for pick and place machines. In the process, I learned about manual pick and place machines. While these sound really compelling, the price certainly doesn't. I did find one for $200, but they don't have any in stock, and they're not answering their emails. So, I decided to see if I could create my own. I've attached an image of what I have so far. This uses 3/4" square aluminum tubes I purchased from Lowes as the sliders, along with 608 bearings. All these parts are very inexpensive. I'm also using 3D printed parts to tie them together.I've also ordered various other parts, such as a Tetra air pump that I can turn into a vacuum pump. What do other people think? Am I going in the right direction?Thanks,-- John

author: sleemanj
author_rank: Super Contributor
timestamp: May 23, 2014, 05:23:33 am
content: http://hackaday.com/2012/11/24/an-inexpensive-manual-pick-and-place-machine/

author: JohnSL
author_rank: Regular Contributor
timestamp: May 23, 2014, 06:16:18 am
content: Cool! Thanks for the link. That will certainly help a lot.
DIY mutimeter-style manual ranging? - Page 1
Forum section: electronics / projects

author: ivan747
author_rank: Super Contributor
timestamp: January 12, 2013, 09:18:47 pm
content: I have been designing a circuit to measure AC voltages, and now I need a way to manually switch ranges. I know many multimeters use a resistor network to do this. I found a ready-made resistor network on Digi-Key, but it is too expensive for my target cost. I plan to have 4 ranges: 2V, 20V, 200V and 600V. My problem is that resistors suitable to make a resistor network seem to be unobtanium. I want to have something like the following resistors in series:9Meg - 900k - 90k - 9k - 1kBut it seems finding these values with decent accuracy and temperature coefficient on low volume is next to impossible.I looked at the Fluke 80-something-A manual and they use something completely different instead. They have a 1:10 and a 1:100 attenuator they can switch on, and a selectable gain amplifier, gain can be 1 and 10. They achieve all ranges by doing this (the ADC goes from 0 to 2V):200mV - No attenuation, gain set to 10.2V - No attenuation, no gain20V - 1:10 attenuation200V - 1:100 attenuation600V 1:100 attenuation, gain set to 10But I am doing AC, so that op-amp and the switches to select the the gain must be rated at my maximum AC bandwidth, 150kHz. I want to achieve 0.3% to 0.1% accuracy on this front-end, in the 20V range and below. The 200V and 600V ranges can be worse. I think the TL082 would be a good choice for an op-amp, maybe, but I haven't looked at the specs closely.What is the best way I can switch ranges cheaply and within my requirements? I am willing to do basic calibration (tweaking trimpots) as long as it doesn't take more than 3 or 5 minutes.

author: SeanB
author_rank: Super Contributor
timestamp: January 12, 2013, 09:44:21 pm
content: TLO82 would not be a good choice, there are plenty of better. OP27 will be better if a tad more expensive, but a really nice old school unit. Analogue switches will do the switching well at the bottom of the dividers, though if you are switching the high end you will need a reed relay or bistable relays.

author: ivan747
author_rank: Super Contributor
timestamp: January 12, 2013, 11:13:10 pm
content: I would like this fonrt-end to be $7 in 100-of quantities. The OP27 and 1 1000V rated reed switch cost $3 alone. I expect the resistors to cost around $0.50 to $0.70 each. I need 4 resistors at least to do the switching. I also need overvoltage protection, a PTC, claimping diodes and a beefy resistor to limit the current going into the clamping diodes. And a rotary switch as well.I think it can be done, but it's going to be more expensive than I thought. If I can't do anything else, I will remove the 600V range, but that can really defeat the whole purpose of this. THe project is an RMS to DC conversion box. The 600V range is great to measure the RMS voltage of dimmers and such in 240V countries.
Manual re-reeling / SOIC trays for pick&place - Page 1
Forum section: electronics / projects

author: LINACboy
author_rank: Contributor
timestamp: March 06, 2017, 04:03:09 pm
content: Hi everyone,I am about to assemble a prototype series of about a dozen 100x120 mm boards. Unfortunately, the number of ICs was not big enouth to justify purchasing an entire reel and smaller quantities were only available in tubes. However, our in-house pick&place machine does not have tube feeders, only accepts reels or trays.We are talking about a total of 33 ICs (8 different types, SOIC-8/14/16) per board. I always have the option to manually place them, but I was wondering, if there is something like a manual reeling kit or a company wich sells something like JEDEC matrix trays but for the SOIC form factor. Any hints?

author: Scrts
author_rank: Frequent Contributor
timestamp: March 06, 2017, 05:00:36 pm
content: Calculate your engineering hour costs vs buying those components from Digikey packed in Digi-Reel.

author: LINACboy
author_rank: Contributor
timestamp: March 07, 2017, 05:41:16 pm
content: Let's assume that I always order re-reeled components for small scale runs, but - thanks to the ingenious ordering system I am forced to use - 9 out of 10 times, items are delivered in the wrong package anyway. Is there some kind of (re-usable) empty reel and tape on the market that allows you to reel looss components by hand? Trays would be an option, too. But I have yet to find a supplier with a version for small ICs like SOIC.
Manual SMD component feeder jig - Page 1
Forum section: electronics / projects

