hybridfree/eevblog-posts huggingface dataset:
GreatScottLab DC clamp - Page 1
Forum section: electronics / projects

author: nuclearcat
author_rank: Unknown
timestamp: August 07, 2022, 10:17:59 am
content: Watched video, where GreatScott makes DIY DC clamp, circuit is at:https://youtu.be/ohQF79cMODw?t=516(also attached as picture)I wonder if 1M resistor in output might cause issues in DC measurements, unless measurement device have very high impedance and no noise around. Or i am wrong?Using TL082 second half as voltage follower might help?

author: Seekonk
author_rank: Super Contributor
timestamp: August 07, 2022, 03:26:22 pm
content: looks like a 10X scope input.

author: moffy
author_rank: Super Contributor
timestamp: August 07, 2022, 04:11:12 pm
content: Quote from: Seekonk on August 07, 2022, 03:26:22 pmA 10X scope input has a 9Meg resistor, with a bypass cap, that feeds into the 1Meg input impedance of the scope. This is more like a 2X input into a scope, not sure why.

author: David Hess
author_rank: Super Contributor
timestamp: August 07, 2022, 06:32:57 pm
content: Quote from: moffy on August 07, 2022, 04:11:12 pmOr it was suppose to represent a 1 megohm oscilloscope input and was drawn wrong, but then the capacitance is low.

author: Kleinstein
author_rank: Super Contributor
timestamp: August 07, 2022, 06:53:09 pm
content: The 1 M resistor is really odd, not so much for DC but for the AC part. 1 M and 10 pF give a time constant of 10 µs and thus a cross over from the more resistor dominated attenuation (1 M resistor and 1 M from the scope) at low frequencies to a more capacitance dominated attenuation (10 pF and the scope input capactiance of some 10-30 pF). If the two don't match there is distorion starting at around 2 kHz in the phase.Some resistance at the output is needed, as the OP does not like to drive a capacitive load like a BNC cable. Normally one would use less resistance, like 100 Ohms or maybe 10 K if some protection against external voltage is wanted. With a lower resistance the cross over would be a frequencies well above the BW of the amplifier and thus not a problem.p.s.: neither the 7805 regulator nor the TL082 OP-amp are a good choice for battery operation. There are lower power ones.

author: nuclearcat
author_rank: Unknown
timestamp: August 07, 2022, 08:03:56 pm
content: Thanks @Kleinstein for confirming my concerns. Apparently, as always, except for eevblog, other DIY bloggers should be treated as a good PoC and inspiration, but definitely not worth copying their circuits as is.Maybe there is some hope he can review this idea and improve, but i doubt, as it is old video.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 07, 2022, 08:20:44 pm
content: Of course. But that's alright. You're already lucky when the information they give is not wrong.GreatScott's videos are educational - not meant as a free professional consulting service.The above circuit has a couple flaws and is certainly not optimal (especially for battery operation), but it sort of works.That's also what will teach you that there is a gap between education, DIY and commercial designs.
Greenhouse Gas Camera - Page 1
Forum section: electronics / projects

author: adammunich
author_rank: Contributor
timestamp: November 14, 2019, 11:09:35 pm
content: I wanted to share with you all this project I have been working on, it is a camera for seeing greenhouse gasses!https://civilpedia.org/p/?pid=282&h=Greenhouse+Gas+CameraThe next step in the project is computer vision software to improve the picture.As well, if any of you have some MWIR cameras laying 'round I am very interested to learn more and possibly take one off your hands to turn into another gas camera :-)

author: Zero999
author_rank: Super Contributor
timestamp: November 17, 2019, 08:30:06 pm
content: Interesting.What are your goals? Are you thinking about turning this into a commercial project? I notice a gofundme. I can't see you getting that much. If it's something people want, the big boys such as FLIR will be able to develop something far better, much cheaper.If it's just a hobby, then good for you!
Greenhouse project - Page 1
Forum section: electronics / projects

author: Tjubix
author_rank: Newbie
timestamp: November 10, 2021, 06:53:06 pm
content: Hi ladies and gentlemen,First day first postNew to electronicsSome explanation:I'm making a greenhouse watering system with 3 relays for the pumps. I'm planning to connect a Nextion TFT LCD for the interface in the future. The whole PCB is about stolen from an Arduino Uno with a FTDI FT232RL for the USB part instead of the MEGA16U2 as on the real deal. The whole system will be powered with a 9 or 12V battery pack.Now to the problem.It seams like there might be some trouble with the USB part. I can't get contact with the Atmega328PU chip when trying to upload sketches. My TX and RX LEDS seams to be on even if no data is transferred. (no LCD connected btw and just on regular VCC) There might of course be a lot of other issues involved alsoCan some one help me with my Frankenstein mess so I can try it out next summer?PS.Sorry for the messy schematic.Br.TobiasFINLAND

author: floobydust
author_rank: Super Contributor
timestamp: November 10, 2021, 07:16:14 pm
content: You need a decoupling cap on pin 17, R6+R7 are already built into the IC so the impedance might be too high for USB.A long time ago, there was twofiasco'swhere the FTDI Windows driver was detecting and killing counterfeit parts. Do you have real FTDI IC's?FT232Rdatasheet.

author: rvalente
author_rank: Frequent Contributor
timestamp: November 10, 2021, 07:16:48 pm
content: Does your mega has the arduino bootloader flashed?Are you sure the DTR is getting the mega to reset?

