hybridfree/eevblog-posts huggingface dataset:
Code for Short Range Radar Arduino Project - Page 1
Forum section: electronics / projects

author: nmoore
author_rank: Newbie
timestamp: February 08, 2024, 02:40:48 pm
content: I am starting to work on a short range radar project using the RCWL-0516 module. I can connect it to an Arduino and see the led light up when it detects motion (my hand for example). What I want to do is add a OLED I2C IIC Display Module that shows how far an object is.I am not finding anything that I can go off of and I am still learning how to do basic coding with Arduino. I know that math needed to find distance but not sure how to program it and for this module. Any help pointing me in the right direction would be greatly appreciated.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 08, 2024, 03:19:28 pm
content: simple search would have ..https://lastminuteengineers.com/rcwl0516-microwave-radar-motion-sensor-arduino-tutorial/https://randomnerdtutorials.com/arduino-rcwl-0516/

author: mikerj
author_rank: Super Contributor
timestamp: February 09, 2024, 10:39:25 am
content: Quote from: nmoore on February 08, 2024, 02:40:48 pmThis isn't really possible, the RCWL-9196 is adopplerRADAR device that measures the speed of an object by comparing the outgoing frequency with the received frequency. It does this by mixing the two signals and measuring the difference frequency. This doesn't give any indication of distance, only speed. There is a pin on the IC that has a voltage proportional to the difference frequency, you could connect this to an ADC input on your Arduino and display the value on the OLED but it doesn't seem very useful.This website has plenty of detail:https://www.rogerclark.net/investigating-a-rcwl-9196-rcwl-0516-radar-motion-detector-modules/

author: nmoore
author_rank: Newbie
timestamp: February 12, 2024, 04:23:06 pm
content: Quote from: mikerj on February 09, 2024, 10:39:25 amThank you. That explains it. Do you know of any other small radar modules that will give me the output that doesn't use doppler?

author: mikerj
author_rank: Super Contributor
timestamp: February 13, 2024, 06:00:23 pm
content: TheAcconeer modulesare the only small and inexpensive ones I know of.OmniPreSensealso make a couple of distancing sensing products, though quite a bit more expensive.
Code in loop simulator - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: April 10, 2017, 01:39:34 am
content: Is there any circuit simulator that allow a piece of user code to be introduced to it?I'm talking about a piece of MCU controller code in a circuit.I know Proteus can do it, but it has only limited selection of MCU models, which doesn't have the one I need.Besides, I want a generic simulator, not depending on a particular MCU family.I know Plecs has a processor in loop option, but that's $7000, plus $7000 base license, way above my budget. Psim has similar offerings in their pro version, but I believe it won't be cheap either.Is there anything (generic, not like Proteus) that does code-in-loop while being cheaper than $1000?I don't need precision modeling (SPICE thing), behavior modeling is enough (like HDL).This is to be used to simulate SMPS, only LCR and ideal switches are needed (MOSFETs and diodes can be derived from LCR and ideal switch models). Linear amplifier operation is not needed.

author: Phoenix
author_rank: Frequent Contributor
timestamp: April 10, 2017, 11:21:01 am
content: I've used PSIM (https://powersimtech.com/) for my power electronics digital control simulations. It can run C scripts using the built in interpreter or precompiled DLLs. On my last solar inverter project the main PWM/control interrupt routines from each DSP (and CLA for that matter) were directly run in PSIM from the real converter source code!The other big strength of PSIM is that it's tailored to switched converter simulations. It uses ideal models for transistors and has a stiff differential equation solver.I'd be surprised if you havn't come across it.

author: joeqsmith
author_rank: Super Contributor
timestamp: April 10, 2017, 05:00:28 pm
content: PIL, would be fun to have a look at it. Taxing my memory but we ran Daisy Systems. They had a hardware co-simulation that allowed you to run your digital with the simulation. This was a separate box, with a ZIF socket to install your micro. I know we could run SPICE but I don't recall if there was any sort of mixed mode. Wiki has a little info...https://en.wikipedia.org/wiki/Daisy_SystemsAnyway, I'm interested in seeing what you come up with.

author: nctnico
author_rank: Super Contributor
timestamp: April 10, 2017, 08:50:38 pm
content: Maybe look at ngspice (open source):http://ngspice.sourceforge.net/extras.htmlhttp://ngspice.sourceforge.net/xspicehowto.html

author: Phoenix
author_rank: Frequent Contributor
timestamp: April 11, 2017, 02:18:09 am
content: Just watch out with the interpreter in PSIM, at least the version I used was a bit buggy in it's code "compilation" (pre run testing). And it's quite slow compared to a precompiled DLL. I would recommend using a DLL.
Codec (PCM3168) input impedance issue! - Page 1
Forum section: electronics / projects

author: MT
author_rank: Super Contributor
timestamp: January 06, 2020, 05:32:44 pm
content: Im fiddling with PCM3168 codec and pondering about input impedance as i try to reduce the over all component count, lots of input and output differential buffers. I wonder about the bolded text, page 54 and 55.http://www.ti.com/product/PCM3168AHow does the input structure look in this sort of ADC's? id like to replace the low gain Fig 60 input buffer stagewith a higher gain current summing stage in which i can fiddle with the settings but at least R7-C3 -3db at 31khz, who both feeds the ADC and a separate low impedance,does R7 C3 muck up the input impedance requirements and the differential balance with low C3 values of the ADC or? Can the Vin- be either to VcomAD reference or C3 to GND as im trying to avoid ofseting suming amp IC1? Maybe either or are OK?Quote

author: MasterT
author_rank: Frequent Contributor
timestamp: January 06, 2020, 11:25:47 pm
content: The problem with ADC is SD switching capacitor architecture. Data sheet for CS5510 has some pictures. Input impedance is affected by sampling rate, and may vary from 45k . What is more important, it's not linear, they put limits : 47-Ω and 0.1-μF to 470-Ω and 0.001-μF, and 470 OHm series resistor is the maximum. No way 5.6k, if respect THD level.