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: April 14, 2015, 12:50:01 pm
content: Hello everyone! I'm about to assemble my first SMT board (eventually I'll make 20 of them) and as a way to mentally prepare myself I decided to make a jig. Here it is:The feeder nozzles are printed on an Ultimaker 2 with PLA, it's a customization ofthis partIf you want more images you can visit my blog here:http://alexanderbrevig.github.io/projects/2015/04/14/SMD-manual-feeders-jig-done/I just wanted to post it up here

author: Psi
author_rank: Super Contributor
timestamp: April 14, 2015, 01:02:36 pm
content: ive always wanted to make a smt soldering assembly jig using two small 'lazy susan's' one a little smaller than the other and mounted on top of it. Maybe 5cm smaller all the way around.PCBs sit on the top smaller platform, laid out in a circle around the edge.SMT tape is mounted between the two platforms and different value component tape protrudes out onto the 5cm exposed are of the bottom platform.The idea that your arm can stay still with the vacuum pickup tool. Rotate the bottom lazy susan to find the SMT part and rotate the top lazy susan to move to the next pcb

author: Thor-Arne
author_rank: Unknown
timestamp: April 14, 2015, 01:37:43 pm
content: Nice feeder jig.You need abetter magnifierthough.

author: StefanHamminga
author_rank: Contributor
timestamp: April 14, 2015, 02:09:28 pm
content: Nice setup!Two things that might speed up your work-flow a bit: I'd try to rotate the text on the feeder sheet back to horizontal columns to make your references easier to spot. I'd also draw center lines for the feeders.Both 'tweaks' are to reduce 'mental clutter'; For example: Scanning for alignment (reference text, feeder strip) is much more mentally intensive than following a line.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: April 14, 2015, 10:18:42 pm
content: Quote from: Thor-Arne on April 14, 2015, 01:37:43 pmThanks, and yeah... I don't have time to wait for onebut I've ordered one for the next time I need magnification. Thanks!Quote from: StefanHamminga on April 14, 2015, 02:09:28 pmA very good point! I will go from left to right on all boards, and I think it should be fine.I will remember this for the next time I think of something like this though. Thanks!
Manufacturing - Page 1
Forum section: electronics / projects

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 12:48:12 pm
content: Hi allI am a 15 year old boy and i had a idea about a phone case and would like to know how to manufactur it!And no nobody in th internet or the hole world didnt came upp with it i did some reasarch and no nobody!If any one can suggest me what to do pls feel free to comment!

author: Jeroen3
author_rank: Super Contributor
timestamp: May 11, 2014, 12:52:15 pm
content: Have it 3D printed or go with your 3D files to an company that does injection molding plastics. Make few thousand and profit.Don't forget taxes.

author: electrolux
author_rank: Regular Contributor
timestamp: May 11, 2014, 01:00:22 pm
content: Quote from: Jeroen3 on May 11, 2014, 12:52:15 pmInjection moulding would be better.

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 01:43:13 pm
content: Yeah i know about the 3D printing the only problem is it isnt like the other cases it will have circuit in itAnd a battery so its a littl bit to much and

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 01:50:52 pm
content: I dont know how to 3d PRINT

author: 8086
author_rank: Super Contributor
timestamp: May 11, 2014, 01:51:47 pm
content: If you tell us some more about it we can maybe help you more.

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 02:46:16 pm
content: i was thinking about the samsung cases with the extar battery they have extra space inde them wich is not used so for exp we will put a AMP in ther and make it a headphone battery backup and amplifier case

author: Sam__
author_rank: Regular Contributor
timestamp: May 11, 2014, 05:00:23 pm
content: Would it be a headphone pre-amp or would there be a speaker in the case too?if just a headphone pre-amp, what is the advantage over the standard headphone circuitry?

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 05:13:12 pm
content: It would be a headphone pre-amp and it would be pretty good cuz some peopel like to hear withhigh sound just like me and they mus downlod some app and some time these are virus.And the idea with a speaker not a bad idea

author: Sam__
author_rank: Regular Contributor
timestamp: May 11, 2014, 05:21:10 pm
content: Depending on where you intend to sell this device there may be regulations on the maximum available output power. This is for safety reasons, as extended exposure to high volume damages hearing. Just something that might be worth looking up. I know nothing of this market, it's just the first thing I thought of when you mentioned you wanted higher volume.

author: Isad
author_rank: Frequent Contributor
timestamp: May 11, 2014, 05:24:22 pm
content: Ohhhhhhh i totaly forgot about that rule!I wanted to sell it on ebay as anyone would do or start a kick starter and sell it there
Many Astron power supply schematics - Page 1
Forum section: electronics / projects

author: nukie
author_rank: Frequent Contributor
timestamp: September 09, 2011, 05:02:14 pm
content: Hello I found this on the interweb thought it might be useful for someone learning about Power Supply design.http://www.repeater-builder.com/astron/astron-index.html, scroll down a few page you will find lots of schematics.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 10, 2011, 12:31:08 am
content: Yeah, I have been trying to make two points on this forum for a while:-(1)The Amateur Radio Websites are a good resource for Engineers & Techs,whether they are "Hams" or not.(2)The best way to learn about various types of circuitry is to see how other people have used the stuff you learned at Uni/Tech School!It isn't really "copying",it's commonsense,as most common circuitry is public domain,anyway!If you think you have a "new & innovative" way of doing something,you may find it has been tried & has not performed as well as traditional methods.Of course,new components may have been developed which make a previously poor circuit a winner.Even if your method is truly innovative,it may not perform as well as the other techniques in use.VK6ZGO

