hybridfree/eevblog-posts huggingface dataset:
What a good AC characteristic for Linear psu means ? - Page 1
Forum section: electronics / projects

author: namster
author_rank: Regular Contributor
timestamp: July 23, 2020, 06:50:17 pm
content: Hi All ,i see in many linear PSU project the terms of AC characteristics bandwitch of the Power supplybut but this concept remains unclear for me could someone clarify this for me

author: bdunham7
author_rank: Super Contributor
timestamp: July 23, 2020, 07:35:07 pm
content: Quote from: namster on July 23, 2020, 06:50:17 pmCan you provide a link to a project or description using those terms?

author: namster
author_rank: Regular Contributor
timestamp: July 23, 2020, 09:20:11 pm
content: Yes , for example this articlehttps://www.analog.com/en/technical-articles/loop-gain-and-its-effect-on-analog-control-systems.htmlthe point that I can't understand is the frequency in Bode diagram of an DC regulator , what determines the frequency of work ?

author: bdunham7
author_rank: Super Contributor
timestamp: July 23, 2020, 09:41:22 pm
content: It's a complex subject and that article is about a fairly advanced characteristic of regulators and supplies, but if I understand your question, you are just asking what a discussion of frequency response is doing relative to DC power supplies, right?So, the short quick answer is that it is a way of describing the ability of the regulator or supply to react to changes in either the input voltage or the load. A regulator should filter out any variation in the supply voltage (ripple) and also keep the voltage constant even as the load current varies. A standard regulator, like an LM7805, is good at suppressing 50/60Hz ripple, but if you feed it with a supply with high frequency ripple, say 1 MHz, it doesn't react quickly enough to filter that out. Likewise, if you have a load that goes on or off too quickly, it won't react fast enough to prevent a dip or surge in the voltage. Another way of looking at is to compare the regulator to an amplifier and say that it has a 'frequency response' curve. A regulator with an extended frequency response will react more quickly to supply or load variations and then can filter out noise and ripple that occurs at higher frequencies. Does that help?

author: namster
author_rank: Regular Contributor
timestamp: July 23, 2020, 10:28:10 pm
content: So , the bandwitch is related to Transient response of the regulator , from what I understood the more is the bandwitch bigger , the more quicky is the transient response is that correct ?

author: bdunham7
author_rank: Super Contributor
timestamp: July 23, 2020, 11:01:10 pm
content: Yes, exactly. And the faster it responds, the closer it can regulate.

author: coppice
author_rank: Super Contributor
timestamp: July 24, 2020, 12:11:51 am
content: Quote from: namster on July 23, 2020, 10:28:10 pmYes and no. Wide bandwidth is needed for rapid transient response. However, without good control of the frequency and phase response of this wide bandwidth control loop you can end up with horrible overshoots, and voltage spikes that might damage the load.
what am i doing wrong? - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: November 09, 2021, 04:13:37 am
content: Hi all im building this octopuss as in the pdf attached,i ham having issues trying to set the voltages on r3+ r4,both sit at about 2.3v and only change about 100milli volt each way i turn the pots,the circuit is built exactly as per the schematic,exept my trans former is a center tapped 20v unit,im just using one leg,do i need different value components,the ac output of the transfo is 14.4v unloaded acording to my fluke 83 and avometer mk 8,any ideas whats going on here?

author: m3vuv
author_rank: Super Contributor
timestamp: November 09, 2021, 09:47:48 am
content: well ive noticed something wierd,on the part where you have to set the voltage on the probes using the pots on channel a,the black probe goes to ground,ground of what exactly?,i had the grounds on the schematic going to mains ground and the body of the transfo,like that i couldnt alter the voltages with the pots more than a couple of hundred millivolts,if i measure between the red probe and the side of the transfo output,oposit the junction with c1,it adjusts fine,any ideas,is it some sort of wierd ground loop?

author: m3vuv
author_rank: Super Contributor
timestamp: November 09, 2021, 10:35:34 am
content: well using the lower leg of the transfo all the voltages setup bang on,could it be a mistake in the schematic?,i dont fancy connecting this to my dso and using that as the ground reference as i can see if i do i will be back with the original issue and all the voltage settings will be off againe,am i loosing the plot??

author: m3vuv
author_rank: Super Contributor
timestamp: November 10, 2021, 11:41:14 am
content: found the issue,it was a leak on the transfo primary,nearly drove me mad,fitted a new 12volt 1.5va transfo and works fine.

author: Terry Bites
author_rank: Super Contributor
timestamp: November 10, 2021, 01:57:27 pm
content: Are you talking to yourself again? - its ok.

author: m3vuv
author_rank: Super Contributor
timestamp: November 11, 2021, 02:38:15 am
content: is it a sign of madness?,i do it all the time,its this darned schematic driving me nuts!

author: m3vuv
author_rank: Super Contributor
timestamp: November 11, 2021, 08:52:37 am
content: Quote the pdf,on how to set output test probe voltages.output voltages following these steps.(1) – Check to make sure that you have 12 V ac at the Octopus input. If so, solder a temporary jumper between CH1A and R3.(2) – Set the variable resistor R3 for 1 V ac between the red and black lead outputs on the PC board. Then disconnect the temporary jumper from R3.(3) – Connect the jumper from CH1A to R4. Set R4 for 5 V ac. Then disconnect the temporary jumper from R4.(4) – Connect the jumper from CH1A to R5. Set R5 for 10 V ac. Then disconnect the jumper from R5 and keep it to CH1A.,how can this work?, as the black wire has no connection to ground without 1b connected!should 1b not be connected in order to set 1 a?
What am I going to do with a tube of 10x Z88C0020VSC Zilog microcontrollers - Page 1
Forum section: electronics / projects

author: wilfred
author_rank: Super Contributor
timestamp: September 09, 2017, 05:35:39 am
content: /.

