hybridfree/eevblog-posts huggingface dataset:
Buck-Boost module with constant current/constant voltage mode - Page 1
Forum section: electronics / beginners

author: shobo
author_rank: Regular Contributor
timestamp: April 29, 2018, 06:35:59 am
content: Is there any cheap modules that have constant current/constant voltage mode ?

author: Ian.M
author_rank: Super Contributor
timestamp: April 29, 2018, 06:57:54 am
content: Google is your friend!Search terms in Google Shopping:+buck +boost +cc +cv
Buck converter. (adjustable) - Page 1
Forum section: electronics / beginners

author: TheMrbunGee
author_rank: Newbie
timestamp: April 17, 2018, 05:53:55 pm
content: Hey There!I have now spent more than a week of my free time to get into buck converters and stepping down DC voltage. I now know how they reduce the voltage, but it is not clear what controls theMOSFET, what decides when it turns on and when off.I started doing this because I need a DC power supply, which ideally is adjustable (2-12V) and can handle 500 W or even more.I have fixed 48V 30A power supply (if it is easier to convert from 48VDC than 230VAC). I have quite high power MOSFETs, diodes, bridge rectifiers, capacitors, inductors and other stuff, what can be salvaged from DC supply. Can such buck converter be made by beginner? Voltage does not have to be smooth, very constant or precise, so there is no need for complex smoothing circuitry.Can voltage be adjusted without complex controllers?Thanks, sorry for lack of some basics, but i can't sleep at night if I won't resolve this.Also - English is not my main language, so it was not easy to say what I need to get done, I might sound more stupid then I am!Thanks!

author: Zero999
author_rank: Super Contributor
timestamp: April 18, 2018, 10:26:27 am
content: The duty cycle should theoretically be equal to the ratio of the output vs input voltage, so if you have 12V out and 48V in, that's a ratio of 12:48, giving a duty cycle of 12/48 = 25%. In reality, there are losses in the inductor, switching transistor and diode, so the actual duty cycle will be slightly higher.The controller circuit should adjust the duty cycle automatically, by monitoring the output voltage and making the required adjustments.As the ratio between the output and input voltages gets higher, the simple buck converter circuit becomes less efficient. If you want 2V out and 48V in, then it's better to use a transformer or a multiphase buck, rather than a standard buck converter.See links below:http://www.ti.com/lit/an/slyt293/slyt293.pdfhttp://www.ti.com/lit/an/slyt449/slyt449.pdfhttps://en.wikipedia.org/wiki/Buck_converterhttps://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf

author: TheMrbunGee
author_rank: Newbie
timestamp: April 18, 2018, 04:21:27 pm
content: Ok, I got that, but how do I control duty cycle? Can it be done without timers? Can I use 555 timer for that? I have those..

author: Zero999
author_rank: Super Contributor
timestamp: April 19, 2018, 08:02:39 am
content: Quote from: TheMrbunGee on April 18, 2018, 04:21:27 pmIt's possible to use a 555 timer, but not recommended, since the efficiency will be poor. The easiest way is to use a switched mode power supply, such as the TL594.http://www.ti.com/lit/ds/symlink/tl594.pdf

author: TheMrbunGee
author_rank: Newbie
timestamp: April 19, 2018, 02:23:42 pm
content: Quote from: Hero999 on April 19, 2018, 08:02:39 amSo I use TL594 to drive MOSFET, which then regulates voltage. and control the chip with potentiometer, is that correct? Sounds doable for a beginner like me.Thanks!!
Buck Converter capacitor calculation - Page 1
Forum section: electronics / beginners

author: soFPG
author_rank: Frequent Contributor
timestamp: July 17, 2020, 04:41:17 pm
content: My plan was to use a JW5033S buck converter (datasheet:https://datasheet.lcsc.com/szlcsc/1906281506_JoulWatt-Tech-JW5033S_C324577.pdf).Unfortunately, I am not an electrical engineer and I don't understand how to calculate values for capacitors. According to the datasheet, they affect "ripple voltage".So, is ripple voltage a good or a bad thing? Should it be high or low?I attached my current schematic. The JW5033S is supposed to run at 2.8V and power a MachXO2 Lattice FPGA, an image sensor (~20mA) as well as a small microcontroller.At the moment, I just adopted the values from the datasheet and only changed the voltage divider.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 17, 2020, 05:01:04 pm
content: Uh, inductor is on the wrong side...!Ripple is undesirable, but because the control is internally compensated, you have no adjustments to allow other component values. Use the recommended values.If you need lower ripple (as you might for the FPGA's PLL, say?), add additional LC filtering.Tim

author: soFPG
author_rank: Frequent Contributor
timestamp: July 17, 2020, 05:07:04 pm
content: Thanks for the inductor hintQuoteI have multiple bypass capacitors (100nF - 22uF) for the FPGA - shouldn't they act as a form of lowpass filter e.g. eliminating high frequency ripple?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 17, 2020, 05:16:49 pm
content: Maybe. Relevant discussion:https://www.eevblog.com/forum/projects/location-and-value-of-decoupling-capacitors-(not-bga)/Bypasses should generally behave as a lowpass transmission line, but there can be modes at high frequencies as well.Within the lower passband, there can be plenty of ripple. Ripple can introduce jitter for example, because gate input thresholds are proportional to supply voltage. Probably doesn't matter. But then, say if your image sensor is internally clocked so you need to synchronize your clock to it -- it might be a concern after all.Tim