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 12, 2011, 12:55:08 am
content: Even designs that normally perform poorer than existing designs can excel in special cases. A good example is using LEDs to drop voltage. The voltage drop varies a good amount and the current limit is small, but if that's fine, it works nicely. And it doubles as a power on indicator.If you have access to it, IEEE is a great source of ideas. You'll easily come across many designs that need careful thinking to understand how they work.QuoteThere are too many examples of that. The switched reluctance motor was invented over 100 years ago, but poor performance caused it to fall into obscurity. Today, however, the world's most efficient air conditioner (as far as I'm aware) uses a switched reluctance motor driving a centrifugal compressor to allow the use of water as a refrigerant. That in itself is another example - water's very low vapor pressure needs a very high (vapor) flow rate to get a reasonable capacity and valve losses are too significant at those pressures. The switched reluctance motor allowed the development of very high speed centrifugal compressors that get a high flow rate in a small size and the lack of valves means no valve losses.

author: TELCO
author_rank: Contributor
timestamp: August 12, 2014, 12:40:59 am
content: I am a ham radio operator since 1997 and the most important stuff I have learned in electronics and RF communications I have done through this hobby and experimentation in it. I am truly thankful.

author: David Hess
author_rank: Super Contributor
timestamp: August 12, 2014, 02:42:29 am
content: Quote from: NiHaoMike on September 12, 2011, 12:55:08 amSometimes these imperfections can be used advantageously. An LED's forward voltage drop versus temperature can be used to compensate for the Vbe voltage drop versus temperature in bias circuits.
Maplin's Weather Satellite Receiving System from 1985/6  - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: March 04, 2018, 06:03:29 pm
content: Hi!Maplin's published a design for a Weather Satellite Receiving System in the mid 1980s built in two 2U size 19" Rack cases, one for the Receiver Project and another for the Decoder/PSU unit, made to operate via an Amstrad PC (with an optional Frame Store design they also published) or BBC Model B.Has anyone got the documentation for this project, and would it be still be feasible to attempt to build this?Does it require any special programmed devices or was the dump published?Are the satellites (NOAA, TIROS, etc.,) still in operation and if so, are they likely to remain operational for long enough to make an attempt at this project worthwhile?I was really interested in this system but it was totally beyond my finances at the time!Chris Williams

author: Kalvin
author_rank: Super Contributor
timestamp: March 04, 2018, 07:55:36 pm
content: If you just want to try receiving NOAA and other satellite signals, you can try with a cheap $20 SDR-dongle and proper antenna:https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/Probably you will need to build a bandpass filter and LNA for better signal quality.

author: Chris56000
author_rank: Frequent Contributor
timestamp: March 04, 2018, 10:07:07 pm
content: Hi!Further to my first query, can anyone point me in the direction of a good kit of parts or fully documented project to make a 130–140 MHz VHF receiver circuit suitable for the APT Weather Signals?Regarding the decoder Maplin's design used, it uses a Ferrari ZN427E–8 CPU and an NS MF10CN, both of which I can get hold of, and the decoder PCB was single–sided so that's reproducible at least!There's another small PCB called a "Sync Tone PCB" using a NE565 PLL chip, again easy to make!Every kit of parts I find reference to exists only in pictures, when you try to order they're either discontinued or it's an old website long closed down!Chris Williams
Mapping of DIN-41612 a+c connector to IDC ribbon cable - Page 1
Forum section: electronics / projects

author: adrifromhh
author_rank: Contributor
timestamp: October 21, 2019, 05:39:34 pm
content: Hello guys,simple question I cannot seem to work out from the datasheet of various manufacturers:With an DIN-41612 64 Way a+c IDC connector, does Pin C1 or A1 map to wire 1 of the ribbon cable?I hope the question is clear. Thanks!-Adrian

author: adrifromhh
author_rank: Contributor
timestamp: October 25, 2019, 02:18:38 pm
content: For future reference: I found that information.Pin 1C maps to wire 1 of the ribbon cable.
Marantz 2235b- P800 PSU problem - Page 1
Forum section: electronics / projects

author: lesabb
author_rank: Contributor
timestamp: February 15, 2015, 05:44:58 pm
content: Hello all,I'm quite the newbie at this so bear with me. I'm giving a go at a Marantz 2235B. It had intermittent sound on right side. Changed the vol pot. Changed the relay and recapped all the supply board due to leakage. Now I get no power from the 13V supply on the P800 board. Caps are working (at least charging up and holding). Look at the schematics and my issues are pointed. The bottom part working fine and getting 35V and other reads as advertised.Another issue is that resistor R807 (150R/5W) is dropping the whole 41V! is that normal?L

author: SeanB
author_rank: Super Contributor
timestamp: February 15, 2015, 05:59:34 pm
content: Did you put C805 in backwards? That is the only thing that will short the rail out to 0V, all other faults will give you a volt or so on the rail. That or the capacitor is shorted or there is a solder whisker across it.

author: lesabb
author_rank: Contributor
timestamp: February 15, 2015, 06:33:38 pm
content: Thanks Sean for pointing me in the right direction!! I found it! Somehow I shorted the cap to ground when re-installed the heat sink for the H804 transistor. Must have omitted some insulator or something. I feel good!L

author: lesabb
author_rank: Contributor
timestamp: February 16, 2015, 02:25:34 pm
content: OK, so I got power to am/fm tuner and main amp. Problem is still there?! Unit will run for almost exactly 90min, then right side goes out. Should I try to bypass the main speaker switch? Can I use an AC meter to see if the signal reaches the main amp?

