hybridfree/eevblog-posts huggingface dataset:
buying caps for a car amp - Page 1
Forum section: electronics / projects

author: phaseform
author_rank: Regular Contributor
timestamp: September 16, 2015, 07:30:35 am
content: I've just got a 12v car amp which I want to power using a 12v Dell Server PSU. I've read that the server PSU wont output peak voltages very well due to being a regulated supply, so I wanted to add some caps to the amp power input. I've been looking around on ebay and it seems the power capacitors for car amp are reasonably expensive, at least $50, and often don't meet specs. I was thinking of using 3 super caps available from jaycar (CAT.NO: RU6705, 1 Farad 5.5V Super Capacitor) in series to do the job, but thought I'd share my plan here in case I'm missing something important.. I haven't seen examples of people using normal caps in car amps before..

author: Psi
author_rank: Super Contributor
timestamp: September 16, 2015, 07:34:09 am
content: Those caps are intended for clock backup and wont be able to handle the current needed for your amp.The easiest/cheapest way is to put a 12V SLA battery across your 12V. It will basically be float charging all the time from your 12V psu.Any peak currents the amp needs come out of the battery.http://www.jaycar.com.au/Power-Products-Electrical/Storage-Batteries/SLA-GEL-Rechargeable/12V-6Ah-SLA-Battery/p/SB2485You also get a auto system that will run for a little while when the power failsJust be sure you don't keep running the battery flat. They don't like that, you want the battery to stay charged.You only need those large farad automotive caps if you want to run massive bass with huge subs.

author: phaseform
author_rank: Regular Contributor
timestamp: September 16, 2015, 03:50:23 pm
content: cool thanks for the reply Psi, I might just see how the PSU goes alone to start with since I'm worried what would happen if the SLA was drained too much then connected to the PSU n I can't be bothered with anything too complicated. Little Surprised high current caps are hard to find, for me at least

author: DanielS
author_rank: Frequent Contributor
timestamp: September 16, 2015, 04:30:21 pm
content: Quote from: phaseform on September 16, 2015, 03:50:23 pmThey are not hard to find: take a bunch of 2200-4700µF 16V low-ESR caps, put them in parallel, done. For $50, you can put together a fairly beefy capacitor bank.You may need to implement some form of current-limiting during power-up though since the power supply might not like having over 100mF on its 12V output during soft-start since the ATX spec only requires correct operation up to 10mF on all rails.

author: djQUAN
author_rank: Frequent Contributor
timestamp: September 16, 2015, 04:41:06 pm
content: I have done a bench supply using a 57A 12V Dell server PSU and it does not like large caps on the output. It shuts down as it sees a short at turn on. Even a single headlamp bulb triggers its protection circuit when cold.If you precharge the cap though, it would run normally.
buying second hand RF amplifier question - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: July 29, 2024, 08:39:16 am
content: Hello,I am looking for a cheap second hand way to buy th ACP11039 device or similar to it.Is there some reccomendations if there is such an option?Thanks.https://www.everythingrf.com/produc...teledyne-microwave-solutions/567-433-acp11039

author: jonpaul
author_rank: Super Contributor
timestamp: July 29, 2024, 09:21:01 am
content: post on RF/Microwave forum here OR on QEX forum etc on Groups.ioOr put free ad in QST if you are a ham, ARRL memberj
Buying/preparing flat flex cable - Page 1
Forum section: electronics / projects

author: rs20
author_rank: Super Contributor
timestamp: April 19, 2014, 11:58:40 am
content: ( Hopefully this hasn't already been answered on the forums, I had a bit of a search but couldn't find anything. )Digikey and element14 have heaps of SMD flat flex connectors, but I can't find the actual flat flex cable on their sites -- do they stock them? What's the normal prototyping procedure -- do you buy more than you need and cut it to length yourself, like the way it is with normal cables? If so, how do you prepare the ends?Basically, somewhere out there has used flat flex in their personal projects, and I want to know how you did it!Cheers :-)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 19, 2014, 12:04:01 pm
content: Search for FFC Cable - Farnell & Digikey stock loads

author: rs20
author_rank: Super Contributor
timestamp: April 19, 2014, 03:08:00 pm
content: Quote from: mikeselectricstuff on April 19, 2014, 12:04:01 pmCorrect!!Yep, they actually have an insane range once you know the right keyword. Not quite sure how I missed that, move along, nothing to see here...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 19, 2014, 09:04:42 pm
content: Quote from: rs20 on April 19, 2014, 03:08:00 pmand if you want custom lengths in sub 1000 qtys, Samtec do some
Buzzer Choice  - Page 1
Forum section: electronics / projects

author: GjBob
author_rank: Newbie
timestamp: April 02, 2014, 06:00:47 pm
content: Since this is my first post i would like to say hello to you all. On second hand i wanted to ask a question here, maybe someone has already stumbled in this kind of thing. I need to introduce a buzzer in my project to alert people in case of a falling uav in situation like technical failures. I need to to be one as loud as possible and i need have a wide range of frequency since i will need to play 2 or 3 different sound

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: April 02, 2014, 07:11:58 pm
content: Fire Alarm KlaxonIs it to be located in a very large/small area, indoors /outdoors, Small room/corridor.