author: MT
author_rank: Super Contributor
timestamp: January 07, 2020, 12:19:15 am
content: Quote from: MasterT on January 06, 2020, 11:25:47 pmThanks for info, yes i suspected it was something like that im still puzzled by the, to low, to short note suggesting impedance to low but not upwards noting dynamic performance rather then THD. CS5510 datasheet refers to, Application Note 30, Switched-capacitor A/D Input Structures, unfortunately i cant find that one and Cirrus own links is dead ends.
Coherent Compass 215M Laser Controller? - Page 1
Forum section: electronics / projects

author: dexters_lab
author_rank: Unknown
timestamp: April 07, 2017, 04:23:40 pm
content: I have a non working coherent Compass 215M laser head and controllerthis model seems to be quite popular, so i wondered if there anyone in the UK with a spare controller they could loan me for a short period?I'd like to see if it's the controller or laser head that's kaput. If the laser itself is ok i might try and source another controller but i don't want to do that if the laser head is dead too!

author: james_s
author_rank: Super Contributor
timestamp: April 07, 2017, 05:05:45 pm
content: You might try contacting Sam Goldwasserhttp://www.repairfaq.org/sam/lasersam.htmHe's not in the UK, but he's an expert in all things laser related and I recall he's familiar with these particular units. He can probably give you some troubleshooting tips and may be willing to test your controller if you want to send it to him. Pretty reasonable guy, I've known him for a long time.

author: dexters_lab
author_rank: Unknown
timestamp: April 07, 2017, 05:23:02 pm
content: i know sams laser faq, it's an awesome resourcei'd worry the cost of shipping there and back might be more than it's worth, it's only the 15mw model

author: james_s
author_rank: Super Contributor
timestamp: April 07, 2017, 06:36:24 pm
content: Well you might ask him for advice on testing it, I've never dealt with those particular lasers but similar units I've worked on have relatively simple analog signals to and from the laser head.
Coil gun - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: November 25, 2010, 03:09:27 am
content: i am going through the proses of rebuilding my coil gun an would like to make i portable would i be possible to use a pwm signal instead of AC.

author: Simon
author_rank: Unknown
timestamp: November 25, 2010, 06:44:42 am
content: you will need you PWM signal to be fed via a Hbridge as it has to be dual polarity for the voltage multiplier to work

author: House91320
author_rank: Regular Contributor
timestamp: November 25, 2010, 04:30:25 pm
content: Ya that is what i was thinking of doing i just wanted to check that.

author: Simon
author_rank: Unknown
timestamp: November 25, 2010, 06:54:19 pm
content: but it needs to be 50% anyhow

author: Zero999
author_rank: Super Contributor
timestamp: November 25, 2010, 09:49:08 pm
content: You don't need an h-bridge, a half bridge will do.What voltage do you need? Using a flyback transformer is normally the best way to go.

author: Time
author_rank: Frequent Contributor
timestamp: November 26, 2010, 01:17:42 am
content: I'd be interested in see the total design. I have a coil gun project as well. I'd be interested in seeing your coil geometry and your efficiency.

author: House91320
author_rank: Regular Contributor
timestamp: November 26, 2010, 09:04:35 am
content: I need aprox 400 to get the full 1.7kj of power
Coil - help undestanding if it is still in working condition - Page 1
Forum section: electronics / projects

author: Nexxen
author_rank: Regular Contributor
timestamp: June 14, 2023, 12:43:16 pm
content: Hello!!I have a motherboard and it has issues.After checking many components I saw this coil (see pic). The coat is coming off at the base. Voltage is still the same at both ends but maybe could it be creating enough ripple (or anything else) to disturb the other components on the board?Thanks a lot!!

author: Fraser
author_rank: Super Contributor
timestamp: June 14, 2023, 12:47:14 pm
content: That is not the healthiest looking high current inductor and it may be suffering from exposure to damp/humid conditions, but if the winding is intact, I do not see it causing your problem.Fraser

author: Nexxen
author_rank: Regular Contributor
timestamp: June 14, 2023, 12:54:22 pm
content: Well, this was a fast!It was in a corroded case, and this motherbaord had multiple corrosion spots on the surface (I went crazy with my phone looking for some broken trace(s)).Exposed to humidity is quite correctI'll check to see if I have a similar one close enough for a quick replacement + test.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 14, 2023, 01:08:01 pm
content: The component is pressed iron powder and solid copper wire -- unless it's corroded in such a way that it's shorting out, or maybe a solder joint has come loose, there's very little short of abject destruction (smashy-smashy) that affects them.The myriad fine (<0.2mm) traces elsewhere on the board, however, are much more likely problems. Not to mention the ones hidden under wide components impossible to inspect.Unless it's a priceless relic, most likely it's not even worth -- well, repairing to be sure, but even powering up at all? I mean...Tim

author: Nexxen
author_rank: Regular Contributor
timestamp: June 14, 2023, 02:40:56 pm
content: No, it's absolutely worthless, even if on ebay they sell these m/b for ~150-200€/$.It's a rather simple design that can be cracked. Unfortunately spares are difficult to locate for this 20+ yo board.The point is "me" learning while trying to repair it. It has no other pourpose. The more I do the more I learn.Yes, the board has many 0.2mm lanes with corrosion, and I'm planning to desolder things and check around.I have manymoments asandwhen I figure out simple things that people like you take for granted (knowledge-wise).This is the noob curseI have acouple more things to ask, you'll probably read me again in a few hours.