author: soFPG
author_rank: Frequent Contributor
timestamp: July 17, 2020, 06:46:04 pm
content: QuoteThe image sensor receives its clock from an external pin. My plan was to generate that clock with the FPGA.QuoteThank you
buck converter for 5V output with high efficiency at light loads (0.1A) - Page 1
Forum section: electronics / beginners

author: davegravy
author_rank: Regular Contributor
timestamp: May 09, 2024, 01:02:12 pm
content: Hi I've been looking through converter datasheets and efficiencies always seem to drop off near the no-load end of the load spectrum.I've been working on prototyping with the LM64460CPP but from myother thread I'm having many challenges(ie burned ICs) and I'm wondering if there are other more beginner-friendly converters with features geared toward maintaining light-load efficiency like the aforementioned IC.Input range: 8-16VOutput voltage: 5VOutput current 0.1A nominal, 0.7A peakI'm hoping for >95% efficiency at 0.1A load.I'm not adverse to a more expensive IC or component set or a largish footprint.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 14, 2024, 12:58:35 pm
content: DC-DC have costs for their own needs and losses.This part is constant and therefore becomes noticeable at low load.If you are carrying an empty backpack, you feel its weight. When you put a 16kg dumbbell in your backpack, you won't notice the whole backpack.You should not worry about efficiency, but about your own DC-DC consumption.Usually, low-power sources have less self power than high-power ones.Just choose a DC-DC close to the rated power.

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 14, 2024, 01:35:24 pm
content: I saw boost converter inside a bluetooth earbuds charging case, It always outputted 5V no matter what, but it only took 100uA from the battery with no output load.

author: ArdWar
author_rank: Frequent Contributor
timestamp: May 14, 2024, 02:16:50 pm
content: I've used TPS62933 and it works fine for me. Pretty low quiescent current, but still high enough that I won't use it on long lasting battery powered devices without some sort of gating. Very simple application circuit but pain in the ass (but reasonably doable) to solder manually.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 14, 2024, 02:25:56 pm
content: Quote from: ArdWar on May 14, 2024, 02:16:50 pmMaybe the voltage divider for FB consumes excess current and charges the Cout, forcing it to constantly recharge?
Buck converter instability (wrong cap size?) - Page 1
Forum section: electronics / beginners

author: step_s
author_rank: Regular Contributor
timestamp: August 04, 2016, 09:45:03 pm
content: Hi.So I have been messing around with this buck converter chiphttp://www.farnell.com/datasheets/608795.pdfSometimes it will be stable, and suddenly, out of the blue, it will act up with the output voltage floating around like crazy (+/- 0.1V).The datasheet says that it needs 0.1uF caps on input and output, but I can't seem to find any, so I'm using 0.33uF ceramics.The question is now, can a bigger cap cause trouble? I mean, the bigger cap should fulfil the same task, right?Also, the input and output caps are 100uF electrolytics instead, but is this a problem with a stable powersupply input?I'm suspecting the ground loop, but the thing is that it sometimes works, and other times, has it's own will.Hope you can help here
Buck converter instability during soft-start - Page 1
Forum section: electronics / beginners

author: Godzilla
author_rank: Contributor
timestamp: January 20, 2025, 09:06:29 pm
content: Hello guys, im having troubles with a buck converter based one the LM5149 IC, my specs are:Vin = 54VVout = 2V - 50V moved with a DACIout = 15AFsw = 450kHzDual-Phase for 30A max current outputFor the project i need an ON-OFF timed function that for example keep the buck on for 1s and then keeps it off for another 1s. Im using the enables pins for this so the buck goes through the soft-start every time it turns on, but sometimes then Vout= 50V the soft start stop at 3/4 of what should be (37V) and stays there until the next ON-OFF. I think it somehow goes out of stability but it doesnt seem to hit the 20A current limit or something else. I tryed to experiment with several compensation network components but i really dont seem to be able to mitigate the problem. What should i check?
buck converter limits  - Page 1
Forum section: electronics / beginners

author: jonovid
author_rank: Super Contributor
timestamp: July 01, 2020, 03:17:23 pm
content: what are the limits of a buck converter circuit ? can a simple DIY circuit do the job?if I have a 150 to 250 volt DC input and I am seeking a 15 to 20 volt output.an example I have this 75watt DC 250 volt brush motor from old or used exercise equipment.now seeking to re-purpose it as a DC generator for charging a 12 volt deep cycle car battery. as part of DIY survival gear.anybody recommend a good circuit do the job? as I have not found one with this level voltage difference when looking online.most DC to DC are a lot less of a jump down in voltage. the motor / DC generator has a 75watt DC 250 volt rating.I thought of looking at old or used TV flyback transformer circuit components. as I have a bin full of old TV pcb's .what 300 volt drive semiconductor is the best for this job here. orthen I need to feed it an AC .any suggestions?has anybody made a similar type of battery charging circuit ?see simple buck converter circuit -an example only, not my circuit.