author: aargee
author_rank: Frequent Contributor
timestamp: April 03, 2014, 01:12:15 am
content: Mounted on the UAV (simple reversing beeper would do?) or an earth based device to notify a wide area on the ground to look up? (Air raid siren)

author: GjBob
author_rank: Newbie
timestamp: April 03, 2014, 12:46:24 pm
content: It will be mounted directly on the uav so it can't weight to much and i rather would prefer something controlled from a pwm to produce different tones ( if i understood well from some datasheet if the buzzer doesn't have an internal circuit it will produce the loudest sound when driven by a signal at the resonant frequency but will produce also sound at other frequencies). It need to be powerd by 5v.

author: tszaboo
author_rank: Super Contributor
timestamp: April 03, 2014, 04:59:21 pm
content: Are you sure, that the electronics solution is the safest/easiest? I would guess, that a CO2 cartridge with an electronic/mechanic firing and some kind of horn would weight less, and be more alarming than any electronics horn. They go for quite some time, 20-30 secs easy for a 9g cartridge.
Buzzer circuit - Page 1
Forum section: electronics / projects

author: alentje
author_rank: Contributor
timestamp: January 11, 2014, 10:21:44 pm
content: Hi guys, I´m Alen and i am new to the EEVblog forum!I want to make a circuit that is going to ding twice when my key is turned / power is applyed to the circuit. You can hear the ding in this videohttp://youtu.be/oPYKs9Jn45M?t=18s. Which buzzer should i get? And can anyone help me with making my circuit?Cheers,- Alen

author: Rerouter
author_rank: Super Contributor
timestamp: January 11, 2014, 10:34:31 pm
content: I greatly think that is the key left in sound, it is the same with hi-ace vans, when the door is open and the key is in off position it will beep,as for how to accomplish what you want, if you want that ding it looks like you will need to use some kind of audio playback chip, all i can find in that respect is a micro controller playing back the ding (its not just a fixed frequency sine or square)if you just want it to beep however, then possibly a 556 timer chip, one is astable at 1 second and you can vary the duty cycle to make it sound prettier, and the other is monostable and after x amount of seconds will disable the first timer, by a transistor or similar,the astable one would drive a regular buzzer,

author: alentje
author_rank: Contributor
timestamp: January 11, 2014, 10:45:36 pm
content: I want the same sound like in the truck from the video. I can get this buzzer from a BMW.It should be fine for that. It would be ok if it dinged once.So i want the 556 timer to give 2 seconds power when the 556 gets power input, this should be easy, or not...

author: Rerouter
author_rank: Super Contributor
timestamp: January 11, 2014, 11:01:45 pm
content: if you can get that buzzer the same circuit i suggested can be used (bottom center pin sounded like your ding)as for what he is doing with the multimeter probe it is either a pull-down to ground or hard connected to ground (automotive love open collector outputs on there panels)

author: alentje
author_rank: Contributor
timestamp: January 11, 2014, 11:12:43 pm
content: I´m a beginner at electronics, what do i need to have, a 556 timer and the buzzer, right? Now how do i need to connect this? Can you make me a diagram?-alentje

author: Rerouter
author_rank: Super Contributor
timestamp: January 11, 2014, 11:55:20 pm
content: You will need to tweak the RC values a little, but it should work,

author: alentje
author_rank: Contributor
timestamp: January 12, 2014, 10:07:48 am
content: These are two 555´s. I think i have ona laying around, just need to get another one

author: Rerouter
author_rank: Super Contributor
timestamp: January 12, 2014, 10:21:32 am
content: a 556 is just 2 555 chips in the same package with the positive and negative supply rail pins tied together
Buzzer volume maximizer (via arduino and few linux scripts) - Page 1
Forum section: electronics / projects

author: dusan
author_rank: Regular Contributor
timestamp: July 23, 2025, 11:11:26 am
content: In my recent project I had to run buzzer from somewhat lower voltage and it was bit quieter than I would like so I tested few different frequencies and duty cycles and quickly found much louder setting. However, that got me thinking, what if I try range of frequencies and duty cycles and plot a scatter chart of the measured volume? And so I did, here are the results for 3 different buzzers. The code is on github:https://github.com/dvhx/buzzer-volume-maximizer(it uses arduino and few command line utilities on ubuntu for recording and processing).Standard passive 12mm 16ohm 5V buzzer (black plastic cylinder):Tiny 16mm 8ohm speaker:30mm 30ohm speaker from headphones:As you can see in the case of the buzzer in some spots just changing frequency by 20Hz can triple the volume, so it's worth to experiment if your buzzer is too quiet. I also tried using ebur128 to measure integral loundness but for some reason it gave -177 for every sample, so I just used RMS.Driving circuit:
Buzzing SMPS under load - Page 1
Forum section: electronics / projects

author: cthree
author_rank: Frequent Contributor
timestamp: December 29, 2013, 06:57:19 pm
content: I built up a 5V SMPS using a LM22676-5.0 and other components. The design is from WEBBENCH. I made a PCB and assembled it but it's behaving badly and I would appreciate a second look. I've attached schematics and scope traces.I'm using this to power a BeagleBone SBC from a 24VAC source. The output (X4) connects to the BBB's 5V DC jack. Unloaded and with a load of up to about 200mA it appears to work great but as soon as the load increases to above 200mA it starts to buzz (120Hz I presume, it is quite audible) and it looses regulation. LED1 provides a nominal minimum load of 18mA.The three scope traces: first is no load. Second is < 200mA load. Third is > 200mA load. CH2 (blue) is VIN, CH1 (yellow) is VOUT. The dip in VOUT seems to grow and shrink with load. This SMPS is supposed to be able to output 5V@3A but clearly thats not happening. Does anyone have any sage advice as to why this thing might be dropping out of regulation like it is? Or likely suspects?