author: moffy
author_rank: Super Contributor
timestamp: February 16, 2015, 10:59:37 pm
content: Follow the signal until it disappears. It might be easier if you could inject a tone from a signal generator into the main amp, leave out the am/fm tuner as a source, only debug 1 thing at a time. Yes you can use the AC Voltmeter to follow the signal.
marconi 2024 control knob - Page 1
Forum section: electronics / projects

author: comprotudo
author_rank: Newbie
timestamp: May 02, 2013, 03:38:40 pm
content: Hello,I have also a 2024, witch a "little" problem.When switch it on and activate the control knob to tune the frequency, level etc. he does not work, even I can see the under line, the values does not change.After waiting a little I switch the generator on/off and everything work fine.Does anyone have the same problem?Any clue about that??RegardsRodrigo
Marconi TF995A/5 FM/AM Signal Generator really funny crystal calibration - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 21, 2022, 09:12:23 am
content: this Marconi TF995A/5 FM/AM Signal Generatorgot a very cool feature, use a headphone to detect the error beat frequency,adjust to zero = generator is now spot on :-)https://youtu.be/GHtrO6m5SCI
Marine Gyrosphere motor specs ? Sperry Litton  - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: June 03, 2024, 08:21:47 am
content: HelloI scored such a unit, and i have trouble finding motor specs,motors are 3 phase induction, with a capacitor so they run on one phase ACplease tell me : AC Voltage, Frequency, expected current,RPM ?other things i like to know if you are an expert with in this field :how could it Loose its liquid mercury ?is there any special kind of gas inside the motor sphere ?I put all details about my unit in this videohttps://youtu.be/10hITIeLjIU

author: SeanB
author_rank: Super Contributor
timestamp: June 03, 2024, 10:08:19 am
content: Very likely either 115VAC 400Hz, or 26VAC 400Hz, and the original fill of that housing would have been a blend of ethanol and mineral oil, not water, as that provides the needed damping, and also lubrication. The mercury wetted contacts are very interesting, likely they are steel with a copper or silver plating on them, thus the mercury contamination. The 0.33uF says 400 or 440Hz, so probably try that, and what was original excitation voltage off the amplifier.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: June 03, 2024, 01:38:29 pm
content: thank sean for the feedback,as shown in the video i already tried with 400Hz +/- a lotsearching for a peak acceleration, that just dont reveal it self what so ever sadly..it is not like i am a lost case, my power stage works and drives avionic equipment fine,maybe you have seen my other gyro worked fine with 115V 400Hz,

author: moffy
author_rank: Super Contributor
timestamp: June 03, 2024, 11:39:49 pm
content: They should not be making that grinding noise, they are meant for high RPM because of their small size, like 12000 RPM, or some multiple of the 400Hz, maybe a bad bearing?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 05, 2024, 09:07:19 pm
content: 400Hz is already 24000rpm

author: moffy
author_rank: Super Contributor
timestamp: June 05, 2024, 09:59:25 pm
content: Quote from: Doctorandus_P on June 05, 2024, 09:07:19 pmTrue enough, but it does depend on the number of poles e.g. 4 poles@400Hz = 12000 RPMhttps://en.wikipedia.org/wiki/Synchronous_motorbut not necessarily a multiple of 400.
Marine Isolation Transformers - primary shield windings - Page 1
Forum section: electronics / projects

author: damn_dirty_ape
author_rank: Contributor
timestamp: March 22, 2017, 03:31:08 pm
content: Hello everyone,If this is not the right forum for this question, feel free to let me know.I'm wondering how important primary/electrostatic shields are in isolation transformers, particularly transformers that are meant for use in a boat. Is the shield winding totally necessary for 480V three phase? What does it do? Can someone point me to a schematic to show how all the windings are actually hooked up for three phase power?I learned a little bit of power stuff in school, but never went into the particulars of transformer design. I've never heard of a primary shield until now. The reading I've done makes me think it should only be necessary in sensitive equipment, typically in the medical industry, but I'm not sure if theres a benefit in other applications.Thanks

author: tecman
author_rank: Frequent Contributor
timestamp: March 22, 2017, 06:39:29 pm
content: Shielding can be an important safety issue. Without shielding, capacitive coupling between the primary (480 V ?) and the secondary can result in measurable current induced as a common mode voltage on the secondary. Wiring variations, etc can result in varying results, but it is not uncommon to see roughly 50% of the primary voltage induced on the secondary, as a common mode voltage. The electrostatic shield in a transformer will shield the secondary winding from this capacitive coupling.paul

author: Jeroen3
author_rank: Super Contributor
timestamp: March 23, 2017, 08:00:54 am
content: Marine stuff requires 3x nominal for a lot of parameters. I'm not sure if isolation is one of them.
Marking amplifier THS3202 - Page 1
Forum section: electronics / projects

author: GGMM
author_rank: Frequent Contributor
timestamp: May 30, 2023, 11:56:05 am
content: Hello,I ordered THS3202 amplifier circuits from Ali.The component is rated TI*6 #EP* it’s either 0 or O#G or 8It’s hard to see, very smallI’d like to be sure it's the good circuit, but I can’t find this "SMD" referenceMay you help me and confirmThe 8 pins case seem okThank'scdt

author: GGMM
author_rank: Frequent Contributor
timestamp: May 30, 2023, 04:07:39 pm
content: Hello,i have foundhttps://www.ti.com/packaging/en/docs/partlookup.tsp?partmarking=bepso i think it's goodcdt
Mars Rover Science PCB Schematic Review - Page 1
Forum section: electronics / projects

