hybridfree/eevblog-posts huggingface dataset:
Balanced Charging of ZOP 2s lithium ion battery - Page 1
Forum section: electronics / projects

author: Zee9696
author_rank: Newbie
timestamp: May 15, 2019, 11:27:50 am
content: Good day everyone,I recently purchased a “ZOP Power 7.4V 2200mAh 2S 35C Lipo Battery T Plug” for a project. I have designed a circuit to charge the battery, but now I am wondering if it is necessary to ensure the batteries are balanced when charging. I am using an 18V, 10W solar panel to charge my battery through a buck converter which controls the charging modes (CC/CV), the battery is connected to an RC car to extend running time. Through research, there are websites and forums with completely conflicting views, some say it is very important to balance charge batteries in a pack, whereas others state since there are only 2 cells present balanced charging can be ignored and the battery can be charged normally in series.There doesnt seem to much information on these batteries, but this website contains some basic information on it:https://www.banggood.com/ZOP-Power-7_4V-2200mAh-2S-35C-Lipo-Battery-T-Plug-p-992114.html?cur_warehouse=CN#jsReviewsWrapI look forward to hearing peoples advice and opinions!
Balanced ternary - Page 1
Forum section: electronics / projects

author: macks
author_rank: Newbie
timestamp: July 05, 2016, 01:16:10 pm
content: After rediscovering an old Falstad sim of some balanced ternary logic gates I came up with after being unable to find examples of such circuits, I thought I'd post it here for interest's sake.I'm not sure if these circuits are at all practical and I seem to remember having a hard time getting them to work in LTspice.
Balancer Circuit of Two 12V Acid Batteries - Page 1
Forum section: electronics / projects

author: KerimF
author_rank: Frequent Contributor
timestamp: February 20, 2025, 09:12:11 pm
content: Hello,Lately, I designed and built a balancer circuit for two 12V acid batteries in series.And perhaps some of you would like to add remarks or comments about itI attached its LTspice files in ‘balancer_ver01.zip’ with 3 screenshots.On the screenshot ‘balancer_ver01.png’:C_bal=9400uF is actually 2*4700uF/35V, ESR of each is around 33mR.In the attached example, the initial voltage of the first battery (Vb1) is lower than of the second one (Vb2), Vb2 > Vb1 with Vb1=12VTheir maximum voltage difference is 2V (simulated for 20 steps of 0.1V, up to Vb2=14V).At boot, C_bal is charged separately (by Vb1 via 300R, not shown) till its voltage reaches Vb1-0.15V.Then, the N-MOSFETs, M3 and M4, are on for 500us so that V(C_bal) = Vb1The P-MOSFETs, U1 and U2, are on for 364us to transfer chargers from Vb2 to C_bal.Again, the N-MOSFETs, M3 and M4, are on for 500us to transfer chargers from C_bal to Vb1.The P-MOSFETs/N-MOSFETs loop will go on while dV (Vb2-Vb1) decreases gradually towards zero Volt.On the screenshot ‘balancer_ver01_data1’ and ‘balancer_ver01_data2’:dV = Vb2-Vb1 [from 0.1V to 2.0V]Ipi  = maximum initial current on the side of P-MOSFETsIni  = maximum initial current on the side of N-MOSFETsIp [A = maximum repeated current on the side of P-MOSFETsIn  = maximum repeated current on the side of N-MOSFETsIdc  = average transferred currentP_pair  = average power dissipation of P_MOSFET (U1) and N_MOSFET (M3)Pc  = average power dissipation of C_balVr  = ripple voltage on C_balNote: The same process works if initially Vb2 < Vb1Cheers,Kerim

author: trobbins
author_rank: Frequent Contributor
timestamp: February 20, 2025, 11:30:24 pm
content: Can you elaborate on the application you have for this balancer? Is the intention to operate the balancer 24/7, or just during events or phases of operation like a dischargeWere you able to estimate the SoC transfer and the energy lost over an episode of balancing that was needed for your application? If the balancer is just acting as a controllable pass element, then what loss of energy efficiency do you anticipate for your application?
Balancing 4 Li-ion batteries with 4 chargers - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: April 19, 2012, 01:42:37 am
content: I was wondering if you can charge and balance 4 Li-ion with 4 different chargers, one per batteries?

author: bfritz
author_rank: Regular Contributor
timestamp: April 19, 2012, 02:23:45 am
content: If the output of the chargers is floating with respect to ground... Yes.If all the outputs are grounded... No.

author: House91320
author_rank: Regular Contributor
timestamp: April 19, 2012, 02:31:09 am
content: That's what I figured, thanks. I've deiced to use one charger and a balancing ic, (BQ77908A).

author: Psi
author_rank: Super Contributor
timestamp: April 19, 2012, 02:51:19 am
content: I think some li-ion chargers charge them all in series while monitoring individual cell voltages.As soon as one cell reaches max volts it switches modes to slow charging the remaining cells individually.Probably because the series wires are already thick cable (for discharging) so they're well suited to high current charging.The per cell wires are often thinner so only good for slow charging.

author: metalphreak
author_rank: Frequent Contributor
timestamp: April 19, 2012, 11:37:54 am
content: Many of the single cell charging ICs share a common ground with the battery and the input voltage so you can't use multiple ICs to charge multiple cells *unless* you use an isolated supply for each circuit (which is more effort than just using a proper multicell charging solution).