author: owiecc
author_rank: Frequent Contributor
timestamp: December 29, 2013, 07:11:15 pm
content: You have 10V input voltage ripple at no load. You have no input caps!

author: jmaja
author_rank: Frequent Contributor
timestamp: December 29, 2013, 08:03:43 pm
content: Having just ~10 uF at the input would likely be OK, IF you had a DC source. But you have a rectified AC source at 60 Hz, which means it will have zero output at 120 Hz. Thus your input capacitor needs to supply the ~10 ms in between the peaks. Your current capacitance only somewhat works up to 200 mA and even at lower currents your huge input ripple probably causes quite much output ripple.You need at least an order of magnitude more input capacitance. The actual value depends on the maximum output current and how much input and output ripple you can tolerate.

author: ResR
author_rank: Regular Contributor
timestamp: December 29, 2013, 09:20:24 pm
content: I would use at least 47uF or 100uF 400V capacitor for this purpose, yeah the supply may oscillate little bit longer after disconnecting, but it's much more stable DC that way. Little bit redo the PCB to fit the much larger capacitor is inevitable, so why not to go for keeps.Cheers.

author: owiecc
author_rank: Frequent Contributor
timestamp: December 29, 2013, 09:42:08 pm
content: This circuit is using a 24Vac input voltage. A 1000uF/50V cap would be better.

author: cthree
author_rank: Frequent Contributor
timestamp: December 30, 2013, 06:25:04 pm
content: Thanks everyone!I should have seen it but it got lost in the cracks as things do. I added an additional 100uF and that lowered the input ripple down to ~200mV at 450mA. It's just a first prototype right now and I will need to respin the PCB due to a physical interference problem anyway. Just describing the problem to post it here caused me to see it. Thanks for indulging.
By Design or FUBAR fixed? - Page 1
Forum section: electronics / projects

author: RayJones
author_rank: Frequent Contributor
timestamp: May 27, 2011, 02:09:01 am
content: Just repaired a spa controller and came across this bypass arrangement over the processor.It looks a bit like a FUBAR fixed after manufacture, but then again the positive lead runs to a dedicated hole on the PCB.It certainly provides a low impedance bypass direct to the IC's pins.I have used under C caps in the past which provide the same end effect, and do not get in the way of servicing should the IC need replacing.

author: Neilm
author_rank: Super Contributor
timestamp: May 27, 2011, 05:03:31 pm
content: I cant't quite make out what that dedicated hole is near. Is there is another one under the purple wire? If so, it could be that the processor fitted has gone obsolete prior to the building of this board. the modification with the cap on top might be the manufacturere using another device for the same role and having to "bodge" it in to get it onto the board and working.There are a few reasons I can think of why they would do this.First, they are using up the old stock of PCBs before buying new ones.Second, they don't want to alter the PCB (for what ever reason) and this is what has to be done to sell the units. Generally this is a dictate from either Management or Accountants.Thirdly, the design might be so old they can no longer alter the PCB without having to completely relay it. An example of this would be a good, well selling product that has not been touched for years - so old the PCBs were layed out in a very old (and not supported) CAD system or even with tape.Neil

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 27, 2011, 05:45:08 pm
content: My guess is this is a fix for EMC or ESD problems on a poorly laid out PCB- the copper tape as opposed to wire would provide the minimum impedance.

author: RayJones
author_rank: Frequent Contributor
timestamp: May 27, 2011, 10:28:31 pm
content: As it happens I will need to pull the unit out again today as the fix has failed once again (triac that drives the blower outlet)I will actually look at improving the heatsinking area as it worked for many minutes then fused the triac again.I can tell you however that the apparent copper strip is actually a strip of PCB with a groove across the middle where the cap lies, but yeah certainly a very low impedance path.The red wire also went to a hole with a circle about it, so it seems like by design.I'd rather not have to pull the PCB itself out as it is buried by many mains wires heading in many directions, so to check below the chip where the power runs will not be so easy.Fortunately the triac is a flying leads so it is relatively easy to replace - one you get your tongue in the correct positioning.
C-Bus optocoupler - Page 1
Forum section: electronics / projects

author: hazmoment
author_rank: Contributor
timestamp: October 15, 2018, 09:32:43 am
content: Hey up. Can anyone help with a wee problem Im having. with an optocoupler. Ive Just replaced an Optocoupler and a blown triac out of a C-Bus 8channel dimmer module and managed to get it working but only in the on or off state, I have no dimming. I believe the problem to be with the optocoupler i chose (vishay VO3062) to replace the original IL440-2. To prove that this is the cause of the problem i installed another VO3062 on another known good channel and gave me the same results, But I am not too experienced with optocouplers and what would be causing this behaviour. Can anyone point out the differences between the two which may be the cause of this? Or a more suiting replacement opto!?https://pdf1.alldatasheet.com/datasheet-pdf/view/114398/VISHAY/IL440-2/+0144--VyhSHwadLPzCNpw+/datasheet.pdfhttps://www.vishay.com/docs/83748/vo3062.pdfCheers! Hazmoment.

author: tsman
author_rank: Frequent Contributor
timestamp: October 15, 2018, 01:46:14 pm
content: Basic C-Bus dimmers are leading-edge dimmers so the additional zero-crossing circuit in your VO3062 will interfere with it and stop it from dimming correctly. You need an optocoupler without a ZCC.

author: hazmoment
author_rank: Contributor
timestamp: October 15, 2018, 05:10:08 pm
content: hey thanks! Why have zero crossing current built in to the opto? Any benefit in other applications? I will order a few of another type to try!