author: technix
author_rank: Super Contributor
timestamp: September 09, 2017, 05:46:10 am
content: I am interested in getting 2 of them.

author: bson
author_rank: Unknown
timestamp: September 10, 2017, 06:23:21 am
content: The Super8 was an enhanced Z8 designed to run Forth. Do these have the piggyback 2764 EPROM socket in a 40 pin DIP, or is it the 48 pin DIP, or a PLCC?
What are advantages of different DC motor windings? - Page 1
Forum section: electronics / projects

author: DCHumber
author_rank: Newbie
timestamp: October 26, 2016, 03:26:38 pm
content: For a course project, I must construct a permanent-magnet DC motor out of limited materials. I have 15 metres of magnet wire, a strip of steel, brass, a 35 mm film container and some other bits and bobs.My current design has the film canister on our shaft, and the windings mounted to it. The strip of steel has the same width as the height of the canister, and we will bend it such that it wraps around the canister, but comes up to cup the windings. We are going to have 5 windings. However, we are unsure of what kind of winding connection to actually implement.Our goal is to maximize torque. Would we actually find any advantages to one connection over another?

author: CM800
author_rank: Frequent Contributor
timestamp: October 26, 2016, 03:31:32 pm
content: Quote from: DCHumber on October 26, 2016, 03:26:38 pmHey,It'd be great if you can take a picture of all materials you have next to a ruler so we can see exactly what we are working with to suggest.Does it specifically say brushed motor or just permanent magnet motor? Could make a really nice and easy 3 phase brushless Permanent Magnet motor.EDIT:Also:
What are bi-polarity (Dual) RED LEDs good for? - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: June 29, 2021, 08:05:26 am
content: I came across a bag of these yesterday (Kingbright "T-1 3/4 (5mm) SOLID STATE LAMP" L-57SRSRD). They look symmetrical inside and do indeed light up 'both ways'.Why are they made - are there common applications driving little low power LEDS from AC?

author: Gyro
author_rank: Super Contributor
timestamp: June 29, 2021, 08:12:44 am
content: Yes, exactly that. They achieve maximum light output and no flicker by lighting on both half cycles (unlike using a reverse blocking diode) without the need for a bridge rectifier.It brings the required external components down to a single resistor.

author: tooki
author_rank: Super Contributor
timestamp: June 30, 2021, 01:53:52 am
content: Quote from: Gyro on June 29, 2021, 08:12:44 am* less flicker. It definitely still flickers.

author: Gyro
author_rank: Super Contributor
timestamp: June 30, 2021, 10:40:38 am
content: Ha, true. At least it's no worse than the equivalent Neon though (a lot less when the Neon ages and starts to flicker of its own accord!).Sorry, reading back, I didn't fully answer the original question. Yes there is still common applications for these things as pilot lights. Modern high efficiency LEDs can match the current consumption of Neon indicators and are more reliable. In very low power applications (capacitor dropper PSU with small non-isolated circuit) the LED current can be a significant proportion of the circuit DC current consumption. Running the LED off incoming AC allows you to minimise the dropper capacitor size.
What are common track pitch/width/spacing etc on very high density boards? - Page 1
Forum section: electronics / projects

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: January 15, 2020, 11:39:54 am
content: Due to the frequency range and research nature of my work, the stuff I do is on specialized technologies for prototyping. I use tiny pitches, laser vias, ENIPIG finishes, and expensive fancy substrates.When I make non-high-frequency PCBs they are usually on your standard cheap-process, often with something like 150um minimum track-width and spacing.But I was wondering what you get in high-volume industry. Seeing how the industry is commonly using 01005 and pushing towards 0201m components in things like laptops, tablets and mobile phones, which have pads on the order of 100um: What kind of pitches and clearance and track width are standard there? What is the cost of such a PCB in ultra-high-volume?

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2020, 12:44:43 pm
content: Nowadays 0.9mm width/spacing shouldn't be a problem c.q. very costly.

author: KaneTW
author_rank: Frequent Contributor
timestamp: January 15, 2020, 01:11:10 pm
content: Jlcpcb has 90um track widths.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: January 15, 2020, 03:57:37 pm
content: Quote from: KaneTW on January 15, 2020, 01:11:10 pmIs 90um what you can expect in HDI boards for smartphones and laptops? Still seemed rather big to me. I'm used to running 80um or lower and we still struggle with routing.

author: KaneTW
author_rank: Frequent Contributor
timestamp: January 15, 2020, 04:21:37 pm
content: Not HDI at all, just their default for multi-layer prototypes. Low-cost, Chinese HDI should go down to 60um-ish.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2020, 07:15:12 pm
content: Quote from: TheUnnamedNewbie on January 15, 2020, 03:57:37 pmIt seems that there is a limit to what PCB manufacturers want to produce on a generic production line. Nearly a decade ago I tried to have a board made with 60um/40um but that was a no-go for a couple of 100 boards. Back then 100um was the lower limit for sane pricing. Personally I don't like to push the boundaries. I usually design with wider traces / wider clearances than what the PCB process allows for and only go for the minimum widths / clearances if it is absolutely necessary. It helps to improve yield.

