hybridfree/eevblog-posts huggingface dataset:
Ganged Preset Resistors - Page 1
Forum section: electronics / projects

author: German_EE
author_rank: Super Contributor
timestamp: March 01, 2019, 09:21:18 pm
content: We've all done it, once in a while we've come across a need for something that just isn't made, and now it's my turn.I need two 20K ohm preset resistors that are ganged together, just like a stereo volume or balance control but a lot smaller. If it doesn't exist then I might get the smallest dual gang pot I can find and cut the shaft off but that's a bit of a hack.Any ideas?

author: Benta
author_rank: Super Contributor
timestamp: March 01, 2019, 09:50:28 pm
content: How small?Vertical/horisontal?SMD/TH?

author: German_EE
author_rank: Super Contributor
timestamp: March 02, 2019, 08:38:54 am
content: Ideally as small as a couple of normal preset resistors, vertical mounting, through-hole. ALPS make some quite small dual potentiometers which is why I had the idea about cutting down a shaft. Another alternative is a pair of presets with a wheel rather than a screwdriver slot and then carefully glue the wheels together, maybe.

author: Gyro
author_rank: Super Contributor
timestamp: March 02, 2019, 10:31:31 am
content: I can't think of anything other than using a small ganged pot.It seems a bit of an odd requirement for a preset, it raises questions like what degree of wiper matching accuracy is required? - can't you just put the presets side by side and visually match them?Presumably these are internal presets rather than external screwdriver slot adjustable?

author: beanflying
author_rank: Super Contributor
timestamp: March 02, 2019, 10:51:51 am
content: Two Vertical mounted Trimmers with side adjustment like below. Place them on the board front face to face with a 3D printed wheel in between with an appropriate blade connecting the slots one to the other or two blades go get the alignment correct if needed. Should be able to be made 2.5-3mm width wheel plus the two pots wide.The thing you haven't made mention of is what sort of Accuracy or Linearity you need? Pots aren't always as good as you may want.

author: duak
author_rank: Super Contributor
timestamp: March 02, 2019, 08:11:46 pm
content: Piher makes trimpots with an internal hex drive. (see attached image) I don't know if they also make a knob with an extended hex shaft to drive two or more. Perhaps a plastic hex alignment tool could be found.Cheers,

author: Benta
author_rank: Super Contributor
timestamp: March 02, 2019, 08:14:31 pm
content: Piher also supplies the hex shaft. Good idea!
Gap/slot type opto-sensor debouncing - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: April 21, 2021, 09:32:38 pm
content: Hi,do you ever need to debounce the transmissive/gap-type opto-sensors?In the past I always used schmitt-triggered ones and never had any need for it but I have been writing code for a PCB where there is no information available on the type of opto nor access to the signal itself to see if there is any bouncing.Thank you

author: floobydust
author_rank: Super Contributor
timestamp: April 21, 2021, 09:36:12 pm
content: The slotted optical sensors, they pick up sunlight or room lighting with AC mains flicker which can be a problem.I've never had to debounce them, just use a Schmitt trigger for clean switching.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 21, 2021, 09:49:26 pm
content: When I have the opportunity to, I like to use a CCS load to give just that bit better signal gain, switching speed, and guard banding with respect to CTR. To be immediately followed by, yep, a schmitt trigger.The CCS can even be electronically controlled, in case that's useful for accommodating further variation in diode current, ambient light or CTR.That should pass pretty much any situation you'd ever want to get into. The next step up would be a lock-in style approach, pulsing the LED and watching for coincidence at the detector. This requires a resistor load (or even a logarithmic load in extreme cases) and an analog input. Maybe more practical for long distance retroreflector things, like a garage door closer or light curtain.Tim

author: ricko_uk
author_rank: Super Contributor
timestamp: April 21, 2021, 10:52:10 pm
content: Thank you Tim and floobydust
Garage A/C control system.  - Page 1
Forum section: electronics / projects

author: Shaggy
author_rank: Newbie
timestamp: August 06, 2010, 05:05:21 am
content: HelloI've been following the blog for a while now and decided to finally join up!I'm working on this project at the moment.. but I'm sort of stuck. I love electronics but I'm no expert yet. xDAlright, so I'm making a control system for a DIY A/C project for my garage. (The heat out there is insane, I could probably melt solder to the wall just with air!) I know how I want the system to work but I'm just not sure how to make a circuit board/control module. Basically I have a refrigerated water cooler I plan setting up to run cold water inside the garage to a fan/radiator to cool it down.Here's what I have so far. (sorry if this is a poor diagram, don't have money for a good diagram program.)What the diagram means: Basically I need to find a way to delay start up of components, the water circulation pump needs to start approx. 1-2 minutes after the compressor turns on. The compressor needs to turn on 30 sec. after the cooling fan turns on. How can I make a time delay circuit? (It'll actuate a relay/contactor for each part)Second problem is the thermostat type of control circuit. I could just get a normal thermostat but that's not part of the DIY spirit. xDI just need something that will turn a relay on/off and a settable temperature. This relay will actuate the time delay circuits which will actuate the components.This is probably an extra elaborate system but the more complex it is the more fun it is in my opinion!