author: tsman
author_rank: Frequent Contributor
timestamp: October 15, 2018, 05:19:21 pm
content: It causes less interference and lower inrush current since it'll be switching when the AC waveform is at 0V. They're useful if you just need on/off and not trying to do phase angle control.

author: hazmoment
author_rank: Contributor
timestamp: October 15, 2018, 06:02:43 pm
content: Gotcha. I have found this opto i hope will do the job seems to match the specs at least as far as i can tell.https://nz.element14.com/vishay/il420/optocoupler-phototriac-5300vrms/dp/1469561
c0g capacitor change in voltage coefficent with temperature? - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 30, 2014, 09:58:38 pm
content: Does anyone have a graph of a C0G capacitor that shows the different voltage coefficient curves with temperature?I want to determine how distortion changes with temperature in a C0G capacitor, perhaps a few curves showing the coefficent at different temperatures, or one of those nice fuzzy plots.I like the temperature coefficient of these capacitors and distortion should be OK unless it changes with temperature.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 30, 2014, 10:25:15 pm
content: Don't think I've seen voltage coefficient spec on those. Possibly because they're dead flat, as tempco is?I've used 50V devices at 500V before, with no obvious change in value (resonant application; variation of more than a few percent would produce visible distortion). I'm sure there's some amount, but how much I have no idea.Tim

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 31, 2014, 07:55:23 pm
content: well I am pretty sure that C0G distorts alot more then a film capacitor, I understood that distortion in all ceramics came about due to a voltage-coefficent. I read something like 100db for a C0G and 160dB for a film and alot more for a class II ceramic. I can account for the power loss due to distortion so long I have an idea of how consistent it is.I am trying to figure out which capacitor will screw up my signal most consistently. I decided to not worry about dielectric absorption effects at high frequency, I only see the need to take this consideration where 1/f noise is a problem.
C14 socket 120-240v mains to PSU - Page 1
Forum section: electronics / projects

author: e97
author_rank: Newbie
timestamp: March 25, 2016, 12:42:58 am
content: Hi,I'm trying to use this power supply and a C14 socket to get mains power:http://www.mouser.com/search/ProductDetail.aspx?R=0virtualkey0virtualkeyRD-65AI think I need a fuse and/or line filter, is there anything else? Or does the PSU have this built in? The datasheet has a block diagram:http://www.mouser.com/ds/2/260/RD-65-SPEC-806447.pdf

author: Xenon Photon
author_rank: Unknown
timestamp: March 25, 2016, 12:59:27 am
content: Mean Well is a good brand and it should have built in fuse and filters. from the picture in the datasheet you can see a common mode choke. Personally I used the 5V and 12V and they both have had all filters and built in fuse but I still prefer an easy to swap fuse outside the supply.

author: Monkeh
author_rank: Super Contributor
timestamp: March 25, 2016, 02:17:50 am
content: Quote from: Xenon Photon on March 25, 2016, 12:59:27 amWhy, do you have a habit of blowing up the primaries of your supplies?

author: Xenon Photon
author_rank: Unknown
timestamp: March 25, 2016, 10:04:33 am
content: Quote from: Monkeh on March 25, 2016, 02:17:50 amOf course not. It is based on an old story with a 5V 5A supply which had its fuse blown and taking the supply out of the project to replace the fuse costed a lot of time. Also, the fuse was soldiered to the PCB. So, I prefer to use a slightly lower value fuse at a place easy to be accessible.

author: e97
author_rank: Newbie
timestamp: March 29, 2016, 01:29:49 am
content: Thanks for the fast response!I ended up using a C14 socket from another PSU and it has a line filter / fuse. I don't think its necessary for the next version as you mentioned the Meanwell PSU has it built it.It works smoothly, time will tell if it lasts
C245 pinout - Page 1
Forum section: electronics / projects

author: AccountRemovedPerUsersRequest
author_rank: Regular Contributor
timestamp: May 11, 2021, 07:25:12 pm
content: Hello. I thought this was easy to google.. but it seems that there are at least two versions of what is the "correct" wiring of C245.I think I saw some discussion about this but couldn't convince myself about the right answer. Is Scott heating thru TC?A
C2/C30 Varactor Tuning Ratio - Page 1
Forum section: electronics / projects

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 03, 2015, 11:04:18 am
content: I've looked in lots of datasheets and Google is also not my friend today. Nowhere is the statement of C2/C30 Varactor Tuning Ratio explained.I have used varactors before, in servicing replacement or from a schematic design for projects I found on the net.So the question to you smart folks, which I am sure has a simple answer, is what does it mean?

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: December 03, 2015, 11:35:01 am
content: Some handy footnotes appear athttp://www.onsemi.com/pub_link/Collateral/MMBV2101LT1-D.PDF1. CT, DIODE CAPACITANCE(CT = CC + CJ). CT is measured at 1.0 MHz using a capacitancebridge (Boonton Electronics Model 75A or equivalent).2. TR, TUNING RATIOTR is the ratio of CT measured at 2.0 Vdc divided by CTmeasured at 30 Vdc.In this case C2 refers to the capacitance with 2 volts applied and C30 to the capacitance with 30 volts applied.A large ratio between lowest and highest capacitance is essential for applications where you need the diode to cover a large tuning range. Eg an AM broadcast receiver with a large tuning range (eg 520 - 1600 kHz)Whereas if your project is covering a narrower band segment, such as the 88 - 108 MHz FM broadcast band or part of an HF amateur band then a narrower tuning range (and thus smaller ratio) will suffice.