author: Daixiwen
author_rank: Frequent Contributor
timestamp: January 16, 2020, 07:44:08 am
content: I like ACB's design rules table to get an idea of how complex a PCB will be to manufacture.Note that ACB has rather high prices, which get crazy high if you go over their classification level 8https://www.acb.be/wp-content/uploads/2018/04/DRC_table.pdf
What are different type of PCB mount connectors - Page 1
Forum section: electronics / projects

author: Sai teja
author_rank: Regular Contributor
timestamp: September 21, 2017, 03:42:54 am
content: Hello,My application requires PCB mount female and male connectors and number of pins ranging from (12 to 20). Any pin number is fine. Male Box header can be used. But corresponding FRC female connector can not be mounted on PCB. Please help me in exploring different kinds of PCB mount male and female connectors.Thank you
What are GX16, GX20 a clone of? .. Generic Multipole Connectors Recommendations? - Page 1
Forum section: electronics / projects

author: Chendy
author_rank: Contributor
timestamp: May 25, 2018, 09:29:40 am
content: Looking for some in line connectors ..Something with a- wide range of poles- available cheaply, or clones or generics exist- rubust, with strain relief- say upto 8+ polesgood to haves- options for IP ratings- PCB and Panel connector versionsfor example XLR audio connectors would be fine, but generally only up to 5 pole.I have come across theGX16and GX20 connectors, refered to as 'aviation connectors'.Does anybody know what spec they conform to, or what original model/manufacturer they are a clone of? or are they a unique chinese phenomenon??side question, what connectors exist in in cloned or generic form, for multipole low current signals, relaxing the spec above?rj45- no real inline connections, not robustFTDI ZH, PH.. ?

author: RobK_NL
author_rank: Frequent Contributor
timestamp: May 25, 2018, 01:16:47 pm
content: GX16 looks like a beefy DIN-connector, e.g. Binder 423 series.

author: Gregg
author_rank: Super Contributor
timestamp: May 25, 2018, 07:47:41 pm
content: Jones plugs used to be all over the place and are very reliable with almost infinite variety of connection possibilities
What are some meters, test equipment, probes, we can make ourselves ? - Page 1
Forum section: electronics / projects

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 20, 2018, 09:17:35 pm
content: Like for instance I've made a very simple RF probe, and soon will make a high voltage probe. I've made a few PSUs, soon to be making 3 proper bench PSUs. Later this spring/summer I plan to make a vacuum tube tester.I don't know the names of all the meters/testers/equipment that could reasonably be made with mostly discrete parts. But that would be fun and useful stuff to make from older schematics.

author: CopperCone
author_rank: Super Contributor
timestamp: March 20, 2018, 09:27:38 pm
content: near field probes are fun because mostly people don't really care about absolute magnitude accuracy.You can also make torrodial probes for magnetic field.

author: ikrase
author_rank: Regular Contributor
timestamp: March 22, 2018, 07:02:15 am
content: Directional couplers for measuring power and SWR on VHF and UHF are very easy if you have some diodes, capacitors, copper clad, and a hack saw. (and a steady hand).Current transformers for AC are also very, very simple. I have heard that you can DIY a DC current detector but it's much more difficult and requires meticulous calibration.Some people have been building their own electrometers with some success. The trick is having more than one range.
What are the basics of automotive wire harness designing? - Page 1
Forum section: electronics / projects

author: Dhanushka
author_rank: Regular Contributor
timestamp: January 27, 2022, 11:07:40 am
content: Hi!I am working on a project for designing a wire harness for a vehicle which is used a CAN bus and power cables. I am not coming from automotive industry. So, I highly appreciate if someone can suggest me a recourses about basics (aspects) of wiring harnesses designing, mathematical modes and simulation softwires.Thanks
what are the best practices for calculating output clamping zener diode wattage  - Page 1
Forum section: electronics / projects

author: mj148
author_rank: Newbie
timestamp: August 30, 2022, 03:54:45 pm
content: Sorry if this has been covered before, I did search the forum first!I didn't post this in the repair section as its more of a musing than asking for help.I was recently asked to see if I could repair an old Video 8 video cassette player for an elderly relative who has bought a blu-ray recorder and wants to transfer their old camcorder tapes.. the VCR itself had been in an attic for the best part of 20 years and when they plugged it in it went bang.. good old mid 80s ELNA caps leaking will do that!It's all repaired and been working fine now after replacing the capacitors, switching regulator IC as well as the zener that had shorted.15V zener across the 11.5v line that I assume is there for worst case scenerio as even under standby load the SMPS never goes above 11.5vDuring repair when I was testing it and waiting for the zener to arrive I didn't have it installed.. just out of curiosity I ran the SMPS unloaded to see how high the voltage would climb.. sure enough over about 20 minutes the capacitors slow charged upto 16v before I cut the power (they are only 16v rated caps).I have the service manual and the zener is 15V but 5W!I substituted like for like but most later Sony VCRS and pretty much every other VCR i've ever worked on has the typical 1w zener in this position.So did Sony have a job lot of 5W diodes they were desperate to get rid of? Is it mid 80s overkill or is there some logic to their reasoning?Thanks if you made it this far.. the post got a little long!
What are the connectors on the end of scope probe ground leads called? - Page 1
Forum section: electronics / projects

author: Ionforbes
author_rank: Contributor
timestamp: August 09, 2021, 11:01:10 pm
content: Being the unorganised person I am, some of my scope probe ground leads have disappeared. Buying spares is either uneconomical or across the globe so I tried making my own.Only problem is, I can't work out what the crimp connector on the end that joins lead to probe is called. 'Split ring' yielded nothing. I wouldn't have thought they're custom as they're used on the ultra cheap ebay ones.If anybody knows that'd be greatThanks

author: bob91343
author_rank: Super Contributor
timestamp: August 10, 2021, 12:08:15 am
content: It's just a ground clip. Try that in your search.