author: Tjubix
author_rank: Newbie
timestamp: November 10, 2021, 07:49:50 pm
content: Thanks for the fast answer@floobydust I have got the FTDI chip to work with another design so I should be able to count the fake one out. But that is really good information to know for future project.I'll remove the R6 & R7 and put a cap on the 17Seams like I need to read more data sheets@rvalente Yes the bootloader should be fine it works on the regular Arduino board but I'm not sure if the DTR resets the mega. Is there an easy way to find out if it don't?

author: rvalente
author_rank: Frequent Contributor
timestamp: November 11, 2021, 07:52:20 pm
content: Ain't a arduino specialist nor have used it out of the board but I IIRC the mega has to be reseted in order to get in condition to load the sketchTry tor reset the mega manually and them load the sketch, if it works you know thats the problem. You may have to try a few times
GreenPAK to the rescue, I2C simplicity with SPI speed and distance. - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: January 23, 2024, 04:49:36 am
content: Here is an interesting idea that I have been working on for a few months. It combines the speed and distance of SPI with the simplicity and small number of wires of I2C. This is done by adding addressing functionality to standard SPI devices using GreenPAK SPLDs ICs.This design is of an 1.3" addressable OLED display which uses only 3 common SPI bus signals, CS, CLK, and MOSI. The CS signal indicates the boundaries of the SPI transactions and the GreenPAK SPLD which sits before the OLED display, steals the first byte which contains target address and RST and DC states, and passes it on to its OLED display only if the address matches. I tested this concept with a few SPI devices, including read/write devices that also use MISO and it works pretty well. The SLG46826 GreenPAK is easy to use, does not require glue component, and is cheap but I wish it would have more resources since this design maxes it.Repositoryhttps://github.com/zapta/greenpak_oled
Grid Fed Inverter Electrocuting lines men? - Page 1
Forum section: electronics / projects

author: johnnyfp
author_rank: Frequent Contributor
timestamp: July 04, 2013, 11:33:53 pm
content: How does a grid fed inverter check if it needs to shut of power to the grid if, for example the grid is down due to work or maintenance?Does it stop producing and Poll for a voltage every x ms or does it use something cleverer (<-And is that even a word?)?

author: bilko
author_rank: Frequent Contributor
timestamp: July 04, 2013, 11:38:59 pm
content: A grid tie inverter has to synchronise its output to the AC on the grid else the grid will send the smoke out of the inverter.

author: IanB
author_rank: Super Contributor
timestamp: July 04, 2013, 11:43:28 pm
content: Also if you are wise and you want to ensure your safety, you will place a short (a "crowbar") across the circuit you are working on after you have de-energized it and checked for no voltage. Then if anyone or anything tries to energize the circuit without permission it will trip the overload cutout.

author: johnnyfp
author_rank: Frequent Contributor
timestamp: July 04, 2013, 11:50:51 pm
content: Makes sense.How often does it sync up with the mains? (I know it's dependent on the model but they should all be similar, in the sense is it ever milliseconds or every minutes?).

author: dr.diesel
author_rank: Super Contributor
timestamp: July 04, 2013, 11:55:46 pm
content: At least for Duke Energy, the largest utility in the States, you are in no danger with a grid tie inverter or generator. All line work is done with all 3 phases shorted with heavy gauge wire. Also remember, anything attempting to backfeed would also be feeding whatever portion of the grid it's still connected to, likely a huge load.

author: gxti
author_rank: Frequent Contributor
timestamp: July 05, 2013, 12:03:09 am
content: https://en.wikipedia.org/wiki/Islanding#Islanding_detection_methods

author: johnnyfp
author_rank: Frequent Contributor
timestamp: July 05, 2013, 12:09:05 am
content: Thanks! I didn't know it was called Islanding, but useful bit of information.

author: bilko
author_rank: Frequent Contributor
timestamp: July 05, 2013, 09:17:17 am
content: Quote from: johnnyfp on July 04, 2013, 11:50:51 pmNot sure, I would say at least every cycle.

author: G7PSK
author_rank: Super Contributor
timestamp: July 05, 2013, 03:13:58 pm
content: I would also expect that after the grid has gone down any inverter on line would see the grid load as a short and shut down or burn up, most people will just leave everything on that was on went the power failed.

author: Jeroen3
author_rank: Super Contributor
timestamp: July 05, 2013, 10:31:55 pm
content: If there is no grid, there is nothing to sync to.You probably need to manually restart it, after opening your grid circuit breaker. (you don't want to power the neighbors do you?)It must make sure there is synchronisation. If it loses that, energy might want to go back in the inverter.
Grid Tied inverter for 200W - Page 1
Forum section: electronics / projects

author: ocset
author_rank: Super Contributor
timestamp: April 06, 2018, 05:28:51 am
content: Hello,I have simulated a grid tied inverter by simply having an isolated 400V supply….then having a PWM with a sinusoidally varying duty cycle which switches via a bridge into a Filter to filter out the switching harmonics and leave behind the 50Hz waveform.Would you say this is a good modus operandi?Its as in the attached simulation in LTspice

author: Phoenix
author_rank: Frequent Contributor
timestamp: April 06, 2018, 06:23:19 am
content: Is this a real product you are proposing? I mean I've done this plenty of times in simulation just guessing magnitude and phase of the sinusoid but only as a quick hack to test something else. All real grid tied inverters I've developed use sinusoidal current regulation from a reference real+reactive quantity.That being said micro inverters may also use a current source inverter derived topology to avoid the need for a high voltage DC bus.
ground connection  on transformer secondary blowing fuse? - Page 1
Forum section: electronics / projects

author: ftransform
author_rank: Frequent Contributor
timestamp: July 05, 2013, 12:38:40 am
content: So I have a isolation transformer, and I wish to add a switch to ground the transformer 2ndary so it is not floating. However if I do ground one of the transformer secondaries (to earth ground that is) the fuse just blows. Why is there a rush of current created by grounding one of the transformers secondaries?