author: w2aew
author_rank: Super Contributor
timestamp: December 03, 2015, 07:40:29 pm
content: VK3YE gave you the right answer - it is simply the capacitance at 2V reverse bias divided by the capacitance at 30V rev bias.While my video doesn't talk about this parameter, it does give you the basics of varactors, and shows a jig I put together to measure capacitance at different bias voltages:

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 04, 2015, 01:57:06 am
content: Thanks Peter & Alan, that pretty much explains it all.I wonder though why the total capacitance range is not just listed in the specifications in the datasheet.Another one that gets me is transconductance parameters for JFETS. A simple notation in µMhos are given in the older sheets but no such things in the later ones.Signed an Extra class who doesn't know it all....
C64 LCD display - Page 1
Forum section: electronics / projects

author: FrankBuss
author_rank: Unknown
timestamp: June 04, 2017, 09:08:20 pm
content: Just a quick Sunday hack:https://hackaday.io/project/25257-c64-lcd-display

author: MK14
author_rank: Super Contributor
timestamp: June 04, 2017, 09:47:11 pm
content: The LCD display has probably got a much more powerful cpu in it, than the Commodore C64 has got.JOKE(Although it might have, actually. Maybe 4 bits, but possibly a higher frequency capable and/or MIPs per clock-cycle/MHz version, than the 6502, I'm not sure).

author: FrankBuss
author_rank: Unknown
timestamp: June 04, 2017, 09:53:37 pm
content: Well, minimum enable cycle time is 1.2 us, so might be as good as a 6502

author: MK14
author_rank: Super Contributor
timestamp: June 04, 2017, 10:23:48 pm
content: Quote from: FrankBuss on June 04, 2017, 09:53:37 pmNot nearly as much potential vintage fun though.Arguably, the 6502, is one of the main, influential Microprocessors, which has started off this massive computer revolution, which is still occurring. With the 8080/Z80, (possibly the 8051) and especially the 8088/8086, as well as others.Also arguably the Amazon Echo (and google and other variants, such as Apple's Siri). May also be looked back to in 20, 50 or 100 years time, and be blamed for being the start of a new AI revolution.The 6502 was probably the first truly affordable (cheap) and generally/freely available cpu, which helped spark off a massive computer revolution. But the others had major roles to play as well.Apparently the Arm (which is one of the biggest by sales volume cpus), originally comes from the 6502, rather indirectly though. Through the BBC micro (6502), and that teams attempts at making a new processor for the future BBC micro computers. Hence the start of Arm (both company and cpu chips).

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2017, 03:30:08 am
content: Quote from: MK14 on June 04, 2017, 09:47:11 pmCharacter LCDs don't have CPUs, they just have controller chips.I doubt they run at more than a couple of hundred KHz.

author: MK14
author_rank: Super Contributor
timestamp: June 05, 2017, 01:45:11 pm
content: Quote from: tooki on June 05, 2017, 03:30:08 amMy comments were really meant as a light hearted joke. Not a serious technical claim about modern day LCD controllers.If there was a modern 4 bit microcontroller in it. It would probably do something like 10+ MHz, and so it probably would be faster. But would run at a much lower frequency to save power, when driving the LCD.Dedicated non-MCU LCD controllers make a lot of sense.
C7324K 10 pin IC Info Please - Page 1
Forum section: electronics / projects

author: biggertv
author_rank: Newbie
timestamp: July 12, 2025, 05:57:02 pm
content: I cannot identify this Dinosaur. Lost all my old ECG books in a fire, Can anyone Identify the Purpose of the 10 pin C7324 IC? Yes I've tried UPC7324 and even LM7324. This is almost old as I am, Metal case, Gold Pins...eBay auction: #https://ebay.us/m/edvgCQThanks!
cable carrying display and camera streams - Page 1
Forum section: electronics / projects

author: andrea.longobardi85
author_rank: Contributor
timestamp: June 25, 2020, 11:02:14 am
content: Hi All,I am working on a project involving a PI-0 and a remote display and remote camera. For remote I mean 2 meters away.Current solutions is to connect them via long flex cables...I though I could replace them with serdes and coax/Twisted pairs.I also need to carry a little bit of power over the cable to power the remote unit...let's say something around 2.5W MAX.How would you address that? My initial thought was to look for a dual coax cable, but cannot find a proper one...Second option would be to use a STQ (2 twisted pairs in shielded cable) but I need to find a way to carry the power...third option USB type C cable...Any hints?Thanks!

author: fcb
author_rank: Super Contributor
timestamp: June 25, 2020, 11:18:35 am
content: Depending on the camera/display protocol (analog, digital?), you can send DC down the coax and AC couple the video - very common technique.

author: andrea.longobardi85
author_rank: Contributor
timestamp: June 25, 2020, 12:05:48 pm
content: Display and Camera both with digital Input/Output. Also I need to carry the I2C bus across but this comes handy with a serdes.I agree with power over coax, I wonder if I can do something similar with a twisted pair and the shield...