author: EEVblog
author_rank: Unknown
timestamp: April 20, 2012, 07:11:58 am
content: Quote from: Psi on April 19, 2012, 02:51:19 amYes, and it's common to see this in high current LiPo battery packs for RC stuff.They have the high current battery connector, and a separate individual cell voltage sense line for the charger.e.g.:http://www.hobbyking.com/hobbyking/store/__11060__HobbyKing_ECO6_50W_5A_Balancer_Charger_w_accessories.htmlhttp://www.hobbyking.com/hobbyking/store/__9491__Turnigy_1000mAh_3S_30C_Lipo_Pack.htmlBTW, these things are so stupidly cheap, I've considered bolting these chargers inside gear instead of doing custom circuitry.http://www.hobbyking.com/hobbyking/store/__7637__Turnigy_balancer_Charger_2S_3S.htmlDave.
Ball bearing spark gap - where to buy? - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: April 16, 2014, 04:07:57 am
content: The flashover voltage between a separated pair of spherical conductors for a given diameter, spacing and surface smoothness is well documented. Measure the spacing that you can make the spark jump, look up the chart and there you have the kV. I want to buy a ready made one of these things for the testing and characterisation of car ignition coils so I need something that will go up to say 60kV.Does anyone know where I could buy one of these things?

author: acbern
author_rank: Frequent Contributor
timestamp: April 16, 2014, 07:34:12 am
content: there is one for sale on ebay germany currently. look for spark gap.

author: Circlotron
author_rank: Super Contributor
timestamp: April 16, 2014, 12:28:09 pm
content: Yep, that's exactly what I mean.Thanks for that.http://www.ebay.de/itm/FUNKENSTRECKE-f-HOCHSPANNUNGSTRAFO-TESLA-TESLASPULE-HV-HIGH-SPARK-GAP-/251483252621?pt=Bauteile&hash=item3a8d91e78dEnglish language ebay seems to be broken at the moment.
Ballpark budgeting for a 3.3VDC power supply - Page 1
Forum section: electronics / projects

author: AJMansfield
author_rank: Newbie
timestamp: March 20, 2017, 08:29:37 pm
content: I'm working on developing a product that will need to run off mains power (without any external brick) and I'm trying to figure the ballpark amount I need to budget for including a AC mains to 3.3VDC power supply on the board.The board is already going to be handling mains-voltage stuff as part of its functionality. It only needs to supply around 300 mA for my design (150mA for the MC, 20mA for a character LCD backlight, and then few misc optocouplers and stuff.)Volume is probably going to be somewhere from 50-5000, and it doesn't need to be terribly efficient or anything.What is a good ballpark price to use for budgeting this?I'm mostly using this to sanity-check my target price point to make sure there will actually be a profit margin left after it's all manufactured.Also, if there are any more general resources about how to budget out a device like this, I'd be glad for any links or other help.

author: t_ryner
author_rank: Regular Contributor
timestamp: March 21, 2017, 03:53:34 am
content: Hello! I did some browsing on digi-key and found these. The first one is a 5 volt regulator to put after the rectifier, and the second is a 3.3v converter that puts out 300mA. Hope I helped!5 volt reg-https://www.digikey.ca/product-detail/en/texas-instruments/LM2576T-5.0-NOPB/LM2576T-5.0-NOPB-ND/212636dc-dc converter-http://www.digikey.com/product-detail/en/cui-inc/VBSD1-S5-S3.3-DIP/102-1373-ND/989828

author: mariush
author_rank: Super Contributor
timestamp: March 21, 2017, 07:04:16 am
content: TME (a European distributor) sells classic transformers ... 1.8va (12v ac 100mA) for 1.19$ if you get 100, probably cheaper if you get 500+ here's example :http://www.tme.eu/en/details/bvei3022002/pcb-transformers/hahn/bv-ei-302-2002/2.3 va transformers are 1.26$ in 100pcs :http://www.tme.eu/en/details/bvei3032011/pcb-transformers/hahn/bv-ei-303-2011/.. a dc-dc converter would cost maybe 1$ (at 100+) so overall you'll be at less than 2.5$farnell has versions with 6v AC output ... A 2.3VA isolation transformer is about 2.5$ when you buy at least 50. If you order 500 or 5000, I'm sure you can get much lower price. Here's an example:http://uk.farnell.com/myrra/44157/transformer-2-3va-6v/dp/1689061(available in 110v or 230v versions)From there, a bridge rectifier, a capacitor and a linear regulator would be less than 50 cents if you order hundreds.No silly certifications to get your product through, easy design (transformer has pcb pins, so it goes directly soldered on pcb, no screws or potential vibration issues etc) , only downside is maybe height of transformer and maybe weight and maybe the fact that your product may not be under 0.5w when in standby or whatever the number is these days (EU certifications)
Balnaced XLR to Mini PL POWER MIC how to? - Page 1
Forum section: electronics / projects

author: banon
author_rank: Newbie
timestamp: January 07, 2025, 04:28:40 pm
content: HiIm trying to connect a wirless mic Sound Devices A20 tramsmiter to my Sony FX3camera with XLRH1 sound adaptorthe out put from the transmiter is a line level mini xlr connectorthe input 3 on the Sony sound adaptor is a mini PL power micwhen i connect the cable i have made - pin 1 ground - tip to pin 2 ring to pin 3i get a low buzz sound on top of the sound from the miccould not find any diagram or any info on this type of configuration.Please anyone who can help on this will be highly apriciated willing to pay for a working solutionthank you in advancealbert

author: The Soulman
author_rank: Super Contributor
timestamp: January 07, 2025, 06:51:57 pm
content: Quote from: banon on January 07, 2025, 04:28:40 pmNot sure I understand correctly.You have:*Sound Devices A20Transmitter(should be carried by the person who's being filmed).*Sony FX3 camera with optional handle that provides XLR audio input.You are having problems interfacing the signal from thereceiverto the camera audio input?What receiver are you using?The Sound Devices A20Receiverhas mini-XLR outputs, use mini-XLR to XLR cables to connect to your camera (handle).Again, not sure I understand your situation.