author: rapsforlife
author_rank: Newbie
timestamp: October 16, 2020, 02:57:49 am
content: Hey y'all! My robotics team is preparing for the University Rover Challenge and just completed revision 2 schematic of our science mechanism. Would appreciate a fresh set of eyes before we move on to layout.https://github.com/uwrobotics/MarsRover2021-hardware/blob/master/Projects/Science/Rev2/Science.pdf

author: MrLau
author_rank: Newbie
timestamp: October 16, 2020, 06:09:30 pm
content: Just quickly looked it over, and noticed a few things:Your pull ups for the I2C bus seems pretty low, I think you could get away with something higher unless you really have a lot of devices on the bus.You LEDS are also really brightly lit with 10mA, If they have to be seen from far away this might be intended. But if it's just for debugging/development I think they will be to bright, might become annoying.Your buck converter uses 1uH make sure this gives you a low enough ripple for your calculations.Lastly why not use the split termination available on your CAN transceivers?

author: Pack34
author_rank: Frequent Contributor
timestamp: October 16, 2020, 11:29:21 pm
content: You may want some circuit protection on those limit switches. At least something for ESD.
Marshall 6100LM tube amp bias repair - Page 1
Forum section: electronics / projects

author: jcrubin
author_rank: Frequent Contributor
timestamp: October 27, 2017, 12:28:24 pm
content: This was unique in that it was requested that a minimum amount of work be accomplished to solve for the issue. As you can see in the diagrams in the video, almost certainly, DC flowing through one or more of the two finter caps after the rectifier is the culprit here, shunting the resistor got it to the show, so to speak...
Martin Hot-Beam-04 IR heatplate many isolation issues - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: February 16, 2025, 09:51:32 am
content: I think this product is sold in quite high volume,so a few of you might even own one, or there is one at your work ?i like its flat design, and it is fast and easy to use and all that.BUT it contain a few safety and isolation issues,something you can fix quite easy,Full explain in this videohttps://youtu.be/5NZTGznHeRY

author: inse
author_rank: Super Contributor
timestamp: February 17, 2025, 12:49:38 pm
content: We have a similar unit at work, the control unit is separate from the heater.It never created an issue during the regular electrical safety check..

author: oz2cpu
author_rank: Frequent Contributor
timestamp: February 17, 2025, 12:53:28 pm
content: sounds like yours is a different brand ?i hope it dont contain the same issues,could be fun to hear if any other Martin Hot Beam 04 owners also have a problem with it ?

author: inse
author_rank: Super Contributor
timestamp: February 17, 2025, 01:05:23 pm
content: It is Martin HB-02
Marx Generator With Inductors - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: May 01, 2022, 07:02:44 pm
content: I'm sure someone out there has some know how about Marx Generators that use inductors in place of the charging resistors- I've seen one demo on your tube and a referrence to a massive rock smasher Marx but little else- I'm looking for some help with this, mostly from a design point of view.The indcutors allow for very fast charging to the full HV input all the way to the final stage so much larger caps can be used. This topology is capable of very high repetition rates. I need some guidance on dimensioning the circuit. The indcutors also clearly store energy, how does this impact the system? Damping?Ideas, tales of woe, done it, simulated it?

author: Marco
author_rank: Super Contributor
timestamp: May 01, 2022, 07:17:59 pm
content: The inductors don't necessarily store a lot of energy, you can use coupled inductors (ie. common mode chokes). Very low inductance during charge, very high inductance during discharge.https://apps.dtic.mil/sti/pdfs/ADA638559.pdf

author: Terry Bites
author_rank: Super Contributor
timestamp: May 02, 2022, 02:49:26 pm
content: True that.
Maschine MK3 "clone" - Page 1
Forum section: electronics / projects

author: polli
author_rank: Contributor
timestamp: September 30, 2017, 08:27:01 am
content: Hi! First of all, this is my first electronics project ever. Just pretend this was posted in the Beginners section. I just printed "Designing Analog Chips", free book, which apparently should be good to learn electronics in general - I'm just going to look up stuff I don't understand anyway - and right now my electronics knowledge is just ohm's law :DHere's the plan. I'm going to make a "clone" of this thing:https://www.native-instruments.com/en/products/maschine/production-systems/maschine/I'm using clone loosely here:I'm not going to make an audio interface, as I just need a midi controller.I think it has two displays, but I already have a cheap hdmi display meant for a raspberry pi, so I'm going to use a single one.It has a bunch of buttons not dedicated to midi, and I think I'm going to have very few of those, and use sort of a "Fn" button that combines with midi buttons.It has 16 main buttons, I think I want 64.It's made of cool metal stuff, and I'm going to use wood.It's actually well made, and mine is going to be terrible :PI'm going to use this thread to document my progress and to ask for advice. This is going to be a long project, both because I will use it to learn electronics, and because I wouldn't be able to afford every component at once.Having only programmed on processors with C/C++/Python and so on, I've always wanted to try an FPGA. I'm not sure I will be able to design a PCB for it, so I might have to buy a dev kit, but then i'm not sure I'd have enough IO. We'll see.That's it for now!
Massive VICOR module failure - Page 1
Forum section: electronics / projects