author: lamja
author_rank: Contributor
timestamp: August 06, 2010, 06:21:18 am
content: An Arduino will be perfect for this project. You can use a temperature reader and some logic-level FET's to control your releys.Even easyer: If you don't want relays, like this guy did with an Arduino and some servos :

author: Pyr0Beast
author_rank: Contributor
timestamp: August 07, 2010, 06:07:42 pm
content: I am not sure why do you want to complicate things.Cooling fans can be started with compressor. You could just add a simple bimetal switch to start compressor when water temperature gets above a certain threshold, same for the pump it could run with fans-radiators in the garage.If the compressor is any less than 500W just forget about cooling the garage down.

author: Shaggy
author_rank: Newbie
timestamp: August 10, 2010, 02:52:01 am
content: Well, the way I was designing it was so the fan cooled the compressor before start up (Seeing as its 100 degrees out here and this'll be outside.) But I've since changed the plan, now the fan runs all the time and the compressor gets cooled by a separate system. Now the compressor will have a 5 minute anti-short cycle delay and the pump will turn on the same time delay as before.I don't really intend to keep the garage at 70 degrees, just something less than 100 would work good. I've tested it with a "small scale" radiator and fan and it seems to have plenty of cooling power to spare.
Garage door safety sensor hack - Page 1
Forum section: electronics / projects

author: yamanoorsai
author_rank: Contributor
timestamp: November 20, 2013, 01:42:48 pm
content: I wanted to use a garage door safety beam sensor in one of my projects assuming that it would have a relay output that would change states when the beam is interrupted. The IR transmitter and receiver has only 2 leads to power them up. There is no documentation on how these things work.I found a video where I learned that the receiver works like a one wire interface. The transmitter sends in a unique signal and the receiver sends in a PWM signal. There is no documentation available on the nature of the signal expected by the receiver from the transmitter.I learned that the transmitter sends in a 154 Hz signal at 7.7% duty cycle. This may vary from brand to brand. Has anyone had experience with getting the garage door safety sensor working? Is there any solution to get it working off-the-shelf?

author: G7PSK
author_rank: Super Contributor
timestamp: November 20, 2013, 03:36:14 pm
content: Never used a garage door sensor but have used motorised gate sensors and all of them have had an onboard relay. Like these.http://www.easygates.co.uk/product_info.asp?ProductID=909

author: strangelovemd12
author_rank: Regular Contributor
timestamp: November 20, 2013, 04:10:02 pm
content: Sorry I can't offer any help, but you've certainly peaked my interest. Any chance of linking to the resources you managed to dig up?

author: RABeng224
author_rank: Contributor
timestamp: November 21, 2013, 04:22:34 am
content: You are on the right track. The reason they're not a simple relay contact comes down to safety. The door opener needs to insure the the safety sensors are operating each closing cycle. A normally closed contact doesn't qualify. Each manufacturer has their own way of doing it. Usually, there are two ways of doing it. Easy way is to power the transmitter and analyze the output of the receiver. Usually the frequency will go down when the beam is blocked. This can be rectified and then you can just monitor the change in voltage. Otherwise, you can actually calculate the frequency in your micro.
Garage door sensor UART? - Page 1
Forum section: electronics / projects

author: nyo
author_rank: Contributor
timestamp: April 24, 2011, 02:31:00 am
content: I have a garage door motor, board and sensors that I'm taking apart. For the sensor it has logic behind it, trying to figure out how to read it. Is it UART?Main boardSensorSignal on oscilloscopePlain logicUART?

author: tecman
author_rank: Frequent Contributor
timestamp: April 24, 2011, 11:17:49 am
content: It is actually a custom chip designed for door openers. It has the logic, various timers and decoding logic for the transmitted coding for the opener. Not much use other than an opener.paul

author: Lawsen
author_rank: Frequent Contributor
timestamp: April 26, 2011, 10:12:49 pm
content: The chip might be those ASIC, application specific intergrated circuit chip, not a general purpose UART. It is designed to lower manufacturing costs by high volume. Omerons are magnetic relays to drive the higher current motor to open and close the garage door and buffering for the sensors. Is this from a Chamberlin, Genie Overhead Doors, or Stanley? These are the most popular brands in California, U.S.A.Lawsen

author: nyo
author_rank: Contributor
timestamp: July 10, 2011, 12:45:34 am
content: Thanks for the replies guys
Garage door wall control communication - Page 1
Forum section: electronics / projects

author: joegtp
author_rank: Contributor
timestamp: October 22, 2013, 03:39:06 am
content: I've been trying to figure put how my garage door wall control communicates with the motor. It's definitely bidirectional because it can display sensor status. What I find puzzling is that there are only two wires going from the wall control and the motor box. I guess it could be RF but that seems strange since it has a lock out button as well.

author: David_AVD
author_rank: Super Contributor
timestamp: October 22, 2013, 08:46:26 am
content: Low voltage DC with the data modulating the power would be my guess.

author: amyk
author_rank: Super Contributor
timestamp: October 22, 2013, 10:04:29 am
content: Should be rather easier to figure out if you can take it apart...