author: The Soulman
author_rank: Super Contributor
timestamp: January 07, 2025, 07:23:35 pm
content: I had a look at the user manual of the XLRH1 handle, like most Sony manuals it is pretty much useless.I think, you want to use the xlr inputs for different microphones and use 4 channel recording mode on the camera?I've read somewhere on the Sony website that input 3 (the mini-jack on the handle) supports stereo line-level audio, if so, that would be a setting in the camera menu, I'm not going to read the full manualso that is something for you to find out..If that is the case you could use this schematic:If you need something made you could ask these guys:https://www.aemstore.nl/
Baluns and Smith Charts - Page 1
Forum section: electronics / projects

author: NoName
author_rank: Newbie
timestamp: February 04, 2013, 10:25:49 pm
content: Hi all,I have been delving into RF design using several online tutorials on impedance matching etc. However, I have reached a stumbling block regarding how a balun affects impedance; more specifically how it is represented on a smith chart.As an example, I have been studding the CC2420 and the Anaren balun as outlined inhttp://www.ti.com/lit/an/swra155/swra155.pdf,but the “Impedance Matching” section on page 9 has confused me.How does the balun transform the impedance 45-j2 into 239+j29, or rather, how is the transformation calculated and plotted on a smith chart? (balun is a 50 ohm single ended into 200 ohm balanced)I have Googled but have not turned up an answer.I would appreciate any clarification.Regards,Mat

author: PA4TIM
author_rank: Super Contributor
timestamp: February 04, 2013, 10:51:51 pm
content: A balun is something that makes it possible to go from balanced to unballanced.You have current baluns and voltage baluns. You can combine a balun with a transformer.A transformer transforms voltage in the ratio np: ns but also impedance is transformed. The oldest example is the output transformer of a tube radio. It transforms the high anode impedance to the low speaker impedance. The same with radio.The anaren baluns are transformer-baluns made from microstrip/coplanar waveguides.You can transform impedance by use of wavelengths of transmision line. Like you can transform impedance by coupling a piece of 75 Ohm cable to 50 Ohm, or using shorted or open stubs.And they behave in smith like other transmission lines
Bamboo sticks in radar homing missile - Page 1
Forum section: electronics / projects

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: April 01, 2015, 08:28:08 pm
content: Hi, I found these photos of Soviet/Russian radar homing missile. Not very recent design - probably 80s years old or so or even older. People were talking about them on one Chinese mil equipment forum. Apparently nobody gave good explanation on what these plastic "bamboo" sticks are. I am very curious now. Does anyone know what these are for? What type of antenna it is? Is it possible to determine the frequency band from photos?

author: ConKbot
author_rank: Super Contributor
timestamp: April 01, 2015, 09:27:44 pm
content: Dielectric rod antennas. Works similar to fiber optics in that a mismatch the velocity of em waves (dielectric constant for microwave, refractive index for optics) reflects it, and with shaping you can make your desired pattern result. Guessing these were in the 10+ ghz range?Edit:http://hamwaves.com/antennas/diel-rod.htmlif those are 10 ghz antennas on that page, then the ones in the attached image could be for c or s band maybe.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: April 01, 2015, 11:01:00 pm
content: Wow it is fascinating! Thanks for the reference ConKbot.Now I a want to make one for myselfI am not sure it it will be too large and unpractical for 5.8GHz.
banana jacks with missing contacts? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: November 01, 2024, 06:43:05 am
content: I got a assortment from pomona on digikey and they gave me some banana cables that don't have the spring leafs on them.Is this something special? Did they just forget to install it?Mad shoddy QC for the premium price. Its just like a metal pin with the spring loaded safety cover on it.I don't think I am the first one noticing problems with them. I guess too many people said their good so now they are gonna start robbing usI wonder if they have a hand held DMM with binding posts on it. instead of these nanny meters.
Band Pass Filter, shift gain down?   - Page 1
Forum section: electronics / projects

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: September 10, 2016, 03:31:49 am
content: HelloI made up a BPF for with the attached circuit [RoboArm-Output.png].I then fed in a 5mV sinusoidal waveform at various frequencies and measured the output waveform amplitude with my analog oscilloscope (rough measurement), this gave me the attached BPF response [BPF response - actual.png].Now my question is, is there anyway to "shift the curve down"? As in I would like to have a gain of say +10dB @ 100Hz so that below 25Hz or above 300Hz I would start attenuating the waveform [BPF response - desired.png]