author: xrunner
author_rank: Super Contributor
timestamp: August 10, 2021, 12:11:32 am
content: I have never run across them. I think they call it a ground collar clip. I think they are specialized diameter clips for specific probes so may only be in the probe manufacturer's parts in the factory.This discussion may be of help -https://electronics.stackexchange.com/questions/86047/is-there-a-common-name-for-scope-collar-clips

author: Ionforbes
author_rank: Contributor
timestamp: August 10, 2021, 12:26:15 am
content: All my probes have them in 5mm diameter and they're a mix of brands. 'Ground clip' and 'collar clip' yielded nothing, so I may just buy the leads. It would still be interesting to find the clips though as it would allow a whole load if custom leads, like a hook/plunger clip or maybe even a banana jack, and sacrificing whole ground leads would be a bit expensive.

author: Ian.M
author_rank: Super Contributor
timestamp: August 10, 2021, 12:55:25 am
content: Seehttps://www.eevblog.com/forum/testgear/sourcing-the-fork-terminals-used-on-oscilloscope-probe-ground-leads/The consensus was they are custom OEM parts, and are virtually unobtanium except pre-attached to a ground clip lead.Here's an Amazon UK link to some ground clip leads:https://www.amazon.co.uk/Oscilloscope-Probe-Accessories-Ground-Cable/dp/B08HV4FF1V/Dirt cheap and you could have them the following day. Its anyone's guess how well they'll fit your probe but if they don't fit and your probe's ground ring is the modern 5mm standard, just send them back!

author: bob91343
author_rank: Super Contributor
timestamp: August 10, 2021, 06:16:04 am
content: Try this:https://www.ebay.com/itm/222659358233?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=222659358233&targetid=1263104805766&device=c&mktype=pla&googleloc=9031162&poi=&campaignid=11755693419&mkgroupid=121536625399&rlsatarget=pla-1263104805766&abcId=9300462&merchantid=101698380&gclid=CjwKCAjwpMOIBhBAEiwAy5M6YLIEmqZ0PjosqWLG_YXj9z7VwppL26T8TPOp5bfI9nw9nDfU9X092BoClrMQAvD_BwE

author: Ionforbes
author_rank: Contributor
timestamp: August 10, 2021, 12:30:49 pm
content: Don't know how I missed that thread, I'll just have to buy them and live with poor measurements for a few weeks
What are the emc requirements for military ? - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: June 30, 2012, 07:11:35 pm
content: Just a thought as at work we just buy expensive emc filters and use them blindly. What are the actual requirements of military stuff ?

author: Short Circuit
author_rank: Frequent Contributor
timestamp: June 30, 2012, 07:34:49 pm
content: MIL-STD-461C for the americans, I'm sure every country has their own variations, but requirements are probably quite similar.

author: Rufus
author_rank: Super Contributor
timestamp: June 30, 2012, 10:39:34 pm
content: Quote from: Simon on June 30, 2012, 07:11:35 pmObviously depends on what the 'military' stuff is. Def Stan 59-411 which runs to about 1000 pages covers most of the current UK MOD requirement. It should be available free if they let you register atwww.dstan.mod.uk
What are the TPS2024B AC Adapter PSU specifications? - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: October 02, 2023, 07:04:59 pm
content: I've seen some non-OEM PSUs (on eBay) and the one whose label I could read said 15V, 2.5A, centre +.Does anyone have an actual Tek PSU for this scope - and if so, please could you post a photo of the label?The manual has no details on the AC adapter, and Tek have failed to respond to enquiries.I'd like to know what is the acceptable range of output voltage, and how much current the PSU should be rated for. If the "centre +" can be verified, even better

author: coromonadalix
author_rank: Super Contributor
timestamp: October 03, 2023, 10:39:49 am
content: sv manual page 22https://res.cloudinary.com/iwh/image/upload/q_auto,g_center/assets/1/26/Tektronix_TPS2000B_Digital_Storage_Oscilloscope_-_Service_Manual.pdfExternal DC InputTable 6: External DC input Characteristic DescriptionVoltage 15 V, ±1 VThe input is not protected from the electrically harsh automobile electrical system. Operationfrom a vehicle requires a specifically designed external power supply.Typical Power draw from External DC input:2 channel models, charging a battery: 21 W2 channel models, no battery: 13 W4 channel models, charging a battery: 30 W4 channel models, no battery: 18 WCharging only, instrument OFF: 28 WCurrent consumptionMaximum power draw from AC line by AC Adapter, 36 wattsConnector type 2.5 mm male. Use a mating connector with a 2.5 mm barrel hole.Center conductor: positiveOuter conductor: negativeI would say 2.5 amp is ok, even 3 amps .... to give good margin, and the adapter will heat less ... it seems the maximum wattage is 30 watts, witch is 2 amp

author: eevcandies
author_rank: Regular Contributor
timestamp: February 08, 2025, 05:09:39 pm
content: It's funny...sellers on the bay or amazon will advertise a TPS20xx wall wart/adapter for $39.95, or $50,or even $100. They hide/blur the adapter specs so you can't see it's just a $10-$15 15V adapter you can get yourself. In fact, one seller wanted about $250 !!!
What are the video tutorials for filter design with applications? - Page 1
Forum section: electronics / projects

author: Dhanushka
author_rank: Regular Contributor
timestamp: November 16, 2020, 10:25:32 am
content: Dear all,I am looking for a tutorial for analog and digital filter design with practical applications. Most tutorials are based on theory and does not contain any valuable application with circuit design of analog filter or DSP implementation except Matlab. If you know any tutorial about this topic please mention that here.Thanks.
What are these called, and where can I find more of 'em? - Page 1
Forum section: electronics / projects

author: precaud
author_rank: Frequent Contributor
timestamp: December 12, 2017, 05:01:31 am
content: I know these as spring-loaded component clips, but a search for that returns everything but. I've have a couple of them for many years and would like to have a few more. Any ideas?