author: SeanB
author_rank: Super Contributor
timestamp: October 22, 2013, 07:36:01 pm
content: Simplest is to use a set of resistors switched to show the various functions in the box, and provide a constant current down the wire that drives a LED for status, with the current being lowered to indicate a fault. Other method is to modulate the data over the wires and have a micro inside the remote side that reads the supply voltage to get data and pulses the line to a low level to send data back.
Garmin Flash Data Card - Page 1
Forum section: electronics / projects

author: JLM
author_rank: Contributor
timestamp: April 09, 2014, 02:22:40 am
content: I just got a Garmin GPS for my aircraft. The unit is model GNS 430W. The data card is a 16mb flash memory in a special plastic case. I understand that the card is in a "proprietary" Garmin format. Shockingly, the cost for replacements is $195 USD! (Note that it is 16mb, not 16gb!). How difficult would it be to reverse engineer the card to make a reasonable-cost replacement. Thanks

author: andtfoot
author_rank: Unknown
timestamp: April 09, 2014, 08:59:04 am
content: If you can put it into a card reader, you might be able to use something likeOnBelay v2to do a low-level backup and restore to a new card.Put original card in, then:Tools > Backup > (select filename) > (make sure 'Exact duplicate...' is ticked) > BackupInsert new card, then:Tools > Restore > (select previously backed up .FMB file > Restore

author: amyk
author_rank: Super Contributor
timestamp: April 09, 2014, 01:26:32 pm
content: Apparently it's just a raw NAND flash, small-block type:http://www.lbodnar.dsl.pipex.com/garmin-datacard-DIY.htmlhttp://web.archive.org/web/20031205184030/http://home.fuse.net/pagrosse/mem_cart.htmhttp://www.ukgser.com/forums/showthread.php?6700-Converting-a-16M-Memory-card-to-a-128M-memory-cardNo explicit pinout given but you could probably RE something (do post it if you manage to!)It could be difficult to find small-block NAND these days, however.

author: Azito
author_rank: Newbie
timestamp: September 22, 2025, 02:16:33 pm
content: Hi Everyone. It's necroposting time.Did not find anywhere pinout of gatacard. Got a 256 MB Version that works with my 174.Didsassembled and made pinout for future generations.CE(1) and CE(2) - ChipEnable pins for upper an lower NAND chips. All other pins for both chips are in parallel.Chips installed in mine - k9k1g08u0m-ycb0.
gas discharge tube color code - Page 1
Forum section: electronics / projects

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 06, 2013, 06:03:34 am
content: I have a bunch of gas discharge tubes (from old telephone equipment) that look like big glass diodes (about the size of a grain of rice) with 3 color stripes on them. Is there a standardized color code for them? One (randomly picked) has blue, brown, (larger space) and white stripes.

author: ElectronicTonic
author_rank: Contributor
timestamp: December 06, 2013, 05:45:36 pm
content: This is purely speculation, but I would guess that the first two bands are one significant figure, then a multiplier.Blue Brown = 6 x 10^1 = 60 V breakdown voltage. Probably for surge protection.What are the colors on some of the other tubes?Can you test them to measure their breakdown voltages and compare that with the color bands?

author: calexanian
author_rank: Super Contributor
timestamp: December 06, 2013, 06:07:37 pm
content: If I am not mistaken thats an old ring detector. there was 48 volts DC on the system. The ring signal was 90VAC and the the spark gap would conduct and run current to the bell or ringer. Or they are just protection, but I know I have seen old telephone ringers that worked on that principal.

author: minime72706
author_rank: Frequent Contributor
timestamp: December 06, 2013, 09:57:45 pm
content: 90VDC standoff voltage seems quite reasonable in the purview of telecommunications systems. 60V would be valid if there wasn't a high-voltage ring signal. I think "telecommunications" doesn't really imply that you have a system that shares lines with the POT (plain old telephone) system. I just know that telecom stuff uses 48V pretty often. I have a few beefy regulators that run off of 48V and output some sensible digital electronics voltage value that I got at a flea market (MIT Flea). I got some 90V GDTs from Electronics Goldmine as well as some different ones at the same flea market which means that value is common. I got the 90V GDTs from the same seller at the flea market that I just mentioned.You can also totally just test them if you have a power supply that goes high enough. If you have a few (at least a couple I guess) DC power supplies with isolated output, you could put them in series for higher voltage. Be sure to turn the voltage up slowly and keep the current limit low. I personally tested one for fun by attaching it to the output of a CW multiplier I made. That surely made it glowThe moral is: 90V is a common GDT stand-off voltage for telecommunications and 60V also seems reasonable assuming it's not for POTS. 60V would be better for more sensitive electronics. It would not surprise me if the first reply post is entirely correct.EDIT: By the way, if you are able to test them, remember that they won't break down at the rated voltage - it may easily need to be 10% more. The rated voltage is the "Stand-off voltage", I believe. This means that it can avoid breaking down at that voltage effectively indefinitely.
Gas discharge tube voltage rating selection - Page 1
Forum section: electronics / projects