author: LM21
author_rank: Regular Contributor
timestamp: June 14, 2023, 03:27:50 pm
content: May or may not apply here, but have seen badly washed PCBs where solder connections looked well, but were really open.

author: Nexxen
author_rank: Regular Contributor
timestamp: June 14, 2023, 06:25:30 pm
content: Giving a round of joints' resoldering ain't gonna make me broke.I suspect something is issuing a reset signal that makes the clock generator get hot.I have a BIOS in 40 2KB files I can't use, don't know how to assemble. I could at least try a fresh reprgram.
Coil Inductance and Q Calculator - Page 1
Forum section: electronics / projects

author: k6sti
author_rank: Contributor
timestamp: January 15, 2024, 11:00:46 am
content: The program now accounts for radiation loss when calculating coil Q. You can include radiation as a small loop, as a short Hertzian dipole, both, or neither. Some coil radiation may be beneficial and you can exclude it from the loss calculation. An example is an antenna loading coil where incidental dipole coil radiation augments that from the antenna.When I rechecked my program calibration set (coils carefully measured with an HP 4342A Q meter), the average error magnitude for Q dropped when I included both radiation types. This convinced me that coil radiation loss is significant. I was surprised because I had not checked any coil above 25.2 MHz. Coil radiation is much greater at VHF where dimensions in wavelengths are larger than at HF. But evidently HF dimensions are large enough to cause measurable coil radiation.The optimizer handles radiation automatically. For example, dipole radiation is proportional to the square of coil length and is sensitive to that dimension. With dipole radiation enabled, the optimizer will find shorter coils when maximizing Q because the longer ones have a radiation loss penalty.http://ham-radio.com/k6sti/coil.htmBrian
Coil specifications vs induction heating performance - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: September 02, 2018, 09:26:45 am
content: I have an induction heater that works from 12-48V with 1000W of power that came with its own coil.My question is how does the number of turns, diameter of the piping and the diameter of the coil affect the heating performance?Will a smaller coil diameter heat up objects that have a smaller circumference for example?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 02, 2018, 12:42:04 pm
content: You're making an air core transformer. The work (secondary) is a single turn, the primary is many turns. The turns ratio gives an impedance ratio. The inverter is only rated to supply so-and-so voltage and current, so a similar value should be used for the resonant tank.Resonant impedance is given by: Zo = sqrt(L/C)The load resistance, for a parallel resonant tank, is Q times Zo. This is the resistance the transistors are driving. The load should be on the order of (Vsupply / Imax) ohms.Coupling depends on the ratio of diameters of the work coil to work piece. Work just barely fitting inside the coil gives very tight coupling, and a lower Q. Medium coupling might be, say, work diameter being 50 to 75% of coil i.d. Loose coupling say 25 to 50%. Below 25% you should probably consider making a new coil.The Q factor of the loaded work coil depends on coupling and work resistivity. A low-Q material, like steel (especially cold, magnetic steel) can have a Q from 2 to 10 at tight to medium coupling. A very conductive material, like copper or aluminum, can have a Q of 10 to 30 for the same coupling.An unloaded coil might have a Q from 50 to 200, depending on geometry and frequency. If the work reduces Q by half, efficiency will be about 50%. It's always best to start with a high-Q coil, and aim for a low loaded Q.Tubing diameter makes little difference to the magnetic field. More copper in the coil (to a point) does give higher heating efficiency (higher unloaded Q).Yes, smaller coils couple more effectively to small items. Downside, small coils have less inductance. I don't know if your oscillator will start up into such a load. It won't start up into very low Q loads, either.Tim
Coil, Transformer Winding Machine Control Board - Page 1
Forum section: electronics / projects

author: gevv
author_rank: Contributor
timestamp: September 22, 2022, 04:26:23 pm
content: Hello,Coil Transformer Winding Machine Control Board can count from 0 to 99.999 turns. Common cathode or common anode display can be used. I made the PCB design with a single layer. The software has source code. For CCS C, MPLAB IDE V6.61 and GREAT COW BASIC 4 compiler.https://youtu.be/NjYE-BiQS5800:07 General description of the circuit03:17 Circuit settings and operation05:52 Testing the circuit with the motor07:26 Notes..08:51 Circuit diagram, PCB drawing, sensor module diagram, circuit picturessource:http://picsource.com.br/archives/12456
How Do I Determine Coil Specifications for a Coilgun? - Page 1
Forum section: electronics / projects

author: ZaiGuy
author_rank: Newbie
timestamp: January 23, 2023, 07:50:04 pm
content: Hello all.I am in the process of designing a coil gun, currently using a three stage design. The first stage will have four 1000uF @ 400V capacitors in parallel, a thyristor controlled by a mechanical switch and the coil with a flyback diode in parallel and reversed from the coil.The second and third stages will have the same configuration, but be triggered optically (by triggers in the barrel) and only have three caps each.My question is this: how do I determine the wire gauge, length, thickness and any / all other specks for the coils for optimal performance?The attached PDF is the current schematic.