author: ataradov
author_rank: Super Contributor
timestamp: December 12, 2017, 05:41:58 am
content: I don't understand how this would be used. They appear to be panel mount, so distance between them will be fixed. What sort of equipment they are used in?

author: Cyberdragon
author_rank: Super Contributor
timestamp: December 12, 2017, 05:59:39 am
content: Quote from: precaud on December 12, 2017, 05:01:31 amThey're called binding posts, not "component clips".

author: ataradov
author_rank: Super Contributor
timestamp: December 12, 2017, 06:01:05 am
content: Quote from: Cyberdragon on December 12, 2017, 05:59:39 amBut what's the advantage compared to regular isolated binding posts with holes for wires? Quick release is nice, but I would not want to have so much metal exposed.

author: Cyberdragon
author_rank: Super Contributor
timestamp: December 12, 2017, 06:16:24 am
content: Quote from: ataradov on December 12, 2017, 06:01:05 amThese all metal ones should only be used for low voltage stuff like speaker wires.

author: DTJ
author_rank: Super Contributor
timestamp: December 12, 2017, 06:19:55 am
content: Image searching Google using 'spring loaded binging post" turns up some interesting hits.https://www.google.com/search?q=spring+loaded+binding+post&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjggL7a6YPYAhWD5YMKHc47BzYQ_AUICygC&biw=1366&bih=636Particularly this one:https://www.alliedelec.com/images/products/Small/70217204.jpg

author: Nusa
author_rank: Super Contributor
timestamp: December 12, 2017, 06:49:37 am
content: https://www.alliedelec.com/grayhill-29-110/70217203/

author: precaud
author_rank: Frequent Contributor
timestamp: December 12, 2017, 01:38:31 pm
content: Good find, Nusa! They're Grayhill push-post terminals! Now why didn't I think of that?As to what they are useful for: yes, low voltage only but still rated for 20A. The advantage of these is they are small (1/4" dia.) and short (less than 1") and hence will add minimal inductance at high freqs. They are very convenient to insert/remove parts from, can be spaced more closely together than a standard binding post (of which I have many types), and they have very low contact resistance. I want to put together some test fixtures that have different terminal spacing for radial-lead parts.
What are these cheap Raspberry Pi cases made out of? - Page 1
Forum section: electronics / projects

author: adjustttt
author_rank: Contributor
timestamp: December 18, 2017, 07:52:44 pm
content: Found these super cheap RPI cases on Ali expresshttps://www.aliexpress.com/item/Raspberry-Pi-Aluminum-Case-Silver-Case-Metal-Enclosure-Compatible-with-Raspberry-Pi-3-Raspberry-Pi-2/32742883169.htmlBut what are they made out of?The listing says aluminum but they have a weird dull silver color to themCould it be anodized? Or some kind of cadmium or somethingI am considering buying 10, these seem really good for clusters especially compared to the aluminum competition which is if I remember correctly, are 80 dollars per case.

author: ataradov
author_rank: Super Contributor
timestamp: December 18, 2017, 08:01:43 pm
content: I think they are painted. And they are probably made out of some cheap aluminum alloy like silumin.

author: ebastler
author_rank: Super Contributor
timestamp: December 18, 2017, 08:37:55 pm
content: The vendor says that it's aluminiumalloy, not pure aluminium. Aluminium alloys with silicon and/or magnesium can look a darker grey, apparently. Or maybe it is even anodized?I don't think it is painted; the color looks too even on the inside. Low-cost spray painting is typically just applied to the outside, with some "fog" visible inside. And since they claim to have two cooling fingers to touch the main chips on the Raspberry, painting it from the inside would actually be detrimental.

author: pigrew
author_rank: Frequent Contributor
timestamp: December 18, 2017, 08:48:29 pm
content: I like the case, though I worry that the "heat sink" spires may crush the ICs? Perhaps a soft thermal pad is needed along with grinding down the case?

author: ebastler
author_rank: Super Contributor
timestamp: December 18, 2017, 08:53:38 pm
content: Quote from: pigrew on December 18, 2017, 08:48:29 pmYes, I've been wondering. With the burrs from the mold still visible, these fingers don't look like they will make decent thermal contact anyway. Hopefully they are designed to leave a small gap, to be filled by a thermal pad.Well, you can always file them down if they are too long!

author: David Hess
author_rank: Super Contributor
timestamp: December 18, 2017, 10:33:15 pm
content: Quote from: ebastler on December 18, 2017, 08:37:55 pmIn other words,pot metal.
What are these connectors? - Page 1
Forum section: electronics / projects

author: mtbspace
author_rank: Newbie
timestamp: April 28, 2020, 12:03:55 pm
content: Can anyone help me identify these connectors, please? Do you know if they can be sourced? They are on the multi-function display on a 2004 Renault Clio. I'm replacing the display and the board that drives it with my own stuff, but would like to use the same sockets as on the original board. The plugs can also be connected to a standard male header.There are 15 pins, spaced at 2.54mmThanks

author: 16bitanalogue
author_rank: Regular Contributor
timestamp: April 28, 2020, 02:07:10 pm
content: The path I would point you in is to see if Renault has a catalog of connectors or pigtails or connectors.Ford Motorcraft has an awesome pigtail wiring catalog:https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/wire_sets_wiring/18376-Pigtail-Book-2016.pdfYours is a board interconnect, so it seems to me it would be more standardized. It looks like an edge card connector with board lock.That's my best guess.