author: subliti
author_rank: Contributor
timestamp: April 26, 2020, 06:22:02 am
content: HiI dont have experience with GDT, so i wanted to ask if a Gas Discharge Tube with a DC Sparkover ±20 % @ 100 V/s voltage rating of 470V is suitable for AC mains 230Vrms +-20V protection. Often if not every time you see GDT with a rating of 600V for mains protection (230Vrms), why ? Why not 500V or even 470V ?470V +-20% would be 376V min, which is close to the Vpeak of 353 @ max 250Vrms AC mains.Protecting L to PE, N to PE and L to N....do you think that using 3 discrete 2-Terminal GDTs would be more robust in terms of protection than using one with 3-Terminals ?
Gas Filled Tubes  - Page 1
Forum section: electronics / projects

author: LaserSteve
author_rank: Super Contributor
timestamp: May 03, 2021, 04:11:41 pm
content: There recently was a discussion on this forum about the implications of small thyratrons.Some people were confused about the gas fillings used.Gas based devices are still used by some of us, and I'm in the process of designing a gas based sensor tube for my job.Please see attached Document from RCA, it clears up many of the fine points as to gases used, lifetime, materials. etc.Well, I find attachements are not working today:Link to whole book, not just gas subchapter...https://www.pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_51/4396_Electron_Tube_Design.pdfSteve
Gas gauge IC & battery swap - Page 1
Forum section: electronics / projects

author: Dominique
author_rank: Newbie
timestamp: May 09, 2014, 02:07:25 pm
content: Hi,I'm working on an handheld device project powered from a removable 3200mAh single-cell Li-ion battery and running Windows CE (maybe Linux in the future). The remaining battery charge should be reported accurately to the user. Normal operation includes charging over USB, however the user may swap different batteries - e.g. replacing a depleted battery by a fully charged one, using an external charger.I'm looking at various li-ion gas gauges datasheets, and I don't understand how they would handle a battery replacement. They all seem to keep track of the charging status using non-volatile memory, so I guess they would start with a wrong estimation of the charge when a new battery is inserted.Can somebody enlighten me on the subject ? Specific IC suggestions would also be of great help.Thanks,Dominique

author: SeanB
author_rank: Super Contributor
timestamp: May 09, 2014, 05:33:06 pm
content: If using a battery pack put the management IC into the pack and connect it into the circuit via a multipole connector. That way you also have memory in the pack to store info about the pack, and most management IC' s allow you to charge the pack and have it balance the cells with pretty much no external control other than a preset set in the pack.

author: ohmineer
author_rank: Contributor
timestamp: May 09, 2014, 07:42:43 pm
content: Actually there are gas gauges that are designed to be placed into the battery pack and others into the system. You can usually filter by this options in manufacturer's website (See Texas Instruments or Maxim Integrated).In general, gas gauges that allow changing the battery pack (System side gas gauges) rely their estimations on open circuit voltages (relaxation) and dynamic behaviour of the pack (during charge and discharge). Data stored in ROM is used to improve accuracy when battery pack is connected.For those reasons, the cell modelling stage when designing the system is very important if you want to be accurate.
Gate drive current selection - Page 1
Forum section: electronics / projects

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 18, 2016, 11:43:42 pm
content: Hi everyone,am just reading about DRV8701 , basiclly it's a H-bridge driver. what get my attention is that you can actually select a current limit on a mosfet gate driver. i don't understand the purpose of that. If the chip is capable of 300mA sink and 150 source what will anyone use 12.5mA sink and 6mA source !!! most mosfet power waste accure on switching on and off so you should always make the switching as quick as possible , so why anyone will make it slower. i don't get it !

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 19, 2016, 06:05:21 pm
content: Hi thanks for your answer, i should read more about MOSFET theory of operations , i use them all the time had same problem before but nothing serious. i think i should go back to basics on this

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 19, 2016, 07:26:18 pm
content: Slow turn-off is sometimes present on large IGBT drivers during fault conditions. An IGBT module can draw 5000A+ short circuit. Turning off 5kA at normal speed (~100ns?) would cause a massive voltage spike, transferring all the magnetic energy into avalanche breakdown of the transistor, destroying it. (The magnetic energy is stored in the device stray inductance, ~20nH, at the very least. Poorly designed converters can have over 100nH.) Turning it off slowly causes the pulse to last longer (and the transistor is already dissipating about a megawatt, which it can only sustain for ~10 microseconds), but allows the transistor to survive, rather than be destroyed by excess voltage.In other cases, the series gate resistor provides the current limiting, usually for slow applications (general purpose outputs, relay drivers, etc.), or small power supplies with EMI issues (slower gate dV/dt = slower drain dI/dt = less switching harmonics).Tim

author: owiecc
author_rank: Frequent Contributor
timestamp: February 19, 2016, 07:31:39 pm
content: dV/dT on the output of an H-bridge leg can also turn on the complementary device. Read this one: Design And Application GuideFor High Speed MOSFET Gate Drive Circuits by Laszlo Baloghhttp://www.radio-sensors.se/download/gate-driver2.pdfA very good article on the subject.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 19, 2016, 08:20:33 pm
content: Quote from: T3sl4co1l on February 19, 2016, 07:26:18 pmbut how to define the proper turning off speed. is it safe enough to take the fall time and the fall delay time as the minimum switching off period. as this in a random datasheet will be around tenth of ns. and that's an order of magnitude less than 100ns or so.in case inductive load such motors should load inductance be determined in order to limit the voltage spike and make slower than the body diode conduction speed