author: skylar
author_rank: Contributor
timestamp: June 25, 2020, 05:06:45 pm
content: Regarding the dual coax cable, you can look at using VGA display cables as they are 3x coax and ~10x 28AWG sideband conductors in a 6mm OD package.
Cable coax 75ohm with HD Mini BNC - Page 1
Forum section: electronics / projects

author: mr1979
author_rank: Contributor
timestamp: September 12, 2017, 03:47:27 pm
content: Hi Guys , i can't find a cable with two HD Mini BNC connector that is the type of connector in the picture. I need a coax video cable 75 ohm, 3 meters. Any suggestion?Inviato dal mio PLK-L01 utilizzando Tapatalk

author: ConKbot
author_rank: Super Contributor
timestamp: September 13, 2017, 05:23:16 am
content: https://www.markertek.com/product/hdbnc1505-mm01/laird-hdbnc1505-mm01-high-density-hd-bnc-male-to-hd-bnc-male-6g-hd-sdi-cable-1-footThe 10foot version would be what you're looking for? Find a local A/V broadcast video vendor, (makertek specializes in broadcast video supplies in the US) and you should be able to find something similar. Be prepared for a broadcast video pricetag attached though. But the quality should be high too though.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: September 13, 2017, 08:06:24 am
content: Here:http://nz.mouser.com/ProductDetail/Amphenol-RF/095-850-188M100/?qs=sGAEpiMZZMufBZYvsU%2fbe2VgDW4LZ82zPgTfIYVx2x8hU2EFNeWEfQ%3d%3dor more here:http://nz.mouser.com/Amphenol/Wire-Cable/Cable-Assemblies/RF-Cable-Assemblies/HD-BNC-Series/_/N-bkrix?P=1yyq07nZ1z0zp68
Cable Copulation Prophylaxis Found - Page 1
Forum section: electronics / projects

author: rhb
author_rank: Super Contributor
timestamp: January 18, 2025, 10:35:42 pm
content: For many years I've used a set of slotted Pomona cable racks. Inevitably, no matter which cable I wanted it was actively copulating with at least several other cables. If they reproduced I wouldn't object, but as they do not, I've had enough. Strict chastity will be rigidly enforced. Promiscuous copulation will no longer be tolerated.I scavenged from the trash a couple of old hollow core closet doors which have been sitting waiting for a new purpose in life. It has been granted.Basic idea is to screw slit pieces of tubing with very small wood screws to the door to hold the cable. My first choice was polyethylene. I found that I had to cut a strip off the tube because forcing RG-58U through a simple slit split the tubing. This used up the 4 ft of polyethylene, so I'll try vinyl or neoprene next. Very likely you could staple vinyl tubing to a plaster board wall and not even leave any marks.The doors will be mounted to the wall or end of the rack (TBD) so that I can select cables from any of the 4 sides. Ultimately there will be a pair of 6 bay wide racks facing each other with a moveable bench about 5 ft long running between the two racks.FWIW the racks are DIY 14 gauge 1" x 2" rectangular tubing for the uprights and 1.5"x2"x1/8" steel angle with cable bracing. Final configuration will have all graphic displays at standing height. Hence the need for 12 bays in total. Angle is predrilled and secured by self drilling screws. No rack HW needed and excellent air flow. Stick the instrument exactly at the height I want.Have Fun!Reg

author: inse
author_rank: Super Contributor
timestamp: January 18, 2025, 10:43:25 pm
content: Reg, why wouldn‘t you allow your cables to have some fun without consequences in the lab after hours?No, fun aside - this would be much too tidy for me, I am a confessing untangler.Even more fun aside: nice solution

author: rhb
author_rank: Super Contributor
timestamp: January 18, 2025, 10:57:36 pm
content: It was the consequences during working hours trying to separate them that made their extracurricular activities no longer tolerable. Proper conduct will be maintained.Fundamental problem is if you don't have a specific place for the profusion of essential cabling you spend a lot of your time trying to untangle things. The Pomona racks just dump several slots on the floor for you to pick up.Based on this experiment, I'm going to try stapling clear 3/8" ID vinyl tubing using a light staple gun that shoots office stapler size staples. Super handy. I secure computer cables using velcro strips stapled to the wall. Super easy to access a single cable or reroute for a change.
Cable for MEMS array - Page 1
Forum section: electronics / projects

author: rkv
author_rank: Newbie
timestamp: January 01, 2021, 09:56:46 pm
content: Hello,I need your advice. For a project I need to connect 16 MEMS microphones to a PCB. Each MEMs mic is mounted on a small extra PCB. Each mic needs two lines, data and clk, two mics share one data/clk pair. The clock rate is 6.144MHz. So I have in total 8 data/clock pairs. Now I want to connect the mics with a mainboard PCB because due to the mechanical design, the mics cannot be mounted on the mainboard PCB. The cable length will be ~5cm. The problem is, there is not much space. Even a flatband ribbon cable with 1.27mm spacing will be too big especially the IDC connectors (would require 32 positions if running one ground wire between each signal wire). Any idea what type of cable and connectors I can use and still keep a good shielding to avoid radiation from the clock and data lines?Thanks in advance,Raphael

author: jbb
author_rank: Super Contributor
timestamp: January 01, 2021, 11:32:43 pm
content: If you want small, I suggest a Flex PCB (FPC). Possibilities:- easy to do a 0.5mm pitch connector (or smaller)- 2 layer is pretty standard, can do 3 layer or more- can get an EMI shielding layer applied to the outside (extra cost)- can solder some components straight onto the FPC; maybe your microphones (and associated decoupling caps) - talk to your assemblers- can put extra stiffeners under some parts of the FPC to keep parts flat; maybe under your microphone array- can turn wire looms (aggravating to assemble) into fewer pieces (easier to assemble)- can integrate a key mat or indicator LEDs- you don’t need to go all the way to rigid-flex, which is cool but more expensive
Cable for radio antenna - Page 1
Forum section: electronics / projects

author: steve30
author_rank: Frequent Contributor
timestamp: April 07, 2013, 11:45:41 am
content: I have a very nice radio, an Aiwa R22 from the 1980s, and it is used with a T shaped antenna, which connects to the 300R terminals on the radio.Reception was pretty hopeless with the antenna in the middle of the house, so I moved it to the window, and there it works fantastic. But I want to keep the radio at the other side of the room. I tried running a bit of bog standard equipment wire across the room to connect the antenna to the radio, and it didn't really work.So, what kind of cable to I need to connect the antenna on the window to my radio across the room?Thankssteve30

author: David_AVD
author_rank: Super Contributor
timestamp: April 07, 2013, 11:50:23 am
content: Many years ago 300 Ohm ribbon cable was used from your roof antenna right to the back of the TV. Once 75 Ohm coax became the standard, ribbon went by the wayside pretty quickly.