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: September 10, 2016, 04:50:55 am
content: I think I figured it out, with this circuit the only way to do it is by changing the gain of the instrumentation amplifier.The next revision of the circuit will need to have the instrumentation amplifier gain constant and then have an opamp after the BPF for adjustable gain.
Bandpass Filter Design Advice - Page 1
Forum section: electronics / projects

author: Gumbysauce
author_rank: Contributor
timestamp: December 04, 2017, 02:58:07 am
content: Hey guys,So I am working on a project right now that uses a piezoresistive sensor to do event detection in a fluid line. I have been having some issues designing a front end filter. I'm working with an attiny 85 atm, however I am in the process of moving to the Read Bear labs BLE nano development board. The device has some fairly stringent design requirements: I need it to be ultra low power, small form factor, Bluetooth enabled and have fairly robust event detection. Currently I am doing event detection by comparing the derivative of resistance against a threshold set by an external potentiometer. (I can't have a threshold for the resistance due to significant variability in the initial sensor value and the fact that there is quite a bit of drift while the sensor is in operation.) The problem is that I cannot get enough precision out of the ADC (seems like 10 bits is the best I can do reasonably) to measure the measure the change (I'm working on sensor sensitivity atm. But to give you an idea of what's involved, in order to do that I will need to have access to a clean room and some very specialized equipment, so that's not happening any time soon.) Anyway, that's probably enough background information to get started. My current design is a voltage divider w/ R1 selected to compliment the initial value of the sensor (I'm thinking about using a digital potentiometer here to do some on board calibration and to later use feedback to account for sensor drift.) and the signal from between the resistors is sent though a LPF to the ADC of the MCU.I was thinking about instead implementing a BPF with gain, but unfortunately the frequency components of the desired signal also vary significantly, so I will need to have a pretty wide response up to the sampling frequency of the MCU (RN I'm guessing that I will sample at ~ 250Hz, but that is sure to change as the device is better characterized). At frequencies this low, the passive components of the Sallen key topology tend to get pretty bulky, so I was hoping that there was a different topology that I could use, or perhaps a configurable IC that would do the trick, but unfortunately I have no idea where to start looking for something like this. Hopefully you guys have some suggestions.Thanks,Gumby!

author: danadak
author_rank: Super Contributor
timestamp: December 04, 2017, 12:56:19 pm
content: Use TI or Analog Devices design tool, and tradeoff higher R valuesfor lower C. There are noise consequences for doing this. Toolswill cover this.Or consider digital filter, IIR approach. There are tools on the webfor calculating coefficients. But then you need a DAC if you need topass filtered value onto other parts of design. Could consider a PWMDAC approach.http://www.ti.com/lit/an/spraa88a/spraa88a.pdfhttp://www.analog.com/en/design-center/design-tools-and-calculators.htmlhttp://www.ti.com/tool/filterpro&DCMP=hpa_amp_general&HQS=NotApplicable+OT+filterproRegards, Dana.
Bandpass filter design - Page 1
Forum section: electronics / projects

author: jbushnel
author_rank: Contributor
timestamp: December 15, 2014, 02:42:59 pm
content: I was going to order this kit from jameco but I had some questions about the filtering!http://makezineblog.files.wordpress.com/2010/10/ledcolororgan-schem_r2.gifI wanted to pretty much keep everything the same but I wanted to change where the bandpass occurs (and maybe slightly change the bandwidth). I noticed that the only thing that changes for each filters are the three capacitor values. How would I go about choosing the values for the filter components? I have done an "online filter calculator" but all of the values are not as rounded as the one in this schematic...To me, they look like third order filters: The first two stages is an active filter where there is multiple feedback. Then the third stage is the passive high pass filter that is connected to the output of the op amp. I don't know how to go about fitting it for my need. Thanks!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 15, 2014, 03:12:07 pm
content: If you keep the resistor values constant and vary the capacitors in proportion, the break frequency will vary in direct proportion as well. As such, you can round the values to the nearest common value to get something pretty close.Tim
Bandscope GUI Design  - Page 1
Forum section: electronics / projects

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 09, 2017, 04:19:41 pm
content: My latest project is more software than hardware based - a welcome change from puttering away in the lab all day!It's a simple bandscope - originally running on a Raspberry Pi (with an optional touchscreen) and using a USB RTL-SDR dongle as the detector - simple enough: but I was unhappy with the software availability so I said "F***" it and made my own.(note, that bottom button is just a placeholder to allow me to access the debugger script on-the-fly!)So far it works decently well - it's still running on dummy data rather than actual spectral data but that side of things should be fairly simple to implement with the RTL-SDR Wrapper: though this might affect the framerate depending on the sweep distance!It's written in Python(2.and uses WxPython (a wrapper for the WxToolkit) for the GUI - and will hopefully be extensible to almost any SDR provided it has a python wrapper.The question is: what sort of features should I implement in it?So far it has:-USB RTL-SDR Support-Spectrum display (frequency sweep)-Max/Min signal strength indicators-Frequency indicators (highlights top 5 peaks)-Waterfall display (frequency sweep / time)-Hybrid (combined) Spectrum/Waterfall display (one above the other)-Custom spectrum/waterfall palettes-Zoomable Displays-Optional Hardware controls (i.e an optocoupler for a dial and keypad digit entry)-Multi-Platform (tested on windows and linux)What other things would people like to see?Some things I've already considered are:-Grid overlay on the displays-Distance between peaks/peak measurements-Adjustable Noise Filters (might be hard on performance!)-Audio-receive-this would required adjustable bandwidth controls as well-Audio Recording-Trigger level control (don't display any signals weaker than a setpoint)-Data logging (log the spectral data over time)-

author: danadak
author_rank: Super Contributor
timestamp: February 10, 2017, 02:54:55 pm
content: Capture and compare plots.Simple statistics, dbm, avg, sigma, .....Look at a manual for a modern analyzer from Agilent, Tek, Yokogawa.....Regards, Dana.