author: johnkenyon
author_rank: Regular Contributor
timestamp: April 29, 2020, 05:27:08 pm
content: Quote from: mtbspace on April 28, 2020, 12:03:55 pmA quick google seems to indicate that a similar connector is used on Renault Clio and Master clock modules.I would suggest salvage from a scrappy, trying your luck on Ebay for a clock module.The chances of buying a specialised automotive connector in anything less than a bag of a thousand is slim to none.Another place to try is somewhere that refurbs/repairs instrument clusters and/or ECUs (e.g. BBA-Reman or Cluster Repairs UK) and ask if they have one in their spares bin.
What are these IC's? - Page 1
Forum section: electronics / projects

author: etbusch
author_rank: Newbie
timestamp: November 15, 2015, 09:09:12 pm
content: I got a handful of these packages in a grab bag of 74 series logic from eBay. I have never seen these tall DIP packages before, do they house a battery like a small NVRAM?A google search for part numbers has brought up nothing.Any guesses?

author: gibbled
author_rank: Regular Contributor
timestamp: November 16, 2015, 12:20:15 am
content: Magnetics.

author: etbusch
author_rank: Newbie
timestamp: November 16, 2015, 12:34:16 am
content: Quote from: gibbled on November 16, 2015, 12:20:15 amCould you elaborate on that?

author: ataradov
author_rank: Super Contributor
timestamp: November 16, 2015, 12:37:49 am
content: Quote from: etbusch on November 16, 2015, 12:34:16 amThey are transformers. Most likely for communication applications, like Ethernet, for example.Search on the name Sprague confirms this.

author: etbusch
author_rank: Newbie
timestamp: November 16, 2015, 05:41:00 am
content: Quote from: ataradov on November 16, 2015, 12:37:49 amMakes sense. Thanks much!
what are these odd transformers for? (sin/cos) - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 25, 2015, 06:49:22 pm
content: I can't find nothing on google.

author: helius
author_rank: Super Contributor
timestamp: April 25, 2015, 06:56:30 pm
content: analog rotary encoder magnetics

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 25, 2015, 07:21:51 pm
content: Quote from: helius on April 25, 2015, 06:56:30 pmCan you elaborate?

author: wraper
author_rank: Unknown
timestamp: April 25, 2015, 07:29:48 pm
content: Where did you get those? Should be some custom stuff from Perkin-Elmer laboratory equipment.

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 25, 2015, 07:35:27 pm
content: Quote from: wraper on April 25, 2015, 07:29:48 pmthe trash, yea i figured as much

author: johansen
author_rank: Super Contributor
timestamp: April 25, 2015, 07:45:30 pm
content: those are scott T transformers for converting between three phase and two phase.usually three phase encoders, synchros and differentials are converted to two phase, then sent to the electronics for decoding into digital or analog feedback systems, or for data transmitted somewhere.. fewer parts to do that with two phase than three, but three is more accurate at the mechanical side

author: Smokey
author_rank: Super Contributor
timestamp: April 25, 2015, 07:59:19 pm
content: http://en.wikipedia.org/wiki/Transformer#Types

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 26, 2015, 01:50:01 am
content: Wow, hand lettered Perkin-Elmer. Regardless of whatever the hell they are: you know they were blessed by white bearded virgins (not necessarily in that order)!Tim

author: calexanian
author_rank: Super Contributor
timestamp: April 26, 2015, 06:49:02 am
content: you know the people who made those had the right tongue angle!
What are these spacers called? - Page 1
Forum section: electronics / projects

author: tomazic
author_rank: Newbie
timestamp: December 19, 2013, 06:47:59 pm
content: Hi guys,I've came across these spacers several times before and they might come very handy for my future projects. The problem is I don't know what they're called. I've browsed through farnell, Mouser and Digikey but I just can't find them. They're used for fixing msata and similar PCBs to motherboards. Anyone knows what they're called and also a good source of them?Thanks!

author: angst7
author_rank: Contributor
timestamp: December 19, 2013, 07:31:41 pm
content: Looks like a typical aluminum Standoff, albeit with a diamond-knurled surface. Mouser has a bunch of themhttp://www.mouser.com/Electromechanical/Hardware/Standoffs-Spacers/_/N-aictf

author: free_electron
author_rank: Super Contributor
timestamp: December 19, 2013, 07:40:56 pm
content: nope. these are pressed into the board.they are called PEM nuts. after the company that invented them : PEM engineeringhttp://www.pemnet.com/fastening_products/pem-self-clinching-fastener_new.htmothe rname is self-cinching fastenerl

author: Kjelt
author_rank: Super Contributor
timestamp: December 19, 2013, 07:44:29 pm
content: I only know the hexagonal versions see attached pdf you can get them almost anywhere incl. Farnell. in metric and in other countries probably also imperial standard. You also have them female-male versions.But you want this specific look? So you want the looks or the functionality

author: Kjelt
author_rank: Super Contributor
timestamp: December 19, 2013, 07:50:41 pm
content: Quote from: free_electron on December 19, 2013, 07:40:56 pmreturns error on page, correct URL:http://www.pemnet.com/fastening_products/pem-self-clinching-fastener_new.html

author: tomazic
author_rank: Newbie
timestamp: December 19, 2013, 09:19:47 pm
content: Yup, that's it. Many thanks guys!
What are these Stone-like things on the induction heater working Coil? - Page 1
Forum section: electronics / projects

author: MatthiasD
author_rank: Newbie
timestamp: December 30, 2016, 07:28:58 pm
content: Hello,i today tore a Induction heater apart and found this working Coil.To the Coil ar six stone like plates attaches which are magnetic. So i asume some ferromagnetic Stuff to shape the magnetic field, but i am not shure. Does someone know the purpose of this plates and can help me with some Details or resources?Thanks in forewardMatthias