author: C
author_rank: Super Contributor
timestamp: April 07, 2013, 01:24:33 pm
content: http://en.wikipedia.org/wiki/Twin-leadYour window Tee antenna is 300 ohm Twin-lead.If you read the fine print in the above link you will find that twin-lead does not work as well when not suspended in air.Your antenna to a balun to 75 ohm coax cable.If your radio does not have a 75 ohm connection then use a second balun to convert back to 300 ohm

author: KJDS
author_rank: Super Contributor
timestamp: April 07, 2013, 01:27:47 pm
content: There's a few sellers of 300ohm ribbon cable on ebay.How much do you need? I've got some buried somewhere in a cupboard.

author: steve30
author_rank: Frequent Contributor
timestamp: April 08, 2013, 05:53:46 am
content: So I guess I just need to run some more 300R cable between the aerial and the radio.I'll probably buy a load off ebay as I may relocate the aerial again... maybe to the loft or outside.Now to sort out a decent AM aerial.

author: SeanB
author_rank: Super Contributor
timestamp: April 08, 2013, 06:27:05 pm
content: Just go and look for 2 baluns for FM radio, as thety are pretty cheap, and work well. Otherwise just use 75R coax ( the same as used for satellite dishes) and connect it direct to the one antenna lead and the shield to a ground ( AM side ground is good, normally right next door to the FM terminals as well) and simply strip around 1m of the shield off at the window end. Works quite well, and is cheap. For AM use just do the same, but make the wire 5m long, either out the window or just hanging down if you are high enough.

author: steve30
author_rank: Frequent Contributor
timestamp: April 13, 2013, 06:53:48 pm
content: I got some 300R cable off ebay.I moved the dipole antenna into the loft and played around to find a good position. Then I ran the 300R cable down the wall and to the radio set.Works pretty well
Cable from board to sensors - Page 1
Forum section: electronics / projects

author: metRo_
author_rank: Regular Contributor
timestamp: April 14, 2016, 11:43:27 am
content: Hi allI'm designing a PCB that will have some sensors as inputs and now I'm choosing the connectors and also asking for cable manufacturing cost.The sensors are ultrasonic sensors so the 4 wires is for power and 2 signals, trigger and echo. What is the rule for that kind of application?Should I use individual power conductors for each sensor or can I get one pair of power conductors from board and split for all sensors?If I use all the 4 conductors which order should I adopt?Thank you

author: Rerouter
author_rank: Super Contributor
timestamp: April 14, 2016, 11:52:45 am
content: I would say the first option would be easier for them to automate, however i have to wonder, what is the stub length to each sensor?

author: tszaboo
author_rank: Super Contributor
timestamp: April 14, 2016, 12:17:39 pm
content: Cable manufacturers dont like Y connections. You either put two wire into a crimp and place that into a connector, or all kinds of mess happens. With that being said, I would go for the first configuration, with 3 separate connectors. In that case, the 3 cable has 1 drawing, with separate length. It is probably the most expensive though.

author: metRo_
author_rank: Regular Contributor
timestamp: April 14, 2016, 01:02:39 pm
content: Quote from: NANDBlog on April 14, 2016, 12:17:39 pmThank you,What about electrical performance? On the gray box where I wrote the distance it means the cables goes together using some kind of mesh.Quote from: Rerouter on April 14, 2016, 11:52:45 amWhat does stub lenght means?

author: Rerouter
author_rank: Super Contributor
timestamp: April 14, 2016, 01:04:10 pm
content: the length from the split to sensors

author: metRo_
author_rank: Regular Contributor
timestamp: April 14, 2016, 01:44:38 pm
content: Quote from: Rerouter on April 14, 2016, 01:04:10 pm~10cm
Cable labels for little wires - Page 1
Forum section: electronics / projects

author: jeremy
author_rank: Super Contributor
timestamp: November 05, 2014, 01:16:16 pm
content: Hi all,I build a lot of one-off devices (often on vero), and I'm looking for a good way to label individual wires. I would also like to do it to label wires on my logic analyser so I don't forget which signal is which. Unfortunately, most cable labels are for just that, cables. I'm talking about labelling breadboard sized wires aka AWG 20-24. Has anyone tried to do this before? Or alternatively, do you think the standard office labeller would be good enough?