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2020, 03:20:32 pm
content: 250 volts down to 15 volts would require an awfully low duty cycle, which is not impossible, but it makes things more difficult so usually some other topology would be used like a transformer isolated buck converter or a tapped inductor buck converter.
Buck Converter Module issues - Page 1
Forum section: electronics / beginners

author: FotatoPotato
author_rank: Regular Contributor
timestamp: April 27, 2019, 09:46:43 pm
content: Hi all,So I just finished building a breadboard DC-DC converter module (on a pcb) based off of the LTC3864. I have my converter set up to operate in burst mode since every time I set it to run in Pule skipping mode it pulls 100mA and the LTC3864 reaches 100C within seconds. My design is based on the DC2434A evaluation board with only minor changes made to the feedback line (I'm just using a 10K resistor and 100K pot to set the output voltage.Anyway, when there is no load attached the converter board works fine and the output can be adjusted from 0.8v all the way to 30v with an input of 32v. This is great and all but the problems occur once I attach a load on the output. I set the output of the converter to 12v and hooked it up to my electronic load. I then started to increase the current draw in steps of 10mA. I also added a thermocouple on the LTC3864 to monitor its temp. I designed the converter to go up to 5A but once I draw over 60mA the LTC3864 quickly heats up to 80C and then shuts down and pulls a constant 140mA with 0v on the converter output. I have gone over my schematic and the eval board schematic multiple times and I can't figure out what's going on. Do any of you guys know what's going on?Thanks

author: paulca
author_rank: Super Contributor
timestamp: April 29, 2019, 06:39:25 pm
content: I tried to breadboard a DC-DC converter and it didn't work either.I soldered it onto proto-board and it worked fine. They are usually sensitive to the resistance, flakey connections and capacitance in the breadboard.You shouldn't really attempt to run anything near 5A through a breadboard, 1A is really the limit.Try implementing the "Typical application" circuit in the datasheet on a bit of proto board and see if it works.
Buck converter not outputting correctly unless input dips below ~7V - Page 1
Forum section: electronics / beginners

author: cbc02009
author_rank: Regular Contributor
timestamp: September 23, 2018, 11:34:25 pm
content: Hello,I got my board in for the MPPT controller I'm building, and I got all the parts on it, and for the most part it works perfectly, but I am having a very strange issue with it.For any input voltage higher than around 7V, the buck converter initially outputs .6V no matter what the input is, but then if I dip the input below 7V, even for just a fraction of a second, something kicks in and it just starts working like it's supposed to, even if I raise the voltage back up above 7V.My gut is telling me that it's a problem with high-side mosfet not getting boosted correctly. Maybe the boost capacitor can't charge quick enough?The picture of my schematic is attached, as well as the datasheets for the mosfets and buck controller.Any advice on how to isolate the problem would be greatly appreciated.Thanks!

author: killcode
author_rank: Contributor
timestamp: September 24, 2018, 01:12:59 am
content: Your bootstrap cap is lower than the datasheet typical application - did you calculate the required size for your particular switching freq and fet gate charge?Maybe try some decoupling on vcc as well.

author: cbc02009
author_rank: Regular Contributor
timestamp: September 25, 2018, 04:33:27 pm
content: Quote from: killcode on September 24, 2018, 01:12:59 amSo I finally got into school to use the scope, and you are absolutely correct with your second suggestion. This is what my clean Vcc looks like after I hook it up to my circuit:Now I just need to figure out how to modify my board to add decoupling. I can't believe I missed it on the original schematic.

author: cbc02009
author_rank: Regular Contributor
timestamp: September 25, 2018, 05:21:18 pm
content: And one bodged ceramic capacitor later, everything is working as it should. Thanks!

author: killcode
author_rank: Contributor
timestamp: September 30, 2018, 12:53:59 am
content: Glad I could help.When in doubt, sprinkle a little 100nF pixie dust around.
Buck Converter with NE555 in LTSpice - Page 1
Forum section: electronics / beginners

author: Harun
author_rank: Newbie
timestamp: May 11, 2020, 02:49:52 pm
content: Hi, I am trying to make a Buck-Converter with a NE555 as a switch. But I do not understand why the output signal is not even a bit attenuated. I attached here my circuit and the measurements of the output and between the Gate and Source of the PMOS.Thanks

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 11, 2020, 04:09:00 pm
content: There's no load...That's also way too much Vgs(on) for M1. The simulation doesn't care, but don't do this with real parts.The rise/fall times are also very poor. Not that you're running much frequency, which is part of the problem as well, i.e. the L1-C3 time constant isn't much longer than the (R1, R2)-C2 time constant.This is also not a great topology in general. Suppose the load were shorted; the 555 should deliver almost zero duty cycle in that case, but how can it know? Even if the load current is merely varying over a nominal range, or the supply voltage, the output voltage won't stay constant, it's completely open loop.These problems are addressed with a control circuit like this,https://www.seventransistorlabs.com/Images/555%20Boost.pdfwhich uses the 555 as a flip-flop, and senses the switching current. Operation is similar to the UC3843 boost/flyback current mode controller.For buck architecture, if you don't need a common-ground output, you can simply use an NMOS switch, and buck towards +V; this allows the same (555 or other) control circuit to be used. Otherwise, a level shifter (high side gate driver) is preferred. Buck regulators simply integrate all this circuitry for you.Tim

author: Harun
author_rank: Newbie
timestamp: May 13, 2020, 03:04:47 pm
content: Thanks for your advice, it helped me a lot
Buck converter - Page 1
Forum section: electronics / beginners

author: abdulsamaddabu
author_rank: Contributor
timestamp: November 30, 2017, 04:07:18 am
content: Hey i was desinging a buck converter using LM2576 IC.i have two questions:1. More Capacitor at input and and output means better, Right ? currently there value are 100uF and 470uF respectively.2. What should be the value of inductor, i was thinking of 330uH