author: atum
author_rank: Newbie
timestamp: December 02, 2024, 09:26:15 am
content: Dear all,I have an old design, which use 4 VICOR modules (V24A48C400BL).The schematic is an Serie/parallel operation. All modules are powered from single 24V battery pack.2 modules are parallel wired configured at 45V output2 others modules are also parallel wired configured at 25V output.45V and 25V outputs are then wired in series to get +70V output.The 70V ,output power a full bridge PWM amplifier.The full schematic is attached to this post.According to this VICOR NOTE (page 9 figure 2.10):https://www.vicorpower.com/documents/applications_manual/fas_trak_apps_manual.pdfVicor module Sense must be connectedafterORing DiodeAccording to this VICOR NOTE:https://www.vicorpower.com/documents/application_notes/an1_high-vout.pdfVicor module Sense are connectedbefore"ORing Diode"I put ORing between quotes because, as far as modules are not connected in parallel, thoses diodes are not oring diodes (to my understanding), but vicor said in it's note :Furthermore, D1 and D2 provide an additional voltagedrop to compensate for the forward voltage drop of D3 and D4 under this condition.Additionnal protection diode are added (D3 and D4 on figure 1 of the note) =>diodes D3 and D4 prevent the output from goingnegative if only one converter is operational.As you can see on the attached schematic, those protection diodes are not present in my old desing, furthermore, each pair of modules are switched on/off by an independant relay (short circuit PC and -VIN of the Vicor module)This old design works like that for more than 10 years, and recently, i was troubleshooting something, andALL the four VICOR modules burned !!I feel like we have a design weakness. It is unbeleavable that the four modules failed at the same time. What do you think could be the cause of the breakdown?One module did not start and the other had reverse voltage ? Vicor Said in another note than Sense pins shound be never driven negatively. In case of one voltage failure, the other module output in driven negatively isn't it ?It can explain failure of two modules, but the others ?Thanks in advance for your help...
Matched Pulse Proof resistors - Page 1
Forum section: electronics / projects

author: luky315
author_rank: Regular Contributor
timestamp: February 28, 2014, 11:26:43 am
content: I need a few hundred 100k matched (better than 0.1%) and pulse proof (MELF or 1206) resistors for a 2:1 input divider in a harsh industrial environment and the same amount of "normal" matched 0603 Resistors (10k) for use in a safer environment. The absolute resistance is in both cases not important as long as they are matched.Unfortunately my volume (and/or my internet fame) is not big enought to get the attention of the manufacturers. Where can I get the parts for a reasonable price and without selecting them manually?

author: Dago
author_rank: Frequent Contributor
timestamp: February 28, 2014, 11:57:34 am
content: I guess the answer (without knowing what a reasonable price is) is that you can get them from any distributor you have been accustomed to use.Quick look on Digi-key reveals that there are over a thousand different resistors that are 1206, have an accuracy of 0.1% or better. Pricing (for single quantities) seems to start at around 0.52€/piece. If you buy a whole reel it is under 10 cents a piece:http://www.digikey.fi/product-detail/en/RG3216P-1803-B-T1/RG32P180KBTR-ND/1272612

author: luky315
author_rank: Regular Contributor
timestamp: February 28, 2014, 01:10:36 pm
content: Thanks, but I am perfectly able to order standard components form Distributors.The point is that I need pulse proof resistors. Pulse proof resistors usually have a higher absolute tolerance unless you buy special (expensive) components which I try to avoid because I am not interested in the absolute resistance as long as they are (nearly) equal.
Matched Trace Lengths on AD5547 DAC - confused - Page 1
Forum section: electronics / projects

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: January 31, 2018, 09:55:06 am
content: I was reading the datasheet on theAD5547 from Analog Devices. It is a 16 bit multiplying DAC.It says the following on page 13 of the datasheet:"The PCB metal traces between \$ V_{REF}\$ and \$R_{FB}\$ should also be matched to minimize gain error".I'm quite confused what they mean by this. Do they refer to the length of the trace from the reference generator to the \$ V_{REF}\$ pin and the length of the trace from the feedback network to \$R_{FB}\$?I've attached the part of the text it was in to provide context as well as one of the example designs they provide.

author: David Hess
author_rank: Super Contributor
timestamp: January 31, 2018, 05:17:25 pm
content: They mean the external resistance including any temperature coefficient. The internal input and feedback resistors are matched to each other to limit gain error.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: February 01, 2018, 06:33:02 am
content: So that any trace resistance between the reference and feedback path are the same? That makes sense I guess. Thanks!
Matching Network Design for SX1262 - Page 1
Forum section: electronics / projects

author: miket6000
author_rank: Contributor
timestamp: September 19, 2025, 04:04:57 am
content: Hi all, I'm trying to design a matching network for the SX1262 PA at 433MHz for 22dBm. The hardware supports this however there is no information on the output impedance or z-opt for the PA at anywhere near this frequency in any datasheet, reference design, or application note. All I can find is a result at 915Mhz and recommendation to do a load pull test for other operating points. I don't have access to a tuner so I would need to do a load pull by hand soldering components which will be excruciating slow so it would be great to have a close starting point.I have found a reference design for the SX1276, but I understand this part uses the previous generation of LoRa IP and there are major internal architectural differences so I don't know how usable this data is.I guess I'm hoping someone out there has done something similar before and either has a load pull result they'd be willing to share, or at least someone could provide some advice for how I might estimate better than using the result at 915MHz?Thanks,Mike

author: uer166
author_rank: Super Contributor
timestamp: September 19, 2025, 06:49:40 am
content: I don't have much value to add other than I dealt with the same issue on SX1276, but ended up just copying the reference design exactly.Since it's a split Tx/Rx architecture, the Rx side matching is much more difficult, and for both SX1276 and SX1262 they seem to require you to inject a low-level signal with DUT in a chamber that results in a measurable packet error rate, and try to reduce the PER as you tune the components. Sounds like a giant pain, but probably what you need to do.Perhaps instead of a tuner you can use some high-performance variable caps on your board to adjust those elements, find the maximums, remove+measure, then install 0402 discretes to confirm..Have you tried simply copying the 916MHz design and looking at performance as-is? Perhaps it's close enough where a dB or 2 loss isn't critical.