author: ftransform
author_rank: Frequent Contributor
timestamp: July 05, 2013, 01:17:41 am
content: oh fuck me, i am using a autoformer..................................................................................... I thought it was a 110:220V transformer......................

author: IanB
author_rank: Super Contributor
timestamp: July 05, 2013, 02:56:19 am
content: Yes, 99.9% of step up/step down voltage converting "transformers" are autotransformers.

author: Unknown
author_rank: Unknown
timestamp: July 05, 2013, 03:28:58 am
content: Correct me if I'm wrong, but that means it's not an isolation transformer either, right?

author: IanB
author_rank: Super Contributor
timestamp: July 05, 2013, 03:39:27 am
content: No, absolutely not an isolation transformer. If you test the (unplugged) transformer with your meter you will find continuity between the input and output sides.
Ground connector question - Page 1
Forum section: electronics / projects

author: BFX
author_rank: Frequent Contributor
timestamp: August 24, 2019, 07:29:58 pm
content: Hello all.What kind of connector is that? It's for grounding metal case.Thx

author: Benta
author_rank: Super Contributor
timestamp: August 24, 2019, 07:33:24 pm
content: As it's not apparent whether it's 10 cm or 5 mm large, impossible to say. And from one angle only, who knows?

author: BFX
author_rank: Frequent Contributor
timestamp: August 24, 2019, 07:47:12 pm
content: Thx I found ithttps://www.tme.eu/en/details/bc-115/4mm-banana-sockets/sci/
ground isolating amplifier design check - Page 1
Forum section: electronics / projects

author: snarkysparky
author_rank: Frequent Contributor
timestamp: October 30, 2017, 06:36:27 pm
content: I am trying to measure some relatively low bandwidth signals on a switching power supply where the ground is floating WRT other metal in the measurement area. The ground is noisy. Despite using a Tek battery scope with independent isolated ground channels the probe ground noise is excessive. When I connect the tip to the ground the noise is much larger than the desired signal. So I though of this solution. Is it likely to help mitigate the ground loop noise ?Other options ?

author: macboy
author_rank: Super Contributor
timestamp: October 31, 2017, 02:58:27 pm
content: Are you using a long ground lead with alligator clip? Those things are like antennas, especially when not connected to a "true" ground.I know it sounds strange but try a snap-on ferrite on the probe lead either close to the probe or the scope. Not needed or wanted for true grounded equipment.The differential amplifier ideacanwork. It will need to be trimmed for best common mode rejection. Google "instrumentation amplifier" for a fun-filled afternoon of nerdy reading. Note with your unity gain you are still limited to +-9 V maximum to scope ground. You could make the attenuation higher to improve that but stay within low voltage territory for safety (~50 V maximum). You can place a capacitor across the opamp inputs to create a first-order low pass filter for noise rejection.

author: David Hess
author_rank: Super Contributor
timestamp: October 31, 2017, 05:55:28 pm
content: The problem is likely that the ground lead of the probe is picking up too much interference. Possibly leaking magnetic flux is getting between the probe tip and the ground lead.A better solution is to eliminate the ground lead connection by using a coaxial connection between the probe and circuit. If some additional capacitive loading is acceptable, then what I do is temporarily solder a short coaxial pigtail into the circuit with a BNC on the end and then connect the x10 probe to the BNC via a BNC to probe tip adapter. RG-178 or RG-179 coaxial cable works well for this because it is thin and uses Teflon dielectric which will not melt during soldering unlike polyethylene RG-174 although the later works as well with more care. RG-179 pigtails with a BNC already attached can be cut out of old RGB video cables; they are 75 ohms but I have never seen any that bothered using real 75 ohm BNCs and the cable impedance does not matter for this application.

author: snarkysparky
author_rank: Frequent Contributor
timestamp: October 31, 2017, 07:47:52 pm
content: I will try the reduced ground lead loop test. That may be my problem although I still suspect current is flowing on the probe shield.Thanks all
ground issue when expanding PCB for mechanical strength - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: January 21, 2025, 01:38:22 pm
content: Hello I have designed a PCB with certain width of 0.25mm , the PCB is RF microstrip so the width is important for impedance.However i've been told to add extra FR-4 so the total substrate will be 1.6mm thickness which will fit the connector(data sheet attached)But I need the connector ground to touch the ground of the PCB and I need to keep the impedance.How it could be done?Thanks.
ground loop detection - Page 1
Forum section: electronics / projects

author: bug13
author_rank: Regular Contributor
timestamp: March 07, 2016, 07:55:31 pm
content: Hi guysI am looking for a solution to detect ground loop. I came cross this one:http://www.loopslooth.com/how%20to%20find%20ground%20loop.htmlHave anyone use this? or try something like this? I think it will work, but how well it work?Thanks guys