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 19, 2016, 08:26:10 pm
content: Quote from: owiecc on February 19, 2016, 07:31:39 pmreading it now thanks
Gate driver chip for DC motor control - Page 1
Forum section: electronics / projects

author: XaviPacheco
author_rank: Regular Contributor
timestamp: May 25, 2018, 03:16:21 pm
content: Hello,I'm looking for a proper gate driver for driving a power DC motor (4HP). I do not want to control direction. I attach one that I found while searching in Texas Instruments products, UCC27712. However. I'm confused about that chip when it says High-Side Low-Side. What does that mean by high and low side? How could I use that chip to control DC motor speed in one direction?

author: james_s
author_rank: Super Contributor
timestamp: May 25, 2018, 04:04:15 pm
content: High side, low side is a dual mosfet controller intended for driving a half bridge as shown in that picture. If all you want to do is control a DC motor then what you want is a single low side mosfet driver. One that I recently used for just such a task is IXDI609PI.

author: Siwastaja
author_rank: Super Contributor
timestamp: May 25, 2018, 04:43:05 pm
content: The one shown, dual MOSFET-based half-bridge, has the added benefit of running at higher efficiency (especially relevant in low voltage systems, or systems running at low rpms, high torques) compared to the single mosfet + diode solution; this is because diode has higher voltage drop than a mosfet. Another added benefit is that the dual mosfet half-bridge can do regenerative braking with permanent magnet DC motors. (This can be a downside as well - you need to monitor the input DC voltage, detect overvoltage situation and bring the gate driver enable signal low to make the motor freewheel. This overvoltage situation can happen especially if you have a flywheel-like mechanical load that stores a lot of inertia.)High-side+low-side (as imaged) is often the way to go because integrated bootstrap gatedrivers, as shown, are commonplace and cheap. While single mosfet + diode solution is theoretically simpler (needing simpler low-side only gate driver), there is not that much actual price difference. Also, the increased power dissipation in the diode may increase heat sinking costs.For the diode version, if you want to go that way, just replace the upper mosfet with a diode (doesn't need a gate driver), and the gate driver with a low-side gate driver IC.To make a decent motor driver, especially with bigger motors, you definitely need current sense, though (not shown). For small motors with high winding resistance, just oversizing the FETs (or 1 FET + diode) to handle the stall current (expect 10 times the nameplate current if no other info available) is often enough.For a 4HP motor, I'd definitely do some more homework first. You need to learn about:- current sense- DC link bypassing, and- layout considerations- control schemes, which can be trivial, but nevertheless you need to have an idea how to control the PWM duty based on current and voltage measurements.
Gate driver chips with built in boost/power. - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: November 08, 2024, 04:50:26 am
content: Has anyone seen n-mosfet gate driver chips with built in boost/ isolated-power, which are reasonably priced and not more expensive than the mosfet they are being used to drive. I would class reasonably priced as like 50c.All the high side driver ICs contain them so they cant be that hard to make.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: November 08, 2024, 08:11:20 am
content: Quote from: Psi on November 08, 2024, 04:50:26 amYou need to clarify what you mean byboost/ isolated-power,Standard half Bridge high voltage drivers like x2103 have boost/bootstrap and have high voltage level shifting.Usually you do not need full galvanic isolation Hi to LO side as the bridge is connected.Sometimes designers want 100% duty cycle, in which case you need either charge pump (for modest powers) or simple transformer isolation.Nexperia have just released an example of SOT packaged transformer driverhttps://www.nexperia.com/product/NXF6501DC-Q100If you add that type of power path, you can get 100% from the lowest cost drivers.
Gate driver IC for many, many power MOSFETs - Page 1
Forum section: electronics / projects

author: groksteve
author_rank: Newbie
timestamp: January 06, 2021, 10:08:43 pm
content: I'm working on a circuit that will use a MCU to switch many (>40) power MOSFETs at 60kHz.Does anyone know of a gate driver IC with many channels so that I can minimize the number of parts? I'd really prefer to not have one driver IC per transistor if possible.I've seen that there are several dual driver parts but when I look at the 4 or 8 driver versions they are almost always tailored to a specific purpose like motor driver or PMIC.Thanks for any input!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 07, 2021, 12:32:11 am
content: I suppose you could go to ~1.17 parts/FET with a CMOS inverter/buffer plus complementary emitter follower (get a dual transistor type). Maybe if you have a bus driver with just enough voltage and current for the purpose.Not really going to be any better, any other way, besides the proper dual drivers, or the specials.Anyway, you need a resistor per gate, maybe a diode and another resistor (for asymmetrical drive), and a few bypass caps. Adding one more part to the total isn't a huuuuge deal (but, still, is added assembly cost).*Shrug*, 40 channels is 40 channels, it's not going to be cheap any way you cut it. What application do you have, that doesn't fit any of the standard solutions?Do you really have that many, on a common ground? Just how "common" will it really be, with that much switching going on? I guess these aren't small currents, since they need drivers. Will you need level shifters/translators/isolators to get the gate signals up to the drivers, too?Tim