author: S57UUU
author_rank: Regular Contributor
timestamp: January 24, 2023, 03:28:15 pm
content: With this circuit (all caps parallel) the first thyristor will discharge all of them thru the first coil. Use diodes in the charging circuits.
coilgun - Page 1
Forum section: electronics / projects

author: micxhailo
author_rank: Newbie
timestamp: July 01, 2023, 09:16:13 pm
content: I have made simple stage coilgun that is activated when I connect capacitor to coil, how can I upgrade it, I have lot of turbidity sensors that I can use as sensor in second stage but I don't know how to use them, I have lot of igbts that can withstand about 1350v, 30a and 90a pulse I can use them as switch, I'm currently using rectified 230v ac (rectified about 310v dc) and I have 3 capacitors of 470uf and 400v.
Coin Cell Battery Holder - Page 1
Forum section: electronics / projects

author: sshoptaugh1991
author_rank: Contributor
timestamp: December 23, 2016, 07:02:49 am
content: I am making my first PCB in EAGLE, and everything is pretty straightforward as learning goes. I was curious as to a coin cell battery holder that would hold two batteries to deliver 6 volts to the circuit. Looking at the datasheets of the parts in the libraries doesn't tell me how many batteries each holder can take. I looked at a BK-889 holder, it looks promising, but I am not 100% certain it will do what I need. Any suggestions?

author: Jeroen3
author_rank: Super Contributor
timestamp: December 23, 2016, 07:12:55 am
content: Most of them can take 1 battery. However, there is catch, you've chosen 23mm diameter. And not the industry standard 20mm. (eg: 20 x 3.2mm from the famous CR2032.https://en.wikipedia.org/wiki/List_of_battery_sizes#Button_cells_-_coin.2C_watchIf you take a coin holder for CR2032, it will fit two CR2012 or maybe two CR2016. Because those are thinner.

author: Ian.M
author_rank: Super Contributor
timestamp: December 23, 2016, 07:17:16 am
content: As the third and fourth digits of the CR series battery part numbers are the thickness in tenths of a mm, a CR2032 holder will almost certainly take two CR2016 cells, however its essential that it doesn't use a side contact for the positive terminal otherwise it will short the top cell.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 23, 2016, 08:23:26 am
content: The side contact thing indeed. At least someone is paying attention.
Coin cell contacts for extension of PCB installation - Page 1
Forum section: electronics / projects

author: jmaja
author_rank: Frequent Contributor
timestamp: March 30, 2019, 08:11:03 am
content: I have tried to find something suitable to install a CR2430 battery at the end of a PCB while keeping the thickness at absolute minimum (the attachment shows where the battery should be). The battery would be replaced by opening the thin end of the enclosure. CR2430 is 30 mm thick and I can fit the PCB into a 3.1x24.5 mm slot. Is it possible to fit the battery + contacts into that slot? Where can I find such contacts? All I can find are ones for on top of a PCB installation or with a way too thick battery holder.I don't mind making the slot a bit wider, if that would help. Maybe I could put the + contact to the side or to the end of the PCB touching the side of the battery?The prototype has a battery with solder tabs making it difficult to replace and 3.5 mm thick:https://www.tme.eu/pt/Document/7bb85767ed87a4ab1521fe4f9700c84d/cr2430v.pdf

author: jmaja
author_rank: Frequent Contributor
timestamp: April 02, 2019, 10:40:46 am
content: This one should work for the positive side:https://www.digikey.fi/product-detail/en/keystone-electronics/120TR/36-120CT-ND/5872901But I haven't really figured out how to do the negative side. Is there a standard for the CR2430 dimensions? Different manufacturers seem to give different diameters for the negative side. Energizer defines the minimum as only 8 mm, but the picture shows much larger diameter:http://data.energizer.com/pdfs/cr2430.pdfAre there really batteries with say less than 15 mm negative bottom diameter?Would this work?https://www.digikey.fi/product-detail/en/keystone-electronics/112TR/36-112TR-ND/4499393It doesn't reach long enough when soldered from the middle, but maybe soldering from the other end. Then it could reach to 6-8 mm from the side of the coin cell thus to 9-13 mm diameter. There is a 0.25 mm dimple on top of 0.15 mm thick material. Will it cause a short cut when the battery slides over it. Will it have a good contact? Is it better to to install the dimple away or towards the battery? Maybe I could put a slot in the enclosure for keeping it further from the positive edge, but that may result to bad contact.
Coin Cell - Vibrator Motor - Question - Page 1
Forum section: electronics / projects

author: docmur
author_rank: Regular Contributor
timestamp: January 06, 2017, 12:04:36 am
content: Hey GuysI have a bunch of coin cell motors which I'm currently driving via the digital out from an Arduino and they're working fine. Would it be better / a benefit to drive them with a motor drive chip like the MAX1749? I know for things like Stepper Motors and Brush Motors this matters, but I'm unsure if the coin cell motor requires a driver or any real reason.Thanksdocmur

author: ataradov
author_rank: Super Contributor
timestamp: January 06, 2017, 12:35:26 am
content: You are most likely exceeding absolute maximum rating for pin current. you probably don't need a motor driver, but you at least want to have a simple transistor switch.

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: January 06, 2017, 12:54:45 am
content: You can see in ATMEGA328 datasheet that the absolute maximum rating of DC current from any IO pin is 40mA, and collective current from VCC and GND is 200mA. Until you exceed this level you are safe.l

author: docmur
author_rank: Regular Contributor
timestamp: January 06, 2017, 01:30:37 am
content: I've read the datasheet, my question was asking if there is a good list of reasons to use a motor driver over just using the IO, again just for coin cell vibrator motors.

author: ataradov
author_rank: Super Contributor
timestamp: January 06, 2017, 01:55:47 am
content: Quote from: docmur on January 06, 2017, 01:30:37 amOne good reason - if using a pin exceeds maximum ratings.

author: Ian.M
author_rank: Super Contributor
timestamp: January 06, 2017, 08:30:56 am
content: Brushed DC motors typically have a much higher startup current than their running current. In fact the peak startup current is the same as the locked rotor (stall) current and is only limited by the winding resistance. Check the DC resistance of the motor, and divide the supply voltage by the resistance to calculate the peak current.Its *EXTREMELY* unlikely that its within the permitted max. output pin current for your MCU, and you probably need at least a 200mA rated transistor or low threshold MOSFET. to drive the motor safely + an anti-parallel diode across the motor to protect the transistor against the turn-off back EMF.Failure to observe the MCU's I/O pin voltage and current limits typically results in premature failure.N.B. Its a characteristic of this type of motor that the DC resistance may vary as it turns as the number of coils in series isn't constant. If you don't have the motor datasheet, measure the resistance and note it down, then briefly power the motor. Repeat until you either have ten measurements or have two similar measurements clearly lower than the rest. Ignore the higher measurements as you need the worst case low resistance startup current.
Coin counter with change - Page 1
Forum section: electronics / projects

author: Remark
author_rank: Contributor
timestamp: February 06, 2022, 03:35:50 pm
content: Hello all!For some time I have been looking for an electronic coin counter. What I have found, are coin counter modules that can work with Arduino or other microcontollers. But each of them is missing option to return coins. Maybe someone have used coin readers and could provide some info about distributors of this devices or just share your thoughts where I probably can purchase one with a coin change? I don't need reader, that can simply count coins. Making a coin change is important to me. Or perhaps the return of coins can be done with a separate module that can be linked to a counter? Also, I'm sharing a few pictures of what I was able to find. Thanks for the answers!https://cdn.sparkfun.com//assets/parts/7/6/9/6/11636-01.jpghttps://cdn.shopify.com/s/files/1/2525/8632/products/91X3JrqJ4ZL._SL1500_1024x1024_2x_82d6fdb7-eb8f-40b3-9b59-20bb972a21d8_1024x1024@2x.jpg?v=1527381778https://content.instructables.com/ORIG/FGE/PF7B/H7434ZT3/FGEPF7BH7434ZT3.jpg?auto=webp&frame=1&width=320&md=4cca3be03d14372c562bfa819f61a87a

author: Renate
author_rank: Super Contributor
timestamp: February 07, 2022, 07:11:42 pm
content: Just to clarify (because I don't have anything intelligent to say):It seems to me there are three scenarios. Which do you mean?Put in one coin. It may or may not return it later.Put in some coins. It may or may not return them (in a jumble dump).Accept coins. Maybe individually eject one or more (different coins).#2 you can just add on your own bin and dumper solenoid. (Like an old US payphone.)If you're looking for #3 you need a unit unrelated to a coin collector that will take a neat stack of coins.

author: Marco
author_rank: Super Contributor
timestamp: February 07, 2022, 07:30:46 pm
content: Can't you use a vending machine coin mechanism?

author: thm_w
author_rank: Super Contributor
timestamp: February 07, 2022, 11:57:46 pm
content: Two ways to do this:- Single unit to handle both coin accepting and sorting- One unit to accept coins, one unit to dispense coins (which will only be one type, say 25c).Search on ebay for "mdb coin changer", and you will find various units. Currenza, coinco, MEI, etc. Some are under $100. But you'll need some basic hardware for the MDB connection, 12 or 24V, as well as ability to program it.Google arduino coin changer to see what people have done already.
Cold junction temperature measurement in Multichannel Thermocuple - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: February 10, 2024, 09:12:07 am
content: In a multi-channel thermocuple signal conditioner (for example, 5 channels on a single PCB), should I add 5 separate junction temperature measurements to the thermocuple input of each channel to measure the cold junction temperature, or is one temperature sensor on the PCB sufficient?or

author: TizianoHV
author_rank: Regular Contributor
timestamp: February 10, 2024, 03:04:45 pm
content: Usually one sensor is enought. But you should add a ground plane and keep away heat sources to reduce temperature gradients .You can search for agilent 34901A, it's a scanner card, it uses two sensors for 20 TC channels (and there's a big gnd plane).

author: mzzj
author_rank: Super Contributor
timestamp: February 10, 2024, 05:27:18 pm
content: Really depends on your accuracy target. CJC compensation is the weak point in many otherwise excellent dataloggers if you want anything better than 1-2 Cel accuracy.

author: voltsandjolts
author_rank: Unknown
timestamp: February 10, 2024, 05:48:52 pm
content: Yeh, lots of CJ measurements or alternatively ensure good thermal coupling between CJ's.e.g. the iso-thermal CJ copper block in the Keithley2001-TSCANcard.

author: MathWizard
author_rank: Super Contributor
timestamp: February 12, 2024, 02:34:20 am
content: On the 34901A scanner card, whats the row of grey things above the relays? It looks like terminal blocks, but this is a DMM or something, is it for some external connections if you needed them? Is there wires that get screwed there? Or is it a pin header connector, and something snaps into it ?Maybe it's some block of trimmers?

author: nfmax
author_rank: Super Contributor
timestamp: February 12, 2024, 07:13:06 am
content: They are terminal blocks. The card fits in 34970A & 34972A dataloggers, normally you hard wire the inputs to the scanner cards.

author: Berni
author_rank: Super Contributor
timestamp: February 12, 2024, 02:10:07 pm
content: All depends on how much accuracy you need.Lowest: Use a existing temperature sensor for ambient temp and assume the scanner card is at that temperature.Low: Use a temperature sensor to measure the actual temperature of the scanner card.Medium: Use a single temperature sensor, but thermally bonded to keep temperatures similar.High: Use a dedicated temperature sensor next to each connection point.Highest: Use a dedicated temperature sensor that is thermally bonded to the TC connector terminals using a special TC connector.Usually only the professional dedicated thermocuple measurement instruments do that highest level, since the simpler solutions are usually close enough for what is needed. If you want accuracy go for a high quality PT100 or something like that
Collaboration software - Page 1
Forum section: electronics / projects

author: Brent C
author_rank: Newbie
timestamp: January 21, 2017, 05:06:40 am
content: Our company's primary business is in the building automation industry. The controllers we use in the industry use a programming language called Control-BASIC that is modeled after Basic. We have experienced difficulties in training employees in the Control-BASIC language due to our business being conducted over multiple job sites which limits our senior programmers being readily available to provide one on one training to the junior, less experienced, programmers. We are looking for internet based collaboration software that can be used by our employees while spread amongst various sites. Is there software available that would allow multiple users to collaborate in real time with an employee on a site that requires assistance? The software would essentially have to allow multiple users to see and control the programs running on the PC of the employee requiring assistance.

author: Rerouter
author_rank: Super Contributor
timestamp: January 21, 2017, 05:37:27 am
content: teamveiwer?

author: Zom-B
author_rank: Regular Contributor
timestamp: January 21, 2017, 09:51:33 am
content: Google video hangouts, with multiple-desktop sharing
Collecting Temperature Data - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: March 14, 2019, 02:55:08 pm
content: I'd like to use a Raspberry Pi (or similar) to collect temperature data on water pipes as the water moves through. So the sample rate would be fairly quick, averaged, and then given at maybe a one-second rate. As for a sensor, either a thermistor or a temp IC.Ideally I'd like to monitor several locations spread out across approximately fifty-feet in various directions. I'm having difficulty coming up with a solution that is: cost effective, one cable with all the sensors in series instead of a separate cable from each sensor back to the Pi, and a method of getting DC (or AC) power to each sensor.I've looked at an I2C bus, but got caught with getting power to each board, and also not having to make separate PCBs for each location I wish to monitor.Any ideas would be greatly appreciated.

author: schmitt trigger
author_rank: Super Contributor
timestamp: March 14, 2019, 03:14:14 pm
content: One single cable for all the sensors? There is the 1-wire system which as its name mentions, does not require a separate power line. However it is slow and has worse performance than I2C with respect to receiving reliable data from remote sensors. I have never studied its addressability capabilities.I would suggest using a far more robust protocol, like CANBUS or RS485. Unfortunately this means both power and ground wires, plus a pair of differential signals.

author: Hemi345
author_rank: Contributor
timestamp: March 14, 2019, 03:28:00 pm
content: I've had good luck with Maxim/Dallas 1-wire sensors. There's a document that explains the various topologies for connecting multiple sensors and all the considerations for pullup value and line capacitance. Take a look at theDS18B20[Edited to include link to sensor I've had good experience with]

author: Hemi345
author_rank: Contributor
timestamp: March 14, 2019, 03:29:35 pm
content: Here's that document i mentioned:https://www.maximintegrated.com/en/app-notes/index.mvp/id/148
Color-coded RG174 or similar coax? - Page 1
Forum section: electronics / projects

author: dom0
author_rank: Super Contributor
timestamp: September 09, 2016, 08:15:06 pm
content: For some internal coax wiring color-coded (colored stripes or similar) coax would be useful. Anyone now a source for these? Older Tek / HP gear often had these, but I won't break perfectly fine devices just to rip some coax out...I don't like clip-on color markers - they tend to clip-off as easily as they clip-on. Another option that comes to mind is colored shrink tubing (although I'd like to avoid making the cables stiffer near the connectors where the marking is needed, and often also the bending radius...)

author: TimFox
author_rank: Super Contributor
timestamp: September 09, 2016, 09:25:45 pm
content: I use very short pieces of colored polyolefin shrink tubing: not quite so rigid as pvc.

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: September 09, 2016, 09:31:31 pm
content: dom0, all the major brands of ham radio gear use shrinking tube, right next to the connectors, on all the boards.I've use this system myself few times when is needed, on RF cables, I just put the shrinking tube half on the end of the connector and half on the cable, that way no humidity will go inside of the connector.
color led red green yellow - Page 1
Forum section: electronics / projects

author: jaRON
author_rank: Contributor
timestamp: September 27, 2011, 06:12:55 am
content: I'm looking for a color led red green yellow all in one led

author: PeterG
author_rank: Frequent Contributor
timestamp: September 27, 2011, 06:26:43 am
content: A standard Reg/Green/Blue led can produce what your after.Regards

author: Psi
author_rank: Super Contributor
timestamp: September 27, 2011, 06:35:21 am
content: They do make red/green leds (both on = yellow)Here is a random one i found on digikey, there are lots of others.If you want to mix led colors, wide angle leds seem to work best.http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=754-1471-ND
Color Organ Design - Page 1
Forum section: electronics / projects

author: aep9690
author_rank: Regular Contributor
timestamp: September 11, 2012, 03:26:22 am
content: I am designing a color organ. The idea is that I would plug a headphone plug into it and then the board would filter it into bass, mid and high range which would then use darlington transistors to drive a couple high power 1W LEDs. I simulated it using pspice and it worked they way I wanted, but simulations can only go so far. I attached the schematic I have and was hoping I could get some feedback before I go into PCB layout.
Colored DIP switches - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 04, 2020, 03:53:47 pm
content: I would like some nice DIP switches with color-coded levers. Looks like no one makes em since the 1970s. Everything's bland now.Anyone make these now? I want 8 colors...Maybe my googling is weak, all I get are results about using DIP switches to set the color of something else.

author: Benta
author_rank: Super Contributor
timestamp: December 04, 2020, 07:59:25 pm
content: ITW SpectraDIL

author: CJay
author_rank: Super Contributor
timestamp: December 04, 2020, 09:28:09 pm
content: https://uk.rs-online.com/web/p/dip-sip-switches/0336674/

author: Benta
author_rank: Super Contributor
timestamp: December 04, 2020, 10:19:43 pm
content: Quote from: CJay on December 04, 2020, 09:28:09 pmWhich are... tadaa... ITW ERG SpectraDIL.

author: CJay
author_rank: Super Contributor
timestamp: December 04, 2020, 10:21:11 pm
content: Quote from: Benta on December 04, 2020, 10:19:43 pmHa, yes, they are indeed.
colored rj45 jacks for pcb (NOT KEYSTONE !) - Page 1
Forum section: electronics / projects

author: free_electron
author_rank: Super Contributor
timestamp: March 20, 2017, 04:00:28 pm
content: i am looking for colored rj45 jacks for pcb mount. no leds needed.want 4 colors ( dont care what colors, as long as i have 4 different ones , besides black of course.)no shielding needed.i know yellow and blue exist since they are on my router. question is who makes them and how can i buy a few samples..the keystone jacks are too big. i need to solder these directly to pcb.

author: Monkeh
author_rank: Super Contributor
timestamp: March 20, 2017, 06:23:43 pm
content: These people appear to have black, white, yellow, red, blue and green:http://www.huilyn.com/enus/path289.htmlI think TE might offer a few colours, but they'll be non-stock everywhere and their website is an impossible nightmare.

author: free_electron
author_rank: Super Contributor
timestamp: March 21, 2017, 03:33:52 pm
content: perfect ! thanks.they also have the vertical versions. excellent.
Colour coding - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: December 12, 2013, 08:53:30 am
content: Red for V+, Black for V-, but what if you have dual rails, then what colour for the "common" or if the common is still black, then what colour for the -Vee ? Imagine a desktop PSU with normal DC outputs, so red and black connectors, and imagine the PSU also has +/- symmetric outputs for powering quickly op-amp circuits and such. What colour to choose for the "common" or for the negative rail?

author: tszaboo
author_rank: Super Contributor
timestamp: December 12, 2013, 10:47:34 am
content: V+ red, GND black, V- blue.

author: akis
author_rank: Frequent Contributor
timestamp: December 12, 2013, 10:50:12 am
content: Thank you. Have you ever accidentally used the blue instead of the black (depending on the darkness of the blue they are easy to confuse) ?

author: tszaboo
author_rank: Super Contributor
timestamp: December 12, 2013, 10:52:09 am
content: I blew up stuff every now and then because of wrong or reverse connection. It is part of the job.

author: Psi
author_rank: Super Contributor
timestamp: December 12, 2013, 12:08:49 pm
content: Picking wire colors is quite an interesting topic.Red/black is obvious, but sometimes you get red wire with a black stripe etc..Or speaker cable where one wire has a stripe, do you make that wire the negative or positive and does the stripe color change that decision?Or when you're wiring up power, ground and signal to a 3 wire cable that has only blue, orange and white wire. What do you use for what?i go by the rules"Solid color wires are classified first based on their color (before any striped wires)""Warm colors are positive""Cool colors are negative (with the exception of green which is earth or ground)""Dark and Neutral colors are grounds" (etc black white or gray)So for an example, with a 2 wire black cable (one with stripe) The plain black is neg (rule 1) so the black with stripe must be positive.For voltages i try to stick to the same colors as PC powersuppliesorange for 3.3vred for 5vyellow for 12vNegative rails i usually make blue, aqua or purple

author: Alana
author_rank: Frequent Contributor
timestamp: December 12, 2013, 03:09:44 pm
content: I usually stick to colour ribbon cables so + is red, next to it is blue that goes to ground and next is black that is -This way i have nice + 0 - connection.In case i do not use those ribbon cables i stick to what Psi said.
COM & Nano Com carrier board design - Page 1
Forum section: electronics / projects