author: dwpatter53
author_rank: Contributor
timestamp: March 14, 2016, 06:51:29 am
content: Our electricians have used an industrial versions to find ground faults like these;http://www.multi-tech-industries.com/gfault.htmlhttp://www.eepowersolutions.com/categories/ground-fault-monitoring-detection/?gclid=Cj0KEQiAvJS3BRDd44fjndyii6MBEiQAN4EkPQi9NJyOXubaawHSHBjAL4KhKGxImgeT3vulUhNce64aAvDJ8P8HAQI would see if an electrical test equipment dealer would loan or demo it for you.It can be a difficult task depending how crowded and buried with other cabling is the circuit you are trying to trace.Good luck
Ground loops, computers, and headaches - Page 1
Forum section: electronics / projects

author: Hiemal
author_rank: Regular Contributor
timestamp: January 25, 2019, 10:29:34 pm
content: One of my latest projects was to design and make a microphone pre-amp supplied by USB power.I built it, using two 34063's for a +18 and -18 rail, and a LT1171HV to supply the 48v phantom power for the microphone.The main amplifier is an SSM2019; a chip with quite nice specs. I basically copied the design on thishttps://www.analog.com/media/en/technical-documentation/data-sheets/ssm2019.pdfon page 7 at the bottom. I'm using a capsule from an ADK 51s microphone; one of the leads goes to the center of the Mylar membrane and the other connects to the outer case of it.I tried last night to attempt to record and see if I could get any sound from the amplifier, hooking it up to my computer via a 3.5 mm audio jack.Upon recording, (turning the gain up to the max of about 200 ish) I just get a TON of noise, and 60 hz interference gobblygook, and absolutely no sound from the capsule itself.My questions are;Is this a ground loop issue? Through the noise I can't hear ANYTHING from the microphone so...Am I connecting the microphone capsule up correctly? Or do I need a different design? As I said before, one of the capsule leads connects to the mylar membrane itself, and the other to the outer brass case.Do I need to get an audio transformer?If any of this is unclear, or if you feel like you need more information I could try to put together a schematic.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 25, 2019, 11:06:32 pm
content: Do you have a schematic of your project ?

author: Hiemal
author_rank: Regular Contributor
timestamp: January 25, 2019, 11:18:21 pm
content: Lemme put one together, it'll take a few.

author: Hiemal
author_rank: Regular Contributor
timestamp: January 26, 2019, 12:08:54 am
content: Here's the power supply section.And the SSM2019 section. All as accurate to what I made in person as I could get.Edit: Forgot to put in a 200 pF cap between the SSM2019's terminals. It's there IRL, just forgotten in the original schematic. Added!

author: Hiemal
author_rank: Regular Contributor
timestamp: January 26, 2019, 03:42:09 am
content: So doing a lot more digging, i Believe i I had a fundamental misunderstanding of how to make this work properly...The SSM2019 isn't intended to be hooked up *directly* to the microphone capsule, it's meant for amplification AFTER the initial pre-amplifier. Every SSM2019 design I've found online, outside of the datasheet all have inputs from an XLR connector; not from a microphone capsule itself... So I think I need to make a more basic JFET amplifier first.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 26, 2019, 07:13:32 am
content: R16 is already used for filtering, but it's value is very low.You might consider increasing it to 10k or even 100k and see what happens.
ground plane and star ground for precision low frequency? - Page 1
Forum section: electronics / projects

author: CopperCone
author_rank: Super Contributor
timestamp: December 23, 2017, 08:04:48 pm
content: Does it not make sense to use both star ground, for the parts , and a ground plane, for decoupling capacitors, to give immunity to RF? Joined at the ground power wire.

author: David Hess
author_rank: Super Contributor
timestamp: December 24, 2017, 02:41:02 am
content: Yes, it does make sense. At high precision, undirected return currents in a ground plane can become the the largest source of error so using a ground plane for shielding and return currents and single point grounds for signal references makes perfect sense.

author: Rerouter
author_rank: Super Contributor
timestamp: December 24, 2017, 03:37:23 am
content: Generally a star ground is not needed. Its closer to a tree grounding.Most people when they design, group parts by function. In the same way with precision you want a common ground reference for that grouping but may not need it for other parts of the circuit.Equally you may have a digital area that doesnt matter about a quiet ground. But you would likely want it fed straight from the supply to limit its noise contribution to the rest.Sorry if i am rambling. But for the most part, all wires have resistance. And its very rare that a star ground explains what is required. Instead the circuit will define what needs to link up to what. And in what order.This is what i call return path planning. To make sure that both the signal and the return for a given signal are close. And do not get broken up.
Ground Planes - Page 1
Forum section: electronics / projects

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 26, 2019, 05:51:03 pm
content: Hi everyone,This a PCB that I am trying to complete (the picture that you see is the first layer).. There are separated ground planes as I am using isolated converter.The ground plane on the bottom layer is suggest to be as the top layer (seperated) and place some vias between them to achieve solid ground plane?
Ground pour in double output buck converter - one pcb - Page 1
Forum section: electronics / projects

author: Sombiefog
author_rank: Newbie
timestamp: July 15, 2019, 07:51:35 am
content: Hi!So im making a dc/dc buckconverter using TI's LM5088 and LM5117. These are going to make two different outputs and have two seperate inputs. Im going to use a microcontroller to switch the relays from the input on/off which then gets fed into the two different circuits. And i've come over a little question which i thought somone here might be able to answer. Right now im having the ground pour be seperate for the two different circuits of the LM5088 and LM5117 - BUT they still grounded together inside my AC/DC converter (Im guessing here - should be tought right?).So my question is - is it ok to use the same groundplane for the two different outputcircuits.For some reason i thought it would mess with the fidelity of the output if i leave two different outputs with the same groundplane.(The outputs are 4,5V 15A - 12V 7A.Input is 48V 10A)Thanks for any reply