author: LaserSteve
author_rank: Super Contributor
timestamp: February 10, 2017, 10:53:52 pm
content: Have a way to subtract a baseline, which is easily made by terminating the input with a 50 Ohm load. I have more then one device that cannot subtract the baseline and spurs, and that is annoying. Some times you DO want to turn the baseline subtraction off, but it is very good thing to have.Steve
Bang-Bang phase compensation advice - Page 1
Forum section: electronics / projects

author: grouchobyte
author_rank: Regular Contributor
timestamp: March 29, 2016, 05:19:58 pm
content: I am currently optimizing an old design that generates a 30.5973 Mhz clock synchronized to the power line frequency of either 60 or 50 Hz. It optically sends out the synchronized 30.5973 Mhz clock over an optical fiber to the rest of the system for isolation in a medical application.Currently I use an ultra-stable VCO with a micro-controller( PIC) doing simple synchronous counting and a PLL with a bang-bang phase compensated detector generating the VCO control or error signal.It works a treat. However there is a some sub-optimal jitter on the order of a few microseconds when you compare the 60/50 Hz edges with the 30.597 Mhz clock edge. This jitter is a noise term in aggregate system SNR, so less is better.Is there a better way to do this and is bang-bang compensation on a PLL the best approach in minimizing jitter. Anyone?
Banggood current source - Page 1
Forum section: electronics / projects

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 10, 2019, 06:03:37 pm
content: Has anybody bought one of these and RE'd the schematic?https://www.banggood.com/DC-1V-100V-Constant-Current-Source-Electronic-Load-Board-75W-0-10A-Power-Tester-p-1148591.html?gmcCountry=US&currency=USD&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=frank&utm_campaign=pla-us-ele-prof-1-pc&gclid=EAIaIQobChMI8JTT0eHj3wIVDodpCh1_Fw8yEAkYByABEgKAcvD_BwE&cur_warehouse=CN

author: kjr18
author_rank: Regular Contributor
timestamp: January 10, 2019, 06:30:36 pm
content: You can search for this, just google "xhdz-fz-2e".There is a schematic of 2g version but I think they might be very similar.

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 10, 2019, 06:39:24 pm
content: Quote from: kjr18 on January 10, 2019, 06:30:36 pmThanks, that is good enough! I did search, but not the entire number. Gracias.
Bank switching / stacked eeproms (visual confirmation) - Page 1
Forum section: electronics / projects

author: Hoffy84
author_rank: Contributor
timestamp: September 03, 2022, 03:51:31 am
content: Do I have this right on the yellow highlighted portions? Starting to go cross-eyed looking at schematics, and trying to figure out the best wiring scheme in an array. - Thanks!

author: Terry Bites
author_rank: Super Contributor
timestamp: September 04, 2022, 09:55:23 am
content: That works.Typo A1 on 2764?

author: pcprogrammer
author_rank: Super Contributor
timestamp: September 04, 2022, 10:35:47 am
content: Yes, that way you get 4 banks to work with.I assume you checked the datasheets for the pinouts, and that the A1 (A12) error Terry Bites mentioned is indeed a typo. 30 years ago I would have been able to draw them from the top of my head, but now I have to get the datasheets to verify it

author: Hoffy84
author_rank: Contributor
timestamp: September 08, 2022, 01:08:14 am
content: Quote from: pcprogrammer on September 04, 2022, 10:35:47 amQuote from: Terry Bites on September 04, 2022, 09:55:23 amThanks guys! Yes, that's combination good ol' Excel auto-filling, and me being up past my bed-time. Appreciate the feedback. I have corrected the photo in the OP for prosperity.
Barbed pcb wire crimped end - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: June 24, 2015, 04:36:21 am
content: Hi all. Just looking to find out what these things are called. They go on the end of a wire that is then inserted through a pcb hole and the barb makes sure that the wire is held securely until it is soldered. I want to find out what they are called so I can get some drawings etc as regards what pcb hole size to use with what sized wire and crimp thingy.

author: German_EE
author_rank: Super Contributor
timestamp: June 24, 2015, 06:14:16 am
content: The mechanical termination is called a ferrule but I have never seen lockable devices like this one.

author: Circlotron
author_rank: Super Contributor
timestamp: June 24, 2015, 06:27:58 am
content: Okay. Found it.http://au.element14.com/molex/02-07-2101/terminal-18-24awg-pcb/dp/2063725

author: apelly
author_rank: Unknown
timestamp: June 24, 2015, 07:30:15 am
content: I've often seen them used in PC power supplies, for all of the power leads.16c each et e14 seems to be taking the piss a bit though.
Bare bones battery tab welding - Page 1
Forum section: electronics / projects

author: 6PTsocket
author_rank: Regular Contributor
timestamp: April 16, 2019, 06:37:43 pm
content: I do not do enough to justify a spot welder. I have seen all kinds of controlled and uncontrolled schemes to do it on the cheap. I just saw a video of a couple of stiff wires soldered to a 500fd/2.7V super capacitor charged and then used as a spot welder. I have seen old microwave transformers have the secondary replaced with a couple of turns of heavy wire and used the same way. In the other end I have seen banks of capacitors charged and then discharged through a contactor.I suppose you could use a big battery, too. In the past I just fluxed and soldered quick with good results but welding is preferred.Any thoughts?Sent from my SM-G900V using Tapatalk

author: coromonadalix
author_rank: Super Contributor
timestamp: April 16, 2019, 07:10:51 pm
content: I followed some youtube videos 2 years ago, took an microwave 1.2kw xformer, destroyed / removed the secondary coil, took an zero awg gauge wire, managed to get 3 full turns in it, i had around 3.1 volts at maybe 400 amps ... made the solder clamp with interchangeable cooper needles.Made an pulse driver, some schematics on googlevoila an home made spot welder, did manage to spot weld good awg size metal plates.
Basic cameras to interface with an FPGA - Page 1
Forum section: electronics / projects

author: Pack34
author_rank: Frequent Contributor
timestamp: November 16, 2016, 03:12:30 pm
content: I'd like to look into a video project. A while back I remember seeing a camera setup called a Pixy Cam. It's a small camera that's wired into a NXP chip that does basic image recognition.I was thinking of doing the same using an OVM7692 since it's a lower resolution image and I can find them in abundance for cheap on DigiKey, I think they would be easier (and cheaper) to experiment with. However, the information seems to be lacking as they only have a basic block diagram on the datasheet and their website seems to not be responding. I would assume their still in business since I can see articles from a couple days ago about some new HD sensors they'll be releasing for smartphones.Does anyone here have any experience with the Omnivision sensors and could point in the direction of some developer documentation?

author: daveshah
author_rank: Unknown
timestamp: November 16, 2016, 04:47:12 pm
content: I've used a few Omnivision parts with FPGAs now. The first one I used was the OV5640, which is pretty easy to use and has lots of built in processing so you get a high quality full colour image out. I've posted some register values for itherefor 512x480 at 90fps+ and with RGB565 output. Once you have these register values it's just a case of outputing them over I2C, and handling the parallel pixel data coming in - in my case the parallel input interface was basically a tiny bit of logic to handle timings and a dual-port line buffer.Incidentally I've just posted athreadabout CSI-2 cameras such as the 4k OV13850 camera. These higher res cameras typically need more user processing - debayering, AEC, etc.
Basic high frequency signal delay/phase/trace length doubts - Page 1
Forum section: electronics / projects

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 05, 2021, 04:08:31 pm
content: I'm not used to route very high frequency signals, so I have few questions.I understand that any lenght mismatch between traces will cause phase shifting (delay) between them when reaching the target.As the frequency rises, lambda shortens and the issue becomes more and more critical.Let's take an error of 20mm, which I already consider a lot.- The theorical delay (at light speed) would be 66.7ps.- FR4 boards have a velocity factor of 0.47, so the delay will be actually 66.7/0.47=142ps ?- For 400MHZ: T=2500ps, the phase shift would be 360*(142/2500)=20.45º ?I'm thinking on doing some crazy hacking to an old linux board, extending the DDR2 memory bus to 4 ram chips, interfacing the existing bga bads.I know, I know, this is nuts, It's just I like the pain and the suffering

author: jwet
author_rank: Frequent Contributor
timestamp: December 11, 2021, 04:26:56 am
content: I didn't see a question really but your analysis is spot on. A 20 mm length mismatch is super conservative- its easy to maintain a few mm without getting crazy.
Basic inline preamp diagram required. - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: April 26, 2019, 03:55:19 pm
content: I watch movies on a projector but the 3.5 mm output signal is too low so even when I turn the volume to the max on my sound system, the loudness is not satisfactory.Would like to assemble a basic preamp to double the output voltage of the signal. Does anyone have a circuit diagram I can use to assemble this device?

author: Tek Tech
author_rank: Contributor
timestamp: April 26, 2019, 04:34:23 pm
content: A simple one-transistor amp should work. One for each channel.They can be cascaded if you need greater amplification.[Edited from emitter follower. Thanks to Benta's observation one post below]

author: Benta
author_rank: Super Contributor
timestamp: April 26, 2019, 05:33:05 pm
content: Quote from: Tek Tech on April 26, 2019, 04:34:23 pmJust a little problem: emitter followers have a voltage gain of less than 1. Not the right solution.

author: moffy
author_rank: Super Contributor
timestamp: April 27, 2019, 12:07:43 am
content: Attached is a possible solution. Use an LM833 dual, you get 2 opamps therefore stereo. Has a gain of 2.2 but you need a +/-12v supply as well.Caps should be non polar (not electrolytics) and avoid ceramics for the 1u.

author: MarkF
author_rank: Super Contributor
timestamp: April 27, 2019, 03:12:51 am
content: Here is a pre-amp for a condenser mic. Maybe you can tweak the gain for your case.
Basic logic based pressure trigger - Page 1
Forum section: electronics / projects

author: themacman33
author_rank: Contributor
timestamp: March 03, 2014, 11:01:43 pm
content: I have a fan by my bed hooked up to a remote control unit. The remote has an on and off button. I want to make some sort of circuit where if I press a button (lay down on my bed) it will trigger the on button of the remote, but just once for battery's sake, and then when I get up, it will trigger the off button on the remote, just once again.I would like to use some sort of basic digital logic rather than an AVR. How feasible is this?Thanks!-MacP.S. I know that I could just use a button and do away with the RC unit, but that's not the spirit of the thing! I'd rather learn how such a digital logic circuit would work.

author: Psi
author_rank: Super Contributor
timestamp: March 03, 2014, 11:17:41 pm
content: You could use two 555 timers in monostable mode, one with the switch input inverted.Then you'd get two outputs, one would output a pulse when the switch changes to depressed, the other would pulse when it changes to released.Could also do it with logic gates by delaying one of the inputs so you get a short pulse when there's a edge.
Basic Mux Array Question - Page 1
Forum section: electronics / projects

author: nickm
author_rank: Regular Contributor
timestamp: May 10, 2014, 02:05:45 pm
content: I want to use 4 16:1 muxes in a project, but I don't want to dedicate 16 I/O pins to run them. Is there an industry standard way to operate several muxes independently with just a single uC? First thing I though of is use a quad D-flip flop on each mux which allows you to share the A,B,C,D lines and then clock whichever one you want to change. This would bring the number of pins necessary down to 7, but it still seems overly complicated.

author: nerdyHippy
author_rank: Contributor
timestamp: May 10, 2014, 02:10:30 pm
content: You could use an IO expander or some shift registers.

author: nickm
author_rank: Regular Contributor
timestamp: May 10, 2014, 02:20:39 pm
content: Thanks. The IO expander was exactly what I was looking for.
Basic question on sigma-delta IC - Page 1
Forum section: electronics / projects

author: zphaze
author_rank: Contributor
timestamp: January 26, 2020, 05:10:36 am
content: Hi,I'm considering two chips for current sensing.#1 is this one:http://www.ti.com/lit/ds/symlink/ads131e08s.pdf#2 is this one:https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-8.pdfThe TI one says "simultaneous sampling" at 64 ksps. The Analog one would be better for me because it can be made single ended with 16 channels. The thing is it has a MUX inside and I can't really (or I'm not looking at the right place) find any info on whether at 16 channels it can do 250ksps per channel.So I wonder if anyone who has perhaps worked with those knows if the 250ksps can be achieved with 16 channels or should I expect something like 250ksps/16ch sampling rate per channel.Thanks in advance!

author: moffy
author_rank: Super Contributor
timestamp: January 26, 2020, 06:48:53 am
content: The AD7175 only has 1 ADC for 16 channels, so max rate for 1 channel = 250ksps, max rate for 1 of 16 channels is = 250k/16 (assuming no delays involved in multiplexer switching. Unfortunately sigma-deltas normally incur a switching penalty because of the digital filter). The TI device has a dedicated ADC for each channel so you get the full 64k for each channel.
Basic reverse leakage testing - Page 1
Forum section: electronics / projects

author: Harvs
author_rank: Super Contributor
timestamp: September 03, 2013, 06:53:19 am
content: In case anyone is interested. I'm trying to get the enthusiasm to document more of the test setups I find useful.http://www.electronicsinoz.info/ideas-for-the-lab/testing-reverse-leakage/

author: BravoV
author_rank: Super Contributor
timestamp: September 03, 2013, 06:57:34 am
content: Nice, bookmarked and thank you.

author: tszaboo
author_rank: Super Contributor
timestamp: September 06, 2013, 11:35:14 pm
content: Leakage will change some magnitudes if you heat up them. Try it, it is fun.

author: BravoV
author_rank: Super Contributor
timestamp: September 09, 2013, 06:50:25 am
content: Can I use this method on cap ?
Basic Solder Sucker Desoldering Iron Modification - Page 1
Forum section: electronics / projects

author: jonovid
author_rank: Super Contributor
timestamp: July 28, 2023, 12:24:43 am
content: removing the thin twin wire AC cable was problematicbecause of the way it was connected inside the plastic case.so this workaround.the original molded 2 pin EU type plug was cut off & replaced.the EU 3 pin plug is for a 240v to 220v auto transformerwith a 3amp circuit breaker.
Basic Soldering Tutorial Video (Through-Hole) - Page 1
Forum section: electronics / projects

author: llopis
author_rank: Contributor
timestamp: December 26, 2019, 07:42:31 pm
content: I just released a video explaining the basics of soldering tools and technique for through-hole components. I figure everybody here already knows that, but maybe you can point your friend who is scared of the soldering iron (we all know that one) towards that video and maybe that will encourage them a bithttps://youtu.be/79wPN3DXsH8
Basic ZVS driver question - Page 1
Forum section: electronics / projects

author: kenw232
author_rank: Contributor
timestamp: February 16, 2015, 06:18:29 am
content: I'm trying to build a ZVS driver for a high voltage pulse circuit, but I'm first trying to perfect the driver. My question is, how do I know if my ZVS driver is working properly? I don't think mine is oscillating. I've attached my circuit. The question is are both lamps suppose to light up in this example? Because when I put lamps on my ZVS only one lamp lights up as shown in the other attachment. Is this correct? I would assume the ZVS is suppose to oscillate back and forth and therefore both lamps would be on. I'm confused.

author: bktemp
author_rank: Super Contributor
timestamp: February 16, 2015, 06:31:10 am
content: It will not oscillate without an inductor at the output.

author: kenw232
author_rank: Contributor
timestamp: February 16, 2015, 10:27:11 pm
content: Thank you.
Basics and learning for stm32 - Page 1
Forum section: electronics / projects

author: Dzoro
author_rank: Contributor
timestamp: April 10, 2023, 10:54:23 pm
content: Can someone recommend some site or youtube channel for learning basics for stm32 programing and setup. I want to make more complex projects but i don't have the knowledge to do so.ThanksDzoro

author: barshatriplee
author_rank: Regular Contributor
timestamp: April 12, 2023, 10:03:48 am
content: For the basics, you can start with the following materials:https://www.theengineeringprojects.com/2021/10/first-project-using-stm32-in-stm32cubeide.htmlhttps://wiki.st.com/stm32mcu/wiki/STM32StepByStep:Getting_started_with_STM32_:_STM32_step_by_stepFor advanced projects, you will find some channels like this:https://youtu.be/vzHLPQ25O1Q

author: robca
author_rank: Frequent Contributor
timestamp: April 15, 2023, 04:37:09 pm
content: If all you want to do are some hobby projects and being able to leverage the existing Arduino ecosystem, there is alwayshttps://github.com/stm32duinoIt has a healthy communityhttps://www.stm32duino.comand it's officially supported by ST Micro, for pretty much every processor and board. It's not as flexible as using stm32cubeide, but since it uses the same HAL libraries, it has the same performance as anything written with HAL (which I find cumbersome and wasteful). The HAL doesn't really abstract various processors, each one uses subtly different versions. If anything, stm32duino does a better job at abstractionI have used both approaches, and I prefer going the stm32cubeide route (without HAL) when I need high performance, and stm32duino when I need to do something quickly and I need an existing library. For example, driving a touch LCD is pretty trivial with stm32duino, would take a lot of work using the native ST dev environment.