author: groksteve
author_rank: Newbie
timestamp: January 07, 2021, 01:41:28 am
content: Thanks for the reply!That's what I was thinking, expensive.The application is independently controlling >40 ignition systems based on flyback transformers.I don't have control over the transformer end of things. The requirements are that I deliver a 4V/2A signal with 60kHz 95% duty cycle to each of the igniters.Could you suggest another approach that might work better with the same level of control?Cheers

author: SilverSolder
author_rank: Super Contributor
timestamp: January 07, 2021, 02:43:10 am
content: How long does the signal have to be active for?

author: groksteve
author_rank: Newbie
timestamp: January 07, 2021, 04:03:22 am
content: 400ms minimum, ideally 550ms

author: viperidae
author_rank: Frequent Contributor
timestamp: January 07, 2021, 05:45:45 am
content: If you only need 4V at 2A, I'm sure there are a bunch of logic level MOSFETs you can choose from that won't require a driver.
Gate driver with buck converter in discontinuous mode - Page 1
Forum section: electronics / projects

author: Nimsch
author_rank: Newbie
timestamp: May 07, 2017, 01:37:34 am
content: Hi everyone!I am designing a buck converter that would charge a battery and planning to use an N type MOSFET on high side and FAN7085_GF085 driver to go with it.Datasheet:https://www.fairchildsemi.com/datasheets/FA/FAN7085_GF085.pdfApplication notes:https://www.fairchildsemi.com/application-notes/AN/AN-9052.pdfhttps://www.fairchildsemi.com/application-notes/AN/AN-4171.pdfIf the converter happens to go to discontinuous mode however, the diode stops conducting (current through it drops to 0) -> voltage at MOSFET source becomes something >0, and the internal recharge path of FAN7085 activates (or at least that's how I understand it according to the application note 9052, page 2).My question is what causes the internal switch to activate? A detection of voltage > 0 at VS or something else? (as AN-9052 only states this: "In the event that both of the switch (S1 and S2) are turned off, the internal recharge switch of the FAN7085 will provide the path to charge the bootstrap capacitor.")Doesn't this connect the battery through an inductor to VS pin of the driver circuit (which is connected to the ground at that moment)? What if I put a diode in series with an inductor (like I did in this capture of the schematic)?Thank you in advance.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 07, 2017, 05:58:06 am
content: Did you check the speed on that TLP185, by the way?I suppose 100uH might be big enough to handle that, but geez, to get any useful PWM range out of that, you're going to be down in the audible range, or very nearly. I suppose that gives you plenty of time to control this in software, but, geez...On the upside, you don't need the gate driver IC, or any worries about parasitic reactances in the layout. You've got whole microseconds to burn, while things turn on and off. And the Hall effect sensor will be pretty much real-time, not guesswork.Tim
GB042-50S  0.4mm pitch doublerow SMT  LCD connector - where to buy? - Page 1
Forum section: electronics / projects

author: Yansi
author_rank: Super Contributor
timestamp: March 08, 2016, 07:10:12 pm
content: Hi!Currently working on a project demanding a high-brightness LCD. But the only available LCD for us has not so much available connector.The full type of the connector is GB042-50S-H10-E3000 and the manufacturer is LS-Mtron.Does somebody know where to buy 3 or 4 of these for a reasonable price? Or do you know an equivalent 50pin type that would fit (if the equivalent exists at all)?Here's the LCD datasheet:http://www.avnet-embedded.eu/fileadmin/user_upload/Files/Displays_NEW/Colour_TFT/LG_Display/LG_Display_LB043WV2-SD01.pdfand here's the connector catalogue, search for GB042 series (page 12):http://www.lsmtron.com/pdf/LS%20Mtron%20Connector.PDFThank you!Yan

author: Yansi
author_rank: Super Contributor
timestamp: March 14, 2016, 12:35:41 pm
content: Huh, thanks for help.In case that someone would need them too, I have found them on taobao, for example here:http://world.taobao.com/item/527189970198.htm?spm=a312a.7700714.0.0.pSsopE#detailYou only need a chinese agent to buy that for you - luckily I have a friend who can order them for me.Yan
Gbe signal switch suggestions - Page 1
Forum section: electronics / projects

author: rfdes
author_rank: Regular Contributor
timestamp: June 23, 2021, 01:01:25 am
content: Hi -I need some suggestions as to how to electrically disconnect differential Ethernet signals (Gbe) from a physical connector. Basically a high speed analog switch that can handle the bandwidth and provide adequate off isolation. This seems like a simple in principle design task but I'm struggling to come up with an acceptable topology. I suppose one could use an RF relay but I would rather use a semiconductor solution. I cannot seem to find any analog switches that would provide an acceptable solution.Any ideas would be appreciated.Jim

author: TheMG
author_rank: Frequent Contributor
timestamp: June 23, 2021, 01:20:48 am
content: It would help if we had more details as to exactly what you're trying to accomplish.Most ethernet switch ICs and ethernet PHY ICs do have the capability to enable/disable each Ethernet interface. So why not use a switch IC?