author: mariush
author_rank: Super Contributor
timestamp: November 30, 2017, 04:28:14 am
content: READ THE DATASHEET :http://www.ti.com/lit/ds/symlink/lm2576.pdfSee chapter 8 in particular, starting from 15. It explains everything, and even gives you some tips about how to put the components on the circuit board.
Buck converters and Features - Page 1
Forum section: electronics / beginners

author: LoveLaika
author_rank: Frequent Contributor
timestamp: October 06, 2020, 06:30:50 pm
content: On a previous power supply project, I was using buck converters for the first time. Through deliberation, I went with the LM2673 and the LM2679. They had a good current output (1 amp and 3 amp minimum, respectively), and they worked pretty well. However, another reason that I used them was that they had a 'current limit adjust' pin, whereby adding a resistor, you can limit the output current. Now, I thought that it was a cool little feature, and it would allow me to dynamically adjust the current.However, looking back at the parts, the LM2673 and LM2679 seem to be outdated. It seems that there are other buck converters that are smaller and more efficient, but they don't have this function. This may be a dumb question, but I was just curious as to why such a useful feature would be omitted in newer buck converters, or do other designers have a more sophisticated way of controlling the current.
Buck driver do not stabilize curent - Page 1
Forum section: electronics / beginners

author: stevetto
author_rank: Newbie
timestamp: April 12, 2019, 05:49:56 pm
content: I have been working on a LED buck driver for a while but unfortunately without any succes.The design is based on a MAX 16820 chip.I use an attiny13 to generate the pwm signal for the MAX 16820. This part seems to be ok, I can change the pwm's duty cycle.As the duty cycle changes the LED current also changes.But if I change the input voltage the led current also changes, so the driver do not stabilize it.At first I tested it with an XHP70 led, than I changed it to an xm-l2 (the current sense resistor was also changed) but I still have the same issue.I have attached my calculations and the schematics.I would really apprieciate any suggestions.

author: adamcord
author_rank: Contributor
timestamp: April 22, 2019, 08:29:35 pm
content: It looks like the MAX16820 limits LED current to some maximum based on the sense resistor, but if your supply voltage isn't high enough to push this max current during the LED's on state, they will be drawing some current <= max current. That's my guess as to why the average current changes as it does with supply voltage.
Buck Regulator VIN under required VOUT - Page 1
Forum section: electronics / beginners

author: tomshirvo
author_rank: Regular Contributor
timestamp: October 04, 2018, 08:37:40 am
content: Hi All,So I am working on a little project and I am interested in knowing if the regulator I have chosen (or any buck regulator) will work if you end up feeding in less voltage than you have configured the regulator to output.I have a Buck regulator outputting 24V. (TPS54560DDAR) (http://www.ti.com/lit/ds/symlink/tps54560.pdf)That 24V powers a 19V LDO linear and a 3.3V BuckThere could be a case where I would need to power the device with only a 24V power source that could drop down to 21V. ( Normally 36VIN )The regulator (TPS54560DDAR) states after doing the calculations that the Minimum voltage required at my current would be about 25.3V.What happens when I go under that... does the device stop working and not output any voltage at all?Or does it just start outputting whatever voltage is coming in?What if the VIN goes under the configured VOUT of 24V.With my 19V LDO I can go down to 22V so if my VIN is 22V will the buck regulator just output that 22V?Thanks in advance and I hope I have given enough detail

author: Zero999
author_rank: Super Contributor
timestamp: October 04, 2018, 10:30:46 am
content: It depends on the topology of the buck regulator. The one you've linked to has a bootstrapped N-MOSFET output stage, which means it can't work at 100% duty cycle, which will probably limit the drop-out voltage more than the MOSFET's on resistance.The data sheet says if the output voltage is close to the input voltage, the MOSFET will turn on, until the voltage bootstrap capacitor is too low, causing it to turn off for the time necessary to recharge it. The duty cycle will be near 100% but not quite. The calculation for the drop-out voltage is given at the bottom of page 13: 7.3.4 Low Dropout Operation and Bootstrap Voltage (BOOT)http://www.ti.com/lit/ds/symlink/tps54560.pdfIn short, if the input voltage drops below the set output voltage, the output transistor will turn on for the maximum duty cycle possible. There will be some voltage drop, but not much.
Buck regulator - Page 1
Forum section: electronics / beginners

author: gsingh11
author_rank: Contributor
timestamp: January 27, 2023, 02:40:37 am
content: Hi, I am using a wall adapter that supplies up to 6A output current. and I am using a buck regulator LM2596 to step down to 5V for a microcontroller. Is the 6A an issue for the buck regulator?

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 27, 2023, 07:04:23 am
content: For a buck regulator the current will only be an issue when it is actually flowing and it is not rated for such a current. The input voltage is more of an issue. It should be within the range of what the regulator can handle. Find the datasheet of the LM2596 and look at the characteristics for what it can handle.The answer is in your own writing already. The supply can deliverup to6A.

author: bidrohini
author_rank: Regular Contributor
timestamp: January 27, 2023, 07:59:34 am
content: The maximum output current of the wall adapter is not an issue for the LM2596 buck regulator as long as the input voltage to the regulator is within its specified range and the maximum output current of the regulator is not exceeded. However, you should ensure that the maximum current draw of your microcontroller does not exceed the maximum output current of the LM2596, which is typically 3A.