author: guimtl
author_rank: Contributor
timestamp: October 13, 2018, 01:16:47 am
content: I work in industrial computer for a about 15 years now (more computer before but now focus on industrial stuff, fanless, rugged,...I always wanted to have my own design chassis/enclosure and ports placement. made a few project using Hammond cases and pico itx boards.Since I've made good friends at places where I have access to very decent boards and tech support in major Asian company I started thinking....Curious what you guys think about making a COM or nano COM carrier board for 'fun' learning to manage HDMI ports, USB, high frequency traces, power supply.. it's like making your own arduino but with an i7 insteadlooking around found this;https://www.picmg.org/wp-content/uploads/PICMG_COMDG_2.0-RELEASED-2013-12-061.pdflooks very cool, it says it all.. I could start small, get video(easiest port... ), storage and usb out..what you guys think about a COM board for sustainability, long life, a single computer could be made to last longer than 2-3 years.you get to keep the chassis but simply remove the nano com ''hat''off the main carrier board...even make a pretty decent all in one chassis that can look like a imac.. but with swappable inner CPU/RAM/Chipset module...would be nice to get a group of people working on a global response to obsolescence..I guess I'm not the first one to think about it.. but any reason why it didn`t happened yet? anyone interested talking about it ?I know for a commercial product price is an issue.. but for learning and making a few boards it`s still a good idea?..
Combination 0-10V / 4-20mA Output Circuit - Page 1
Forum section: electronics / projects

author: Evan.Cornell
author_rank: Regular Contributor
timestamp: December 08, 2020, 09:36:45 pm
content: A recent project had a requirement for a 0-10V control signal output port. I had implemented with MCU PWM pin, filtered and gained appropriately via non-inverting op-amp.Then, as is wont, the requirements changed such that the control signal output port had to support either 0-10V voltage output or a 4-20mA current loop output, on the same two-pin connector. The current loop output is supplying the loop voltage, which is backwards from how current loop transmitters usually work.Anyone have any clever ideas on a switchable circuit that can take a 0/3.3V PWM signal in and produce either 0-10V or 4-20mA output signal? Primary consideration is low-cost.I had seen XTR305 which might've fit the bill, but it seems to want bipolar power rails, which would inflate the cost too much.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 12, 2020, 02:33:43 am
content: Look at the datasheet of this optocoupler-the transmitter and receiver 4..20 are implemented there.https://lcsc.com/product-detail/Optocouplers_AVAGO-Broadcom_HCNR200-500E_AVAGO-Broadcom-Avago-HCNR200-500E_C23785.html

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 12, 2020, 02:38:54 am
content: And look tis chip:https://lcsc.com/product-detail/Sensor-Interface-ICs_Texas-Instruments-XTR116UA-2K5_C368611.html

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 12, 2020, 02:46:30 am
content: Quote from: Evan.Cornell on December 08, 2020, 09:36:45 pmit has a unipolar power supply. Due to the specifics of Gnd, it is named V - and using for +/-10V output.
Combination MFB and Sallen Key Filter? - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 12, 2021, 08:17:15 am
content: I don't see that this topology exists anywhere, but it should work?Prototypical circuit:Assume zero-ohm sources.Notice that MFB is inverting, while S-K is noninverting; both can be designed with gain. Suppose we combine the circuits, for the same gain with respect to each input, zero common mode gain, and simplify. We should get something like the above, but the trick is this:What relationships hold for the various values of R and C?R1/R5 = R3/R6 are fixed by the DC gain relationship.That leaves R2, R4 and all the capacitors.What other relations apply?Related reading:- I'm aware there's a fully-differential version; but without complementary outputs handy, what must the circuit look like?- The 1st order version is quite simple: set R2 = R4 = C1 = C2 = 0, and Fc comes from the RC time constant (C4*R6 more or less).Tim

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 12, 2021, 10:27:54 am
content: Playing around a bit (took some wrestling to make the PSPICE model work, as usual...), I see that R1 = R3, R5 = R6, R2 = R4, C1 = C2 and C3 = C4, as you would expect, to maintain good CMRR. Mismatch leads to a bandpass / hump in the spectrum where poles and zeroes don't cancel out.So, it'll have the same issue any other differential filter has, of course -- you need well matched capacitors and resistors to get good CMRR.(The question that prompted this, has low CM anyway, so that's not a killer.)Tim
Combination of DC-DC converters - Page 1
Forum section: electronics / projects

author: lipovi
author_rank: Newbie
timestamp: August 01, 2013, 09:34:50 am
content: Hy!I wanted to ask as a tie-in to my previous thread about construction of DC-DC converter.I selected my DC-DC switching converter, the FAN2108EMPX (Mouser Site), made it to work from 12V (car battery) input to 10V output. This is a buck construction but with a purpose.Now here's a question: can you connect 3 or 4 of these in series or series-parallel to increase the voltage but to retain the current?I also have the other boost tie-in, LT3482EUD (Digikey Site).Could the LT3482 with voltage boost but low current be combined to FAN2108 with low voltage but the constant current to work with each other?Any input or suggestions would be helpful.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: August 01, 2013, 05:01:24 pm
content: Quote from: lipovi on August 01, 2013, 09:34:50 amFirst thing is to draw a schematic of what you want to do. This is very important, it allows you to see things more clearly. After that do some circuit analysis, current usually takes the path of least resistance. Usually after that you have your answer.Your circuit probably provides no isolation between input and output. Therefore you cannot connect two of those in series and expect higher voltage to come out. Just see where your inputs and grounds are connected.You need to have isolated dc dc converter to accomplish what you are describing. This can be accomplished through a transformer. Or separate isolated supplies.

author: justinjja
author_rank: Regular Contributor
timestamp: August 01, 2013, 05:52:32 pm
content: Only if your design is isolated.If the end goal is to get 40v from a car battery why not just make a boost converter?