author: capt bullshot
author_rank: Super Contributor
timestamp: July 15, 2019, 08:22:23 am
content: If their output is at the same GND (as you descibe), just use one ground plane for everything.Regulation will be referenced to that GND, which should be the same for both. If you split the planes (and don't have a connection on your board), the wire resistance from the 48V will induce some (probably small) difference to these two GNDs, if your converters feed two isolated circuits, this wouldn't matter, but if your converters feed two voltages into a circuit with common GND, you don't want this difference. Additionally, you'd create a GND loop then, this isn't a good idea EMC wise.

author: Sombiefog
author_rank: Newbie
timestamp: July 15, 2019, 08:27:23 am
content: Great!Il merge the grounds
Ground problem on dynamic load project - Page 1
Forum section: electronics / projects

author: electricar
author_rank: Regular Contributor
timestamp: April 24, 2016, 03:32:28 pm
content: Hi folks,I made a little dynamic load based on Jay_Diddy_B's design:https://www.eevblog.com/forum/projects/dynamic-electronic-load-project/My schematic is in the attachment. Today I wanted to add a BNC connector in order to be able to connect the dummy load to my scope. The inner pin of the BNC connector is connected through 2x 100R in parallel (50R) in series to the shunt (source of the FET) and the outer case is connected to ground.The funny thing now is that if I connect my right part of the case (on which the BNC connector is mounted) to the rest of my case (which is also connected to ground) I get a much higher and unstable lowest current (the pot is set to minimum). You can see on the pictures that I made the connection simply through a solderwire.Does anybody know how this can be? I mean ground is already connected to the case...Thank you very much in advance!

author: Paul Price
author_rank: Super Contributor
timestamp: April 26, 2016, 04:23:23 pm
content: Despite both units have a common mains ground connection, small ground loop currents will create offset voltages that will upset circuit operation.Your best bet is to isolate the dummy load power line ground connection and this will fix the problem.One solid earthed ground is enough.

author: electricar
author_rank: Regular Contributor
timestamp: April 26, 2016, 06:41:17 pm
content: Thank you for your answer! They don't have the same ground! The +12V supply input comes from an ac/dc adapter, the DUT voltage is an isolated power supply. Even if I connect the negative rail of the DUT to ground, the problem still exists off course.You mean to isolate the ground connection of the supply input (+12V, in the upper left corner) from the case?In this case it would still be connected through the rest of the circuit to the case (shunt ground, bnc ground...).Even if I could manage to do this, what would be with an isolated power supply? In this case the case wouldn't be grounded or am I totally wrong?

author: electricar
author_rank: Regular Contributor
timestamp: April 30, 2016, 07:11:48 pm
content: Anybody?
Ground referenced load - N-Channel mosfet switching - Page 1
Forum section: electronics / projects

author: VanitarNordic
author_rank: Frequent Contributor
timestamp: August 22, 2018, 07:04:49 am
content: as we know if we decided to drive a load by an N Channel Mosfet, we have to connect the load to the Drain. Therefore the load would be referenced to the +Vcc.is there any possibility/circuit design that allows us to drive a load by the N channel Mosfet(s), but the load referenced to the Ground?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 22, 2018, 07:09:30 am
content: It's called a high side gate driver, and yes, they are plentiful.If you need DC operation, find one with an integrated charge pump, or create an additional supply to deliver (+Vcc) + 10V or so.If all you need is the switch, consider using a purpose-made load switch IC, which includes the driver logic, supply, power transistor, and all the protection you might desire (voltage, current and temperature). Also check under "hot-swap controller", those have similar functionality while supporting an external transistor (that can be much bigger).Tim

author: VanitarNordic
author_rank: Frequent Contributor
timestamp: August 22, 2018, 10:17:08 am
content: Quote from: T3sl4co1l on August 22, 2018, 07:09:30 amWould you please mention a circuit example or a link?

author: twistedresistor
author_rank: Contributor
timestamp: August 22, 2018, 11:08:23 am
content: Quote from: VanitarNordic on August 22, 2018, 10:17:08 amHere is a part from Linear, which does the thing.http://www.analog.com/en/design-center/reference-designs/circuit-collections/lt1910-fault-protected-high-side-switch.html#cc-overview

author: Zero999
author_rank: Super Contributor
timestamp: August 23, 2018, 07:58:45 am
content: What are you trying to do? If it's a lamp flasher or speed controller, then the oscillator IC itself can be bootstrapped. Here are a couple of examples using the 555 timer.A lamp flasherA PWM controller
Grounded thermocouple confusion  - Page 1
Forum section: electronics / projects