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 30, 2016, 07:56:46 pm
content: Ferrite. Not stone, but ceramic. "Flux concentrators" or "pole pieces" are adequate English names for their purpose.Tim

author: MatthiasD
author_rank: Newbie
timestamp: December 30, 2016, 08:59:15 pm
content: That was fast, thank you!So i wasn't that far off with my first guess. But what is the technical use for fluxconcentrators in this case? If i am getting it right they would act as a shield for the inner circuit as they bond the magnetic field instead of letting it spread "behind" them. Is that right?Thanks Matthias

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 30, 2016, 09:06:02 pm
content: Yes, and less field on the back side means more field on the front side: better coupling to the load, and better heating.It also means a smaller overall field (less field at large distances), so you only get better coupling while the load is close by. Which is fine for this application.Tim

author: SeanB
author_rank: Super Contributor
timestamp: December 30, 2016, 09:10:07 pm
content: They concentrate the field into many smaller zones on the base of the pot, making for more spots that heat up, instead of a single larger one at the edge of the pot. Basically gives 6 eddy current areas for heating instead of one, and also enable all the field to be coupled into the pot if it does not exactly match the coil diameter.

author: MatthiasD
author_rank: Newbie
timestamp: December 30, 2016, 09:17:02 pm
content: You two have really helped me. Thank you very much!
What are those caps in the datasheet test circuit? - Page 1
Forum section: electronics / projects

author: matseng
author_rank: Frequent Contributor
timestamp: March 25, 2018, 04:17:42 pm
content: Usually I don't care that much about the "parameter testing circuits" that usually are a part of a datasheet. Looking at this example for a BSV52 there are two "caps" at 0.0023u that looks like they would be some kind of feedthrough caps or something like that. Or it might be the capacitance of a coax, but at 2n a crappy rg58 would have to be 20 meters to reach that value, so that probably is not what it is...

author: dmills
author_rank: Super Contributor
timestamp: March 25, 2018, 06:02:54 pm
content: They are just feedthru caps very standard in RF things.Regards, Dan.

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2018, 01:09:50 am
content: Those are feedthrough capacitors and they are expecting construction techniques suitable for <1ns and >350MHz or UHF. I am sure you could get away with careful Manhattan construction over a copper clad board using surface mount parts for the feedthrough capacitors; double them up to raise their self resonate frequency and half the inductance.
What are those components? - Page 1
Forum section: electronics / projects

author: soolsmarco
author_rank: Newbie
timestamp: August 15, 2018, 02:54:47 pm
content: I am doing a reverse engineer project but I can't find what these components are.Does someone know a good methode to find out what they are?The components have the folowing text on it:IC #1 = 7HUHIC #2 = AAPQ

author: Zero999
author_rank: Super Contributor
timestamp: August 15, 2018, 03:06:55 pm
content: What does the board do and can you post complete pictures of it, showing the components around the parts in question?I had some luck Googling for the 7HUH part, but not so much for the AAPQ.https://www.google.com/search?q=7HUH++SOT-5&ie=utf-8&oe=utf-8&client=firefox-bhttp://www.ti.com/lit/ds/symlink/tlv62565.pdfhttp://www.analog.com/media/en/technical-documentation/data-sheets/15175fs.pdfWhat it is can be determined, by looking at the surrounding parts.https://www.google.com/search?safe=active&client=firefox-b&biw=1280&bih=900&ei=QUF0W6-AD5CTsAeJl7LABw&q=%22aapq%22+SOT-5&oq=%22aapq%22+SOT-5&gs_l=psy-ab.12...0.0.0.17974.0.0.0.0.0.0.0.0..0.0....0...1..64.psy-ab..0.0.0....0.1Lcb9IgXUTQ

author: JS
author_rank: Frequent Contributor
timestamp: August 15, 2018, 03:47:50 pm
content: AAPQ apears to be MAX6826SUT but in sot23-6 package, yours seems to miss one pin for that...JS

author: amyk
author_rank: Super Contributor
timestamp: August 16, 2018, 02:04:44 am
content: AAxx may be MCP6001, RN5RT20AA, or XC6114B628MR.
What are "Voltage Conveyors" and how do you work with them? - Page 1
Forum section: electronics / projects

author: Mark_SF_Bay
author_rank: Newbie
timestamp: October 08, 2020, 04:48:10 am
content: I was researching circuits for a precision high speed rectifier and i ran across this article on using Voltage ConveyorsA new versatile full wave rectifier using voltage conveyors.pdf(2446.74 kB - downloaded 95 times.). Never heard of them so I searched around a bit and found they are used for other things. Seems like a general component. They have a sister called a "Current Conveyor" but i did not delve into those. There is second article that goes into some IC circuit design details of the Voltage Conveyor and was written by some of the same authors but files size limitations won't let me post it here. This second one goes by the title "A new rail-to-rail second generation Voltage Conveyor" by Gianluca Barile * , Vincenzo Stornelli , Giuseppe Ferri , Leila Safari and Emanuele D’Amico. It is on the web.Who manufactures these or something similar?How do they work or how does one design circuits with them?