author: Zero999
author_rank: Super Contributor
timestamp: January 27, 2023, 06:34:53 pm
content: The load, i.e. buck regulator or whatever, will only draw as much current as it needs.Often it's necessary to have some over-current protection, such as a fuse or circuit breaker, but in this case, your power supply is probably current limited. If you were using it to power a lower current circuit then it would be required.
Buck/Boost converter IC - Page 1
Forum section: electronics / beginners

author: max91
author_rank: Newbie
timestamp: June 09, 2015, 08:42:12 pm
content: Hi guys,For one of my projects I need a buck-boost converter IC which would take 12-14V as an input and would output a voltage between 5V and 20V with a maximum current of 300mA. I should be able to control the output voltage from a microcontroller, so I have to be able to adjust it either by using a PWM signal or by I2C, SPI,...Does anybody know of an IC that would satisfy this requirements? It would be best if as few external components as possible would be needed, as size is a constraint. I tried searching for something suitable for the past couple of hours, but with no luck.In case there isn't such a circuit, is it ok to cascade a boost converter IC with a buck converter IC? I could first boost my voltage to 22V and then use a digitally controlled buck converter to obtain the needed voltage.Thanks!

author: Cliff Matthews
author_rank: Unknown
timestamp: June 09, 2015, 10:14:21 pm
content: Have you gone to the product selection pages? Here's one from TI:http://www.ti.com/lsds/ti/power-management/buck-boost-converter-products.page
Buck/boost module for LFP battery project - Page 1
Forum section: electronics / beginners

author: gyrex
author_rank: Newbie
timestamp: July 10, 2025, 12:27:03 am
content: Hi guys,Can someone please help me find a buck/boost (step up/down) DC-DC module for a 32700 LFP dashcam battery project I'm working on? Ideally a module capable of 15A constant for an hour (the LFP battery I've built is 18Ah).I can see there's some LTC3780 modules on Aliexpress but these seem limited to 10A and then only peak demand for a short period of time. There's a bunch of buck and boost modules which fit the bill but given that the alternator fluctuates around the bulk charging voltage I really need a module capable of both buck and boost.Thanks in advance for any suggestions.

author: Konkedout
author_rank: Frequent Contributor
timestamp: July 10, 2025, 02:41:33 am
content: You could have both a buck and a boost (separate converters) and maybe get better efficiency.

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: July 12, 2025, 08:02:26 pm
content: Can OP clarify why he needs buck-boost?Is it because LFP battery consists of multiple cells in series (ex. 4s LFP, therefore a voltage range of 11.2-14.4)? If so, commercial MPTT's may work, such asthis one. However you may need to find an MPTT which supports varying the battery charging current & voltage.Or will it be a 1s LFP battery, therefore a buck converter of ~14v (from the alternator) will charge the 1s battery (2.8v-3.6v), with the additional boost being required for powering the dashcam? If so, this is much cheaper & easier and you should be able to use some Aliexpress buck converters.
Budget *wide* logic analyzers? - Page 1
Forum section: electronics / beginners

author: david.given
author_rank: Contributor
timestamp: February 09, 2022, 01:19:54 pm
content: I have an 8-bit CPU bus I want to snoop. This means I need a logic analyser with up to about 32 channels --- sixteen address, eight data, and a handful of data lines.Clearly my existing budget 8-channel Saleae clone isn't going to help here. Are there any recommendations for other cheap logic analysers which might help me? I've hunted around but there appears to be a huge price gap between the 8-channel ones and anything wider.I have thought about building my own; I have some PSoC5 dev boards, which have loads of GPIO and run at a convenient 5V. But I'd rather not!

author: rstofer
author_rank: Super Contributor
timestamp: February 09, 2022, 04:49:02 pm
content: Not cheap but the Digilent Digital Discovery tool will probably do the job. You don't necessarily need the high speed adapter right out of the gate, it depends on how fast you need to measure and for most early uCs, 200 MS/s will be more than adequate.https://digilent.com/shop/digital-discovery-portable-usb-logic-analyzer-and-digital-pattern-generator/There's a lot of capability in that little box.Download and install the free Waveforms software and play with the demo device. See the options!

author: Martian Tech
author_rank: Regular Contributor
timestamp: February 09, 2022, 05:13:31 pm
content: How about a vintage HP like the 1631D? They can be found at reasonable prices.

author: voltsandjolts
author_rank: Unknown
timestamp: February 09, 2022, 05:21:46 pm
content: Quote from: david.given on February 09, 2022, 01:19:54 pmFor what purpose? Reverse engineering?...but then the CPU code is perhaps already available in external FLASH/EPROM?

author: david.given
author_rank: Contributor
timestamp: February 09, 2022, 05:55:24 pm
content: Quote from: voltsandjolts on February 09, 2022, 05:21:46 pmVLSI CPU with onboard ROM.(I actually think this is going to be futile as the onboard ROM is probably on a different bus interface but I won't know until I look.)Quote from: Martian Tech on February 09, 2022, 05:13:31 pmWhere? The only one I can see on our favourite auction site is €400!