author: rfdes
author_rank: Regular Contributor
timestamp: June 23, 2021, 03:22:32 pm
content: Thanks for the responses. Yes, I should have been more clear in my original post. After my post, I found several parts that are designed to do what I want. That is to simply multiplex the signals. The Pericom PI3L110 part appears to be just what I need. Maxim also sells several LAN mux parts MAX4890-MAX4892. I believe this will solve my problem.Jim
GD32F470 ENET - Transmit OK - NO Receive - Page 1
Forum section: electronics / projects

author: jhinkle
author_rank: Newbie
timestamp: March 21, 2023, 11:52:36 am
content: I have been using STM32F427 for years (with ENET).I switched to a GD32F470ZI on a new board -- using the same firmware as on the STM (changed the clock per their doc and kept the freq at 180mhz for the initial prototype test).I have seen a compatibility doc on the GD32F1 series where there are pin assignment issues when using specific I2C or Uart peripherals -- none of those exist.For the test .. I am ONLY using the ENET -- NO I2C, NO SPI, NO UART ... no other peripherals.I'm using wireshark connected to a HUB.The GD470 will transmit as seen by the DHCP Discovery request going out -- I see the "Offer" reply ... BUT - the GD470 NEVER sees the Ethernet packet.I am using MII mode - I have scoped the RXCLK, RXDV, and RXData0-4 and all are good on the board.As a test -- I kept the related MII-RX pins stated above as inputs and monitored them for signal activity from the PHY -- too make sure the signals could actually get into the CPU.The ENET runs without flaw on the STM but NO Receive on the GD470.I have 3 prototype boards all behaving the same way.I have captured the MAC and DMA registers of the ENET and compared them when running on a STM32F427 and on the GD32F470 -- they are exactly the same.After 5 days of debugging I'm out of ideas on debugging .. Any suggestions or comments.Thanks.
GDS810 Scope locked/disabled vertical offset - Page 1
Forum section: electronics / projects

author: nauj
author_rank: Newbie
timestamp: November 08, 2011, 10:33:47 am
content: Good day Guy'sMy GDS801 Gm_Instek Oscilloscope (same as IDS810 from ISO-Tech) is refusing to vary/change the vertical position (DC-Offset) on Ch1&Ch2. It is as if the position-controls are locked or disabled.Auto-Set changes the values to a more applicable level, but again I can't change it, even after that. Power-down doesn't solve the problem. Apart from that, the scope is working fine.Any ideas .. please help !Pieter

author: tinhead
author_rank: Super Contributor
timestamp: November 08, 2011, 11:03:13 am
content: - both front panel rotary encoder are mechanical broken (unlikely, but possible)- the rotary encoder "logic" on front panel PCB is broken (there will be combination of diodes, resistors, mux)- the common voltage source for DC offset is bad (unlikely, but possible)- the S&H opamp for DC offset is brokenI would say take it apart, check first what happes on rotary encoders (changes when turning the knob), thencheck if the changes are also on front panel mux and mainbord (to ensure some cables are not broken).If this works you will have to locate the S&H on the mainboard and of course opamp which supply the DC offsetvoltage to front stage.If you don't know how/where to locate S&H make some pictures of the board, maybe someone here will have an idea.

author: nauj
author_rank: Newbie
timestamp: November 08, 2011, 11:24:57 am
content: Tinhead, thx for the reply.I have a feeling it's the software over-riding my commands. If I turn the position knobs, the offset voltage does change (up/down) by a few mV, but then jumps back to were it came from. The scope is only about 3 years old, and not abused.It feels like something (software?) is locking my effort. But nowhere is this type of function mentioned in the user manual.You're comments ?Pieter

author: tinhead
author_rank: Super Contributor
timestamp: November 08, 2011, 12:47:15 pm
content: i don't know that scope, but i don't think that there is a lock function for dc offset only (if there is a lock then for all settings).

author: Bored@Work
author_rank: Super Contributor
timestamp: November 08, 2011, 05:36:01 pm
content: You can try your luck with GW Instek services@goodwill.com.tw They let us down horrible, but maybe they are good to you.
GE Choice Alert 45132 motion sensor schematic needed - Page 1
Forum section: electronics / projects

author: CaptDon
author_rank: Super Contributor
timestamp: November 03, 2022, 02:57:07 pm
content: Greetings all. I have several of the 45132 battery powered motion sensors. The problem I have is that only 2 of the 5 are suited to operation in the cold weather. The remaining 3 will flag 'low battery' but the batteries are new and test above 9vdc even when cold. I am hoping maybe the battery voltage sense circuit can be modified. The I.R. sensor appears to be connected to an AS516S I.C. There is also an ATMLH328 with additional markings of 46D 1 and 3U4386G which I believe is the r.f. section. Any help to solve this issue would be appreciated. Thanks!!
GE Concord 4 Code readout - Page 1
Forum section: electronics / projects