author: Mark_SF_Bay
author_rank: Newbie
timestamp: October 08, 2020, 04:43:54 pm
content: Second article is attached
What brand of capacitors are these/How critical is electrolytic capacitor brand? - Page 1
Forum section: electronics / projects

author: etc6849
author_rank: Contributor
timestamp: September 06, 2013, 05:50:18 pm
content: A guy on another forum is looking for new amp. However, these electrolytic capacitors in an Emotiva XPA-5 appear to have no brand name?!? I think they are these made by Foshan No. 3 Radio Fty:http://www.powerpulse.net/story.php?storyID=5322based on the part number and pictures of the caps.How much of a deal breaker is it to use off brand capacitors like these? Am I wrong to suggest I wouldn't buy the amp as it uses them since I can't find a spec sheet for the caps, and may not last as long as an American made amp? Does capacitor brand really matter in terms of lifespan (they are right beside a heat sink)? Does it mean Emotiva probably cuts corners elsewhere too?Just curious what other engineers think. I don't do design work everyday, but love the forum here!

author: free_electron
author_rank: Super Contributor
timestamp: September 06, 2013, 06:40:24 pm
content: Brand means nothing. every cap comany makes 20 or more different types of electrolytics. you need to read the datasheet and find out what was the decision criteria for that particular type.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: September 06, 2013, 06:42:59 pm
content: Brand does mean something. Japanese capsgenerallyhave tighter tolerances, longer lifespans, and more conservative ratings than other brands. And many Chinese brands inflate or outright falsify their specifications.Assuming the correct type of capacitor was chosen for a given role, brand can give you some indication as to the degradation curve and lifespan of the circuit.

author: Kjelt
author_rank: Super Contributor
timestamp: September 06, 2013, 06:56:16 pm
content: Quote from: etc6849 on September 06, 2013, 05:50:18 pmWhat do you think?Two and a half years ago they put Seacon brand elco's in the main power supply buffer stage of the XPA-5. See picture in this dutch forum:http://www.htforum.nl/yabbse/index.php?topic=93401.msg1663808#msg1663808I asked some hardware colleagues and the verdict was then unanymous: crap. This doesn't mean you can still enjoy it for some years.But if you can solder you can upgrade to Panasonic/Nichicon or other good brands, would still be a bargain.However another owner reported some "humming" issues in his setup , he got it fixed finally but not without a struggle and Emotiva would sent a new pcb and help but not a new unit or you should pay for the return postage per DHL/UPS yourself which was a couple of hundred $:http://www.htforum.nl/yabbse/index.php?topic=131540.msg2373605#msg2373605Anyway don't expect the quality of let's say Classe Audio which uses A grade components all the way but still it is a cheap amp and a lot of bang for the buck.

author: amyk
author_rank: Super Contributor
timestamp: September 07, 2013, 12:28:30 pm
content: CDxxx are a pseudo-standard series of crapacitors made by miscellaneous companies in China. Quality will probably vary widely.
What buffer for 20MHz clock from osc to 5 micros? - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: March 25, 2019, 12:55:18 am
content: I’ve got a project where a 20MHz oscillator module has to supply five microcontroller clock inputs. The stated load for the oscillator module is 15pF so five micros would load it too much. Thought of using a 74AC04 hex inverter with section 1 that is fed from the oscillator module driving sections 2-6 inputs in parallel, and the five separate outputs go to the micros. Trouble is, I think the paralleled input capacitance of sections 2-6 would be too much load for section 1 output at 20MHz and 5 volts. Could anyone suggest a more suitable buffer? Clock skew is not an issue here.

author: bson
author_rank: Unknown
timestamp: March 25, 2019, 05:43:14 am
content: What voltage? LVC logic has 4pF input capacitance and each 74LVC04 output will drive, if memory serves, 25mA. It does have amaximumtransition time on the input signal of 10ns, and keeping it down to 6-7ns is a good idea.Oh, nvm, for some reason I missed you want 5V. Can't you just use HC04's for fanout?

author: RoGeorge
author_rank: Super Contributor
timestamp: March 25, 2019, 06:15:34 am
content: What you are looking for it's calledfanout, and it specifies how many inputs can a single output drive. For 74AC I think the fanout is 15, so driving 5 x 74AC04 inputs from the output of another 74AC04 gate will be no problem.

author: Circlotron
author_rank: Super Contributor
timestamp: March 25, 2019, 07:23:12 am
content: Yeah, I thought that fanout figure would be frequency dependent so that’s why I mentioned 20MHz. Okay, I’ll look into that.

author: Circlotron
author_rank: Super Contributor
timestamp: March 25, 2019, 12:49:53 pm
content: Quote from: bson on March 25, 2019, 05:43:14 amI would have thought a HC04 wouldn’t produce a convincing square wave at 20 megs. Haven’t actually tried one though.
What can I do to increase the current value? - Page 1
Forum section: electronics / projects

author: oppel
author_rank: Newbie
timestamp: December 26, 2023, 01:57:00 pm
content: There is a laser installed in the aircraft system. Sufficient current cannot be supplied to this laser in time. As the current value decreases, the voltage value also decreases. Is there a circuit (PCB) that needs to be installed or anything else that can be done to increase the current value in this system?I would be happy if you share your valuable thoughts with me.

author: donlisms
author_rank: Frequent Contributor
timestamp: December 26, 2023, 06:55:54 pm
content: Huh?

author: coromonadalix
author_rank: Super Contributor
timestamp: December 27, 2023, 03:03:25 am
content: same hereand aircraft have regulations, find something suitable ....

author: Simon
author_rank: Unknown
timestamp: December 27, 2023, 07:16:21 am
content: please will you stop posting about the same thing again and again, it will make you no friends.