author: Martian Tech
author_rank: Regular Contributor
timestamp: February 09, 2022, 07:27:18 pm
content: Quote from: david.given on February 09, 2022, 05:55:24 pmYou haven't stated a target price range.Patience will often result in better deals on the auction site.There are other models. Perhaps a 1631A or G, a 1630, 1650, 1651, 1652, 1661, 1662, 1672? Just make sure if you do buy one that it comes with the pods/probes.
Budget replacement for my yihua 852d (clone) hot-hair / soldering station - Page 1
Forum section: electronics / beginners

author: tlex
author_rank: Newbie
timestamp: March 22, 2020, 11:15:43 am
content: Hi,I've been using that station bought on ebay for 5-6 years without any issues (light usage here) and now the soldering part is falling apart... I replaced the handle - ceramic etc a few times but now I would like to replace the station for a new one using T12 tips.I have a TS100 for my portable usage and I really like the t12 tips...I was wondering if someone could help me with the following questions :1) Is there any budget friendly combo station (hot-air / soldering) that use t12 tips ? the only one I found was this one so I'm wondering if you have any advice or suggestion on that ? (plus I think it's a bit expensive no ?)https://www.banggood.com/KSGER-STM32-OLED-T12-Temperature-2-in-1-Hot-Air-Dryer-Digital-Rework-Soldering-Station-Solder-Iron-p-1407450.html?rmmds=search&cur_warehouse=CN2) I love my ts100 but I was wondering if any non-portable t12 soldering station would be more powerful ? sometimes it is not strong enought to desolder so that's why I was still using my 852...Thanks for your help

author: Vovk_Z
author_rank: Super Contributor
timestamp: March 22, 2020, 01:56:40 pm
content: As I have seen there is a lot less combo stations, so I would prefer to buy separate devices.T12 is a good choice. My cheap T12 works almost exact as good as Ersa 2000 (I have worked with), I am happy with it. I have Lukey 702 too, but T12 is absolutely at another level from 702.
Buffer selection - Page 1
Forum section: electronics / beginners

author: Muhammad Nasar
author_rank: Contributor
timestamp: July 19, 2012, 04:58:15 pm
content: Hello guys, I want to ask what is is difference between the Logical buffer IC (Like 74hc244) and a buffer made out of op-amp as voltage follower? actually I want to drive some LEDs via a micro-controller, using a 2 meter long CAT-5 cable between the micro and the LEDs. So what may I use, a Logical buffer IC or op-amp as voltage follower?

author: Simon
author_rank: Unknown
timestamp: July 19, 2012, 05:04:45 pm
content: The logic buffer will output VCC or 0V as it only buffers logic levels of 0 and 1. The opamp buffer will match the output voltage to the input voltage whatever it is within a certain range

author: T4P
author_rank: Super Contributor
timestamp: July 19, 2012, 05:08:27 pm
content: a logic buffer is logic (duh!) if you look at CD4050's datasheet you'll know why.and a opamp in voltage follower will output the same voltage ... that's why it's called a followerit "follows" the voltage

author: Simon
author_rank: Unknown
timestamp: July 19, 2012, 05:16:33 pm
content: Quote from: DaveXRT on July 19, 2012, 05:08:27 pmWhy do most of your posts add very little information and border on offensive ? The majority of users around here are oh so sorry if we are not all as clever as you mightyness, but theres no need to ram your "cleverness" down every ones throat, Thank you !
buffer with "diamond" configuration - Page 1
Forum section: electronics / beginners

author: fady232
author_rank: Contributor
timestamp: April 28, 2025, 11:15:02 am
content: Hello, its me once again.I came up with another circuit, which im trying to simulate in order to keep learning.I made this circuit that has 4 transistors, 2 npn and 2 pnp.What i expect from this circuit is the the input sine wave.From what i understood the circuit below should work like this: i apply a sine wave to a npn and pnp transistors, what happens is that the transistors npn ( which is called Q1 in the schematic ) will shift down the signal by 0.7 ( this is what i see on emitter )the same sine wave gets shifted up by the pnp transistor on its emitter ( which is called Q2 on the schematic )At this point, the signal at the emitter of the npn transistor is given into the base of the second PNP ( which is called Q4 ), what the second pnp does it shifting it up again by 0.7 ( 0.7 is an approximation, lets say thats the drop on the diode), in this way u cancel the previous offset given by the npn, same thing work for the pair Q2 / Q3.Now my questions are:1)Is this the correct way to analyze this circuit? i got it well or i misunderstood? and if so then how it works?2)Why the simulation shows that on its output, the signal goes from -4.5 to 4.5V? ( sine wave is 9V amplitude)Thanks.

author: Whales
author_rank: Super Contributor
timestamp: April 28, 2025, 12:09:25 pm
content: QuoteDo you mean you expect the output to look like the input?Your explanation makes sense if your circuit is just a collection of common-collector amplifiers, but your circuit has a difference.Consider this conduction pathway:I am not sure how this would behave in real life where the transistors will not be perfectly matched and your input signal will not be a perfect voltage source.QuoteI don't understand. Is that not what you want?

author: fady232
author_rank: Contributor
timestamp: April 28, 2025, 12:12:05 pm
content: "I don't understand. I that not what you want?"No i wanted 9V but i understood my mistake, there is a voltage divider at the output.Why in real life it would have problems? cus voltages wont be perfectly matched?