author: 9291Sam
author_rank: Contributor
timestamp: July 05, 2018, 09:14:51 pm
content: Precursor:I am working on a soldering station that uses a JBC iron.http://prntscr.com/k31ntgThis is the arrangement inside the iron. I am trying to make this as cheap as possible and to cut cost significantly I am not using a transformer, I am using a 12V 10A power supply from a previous project that I had laying around. My ideal arrangement would be thishttp://prntscr.com/k31qt7, a PFET as a switch and using a MAX31855 to (idealy) read the temperature.Question:After doing a bit of research into the required code for one of these I stumbled across thishttp://prntscr.com/k31takathttps://learn.adafruit.com/thermocouple/arduino-codeand got more than a bit confused.So can I use this sensor with this thermocouple? If not are there any sensors I can use this with?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 06, 2018, 02:24:48 pm
content: Thermocouples generate very small voltages.The heating current through your iron will introduce a voltage drop over the wiring which is much higher than the voltage generated by the thermocouple.So make sure there is no current flowing through those wires during the time you make a measurement with the thermocouple.You also should not use a resistor symbol for a thermocouple.A thermocouple is not a resistor.A thermocouple is a voltage source.Some thermocouples can deliver quite some current. ( A few amps is not unheared of).One of the things you have to take care of is that if your GND connection is loose, then the 12V from the power supply is put on your thermocouple sensor input. Make sure it does not get damaged by that.
Grounding a HV PSU - Page 1
Forum section: electronics / projects

author: Neukyhm
author_rank: Contributor
timestamp: July 15, 2018, 02:16:25 pm
content: Hi everyone, I'm trying to build a PSU for an x-ray tube. I have already built and tested the HV part of the circuit and it works, but the problem is that I'm not very confident about grounding everything. I have to do it because the PSU of the filament is a XL4015 module bought on eBay, so it's not an isolated PSU.However, the HV PSU that outputs 5kV is isolated, I made the transformer myself and I used epoxy as insulation, also the tube and voltage multiplier will be submerged in dielectric oil, soin theoryif I do the grounding as presented in the picture, I should have no problem, but since the voltage is high and so is the frequency, I don't know if it's a good idea to connect one leg of the 5kV transformer to the (-) of arduino and ground them all.

author: PartialDischarge
author_rank: Super Contributor
timestamp: July 15, 2018, 02:23:15 pm
content: X ray tubes have both poles isolated, and the filament voltage is referred to the cathode voltage.

author: PartialDischarge
author_rank: Super Contributor
timestamp: July 15, 2018, 04:29:19 pm
content: Yes it seems that is the case. Those modules are for a monoblock, where you keep the tube and the electronics in the same oil tank, close together. Given your setup you will have no other option than to ground one pole of the hv multiplier...

author: crazyguy
author_rank: Regular Contributor
timestamp: July 16, 2018, 02:56:59 pm
content: Quote from: MasterTech on July 15, 2018, 02:23:15 pmwhen the tube is in operation there is tube current (mA) flow through anode to cathode
grounding between a DAC and a ADC?! - Page 1
Forum section: electronics / projects

author: xzswq21
author_rank: Frequent Contributor
timestamp: December 17, 2017, 12:21:44 pm
content: Helloin my system I have a high speed ADC and a high speed DAC.each one has a star ground under itself. (see below pic)now I have two star grounds. How should I connect these ground to each-other?Thanks
Grounding Cable Sheild - Page 1
Forum section: electronics / projects

author: laingalion
author_rank: Contributor
timestamp: December 30, 2013, 07:56:20 pm
content: I have a project which is powered by a 40 V lithium battery. I then use an H-Bridge to turn it into an AC signal to feed a transformer (at around 20 kHz). The transformer steps up the voltage to around 2 kV to power a transducer. It draws a lot of power, approximately 1 kW RMS.I used a thick shielded cable (maybe 10 ft) from the transformer to the transducer.To where should I bond the cable shield? Should I bond it to the negative terminal of the battery? Should I let it just float?I imagine bonding it to one of the legs of the transformer would defeat the purpose of the shield.I did a search on the forums and see that bonding to the DC ground is best, but in my case the shield is after a transformer and I am worried about noise being fed back to the circuit. The control side is also powered by the same battery.Side concern:I am also really worried about interference to the low voltage (5 V) control side. Even though I put in a ground plain, avoided circuit loops, and put capacitors near every chip, I am worried about the 25 amps flowing across the H-Bridge. I have actually built the system and it works fine but it still worries me. Any suggestions or best practices would be very welcome.

author: Rerouter
author_rank: Super Contributor
timestamp: December 30, 2013, 08:14:04 pm
content: Te idea of a shielded cable is to prevent external interference from entering your circuit, as such should be tied to the lowest impedance return in your case the negative of the battery, and right at that terminal, if you tie it in with the ground that is supplying your inverter, even though its a high discharge lithium you will have some fluctuation in voltage which can turn your shield into an antenna.

author: laingalion
author_rank: Contributor
timestamp: December 30, 2013, 08:28:28 pm
content: Quote from: Rerouter on December 30, 2013, 08:14:04 pmThanks very much for the reply.The negative terminal of the battery is the same as the ground supplying the inverter. I am designing this incorrectly? Am I missing a fundamental step? The battery terminal is only a few inches of conductor away from the inverter. I tried to make it as short as possible to reduce any noise.
Grounding, Earthing and shielding in an Electronics system - Page 1
Forum section: electronics / projects

author: Faringdon
author_rank: Super Contributor
timestamp: July 13, 2021, 10:40:54 am
content: Hi, We have Equipment in plastic enclosure. Fed power by 20W offline isolated SMPS. Mains input cable brings live , neutral and earth to the PCB that has the SMPS on it. Three DCDC’s on the boards. Wires and cables coming in/out of enclosure and between the boards.Do you agree that we will need to screen the entire enclosure with metal foil? (to prevent failure of radiated EMC test?Do you also agree that it would be mad not to earth the secondary ground? After all, some of the incoming comms line grounds might be at earth potential anyway, and so if secondary ground has floated up to some unknown potential , then disaster could ensue?Also, do you agree that the metal foil screen that will surround the inside of the enclosure should also be connected to earth?All incoming and outgoing cables must use screened cable, you agree? Cable Screens connected to the circuit ground (ie earth)?

author: Terry Bites
author_rank: Super Contributor
timestamp: July 13, 2021, 05:09:33 pm
content: This is my bible: Grounding and Shielding Techniques (Wiley – IEEE) Hardcover – 24 Mar. 1998 Still a realy good referrence book.What you need is to first figure out what compliance standard you are working to. Dont just chuck everthing at it untill you know what the actual issues are.It hard to say whats right or wrong with out seeing the entire sysyem layout. In general you want all your grounds 0V referrence ponts and shielding to be at the same potential. So usually you'd run your sheild drain wires, 0V and mains ground back to the same central node. You need this for safety anyway.Understanding how to minimise radiating loops is essential. Input and output common mode filters can work wonders if properly applied.Shielding is not always the best solution. Ther's loads of material on this.https://www.analog.com/en/analog-dialogue/articles/staying-well-grounded.html;https://www.analog.com/en/analog-dialogue/articles/reducing-ground-bounce-in-dc-to-dc-converters.html;https://www.smar.com/en/technical-article/tips-on-shielding-and-grounding-in-industrial-automationYou might want to consdider putting your DCDCs at the point of load. Not on long shielded leads.Earth impedance is a critical parameter and gets higher with working frequency. Earth grounds tend to be very dirty these days with an smps in just about everything.I've had to resort to ground indcutors to keep the crap out before now.Correct choice of materials such as earthing wires and shielding plates or foils will affect the performance.Why not start with a metal enclosure from the outset? Sure its more expensive, but it will probably save you from buying in exotic extra parts.
Grounding Instrumentation project - Page 1
Forum section: electronics / projects

author: dreaquil
author_rank: Regular Contributor
timestamp: April 20, 2016, 10:09:31 am
content: So I've designed and implemented a precision instrument. One issue is that when the oscilloscope probe ground is connected to the board ground it reads perfectly. When I disconnect it, it fluctuates a lot. Does this mean I have to connect the board ground to mains earth for good readings? Whats causing this? I'm very interested in the reason behind it. I think its relevant that I specify I'm using an external SMPS by CUI Inc. P/N ETMA360166UD-P5P-IC (Medical grade PSU).

author: DTJ
author_rank: Super Contributor
timestamp: April 20, 2016, 10:12:28 am
content: Is your power supply output isolated or is the -ve grounded?Do you have sensors or other instruments feeding into the circuit? Grounded?

author: Rerouter
author_rank: Super Contributor
timestamp: April 20, 2016, 10:14:55 am
content: If the 2 devices do not share a common reference, your measurements are meaningless, it would be like trying to measure a battery with only 1 wire,

author: dreaquil
author_rank: Regular Contributor
timestamp: April 20, 2016, 10:17:42 am
content: The output is isolated according to the datasheet. I do not have external sensors. The instrument measure the insulation resistance of cables. so I simply connect one end of a cable to my instrument.http://www.mouser.com/ds/2/670/etma-60w-534969.pdf

author: Rerouter
author_rank: Super Contributor
timestamp: April 20, 2016, 10:28:23 am
content: That is an isolated supply,Now at this point i would recommend sketching up a crude diagram of what your measurement setup is like, (Power goes in here, Device under test connects here, measurement connects here), you can keep your device a black box if you wish, but an image would help clarify,

author: dreaquil
author_rank: Regular Contributor
timestamp: April 20, 2016, 10:57:32 am
content: Something like this? The PSU is a linear one on the PCB and the barrel connector connects to it. All linear regulators are referenced to the SMPS ground terminal.

author: dreaquil
author_rank: Regular Contributor
timestamp: April 20, 2016, 11:08:24 am
content: I can confirm that the oscilloscope probe is connected to earth (checked on my tektronix oscilloscope from probe ground to earth ground pin at the back). So it seems this solves the issue.. just not sure why.

author: tautech
author_rank: Super Contributor
timestamp: April 20, 2016, 11:42:25 am
content: Quote from: dreaquil on April 20, 2016, 11:08:24 amProbe ground has unfortunately been called bymost, just that: ground.While it technically is, as with most scopes the BNC outers are at mains ground.However it is thereferenceto which the signal is referenced, just like in the analogy Rerouter provided.So to avoid future confusion think of the probe lead as thereference leadfor it's a more accurate description.Just be aware it's grounded of course.
grounding metalwork for EMC - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: July 19, 2018, 10:36:28 am
content: We are in a conundrum as to how to ground our metalwork. Much of it is just framework and some is enclosures for electronic items. With every part coated nothing is electrically connected so we would have to pick which items need bonding together and then to vehicle chassis. The whole bonding to a chassis has always confused me as if the vehicle body is a Faraday cage why worry?

author: ocset
author_rank: Super Contributor
timestamp: July 19, 2018, 10:56:52 am
content: You definetely need to electrically ground your circuits to vehical chassis. -And this is for electrical noise reduction (EMI reduction). You will often find that you can sometimes pass EMC tests by grounding to the chassis at a slightly different point.........but this is often by trial and error, its very difficult to actually calculate to exactly where on the chassis you have to connect ground in order to get the best EMC test results...its all like microwave engineering

author: Simon
author_rank: Unknown
timestamp: July 19, 2018, 11:09:34 am
content: Quote from: treez on July 19, 2018, 10:56:52 amYea, and we are metal bashers
Grounding the tip of an Ersa i-CON Pico - Page 1
Forum section: electronics / projects

author: W0mba
author_rank: Newbie
timestamp: March 23, 2021, 08:16:25 pm
content: Hello,before I start: I'm a newbie in this forum so please leave a hint if I do something contrary to the way the communication should be held.Last christmas I've got an Ersa i-CON Pico - the non ESD/ non grounded tip version. Because of sentimental worth I really want to keep this station but I would feel safer if the tip would be grounded.I had a look with my oscilloscope and the tip has a nice sinusoidal voltage of about 6 V (peak to peak or max... not sure anymore). This makes me uncomfortable. I haven't looked at the current but i guess it won't be close enough to 0 A to not potentially damage something.While searching for a solution I've found a video () of a guy grounding the tip.I have noticed that the board version of the Pico changed since. The board of his Pico was labeled as i-CON nano V5, mine is labeled as i-CON pico nano V1. Mine is from 2018 and his revision seems to be from 2009.

author: ThomasDK
author_rank: Regular Contributor
timestamp: March 23, 2021, 08:49:49 pm
content: Sure:

author: W0mba
author_rank: Newbie
timestamp: March 24, 2021, 06:48:39 am
content: Thank you very much!Looks good so far - seems to be equally populated and the PE connection seems to be the only difference!It looks like you have the old version, is there maybe anyone with the new version (approximately later than 2018, with the pcb mark "i-CON pico nano V1")?A picture from that would be a good complement for the internet database (haven't found a picture of the new nano despite extensive search).Thanks again!
Grounding unused Vcc pin - Page 1
Forum section: electronics / projects

author: Cicada
author_rank: Regular Contributor
timestamp: February 09, 2024, 05:22:03 pm
content: HiI have a compound device with an Avalanche Photodiode (3 external pins) and a separate RDT-based temperature measurement with I2C interface (4 pins: Vcc, GND, clock, data). I do not want to use the temperature measurement function at the moment. I plan to ground the clock. Data should probably be connected to ground through a 10k resistor, but does it make sense to ground Vcc? If so, should it be shorted to ground or connected through a resistor?Or should Vcc be left floating?ThanksCicada.

author: TomS_
author_rank: Frequent Contributor
timestamp: February 09, 2024, 07:25:02 pm
content: If the temperature sensor is completely separate from the photo diode and they don't share any power or logic connections, I would just leave all of the temperature sensor pins unconnected. It doesn't make sense to ground the VCC pin, and if the device is unpowered then the other pins don't need to be grounded either, just as if you were holding a chip in free air (it will do nothing and can't misbehave without power.)If the photo diode section is relying on power from the same pins that also power the temperature sensor, then pull up or down the unused temperature sensor pins as makes most sense for their function. For I2C I'd pull up as that is the idle state from an I2C bus.

author: Cicada
author_rank: Regular Contributor
timestamp: February 12, 2024, 07:53:41 am
content: Quote from: TomS_ on February 09, 2024, 07:25:02 pmYour thoughts is my thoughts exactly. The I2C temperature device is completely separate. I just had to check since someone less knowledgeable of electronics involved in the project asked that they be grounded. A physicist; so not completely oblivious to the field of electronics. So I just had to check myself.Thanks
grounding - Page 1
Forum section: electronics / projects

author: ant17
author_rank: Regular Contributor
timestamp: December 19, 2013, 11:20:26 pm
content: hi guys i have a backlight inverter with ac output of about 1500vac. Which i convert for my pmt scintillation project to dc through a bridge recitifre . I have no problems with it but being battery powered the inputs and grounds are floating at high voltage so you can get a zap from it from the ground terminals. I don't think its a good idea having hf ac floating around circuit is there anyway to correct this with out fixed ground as i would like keep it hand held in a metal case
Grove connector HY2.0-4P - Who is manufacturing them - Page 1
Forum section: electronics / projects

author: sylvanoMTL
author_rank: Contributor
timestamp: May 23, 2025, 09:17:33 am
content: I have a brand new crowpanel. It is nice, it seems awsome, but...Most of the connectors are type "Grove 2mm HY2.0-4P". I look for compatible plug connectors and I can find only prewired pigtails. It seems a chinese-designed-produced connector, with absolutely no availability.Does anyone know where to find a kit so that I can wire my cable myself?Thanks,sylvano

author: aeg
author_rank: Regular Contributor
timestamp: May 23, 2025, 09:47:09 am
content: These might work, but I'm not sure.https://lcsc.com/product-detail/Housings-Wire-To-Board-Wire-To-Wire_CJT-Changjiang-Connectors-A2008H-4P_C5340508.htmlhttps://lcsc.com/product-detail/Housing-Contact_CJT-Changjiang-Connectors-A2008-TP_C339218.html

author: thm_w
author_rank: Super Contributor
timestamp: May 24, 2025, 12:24:16 am
content: https://forum.digikey.com/t/elecrow-crowtail-connector-industry-standard-name-or-classification/51472https://www.reddit.com/r/AskElectronics/comments/jgo5hq/mysterious_hy20_connectors/

author: sylvanoMTL
author_rank: Contributor
timestamp: May 26, 2025, 05:30:34 pm
content: Thank you all, seems like Aliexpress has some.