author: peter.mcnair
author_rank: Contributor
timestamp: November 05, 2014, 02:16:43 pm
content: I've used RS heat shrink 3 mm internal diameter cable markers for small (7/0.2 about 1.2 mm overall diameter) wires. They shrink small enough to stay put.Interestingly, the letter Y is the cheapest.(e.g. RS 392-747 Heatshrink cable marker ' Y',3mm i/d)

author: ElektroQuark
author_rank: Unknown
timestamp: November 05, 2014, 03:32:42 pm
content: I have a little entry in my blog about this:CLICK!It's in Spanish, but with many images, easy to understand.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 05, 2014, 03:51:19 pm
content: For really small wires, get some small white heatshrink, mark with a fine permament marker before shrinking, and then shrink - the writing will shrink with the sleeving

author: jeremy
author_rank: Super Contributor
timestamp: November 05, 2014, 09:03:05 pm
content: Ah perfect, thanks guys. This is exactly what I was looking for.
Office Chair Audio Cable or Connector Solution - Page 1
Forum section: electronics / projects

author: gnif
author_rank: Unknown
timestamp: March 19, 2018, 10:04:04 am
content: Hey All,I like many really enjoy my audio, but due to noise levels running a sub at 2AM is not a great idea when my wife is sleeping, so I decided to give some bass tactile inducers a try, welded up a plate and mounted one to my office chair which I have running off an old amplifier. It works great, but the problem I now have is cable management. Like any office chair I need to be able to move, rotate, etc, and through daily use I can see this cable getting hammered, tangled, etc.The only idea I can come up with is to use a connector so that if the cable is tripped on it will disconnect in a non destructive manner. Because there is a decent amount of current/voltage I figure a decent connector will be required, i'd use RCA but the friction fit on those isn't always great. Is there a connector like a RC Deans plug, but panel mount female and inline male with a hood and strain re-leaf?I'd like to avoid a wireless solution simply because of the power requirements of running a 50WRMS amplifier, I am not keen on strapping batteries to my chair.

author: ajb
author_rank: Super Contributor
timestamp: March 19, 2018, 02:23:39 pm
content: Batteries and Bluetooth? 50Wrms, so a couple of amps?I would think that the best way to run a cable would be from the top of the back of the chair up to the ceiling, with either some coil cable or bungee or other soft spring mechanism to take up a bit of slack.If you really want a breakaway connector, maybe a jumbo magsafe style arrangement, with clusters of pogo pins sized to however much current you need?
Cable, plug and connector service, any interest? - Page 1
Forum section: electronics / projects

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: March 07, 2016, 09:21:29 am
content: HelloA colleague and myself have over the last few projects gotten familiar and confident with sourcing of kable with plug assemblies.No design, no branding, no nothing. Just a sketch.I just spent 30 minutes trying to capture the rough idea herehttp://jsfiddle.net/vf6764xb/1/embedded/result/and now the question: do you think there would be any interest (in the beginner to non-professional segment) for such a service?Wouldyoube interested?We would of course need to have a markup but it seems we can at least beat the grab bags from sparkfun etc.Be honest, be mean.I don't really need another project, but this is one of those things I would use a lot.Best regards,Alexander
Cable shielding - Page 1
Forum section: electronics / projects

author: Ax_6
author_rank: Contributor
timestamp: June 11, 2013, 09:06:24 am
content: Hi,I have some data cables that are passing pretty close to a speaker, unfortunatly i'm obligated to do that. Can be there, because of the speaker, some serious interferences on the datas? And if yes could I shield those data cables? How?

author: _Steven_
author_rank: Contributor
timestamp: June 11, 2013, 03:12:36 pm
content: Aluminium foil wrap around it? Just thinking at loud.What frequentie is on that data cable?

author: c4757p
author_rank: Super Contributor
timestamp: June 11, 2013, 03:25:28 pm
content: I seriously doubt you will have any interference. Test it. If you do, try a differential interface like RS-422.

author: ejeffrey
author_rank: Super Contributor
timestamp: June 11, 2013, 07:01:18 pm
content: Try not to run the data cable parallel and close to the speaker cable. Keep any parallel sections as far apart as possible, and have crossing be at 90 degrees. It is unlikely you will have any problems in any case, but that is how you minimize it. If you do have problems and you can't move the wiring any further apart then use differential signaling. Aluminum foil will not be an effective screen at audio frequencies.

author: Ax_6
author_rank: Contributor
timestamp: June 11, 2013, 07:16:26 pm
content: Perfect! Thank you all
Cable strain relief for off-the-shelf enclosures? - Page 1
Forum section: electronics / projects

author: george graves
author_rank: Super Contributor
timestamp: August 18, 2014, 01:31:04 am
content: I'm having a hard time looking for something like this. I don't really know what they are called - so it's hard to search for.Basically, need to have some wires exit a standard Hammond type case. And want to add some "strain relief" - and not just a hole in the case with wires coming out.I found something kinda close searching for "Sleeved Grommet" - blah - not it.But it's not exactly what I was looking for.I was looking for something a lot like this:Anyone point me in the right direction? What term should I be searching for?They should be super cheap - I would think. Something like 100 for $10-$15 USD?(And be installed like a grommet where it get locked into a hole drilled into the case.)

author: Rufus
author_rank: Super Contributor
timestamp: August 18, 2014, 02:27:44 am
content: They are called grommets, sometimes sleeved grommet, and sometimes strain relief like this onehttp://www.newark.com/hellermann-tyton/hv2228-pvc-bk-d1/strain-relief-pvc-5-6-5-5mm/dp/93R5141?ost=1827047The data sheet for that part shows a small range and calls them "Bend Protection Grommets".

author: george graves
author_rank: Super Contributor
timestamp: August 19, 2014, 08:57:07 am
content: Yes, as I posted. "Sleeve grommets" are a close thing - but not quite.Bump!

author: GeoffS
author_rank: Unknown
timestamp: August 19, 2014, 09:37:09 am
content: A search for "strain relief grommets" turns up a few that match your photo.