author: djsb
author_rank: Super Contributor
timestamp: April 15, 2023, 05:20:21 pm
content: The above link in the last post does not work. This one does.https://www.stm32duino.com/

author: Dzoro
author_rank: Contributor
timestamp: April 15, 2023, 05:31:56 pm
content: Thanks allot guys for the great recommendations i will look at them

author: robca
author_rank: Frequent Contributor
timestamp: April 15, 2023, 06:47:06 pm
content: Quote from: djsb on April 15, 2023, 05:20:21 pmGood catch, for some reason the forum software added the comma to the url itself, instead of keeping it separate. I fixed it now, just in case. Thanks for pointing this out
BAT48 for Bridge Diode? - Page 1
Forum section: electronics / projects

author: sansan
author_rank: Contributor
timestamp: October 07, 2022, 08:33:21 am
content: I have some BAT48. Can I use it as a casual rectifier?Datasheet says:IFis 350mA, IPkis 7.5A.The trafo is 200mA, expected load is about 20mA. But, will the diode damaged by the large reservoir cap?

author: mariush
author_rank: Super Contributor
timestamp: October 07, 2022, 09:58:43 am
content: You would want to be careful about peak reverse voltage, they're kind of low at 40v but probably fine with that transformer.The capacitance doesn't seem that high to me... don't think's gonna be an issue. Consider if you really need that big capacitors though, as you say the load is only 20mA ... you can sort of approximate capacitance needed with formula C = current / [ 2 x ac frequency x ( Vdc peak - Vdc min desired)]At 20mA, you're probably fine with a couple 470uF capacitors. Guess it depends how much voltage drop you're willing to tolerate.

author: sansan
author_rank: Contributor
timestamp: October 07, 2022, 10:33:19 am
content: the load will be less than 20mA (2 opamp). I've been using schottky diode near its reverse voltage for years, never had a problem..I'm affraid the surge current (first charge upon start-up) of the caps will blow the diode, but the trafo is only 200mA.I wonder if the caps surge current will be limited by the trafo itself.I think I understand that a big trafo cantake(primary winding?)a lot of surge current upon start-up.But, is this tiny trafo cangive(secondary winding?)way more current during first start-up??thanks mariush, I'll try using BAT48 anyway. I hope it won't blow up

author: Kleinstein
author_rank: Super Contributor
timestamp: October 07, 2022, 11:32:05 am
content: With a small transformer the internal resistance of the transformer coils would limit the current spike.How much resistance really depends on the transformer and small one can limit the current quite a bit. 12 V and 200 mA are only 2.4 VA and thus a rather small one. The better data-sheets give the ratio of unloaded and nominally loaded voltage and one can calculate the resistance from that.With the low load the voltage of the transformer can be quite a bit higher (e.g. 1.5 x) than nominal. So one may not need the low drop of shottky diodes and the peak voltage may indeed become an issue. The didoes have to withstand 2 x the peak voltage. One would more tend towards a ready made bridge rectifier.
Batch file to interact with running dos application - Page 1
Forum section: electronics / projects

author: Unknown
author_rank: Unknown
timestamp: March 14, 2014, 05:24:16 pm
content: I am working on a project and I was given a folder containing a application and a batch script that runs the dos application. The application takes two inputs. is there anything i can add to the script to have the script complete the two prompts in the application? I have tried echo and piping it to the application neither worked.

author: zimzom
author_rank: Regular Contributor
timestamp: March 14, 2014, 05:54:39 pm
content: did you try using expects?

author: calzap
author_rank: Frequent Contributor
timestamp: March 16, 2014, 04:18:25 pm
content: Mike,Your question is not entirely clear. Where are the inputs/prompts coming from? Keyboard, application already running, application that needs to be started, pointing device, A/D board or ?? What type or version of DOS is being used? pre-windows ... what version and what company (IBM or MS or ?) or Windows command line?? An example of the code you've tried so far would help too.There are lots of resource and utility programs available. Books by Peat and Wolverton (different books) and websites likewww.robvanderwoude.com.Mike in California

author: I_may_be_drunk_right_now
author_rank: Contributor
timestamp: March 17, 2014, 02:05:38 am
content: Quote from: MikeJuszkie on March 14, 2014, 05:24:16 pmOh, you want the batch file to send commands to the application while the application is running? Like typing in information and pressing enter? You have to find out if your application has a switch to allow that. In other words, at the command prompt, you need to type something likeapplicationname.exe /?and see if it gives you a little help. In DOS it's not as rich and functional as Unix/Linux unfortunately. You might have to get all greasy and dirty and work with little horrors known as TSR programs to do what you want....But if you are working in windows, you can find software that simulates mouse and keyboard inputs to any application, but then you're not in a batch file anymore.Tell us more, are the applications custom? Do you have the source code?I wonder if Windows Powershell could help?