author: miket6000
author_rank: Contributor
timestamp: September 19, 2025, 07:44:51 am
content: Thanks, the variable cap idea is a good way of finding a rough ballpark figure for sure, it reminded me I actually have some variable inductors as well, I've only used them at a few MHz before but they might work, at lower inducances they're essentially air cored.The filter cutoff frequencies all have to change to avoid polluting the 868 and 915 MHz bands with my 2nd harmonics so using the reference designs won't work, but using the reference design matching impedance was my intended starting point.
Matching new peizo elements to existing ultrasonic driver - Page 1
Forum section: electronics / projects

author: rbm
author_rank: Regular Contributor
timestamp: January 03, 2019, 12:18:19 am
content: I'm planning on replacing piezo elements in an older Whaledent BioSonic UC1-110 ultrasonic cleaner that I own. The driver circuit uses the elements as part of a LRC oscillator. When measured, the original piezo elements are wired in parallel and read 13.3nF. The new piezo elements I bought measure 7.23nF when paralleled.I believe the replacements should match the capacitance of the OEM elements to keep the oscillator characteristics. Would it be OK to parallel an additional 6nF across the new elements to raise the apparent capacitance of the driven elements?

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 03, 2019, 05:37:31 pm
content: Not sure, but I think you need both electrical and mechanical resonance in the same vicinity. You could add some low loss high voltage caps to get the capacitance back where the driver needs it, but do you know the mechanical resonance of the replacement system?

author: rbm
author_rank: Regular Contributor
timestamp: January 04, 2019, 12:13:04 am
content: Thank you for that. I believe the mechanical resonance is 44KHz - 45KHz. I know the driver is capable of 100W of power delivery to the elements and was concerned that any matching capacitors I may introduce into the system needed to withstand this power. I can obtain 4.7nF 1000V polypropylene film capacitors readily. Will these be low loss?
Math: RLC natural response - Page 1
Forum section: electronics / projects

author: Gaktyt
author_rank: Regular Contributor
timestamp: June 16, 2020, 07:00:04 pm
content: Hi,I can't figure out the intermediary steps in the following calculation (example 8.11 Electric Circuits 10th Edition)\$\alpha = 2800 Rad/Sec \quad and \quad \omega_{d} = 6800 Rad/Sec\$The solution is given\$i(t)=B_{1}e^{-\alpha t}cos(\omega_{d}t)+B_{2}e^{-\alpha t}sin(\omega_{d}t)\$Since \$B_{1}=0\$ the cos part drops out and the solution becomes\$i(t)=B_{2}e^{-\alpha t}sin(\omega_{d}t)\$Therefore\$\frac{d i}{dt} = 400 B_2e^{-2800t}(24cos(9600t)-7sin(9600t))\$Herein lies my problem, how did they arrive at the "therefore" part? I can't figure the steps out, I assume the right hand side is the derivative of the solution, but when I try calculate the derivative I get:\$\frac{d i}{dt} = B_2e^{-\alpha t}(\omega_{d} cos(\omega_{d} t)-\alpha sin(\omega_{d} t))\$It looks a bit like above but the constants are not the same, and where did they get 400 from?

author: Andy Watson
author_rank: Super Contributor
timestamp: June 16, 2020, 08:01:02 pm
content: I suggest there was a typo. Try with \$\omega_d = 9600 Rad/Sec\$

author: Gaktyt
author_rank: Regular Contributor
timestamp: June 16, 2020, 08:34:44 pm
content: Quote from: Andy Watson on June 16, 2020, 08:01:02 pmYes 9600 is the correct result when evaluating at t=0\$\frac{d i}{dt} = 400 B_2e^{-2800t}(24cos(9600t)-7sin(9600t))\$becomes\$\frac{d i}{dt} = 9600 B_2\$So I would say it's probably not a typo, it's the 10th edition surely someone would have noticed if it's a typo by now.edit... wait a minute, when I evaluate my derived equation at t=0\$\frac{d i}{dt} = B_2e^{-\alpha t}(\omega_{d} cos(\omega_{d} t)-\alpha sin(\omega_{d} t))\$it also becomes\$\frac{d i}{dt} = 9600 B_2\$So I guess my question is more: what's the difference between theirs and my derivative? do they solve for complex numbers? and 24 and 7 is the imaginary part, but still where does the 400 come from?

author: Andy Watson
author_rank: Super Contributor
timestamp: June 16, 2020, 10:10:12 pm
content: Quote from: Gaktyt on June 16, 2020, 08:34:44 pmI think you are over-thinking this part.Starting with the derivative \$\frac{di}{dt} = B_2 e^{-\alpha t} \left[ \omega_d \cos (\omega_d t) - \alpha \sin(\omega_d t) \right]\$. Fill in \$\alpha = 2800\$ and \$\omega_d = 9600 \$, i.e.\$\frac{di}{dt} = B_2 e^{-2800 t} \left[ 9600 \cos (9600 t) - 2800 \sin(9600 t) \right]\$. Now take 400 out.
MATH4DSO software: improved FFT Spectrum on Keysight/Agilent DSOX - Page 1
Forum section: electronics / projects

author: F6DEX
author_rank: Newbie
timestamp: March 25, 2016, 09:18:59 pm
content: HelloThis is my first post on this forum. Thanks to the various information available here and Dave's Videos, I recently bought a DSOX2022. It is a very good scope. But I am HAM radio operator and wanted more as for the FFT Part of this oscilloscope (~ a poor's man spectrum analyser!). Especially, I noticed that 2 tone test was not practicable above the 80m band.So I wrote my own software to get a better precision of the FFT. By extracting the maximum number of points available (500k vs 65k), I can now perform a 2 tones test up to 30MHZ. See image attached related to the 2 tone test of a KX3 @ 29Mz (29dB below PEP, worst case).Finally, from line of code to line of code... I also added several graphic functions and many commands to control the oscilloscope itself (not All) and even a mixed domain interface which mimics some high-end scope... This is MATH4DSO (free).It has been written and tested with a DSOX2022 and should run with any DSOX2000 and (I hope) with any DSOX3000 (I added the necessary commands to ensure a compatibility). I do not recommend to test this version with any other brand (as far as I can see Rigol uses a different syntax for the Acquire functions).The program uses the USB port and does not requires the LAN interface. The Keysight IO Library is required (Windows 7 minimum).You can download it fromhttp://trx-manager.com/math4dso.htmThe package includes an help file with some tips. Please consider it as beta version.Enjoy... Laurent F6DEX

author: bingo600
author_rank: Super Contributor
timestamp: March 26, 2016, 07:14:28 am
content: Looks niceNow i just need to get lucky @scopemonth/Bingo

author: F6DEX
author_rank: Newbie
timestamp: March 26, 2016, 09:57:18 am
content: HIA test with your next 3000T 1G will be appreciated... To compare with next DSOX4000...Regards, Laurent
MATLAB Oscilloscope Plot and Measure using Tektronix TCP/IP Client - Page 1
Forum section: electronics / projects

author: RonFred2
author_rank: Contributor
timestamp: August 07, 2024, 10:47:26 pm
content: I rewrote the code (from blog post in 2020) for my Tektronix oscilloscope to use a recent version of MATLAB and Instrument Control Toolbox—i.e., no VISA, just the TCP/IP client from the scope.The full article and code can be found here:https://www.biophysicslab.com/2024/08/01/matlab-script-for-tektronix-scope-plot-and-measure/Because I include the pre-trigger sample number ('WFMOutpre:PT_OFF?'), the plot looks like the scope display - i.e., x=0 is not necessarily in the center of the plot.Here are the SCPI commands used for accurate time and scale plotting:Code:% ymult > SCPI command: 'WFMOutpre:YMULT?'% yzero > SCPI command: 'WFMOutpre:YZERO?'% yoff > SCPI command: 'WFMOutpre:YOFF?'% xincr > SCPI command: 'WFMOutpre:XINCR?'% xzero > SCPI command: 'WFMOutpre:XZERO?'% pre_trig_record > SCPI command: 'WFMOutpre:PT_OFF?'Here is the setup code to demonstrate what features I baked into the MATLAB script:Code:%% User Inputs% Controls for oscilloscopeinput_channel = 'CH3';timeout = 10; % time allowed to complete operations in secondsbuffer_size = 3E6; % large enough to capture 2-byte int16 datascope_vendor = "Tektronix";% Controls for Matlab ICT tcpclient scope connect function% for troubleshooting:% - enter the IP address into a web browser (to get eScope utility)% - refer to scope menu: Utility > IO > LanTCPIP_address = "192.168.1.160";TCPIP_port = 4000;% Controls for saving data as an image, figure, or workspace matsave_plot = false;save_fig = false; % may take a long timesave_workspace = false; % may take a long timesave_plot_resolution = 300; % dpisave_plot_extension = 'png'; % 'jpeg' | 'png' | 'tiff' | 'pdf' | 'eps' | ...% example file name for saving data: scope_mso64b_channel1_07312024_131849file_name_base = 'scope';figure_name = "MATLAB script tcpclient_scope_demo.m";plot_channel = plot_channelname(input_channel);plot_color = get_plotcolor();% Position legend inside or outside the plot% my favorites: 'best' | 'northeast' 'northwest'  | 'eastoutside' | ...plot_legend_position = 'northwest';plot_fullsize = true; % false > use default plot size (~ 30% of screen)% Control for user changeable scope and plot measurementsplot_measurements = true;

author: RonFred2
author_rank: Contributor
timestamp: September 02, 2024, 02:51:42 am
content: I spent the last month updating my MATLAB Oscilloscope Plot and Measure script. The script now supports multiple channels, has improved zoom with meaningful time and voltage units, and has better legend management. Same link as before for discussion and code:https://www.biophysicslab.com/2024/08/31/matlab-script-for-tektronix-scope-plot-and-measure/

author: ktgun
author_rank: Contributor
timestamp: September 02, 2024, 09:26:03 am
content: Great job!Getting Matlab to draw normal waveforms in quasi-real time is always a headache.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 02, 2024, 05:13:18 pm
content: Good job, I still have flashbacks from how terrible VISA was.