author: mikerj
author_rank: Super Contributor
timestamp: April 28, 2025, 01:16:31 pm
content: Quote from: fady232 on April 28, 2025, 11:15:02 amThe Wikipedia page on the diamond buffer describes it's operation quite thoroughly:https://en.wikipedia.org/wiki/Diamond_buffer

author: SteveThackery
author_rank: Super Contributor
timestamp: April 28, 2025, 03:21:28 pm
content: Quote from: mikerj on April 28, 2025, 01:16:31 pmIs it me, or is the schematic wrong? T1 appears to be connected directly across the power rails with no load or current limiting resistors.EDIT: Oh, wait. Are IE1 and IE2 constant current sources? That makes more sense.
Build a battery pack with a pcm/pcb... - Page 1
Forum section: electronics / beginners

author: marc.collin
author_rank: Newbie
timestamp: March 02, 2015, 04:36:39 pm
content: hii would like to build a battery pack with li-on 18650 at 3100mAh.i will do a 4S4Pso the pack will 14.8V Pack, 12.4AhBattery will be used for a led at 12V and 2.4A.A driver will be used.when i check on thishttp://www.batteryspace.com/pcbfor144v148vpack.aspxfor a pcm/pcb, there are a lot of choice.i want to use one who support Balance Function.i saw then they manage differentContinuous Discharge Rate(A)andMax Discharge Rate(A).how to know how to select the one i need?
Build a hardware interface for PC with Arduino or other chip. - Page 1
Forum section: electronics / beginners

author: Forser
author_rank: Contributor
timestamp: May 20, 2016, 07:48:37 pm
content: Greetings,I am curious on building a small, hardware interface with a few buttons which could be programmed in the software on the PC to like update a text string showing on a live stream, like if you die in the game, you press the red button.Want to avoid sending the command as a keyboard press or mouse since it can conflict with the game.Is it possible or am i dreaming?Guessing it would require a unique driver if it wants to be able to work against the OS without emulating keyboard / mouse.Thanks in advance!

author: mariush
author_rank: Super Contributor
timestamp: May 20, 2016, 07:59:39 pm
content: Use a usb to serial/uart chip on the arduino board, or just use a PIC microcontroller with usb functionality built in (and configure the usb as generic hid device). Write a custom application that opens the serial port and listens for text coming from the controller, or just read the incoming data if you present your device as generic hid.Configure OBS or whatever tool you use to broadcast to capture the window of your application and you're done.Examples :1.http://www.waitingforfriday.com/index.php/Building_a_PIC18F_USB_device2.http://forum.allaboutcircuits.com/threads/full-usb-tutorial-for-pic-microcontrollers.101891/3.http://www.pyroelectro.com/tutorials/simple_pic_usb_interface/

author: Forser
author_rank: Contributor
timestamp: May 20, 2016, 08:11:30 pm
content: ThanksWas trying to find stuff by googling but found pretty much only Keyboard / Mouse emulation.
Build 'ldeal' Zero forward voltage 3A 50V diode module? - Page 1
Forum section: electronics / beginners

author: incf
author_rank: Frequent Contributor
timestamp: April 11, 2025, 01:27:33 am
content: What would it take to build module that sits on the output of a bench power supply and acts like an 'ideal' zero forward voltage 3A 50V diode. For testing/simulating/charging batteries and designs that interface with rechargeable batteries.I suppose it's nothing more than an op-amp or comparator and some series P and N-channel FETs? (and maybe a heatsink)Are there any considerations when designing and "ideal diode" emulator?

author: Smokey
author_rank: Super Contributor
timestamp: April 11, 2025, 02:31:33 am
content: Lots of ideal diode questions recently.Use an ideal diode controller and an nchan fet (or 2).Some partsKTS1900LM74502LM7480

author: Konkedout
author_rank: Frequent Contributor
timestamp: April 11, 2025, 03:14:15 am
content: It is easy to make an ideal diode controller if you do not need fast response time. You need an op amp for each MOSFET.If you have a higher bias voltage for driving the MOSFET gate then you can use Nch FETs. This LTSpice sim shows that.If you do not have a higher bias voltage available then it can be done with Pch FETs. The op amp polarity needs to be inverted for that.3A should not be a problem without a heatsink and without very large MOSFETs.
Building 1-1,4V battery life indicator advice - under 5$ - Page 1
Forum section: electronics / beginners

author: DuncanSteel
author_rank: Contributor
timestamp: June 24, 2018, 07:06:57 pm
content: HelloI would like to build a battery life indicator that could be hooked up toPhilips oneblade, what are my realistic options? Some quick advice would be appreciated.Goal:Voltage range: 1v to 1,4VDevice size preferably: 0,5 x 15 x 30mmPoints of interests:1. Did not find any already existing solutions a person could buy for this voltage range.2. Could you recommend some components to look into?3. Maybe use cheap arduino clone, boost converter, some LED-s & a push button?

author: Nusa
author_rank: Super Contributor
timestamp: June 24, 2018, 08:12:06 pm
content: Sounds like a job an AA battery tester would work for. They comes in many different shapes and sizes. The cheap ones are under a buck on ebay and other such sites.

author: DuncanSteel
author_rank: Contributor
timestamp: June 25, 2018, 06:49:51 pm
content: I have been thinking & came to conclusion that all I need is a switch that will turn off the led when voltage reaches 1V.Say the led that requires 2V must light on if voltage is over 1V & not light up if voltage is 1V or below.Use Case:1. User holds the switch & voltage is over 1V (led is on)2. User holds the switch & voltage is below 1V (led is off)Is there any simple way to achieve this?
Building a 13.8V DC PowerSupply with a 7812 12V fixed voltage regulator - Page 1
Forum section: electronics / beginners

author: Axel1973
author_rank: Regular Contributor
timestamp: February 02, 2013, 11:18:40 pm
content: Hey ya Experts,i got an old n crapy 13,8V 3A DC powersupply from CONRAD Elektronik/Germany which just uses a transforer, some Zener Diodes, few resistors, caps and two transistors to regulate the output, which is not performing too well. So i wanted to try some improvements from scrap parts i had laying around.So i started experimenting with a 7812 fixed voltage regulator and "raised" the output voltage up to 13.8V with a pot on its "ground pin". It seemed to work "ok". However if draining too much current (~1A+) it also starts to drop the output quiet significant.So i added a series Power transistor to do the heavy work and yet it looks quiet good to me.Here is the schematics. photos will come another day.Requesting for comments/suggestions/improvements/safety. What do you think about it so far?Thanks and greetsAxel

author: grumpydoc
author_rank: Super Contributor
timestamp: February 02, 2013, 11:23:45 pm
content: 1N400x diodes are only rated for 1A, you want 1N540x for 3AEdit: Actually this won't regulate well, the 7812 can only sense the base voltage of the pass transistor not the actual output voltage. Thedatasheetgives the correct boost transistor configuration.

author: Axel1973
author_rank: Regular Contributor
timestamp: February 02, 2013, 11:30:04 pm
content: thanks! good one!in fact, i didnt used diodes at all for rectification. i used a bridge rect that is rated for 3A+.Because KiCad didnt offered me a "fitting" bridge rect i had to use "simple diodes" for the schematics.

author: c4757p
author_rank: Super Contributor
timestamp: February 03, 2013, 03:49:34 am
content: KiCad's built-in library sucks.

author: Axel1973
author_rank: Regular Contributor
timestamp: February 03, 2013, 08:15:58 am
content: Quote from: grumpydoc on February 02, 2013, 11:23:45 pmoh wow! i didnt checked the datasheets for examples. thanks mate. will try that too

author: Simon
author_rank: Unknown
timestamp: February 03, 2013, 03:16:48 pm
content: yes your reg is just acting as a crude voltage reference now
Building a DC converter, need suggestions for IC - Page 1
Forum section: electronics / beginners

author: vgamesx2
author_rank: Regular Contributor
timestamp: February 09, 2018, 11:08:11 pm
content: Basically, I'm wanting a portable power supply, so my requirements are an input of 3V (I don't mind implementing a BMS for a 2S or 3S pack but obviously that isn't prefered) and I would like a minimum of 3V-24V output although what I'm really looking for is closer to 1V-40V and because it'll be running off a battery I want an efficiency of at least 90%, I know of a few ICs that are fit for the task such as the LTC3780, however my problem is that unless you're ordering 100s of them they cost around $10 a pop, which is why I'm asking on here, does anyone know of something similar to the LTC3780 but won't cost as much as buying a premade board and ripping the chip of it?

author: danadak
author_rank: Super Contributor
timestamp: February 10, 2018, 12:30:40 pm
content: If you go onto many manufacturer websites, and places like digikey, you can dofiltered searches to narrow down your choices, many which have unit prices.Just a thought.Regards, Dana.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 10, 2018, 01:07:50 pm
content: It rather sounds like you don't know what you want, and therefore you're going to have to pay for it...This is a single cell boost supply that can be wired as an adjustable CV/CC bench supply,https://www.eevblog.com/forum/projects/building-a-simple-switching-circuit/msg1252706/#msg1252706but as a boost, it will only go down to battery voltage. Change the output stage to a SEPIC configuration to include zero output.Tim
Building a load lamp setup for circuit testing - Page 1
Forum section: electronics / beginners

author: ddewaele
author_rank: Newbie
timestamp: September 03, 2020, 03:39:33 pm
content: Hi,I have a 3 way extension lead that I would like to use to stick it in the wall, put a load lamp (40W oven lamp) in series with it, and then use one of the prongs to insert my circuit under test. (the idea is that the load lamp would prevent the circuit from destroying itself in case of an issue).(I'm in Europe where we have 230v AC, and I would like to setup a load lamp circuit to protect my circuits under tests.)If I cut the extension cord cable , and I take the black wire out (hot), cut it and put a load lamp in between, would that be a valid circuit for a load lamp.My apologies for the drawing, the amateurism reflects my knowledge of basic AC electrical wiringThe goal is to test a circuit that is currently causing some kind of short, and put this setup behind an isolation transformer also.Some questions :Is this the way to do it ?I only have a relatively small 40 watt oven lamp ? Would that be ok ? The circuits that I would test with this are mostly switch mode power suppliesIf I would short one of the prongs in the extension lead would the light simply come on and would nothing else happen ? (it is a bit counter-intuitive to short a prong like that in my head, but the way I see it the circuit would just look a standard AC light bulb circuit)If the circuit under test is running without issues I would hardly see the bulb go on I imagine ?I've seen videos where people put the bulb in series with the black lead, but others that put in series with the neutral / gnd lead. What is the difference ?Does adding an isolation transformer change anything ? (the idea would be to put this on an isolation transformer instead of plugging it in the wall socket directly)

author: ledtester
author_rank: Super Contributor
timestamp: September 04, 2020, 02:53:04 am
content: This device is also called a "dim bulb tester".It's been discussed a lot on these forums. Some recent discussions:https://www.eevblog.com/forum/projects/dim-bulb-tester-totally-enclosed-with-switchable-cooling-fan/msg3180804/#msg3180804https://www.eevblog.com/forum/buysellwanted/ebay-dim-bulb-tester/msg3125264/#msg3125264QuoteGenerally you want to use a bulb that has about the same wattage as the device you are powering. For instance, this page (https://antiqueradio.org/dimbulb.htm) suggests:Quote