author: Tarheel Dave
author_rank: Newbie
timestamp: June 07, 2021, 06:17:37 pm
content: I am trying to retrieve my alarm codes using a process the following process:http://www.malos-ojos.com/?p=823I have followed the instructions multiple times but still get all 0000 outputs. I believe this may be due to my chip being an ATMEL018 25128A which is different than the one noted by the process writer who says the EEPROM should be a Microchip 24LC256. When downloading the software there is no reference for the chip I have. Here is a screen shot of the download if that helps?Any assistance on how I can properly pull these codes using this procedure would be greatly appreciated!Thanks
GE's Firstbuild - Page 1
Forum section: electronics / projects

author: miguelvp
author_rank: Super Contributor
timestamp: April 21, 2014, 06:08:54 pm
content: QuoteThey'll provide community (collaboration with other members, GE designers & GE engineers), rapid manufacturing & product realization.http://firstbuild.com/more info here:http://www.techrepublic.com/article/ges-firstbuild-can-a-big-company-harness-startup-mojo-on-the-backs-of-upstart-entrepreneurs/Less compensation but less risks and more chances to get a product actually done?Edit: more infohttp://www.cnet.com/news/ge-and-local-motors/Thoughts?
Gear VR + Arduino Robot with camera - Page 1
Forum section: electronics / projects

author: polarKaung
author_rank: Contributor
timestamp: August 16, 2022, 09:42:19 am
content: Hello,I am new to developing VR apps to work with microcontrollers, but here is basically what I want to do.I will have a basic arduino (don't have to be, it can be any controller) mobile robot with a camera attached to it. I want to view that camera feed in Gear VR as a big screen. When I turn my head, the screen will follow as well. At the same time the robot will turn. I can control the robot from inside the VR with the controller. In VR I will be able to see other parameters of the robot as well, like battery percents, etc. I planned to develop such an app with Unity but don't know where to start.If you have any idea, feel free to assist.Thank you very much.
gEDA - Page 1
Forum section: electronics / projects

author: benjamin545
author_rank: Contributor
timestamp: April 27, 2014, 01:10:06 am
content: Anyone use gEDA? I use linux as my OS of choice and was looking for a good simulation software to use. I have basically no experience with software design and id consider myself a beginner when it comes to electronics so i was looking for a way to try to simulate circuits on a computer. so far what ive gathered from gEDA is that its more like an organization of small programs that can all work together to do various different things for electronics design/ simulation/ pcb design.the first program i started working with was gscheme, which i find pretty decent to use and easy enough to place components on the screen and link them all together, but then there is this secondary stage where i guess you give the components attributes in a specific way that allows you to run them through a spice simulator, ngspice, and that is where i seem to get hung up. i don't really know whats the easiest way to graphically simulate a schematic or if thats even possible. it all seems a little over my head honestly, or maybe im just not finding a good starting spot to build up from and learn how to use it right.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 27, 2014, 05:58:49 am
content: In the whole gEDA collection gscheme is indeed the most decent part. From there on it goes downhill.E.g. the combination of gscheme with ngspice (or any other spice) was an afterthought. What you get by combining them is all the limitations of the gEDA concept and all the limitations of a classic SPICE. The components (devices) you use in gscheme need to be prepared and have support for SPICE. Only few components coming with gscheme out of the box as part of gscheme's device library come prepared. And you need to set SPICE-specific attributes for the components to help generate input for ngspice out of gscheme schematics. To do this you need to know SPICE.http://wiki.geda-project.org/geda:ngspice_and_gschemgives an example.If you want a reasonable version of SPICE, although also with a GUI that could stand some polishing, try LTSpice under Wine in Linux.

author: benjamin545
author_rank: Contributor
timestamp: April 27, 2014, 04:10:52 pm
content: wow, ok. seems like trying to make gEDA do what i want it to do is a little out of the question at this moment then. i think for now ill try to just stick with a breadboard and maybe sometime give ltspice a try. i like gscheme for the schematic design though, seems like they just need some work preparing a bunch of the library components to be pre configured for spice? and also i guess somehow integrate better with the output from spice to show what is happening.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 27, 2014, 04:17:38 pm
content: gEDA is one of those open source projects where they prefer to start adding new stuff instead of finishing what they have started.
Geiger Counter - Page 1
Forum section: electronics / projects

author: Rbastler
author_rank: Frequent Contributor
timestamp: January 24, 2017, 04:04:03 pm
content: My first project since I'm at university: the first step to a multi module geiger counter, with handpice and arm mounted display.Here I tested the Geiger with 12V and a SBM19. The anode resistor is 4.7M and the load resistor to decupple the pulses is 100k. I later changed the switching frequency of the MC34063A to make it work at 9V to around 6V.I had the PCB made by PCBway. They were as fast as usual and the quality is also very good. One pinheader is for a led and a speaker or a buzzer. The other one is for a display. I have a voltage divider to measure HV and the battery voltage. The header carrys power , aswell the TTL output from the 40106.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 26, 2017, 12:56:32 am
content: Looks nice.

author: Rbastler
author_rank: Frequent Contributor
timestamp: January 27, 2017, 08:59:22 pm
content: I tested a SI-22G, SBM20 and a RFT VA-Z-114in the videos below: