hybridfree/eevblog-posts huggingface dataset:
design methos for RF boards question - Page 1
Forum section: electronics / projects

author: george79
author_rank: Contributor
timestamp: March 03, 2024, 12:29:53 pm
content: Hello,i want to design some amplifier boards for testing, practise and give to some friends to make RF linear amplifiers. Not high frequency, will be limited to the amateur bands with the upper at 50Mhz. I have found a lot of MRF300AN and MRF300BN and i will be focus to this Mosfet. MY main problem is how to make this boards on EASYEDA, and i mean the traces because they are not like the other we design and see everyday, the most of them are rectangular shapes and they connect the SMD parts.Have anyone some experience to this please??i upload some pictures to get an idea what i mean from some manuacturers.

author: mag_therm
author_rank: Frequent Contributor
timestamp: March 03, 2024, 02:21:25 pm
content: Hi George79Why is that rectangular block method needed?It came from the days when proto boards were etched after etch resistant tapes (or painted lines)were laid straight on bare copper forming the gaps between pads.Other (tedious) method , bare copper was cut with knife against steel rule, and the copper peeled off.Similar to your project, I have designed a wideband linear amp as driver for SiC mosfets for 7 ~ 14MHz.As I expose and etch the board here, I break a lot of pcb rules.These boards are on MG Chemicals double sided photo resist coated stock.Only one side is exposed. The bottom side is left as solid shielding layer.M3 stainless screws through the board pull the board down to a 6.3mm aluminim heatsink,and also connect the ground rails on the exposed side.https://app.box.com/s/h0689louibgyzqpooi6g0nsnq4hqputyYour MRF300 look good for HF preamp.My components, referring the the above trackwork image:The preamp is FMB2227A as inside out complementary (top right ).The drivers are FTZ651/751 as inside out complementary (collectors in the big rectangle).Two boards are needed to drive the finals in 45 Watt.Finals are two Genesic G3R450MT17D_GeneSiC in push pull are on a separate heatsink (pads on the upper left edge).I have one 45W linear amp working for a year on 20m ft8 and wspr.I have just improved the track layout. About to try just one board driving the antenna via the filter for wspr.The 45W version : Drain voltage adjustable 50 ~ 200 V. Efficiency about 50%RF In 27dBm, Out 47dBm. Spect. An. is permanently connected to output via a Tee, to adjust the level and monitor the harmonics.Regards

author: MarkT
author_rank: Frequent Contributor
timestamp: March 03, 2024, 02:56:47 pm
content: Quick search suggests using Solid Region in Easy EDA will do what you want.
Design of a 4th Order Sallen-Key Bessel Low Pass Filter for Seismometer Data - C - Page 1
Forum section: electronics / projects

author: hsynylcn
author_rank: Contributor
timestamp: April 28, 2025, 08:26:08 pm
content: I am building a device that converts analog data from a seismometer at school to digital. I need to filter the analog signals before giving them to the ADC. For the low-pass filter I chose a Sallen-Key Bessel type filter because it has low phase delay and group delay. The low pass filter I want to do is to cut above 50 Hz. I made this circuit in FilterPro application. Do you think it is correct? Is there any advice you can give?

author: Benta
author_rank: Super Contributor
timestamp: April 28, 2025, 09:05:29 pm
content: You're mixing up filtertopologyand filterresponse.Sallen-Key is a certain circuit configuration and has nothing to do with phase respone or group delay.I see you've chosen a Bessel response which is optimised for linear phase response (= constant group delay), so a very good choice if that's the main design parameter.But I suggest you choose a MFB filter topology instead, which has superior performance.Seehttps://www.ti.com/lit/pdf/sloa049for more info (especially p.14/15).

author: Kleinstein
author_rank: Super Contributor
timestamp: April 29, 2025, 04:47:09 pm
content: In most cases one would today use some oversampling from the ADC and do the final low pass filtering in the digital domain. So the analog filter would mainly be there as AA filter for the ADC and the exact charcteristics is not that critical. It also depends on the ADC - a SD ADC may need less filtering than a sampling type ADC. Seismic data usually also don't contain much higher frequency background, though maybe mains hum, that could be in the transition region.
Design of Active-ORing - Reg - Page 1
Forum section: electronics / projects

author: electric_newbie
author_rank: Newbie
timestamp: June 15, 2017, 11:06:31 am
content: Hi,I am Designing an Active O-ring circuit. The Circuit has two voltage sources 48V and 36V. The 48V source (battery) is swappable.My Requirement isWhen the 48V source is removed the 36V source should power the circuit and when the 48V is added to the circuit the 36V source should stop discharging.Based on my requirement I have designed an O-ring circuit. Let me know if there is any mistake in the circuit.

author: mikerj
author_rank: Super Contributor
timestamp: June 15, 2017, 11:16:05 am
content: I don't think the DC-DC converter will work very well with it's output connected to it's input...

author: electric_newbie
author_rank: Newbie
timestamp: June 15, 2017, 11:24:38 am
content: The Output and Input are not tied. The line between output and input is just a representation that Switch A and Switch B share the same state (i.e. when switch A is open switch B is open and vice-versa).
Design of compesator for flyback converter.  - Page 1
Forum section: electronics / projects

author: Patrick66
author_rank: Regular Contributor
timestamp: March 07, 2024, 04:56:48 pm
content: Hello everyone, I have a question I would like to ask, based on the figure below is there any way to increase the cross-over frequency to 5 kHz while maintaining the stability of the system because now my cross-over frequency is 42.65 Hz while my switching frequency is 100 kHz. The figure below is the open load transfer function for a flyback converter. Will including gain, PI, PD or PID will help with that? Thank you everyone in advance.
Design of Delta Sigma Modulation for Power Converter - Page 1
Forum section: electronics / projects

author: diegoperez
author_rank: Contributor
timestamp: December 17, 2015, 03:40:12 pm
content: Hi,I wonder if someone has any advice or knows of some documentation that could be used to design a delta sigma modulator (the modulator would be used in a switch mode power converter).Any info, ideas or advice would be appreciated.Thanks!EDITED: just a typo.

author: tszaboo
author_rank: Super Contributor
timestamp: December 17, 2015, 03:56:48 pm
content: TI makes ADCs, which are modulators. Any chance that they are perfect for the job?

author: Kalvin
author_rank: Super Contributor
timestamp: December 17, 2015, 04:22:44 pm
content: Class D amplifiers are typically implemented using PWM technology, but can also be implemented using delta-sigma technology:http://www.analog.com/library/analogDialogue/archives/40-06/class_d.pdfThe AD1990 etc. seem to be obsolete now, though.

author: diegoperez
author_rank: Contributor
timestamp: December 17, 2015, 04:27:45 pm
content: No, I need to implement it on a FPGA, that is why I need to design it first.

author: tszaboo
author_rank: Super Contributor
timestamp: December 17, 2015, 04:38:06 pm
content: Quote from: diegoperez on December 17, 2015, 04:27:45 pmIt is an analog part. Meaning, unless you hack a digital pin to use it as a comparator, and add some passives, you will need something doing the encoding.http://www.latticesemi.com/~/media/LatticeSemi/Documents/WhitePapers/AG/CreatingAnADCUsingFPGAResources.PDF?document_id=36525This might give you some pointers how to start with it.

author: moffy
author_rank: Super Contributor
timestamp: December 17, 2015, 11:22:58 pm
content: I have a rough 2nd order circuit/LTSpice simulation. Gives about 100db s/n ratio at 200Hz and uses some basic op amps etc. The comparator is overkill, but I used it in the simulation for convenience.

author: Scrts
author_rank: Frequent Contributor
timestamp: December 18, 2015, 01:22:43 pm
content: I saw a couple of projects on Google how to make a delta-sigma DAC on FPGA.E.g.http://www.xilinx.com/support/documentation/application_notes/xapp154.pdf
Design of lead acid battery charger - Page 1
Forum section: electronics / projects

author: khatus
author_rank: Regular Contributor
timestamp: October 20, 2021, 07:49:42 pm
content: Hello guys, I wanted to design a lead-acid battery charger using CN3767 4A, 12V Lead-Acid Battery Charger IC. I wanted to know what features a lead-acid battery charger should have?I am following this circuit.Any additional circuitry for improvement??

author: floobydust
author_rank: Super Contributor
timestamp: October 20, 2021, 08:35:07 pm
content: Never heard of Consonace semi before.CN3767does not have temperature compensation for charging voltage. Greenland is arctic weather, no?So the IC is a fail. Shill would not buy.

author: David Hess
author_rank: Super Contributor
timestamp: October 21, 2021, 11:02:56 pm
content: Features I would want in a good lead-acid battery charger:1. Temperature compensation.2. Charge to the equalization voltage, about 14.2 volts, and then once the current drops, switch to the float voltage, about 13.8 volts.3. Remote sense if the charger cannot be located at the battery.4. Input current limit to protect the power source.

author: salihkanber
author_rank: Regular Contributor
timestamp: October 22, 2021, 07:34:25 pm
content: Keeping Lİ-Ion chargers, your work will be easier. I suggest a literature research on the topic, there are lots of online papers on many online resources.For example:https://www.powerstream.com/SLA.htmorhttps://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html

author: floobydust
author_rank: Super Contributor
timestamp: October 22, 2021, 07:43:54 pm
content: What comes first? Selection of the IC to use, or the Project Requirements?For lead-acid, there are anything from 2-stage to 8-stage chargers out there nowadays.OP's IC is fixed 14.8V equalization and 13.55V float, SSOP-10 with no thermal pad yet good for "up to 4A"?The extra reverse polarity protection mosfet does nothing for the buck diode, which will smoke. ButUSD $0.75though. It seems to be a small semi company with good intentions but unrefined products.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 23, 2021, 02:29:02 pm
content: Quote from: floobydust on October 22, 2021, 07:43:54 pmIt doesn't handle the current directly so the chip's "4A" limit is most likely limited by how large of a MOSFET it can drive. Add a buffer and there would be no theoretical limit to how high it can go.
design of linear regulator efficiency tester under differnent load conditions - Page 1
Forum section: electronics / projects

author: yogece
author_rank: Contributor
timestamp: November 04, 2013, 03:28:27 am
content: hi,I would like to design a liner regulator efficiency tester such as 78xx, LDO.can any one suggest me from where to start

author: digsys
author_rank: Unknown
timestamp: November 04, 2013, 04:11:13 am
content: This has to be the easies assignment ever !Open up EXCEL - create at least 7 columns - Vin, Iin, Pin, Vout, Iout, Pout, EfficiencyEff = Pout/Pin x100That's 100% accurate for Resistive loads, for ANY type of Linear Regulator (or use RMS for changing loads).

author: yogece
author_rank: Contributor
timestamp: November 04, 2013, 05:37:50 am
content: No.I thought of designing automated efficiency tester using arduino;I need some suggestions regarding the circuit designing.Thanks for your reply

author: Bored@Work
author_rank: Super Contributor
timestamp: November 04, 2013, 06:11:22 am
content: What digsys tries to tell you is that building a linear regulator efficiency tester is a pointless activity. The efficiency can be calculated with good accuracy and need not be tested.Quote from: yogece on November 04, 2013, 03:28:27 amBy getting your theory right.

author: jmaja
author_rank: Frequent Contributor
timestamp: November 04, 2013, 09:33:41 am
content: Quote from: digsys on November 04, 2013, 04:11:13 amThat's true for switching regulators as well, but how do you know Iin as a function of Iout? For larger loads you can assume Iin=Iout for linear regulators, but not for low loads, since they have ground pin currents from few uA to few mA.

author: digsys
author_rank: Unknown
timestamp: November 04, 2013, 11:58:54 am
content: Quote from: jmajaIt's still a loss DUE to the regulator, therefore included in the efficiency.

author: yogece
author_rank: Contributor
timestamp: November 04, 2013, 02:16:31 pm
content: Quote from: Bored@Work on November 04, 2013, 06:11:22 amI would like to design something like this

author: jmaja
author_rank: Frequent Contributor
timestamp: November 04, 2013, 03:47:25 pm
content: Quote from: digsys on November 04, 2013, 11:58:54 amOf course, but it makes some sense in measuring the efficiency at different loads instead of just calculating it, which you can do very accurately at higher loads.

author: Jon86
author_rank: Frequent Contributor
timestamp: November 04, 2013, 06:41:17 pm
content: Inrush currents and ripple with an arduino? Good luck...
Design of simple/cheap "spectrum analyzer"-like device - Page 1
Forum section: electronics / projects

author: JJalling
author_rank: Unknown
timestamp: April 18, 2018, 09:41:43 am
content: Hello,As the title says, what I think I need, is a spectrum analyzer-like device.I was contacted by a friend, regarding a fun little project. The goal of the project, is to monitor the S/N ratio or signal strength on 10-20 radio transmitters, each with transmitting with their own frequenzy in the 400MHz-450MHz range.My first thought was to use a USB-SDR dongle and a small computer, but I don't find that solution very elegant. Does anyone have an idea of an alternative solution to this?I'm sorry about the very vague description, but it is more or less what I know right now.EDIT: Clarification about the project scope.The goal of this project, is to have multiple receivers in a room (like sports arena) and do triangulation to calculate the relative position of the transmitters.The reason for using the existing transmitters, is that we don't want to add more hardware/weight to the the devices carrying the transmitters.Hopes that this clarifies it a bit.BR Jonas

author: kripton2035
author_rank: Super Contributor
timestamp: April 18, 2018, 10:05:35 am
content: http://j3.rf-explorer.com/available at seeedstudio for $99 model 433MHzwill cost you more to design your own.

author: JJalling
author_rank: Unknown
timestamp: April 18, 2018, 10:36:08 am
content: Quote from: kripton2035 on April 18, 2018, 10:05:35 amHi,yes, besides the frequency range is too narrow, it could be a solution.BR Jonas

author: BravoV
author_rank: Super Contributor
timestamp: April 18, 2018, 10:48:34 am
content: TI MSP-SA430 ?Frequency Ranges:300 – 348 MHz389 – 464 MHz779 – 928 MHzQuite costly though at $249.There was a crazy sales by TI few years ago for this at only $25 with s/h included, and this made quite a riot of buying frenzy ->$25 Spectrum analyzer ...

author: kripton2035
author_rank: Super Contributor
timestamp: April 18, 2018, 11:51:59 am
content: Quote from: JJalling on April 18, 2018, 10:36:08 amthen you can go to the $175 model which has an ISM band.still cheap compared to any other solution IMHOhttps://www.seeedstudio.com/RF-Explorer-ISM-Combo-p-1092.html

author: MasterT
author_rank: Frequent Contributor
timestamp: April 18, 2018, 12:05:08 pm
content: There is product line from SiLabs, Si4432 & Si4463. You may get a module on aliexpress.Seems main objective is to build a radio direction finder. Quite easy for CW and AM, but you didn't tell what kind of modulation, if it's digital may be tricky or not possible in reasonable price range.

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 18, 2018, 01:10:17 pm
content: If your project is strictly for indoor positioning, you may also take a look at this technology:https://decawave.com/products/overview
Design Questions for my own function generator - Page 1
Forum section: electronics / projects

author: jack32
author_rank: Contributor
timestamp: November 07, 2012, 10:51:51 am
content: Hi,I am in the process of designing my own function generator.I am currently planing to use an AD9833 controlled by an atmega.My motivation: i don't have a function generator and building one should be fun.My problem: i don't have a function generator nor have i used one before, soi don't really know what i need.Creating sin, sqare and sawtooth waveforms with an ad9833 should be easy. Iam experienced with microcontrollers, spi and other digital stuff.Do i need an controllable DC offset and amplitude for a usable function generator?Sure, it sould be (almost) useless without...But to what limits? What about 5V amplitude and +-5V offset?Which op amps could i use for that?I don't have a lot of experience planing my own op amp circuits, so that would be the hard part for me.Jack

author: notsob
author_rank: Frequent Contributor
timestamp: November 07, 2012, 11:23:41 am
content: You may be interested in reading this article, All the DDS is done by the Atmel, and the source code is available, output is sine, square, triangle, sawtooth, with adjustable offset & amplitude. However, making a sig gen is a lot of work, so if you are not prepared for this, try looking for good 2nd hand one on ebay.http://www.electronics-lab.com/projects/test/013/index.htmlhttp://www.scienceprog.com/avr-dds-signal-generator-v20/

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 07, 2012, 03:23:46 pm
content: you can slap it 10 minutes...https://www.eevblog.com/forum/projects-designs-and-technical-stuff/ad9850-module-and-dds3x25-dds-based-fg-compared/but if you need more, you can find further in the net. for eg, ad9850 cannot do sawtooth, so adding additional circuit is necessary.
Design review: Revised M103v1-3 Bluetooth-equipped lab PSU (analog section) - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: April 04, 2016, 05:42:49 pm
content: Hitting 10A on my first design is obviously a foolish decision, as efficiency and choice of components both became significant concern. So I scaled the project back.Revised specs:Primary output: CV/CCVoltage: 0-30V adjustableCurrent: 0-3A adjustableMaximum output power: 50W (software enforced,) 90W (hardware limit)Topology: Mixed-mode power supply with linear-only modeRelay-switched outputInterface: banana jacksSecondary output: CVVoltage: 5.3V fixedCurrent: 2.5A maxMaximum output power: 12.5WTopology: Switch-mode power supplyInterface: USB, with programming resistors for iPad chargingControl interfaces:Bluetooth 4.0 BLE (iOS compatible)Isolated UART over USB20x4 LCD display & keypadControl Protocol: AICP/STKP (a binary-oriented packet-switched protocol) over BLE or USBSafety features:Automatic thermal shutdownAll outputs are independently fusedSwitch-mode section:Linear section:

author: ohmedarick
author_rank: Newbie
timestamp: July 13, 2017, 02:51:25 pm
content: Hi:Nice design. I'm new in electronics. since you made this design may be you can steer me in the right direction. I Have a old Condor Power supply from 1990 I suppose. Its old and came out out of a Stress Test ECG machine.. The PS works fine. It puts out +5 at 10amps ; +12v at 3amps ; -12v at 3 amp ; +15v at 3 amp; +28v at 1.25 amps ; -28v 1.25 amps, I would like to regulate the voltage between 1.2 to 30 volts and be able to control the current output maybe from 10 um to 1.10 amps on the plus and minus of the 28 volts output of PS. On the 12 volt and 5 volt side output I would like to control the current output from 10 um to 1.5 amps so I don't burn out any of my components when testing on the bread board... I very prone to shorts. If you have any solution simple for my problem. please I will appreciate the help. Thanks Ricardo
Design review  - Page 1
Forum section: electronics / projects

author: pappkopp
author_rank: Contributor
timestamp: December 29, 2022, 04:41:55 pm
content: HiI'm designing a board that's purpose is to control a brushed dc gear motor and use a weight cell to measure the dispensed amount of material.For the weight cell i'm using a hx711 weigh cell ADC.Motor controller is a DRV8870Switching regulator is a TL2575-05, that outputs to a 3,3 V regulator for powering the ESP32 and peripheralsThings I'm not completely sure about:The 2N7002 driving the piezo buzzer, is this correct? Will it turn on completely when using pwm to drive to piezo?Decupling capacitors on the data lines? for the connector J4 with the hx7111 i will be using a cable of approx. 1 meterThe ESP32 has internal pull-up/down so i haven't implemented that in the design but i have some 0 ohm resistors to ground if extra decoupling is needed.Additional feedback is greatly appreciatedAltium online viewer link:https://altium.com/viewer?token=nqHyDVKl4km552md6KD6%2F7OL

author: Thunderer
author_rank: Regular Contributor
timestamp: December 29, 2022, 08:02:05 pm
content: Yes, the 2N7002 will do just fine. The Vgsth is maximum 2,5V over the gnd.Now, you may experience ESP32 random Reset coming from the motor driver side. The issue is that the interference propagates via the ground circuit. One simple, but not necessarily 100% effective, is to separate the grounds and use ferrite beads (see below).Ground separation is crucial:

author: Martinn
author_rank: Frequent Contributor
timestamp: December 29, 2022, 08:49:36 pm
content: No thermals for pads with plane connection - will be fun soldering.I'd put the antenna at the outside - any reason for the center position?Personally I am not a fan of a topside copper fill, adds extra capacitance to all tracks (particularly with the narrow separation) and adds lots of antennas (like between OLED_SCL and SDA). I'd just fill the bottom side - but that's probably a matter of taste.Effectiveness of your PSU output filter will be limited by electrolytic capacitor ESR - use ceramics?Switcher is very old school - although nothing wrong with that if you don't mind cost/bulk.1m cable length for the serial link? Not sure about the HX711. Maybe add series resistors (can be 0R initially) to slow down the edges if necessary.- Martin

author: bidrohini
author_rank: Regular Contributor
timestamp: January 05, 2023, 10:30:14 am
content: Here already you got many valuable reviews. You can post your design here too:https://www.pcbway.com/project/questionpublishPCB experts often come to this forum. It's a good place for design reviews and corrections.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 05, 2023, 02:01:58 pm
content: Quote from: Thunderer on December 29, 2022, 08:02:05 pmRead the data sheet more carefully.That 2.5 volt max for Vgsth is when the drain-source voltage is the same as Vgs ie 2.5 Volts. That Vds is not compatible with the FET being fully on. Furthermore that max figure is for a drain current of 0.25 mA which may be too low to give enough audio output from the piezo buzzer.
Design rules inverted - Page 1
Forum section: electronics / projects

author: compet17
author_rank: Regular Contributor
timestamp: August 17, 2015, 06:54:29 pm
content: Normally designers of electronic devices (and any other things) try to keep cost and number of parts as low as possible. Every curve in a casing has a purpose, either aestetically or for technical reasons.This device has a switch built in which has no electrical connection and no mechanical function... A free switch for everyone :-) Take it, it makes no difference.

author: helius
author_rank: Super Contributor
timestamp: August 17, 2015, 07:12:06 pm
content: There is another model of the Thermoscan that has a switch in that position, with markings for "Oral or Rectal equivalent".The display location was also done that way, because the unit has a cover over only one side (covering the probe and the display).

author: compet17
author_rank: Regular Contributor
timestamp: August 18, 2015, 05:25:25 pm
content: I have that cover too. It was one thought that they wanted to protect the LCD with that cover...
Design Software & Component Libraries - Page 1
Forum section: electronics / projects

author: sci4me
author_rank: Regular Contributor
timestamp: July 02, 2014, 08:06:37 am
content: Hey guys. So, I run Ubuntu and I need a decent piece of software to do my design. I am fairly certain Kicad will work but it doesn't have a component I need (a DDR2 SODIMM socket). I have tried eagle but had no lick at all. Never got it running. The only other piece of software I know of is Altium which .. well.. I don't really want to spend a fortune on this... I'm already going to spend enough on the project.My questions:1. what software should I use?2. if it doesn't have an option / options for a DDR2 SODIMM socket, how can I get them?Thanks!

author: KJDS
author_rank: Super Contributor
timestamp: July 02, 2014, 08:30:04 am
content: I've never found a pcb layout software package where you couldn't create new parts.I've never found a pcb layout package that came with completely accurate ready made parts.

author: sci4me
author_rank: Regular Contributor
timestamp: July 02, 2014, 08:38:43 am
content: Forgive me, I'm learning. Looking into making the component... found this:http://kicad.rohrbacher.net/quicklib.phpWe'll see how I do with this...Ah, that wont help...

author: nctnico
author_rank: Super Contributor
timestamp: July 02, 2014, 08:56:21 am
content: How to make component symbols and footprints is one of the things you need to learn if you are going to make PCB designs. Even though I have build an extensive library over the years I find myself making several new footprints for about every project I design. So I'm with KJDS: take the time to learn how the symbol and footprint editor works.

author: mark03
author_rank: Frequent Contributor
timestamp: July 02, 2014, 10:20:33 pm
content: If you are using Kicad, that web site for eeschema symbol creation (I think it is at rohrbacher.net but I forget if it is the link you posted or another one) is good to get a basic symbol which you can then tweak within eeschema.For footprints in pcbnew, I am a firm believer in learning the file format and creating them yourself with nothing but a text editor. This is MUCH faster and less error-prone than any of the other methods I've seen.
Design validation: Constant current sink with digital controls (2nd try) - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: May 15, 2015, 05:41:11 pm
content: The last post somehow exposed a bug in the forum software and does not load...This is a dummy load, with Arduino-compatible microcontroller control.The analog section is identical to the design used by Dave, but the load resistor is 0.1 ohms instead of 1 ohm, in order to lower the voltage drop across the load resistor to allow 5V operation. The load transistor is IRL540N, for its lower threshold voltage, also to enable 5V operation. The smaller load resistor also means lower sense voltage. Hence a sense preamplifier is added. This have to be an RRIO amp. In the schematic I used LMV358 but TLC2272 can be used too, probably some other model too. MC1403 is used as the internal reference, which is shared by the analog and digital sections. The adjustment is carried out using a MCP41010 d-pot.The digital section handles controlling the analog section with an ATmega328P microcontroller, and a human interface based on a 16x2 character LCD and 5 buttons. A USB interface based on CH340G exist too to allow both remote controlling and firmware updating. The firmware update mode is compatible with Arduino.
Design validation: Constant current sink with digital controls - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: May 14, 2015, 09:11:18 pm
content: Constant current sinks, everyone should have one. So I rolled this puppy, a good mix of thru-hole and SMT based on what I currently have.This constant current sink used 0R1 30W sense resistor array so the sampling section requires a RRIO preamp! It is a good news that the SO-8 RRIO dual op amp chip happen to have two viable options, LMV358 and TLC2272, both I own a stock of.The power transistor is IRL540N for its lower Vgs(th) and this entire thing runs on USB bus power.The digital section is full compatible with Arduino software (although used the 10-pin ICSP header and CH340G USB to UART bridge)All controls are digital and it is computer controllable using the USB-Serial chip. The adjustments is fed into the analog section using MCP41010 digital pot.Maximum ratings: 100V, 12.5A, limited by heat dissipation.Trying to lay out a board without screwing anything over...
Design validation: M101 DMM, USB interface + digital power section - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: August 21, 2015, 01:32:34 pm
content: Will the battery, DW01A protection circuit, TP4056 charger and SDB628-based boost converter assembly bite me? The converters generating +/-15V used by the analog section will be tapped off the digital section's +5V power rail. Also where to put the power switch bear in mind that charging should not be inhibited when the power is off?SDB628 is a 1.2MHz boost converter capable of 4A switching current.The analog section will include a few TL084's, an LM399 internal reference (maybe always on), a small constant current source (for ohms) and an ADC. The digital section would drive a MCU (not decided whether I should go PIC24 or AVR yet,) and a 1602 LCD screen (backlight can be switched off or dimmed using PWM)Also, how to make the digital section's 5V power rail be able to switch between USB bus power and battery power from the booster? No interrupt allowed.Despite the battery, this project results in a single big PCB and produces a USB bus powered bench DMM.
Designing 600 watts Synchronous buck with LTC3858-1 - Page 1
Forum section: electronics / projects

author: tictactoe
author_rank: Newbie
timestamp: April 05, 2018, 02:14:53 pm
content: HiI want to design the synchronous buck with LTC3858-1 with below specificationVin=13 volts to 35 voltsVout=1 volts to 12 voltsIout-max=50 ampereI want to modify the LTC3858-1.asc proper to my design. How can I modify this file for higher output power ?Its the link of the modified schematic that comes with LTspice .Please help me to change this design.Regards

author: jbb
author_rank: Super Contributor
timestamp: April 05, 2018, 07:45:28 pm
content: OK, this sort of voltage range and power level is manageable, but there are a few issues to look at:Minimum MOSFET on time when going from 35V in -> 1V outInterleaving is highly recommendedHow to set output voltageHow to handle heatHave you worked with power electronics before? This one could be a bit challenging for a first project (likely to blow up some MOSFETs...).

author: tictactoe
author_rank: Newbie
timestamp: April 05, 2018, 08:31:52 pm
content: I want to know with maximum power that can be reach with Synchronous buck?Maximum current at 1 volts output is about 7 ampere. I prefer to complete the schematic and improve the fault in the design.I have attached the ltspice schematic for better helping. If you run the simulation you can see that the output voltage is reach to 6 volts and after some time it drops to zero because of current limiting. Can you help me for improving my schematic?I have worked power electronics before up to 300 watts.Regards

author: jbb
author_rank: Super Contributor
timestamp: April 07, 2018, 03:36:29 am
content: Quote from: tictactoe on April 05, 2018, 08:31:52 pmAs much power as you like. I've gone up to 40kW myself (using quite big equipment) for a test stand.As for your schematic, I see two major issues:You're only using 1 phase! Try using the 2-phase circuit from the end of the datsheet. It's often easier to make 2x 25A bucks than 1x 50A buck.Your use of BJT gate drive buffers (Q5, Q7, Q9, Q10) seems a little strange. Why not use the ones in the chip? Also, Q5's collector should be tied to BOOST2, R1 and R3 are too large, and I suspect R2 and R4 are too large.

author: tictactoe
author_rank: Newbie
timestamp: April 07, 2018, 07:32:09 am
content: QuoteWhich chip do you prefer for drivers? Does TC4427 is proper?By removing totem pole it seems better, but in practice it needs mosfet driver.The mosfet I use is IPP08CN10L .Gg=90 nctd(on)=18 nstr=10 nsPeak current for gate=90/28=3.21 AmpereIs it true?I using the 2-phase circuit. I attach the schematic below. please help me to improve this.Regards.
Designing a 2S BMS with UnderVoltage, OverVoltage and OverCurrent protections. - Page 1
Forum section: electronics / projects

author: Hamza Khan
author_rank: Newbie
timestamp: September 30, 2023, 03:07:07 pm
content: Hello everyone,I spent the whole day today looking for a single chip solution for a 2S BMS that has both Over Current and Over and Under Voltage protection.While there are a lot of BMS chips that provides the UV and OV protection. I could not find a single chip that has both of them.My requirement is that the chip should be under 1.5$ and has less then or equal to 16 pins.Current limit is 10A and I am using LiIon batteries.Has anyone came across a chip like that?

author: Hamza Khan
author_rank: Newbie
timestamp: October 02, 2023, 08:51:00 am
content: So I ended up picking the BQ78Z100 from Texas Instrument. Its a bit out of the budget but for now it will do but if anyone can suggest a cheaper version with the same features then I would be thankful.
Designing a 68000 homebrew computer? - Page 1
Forum section: electronics / projects

author: billybobpickle
author_rank: Newbie
timestamp: July 27, 2014, 02:20:21 am
content: I was going to make a "homebrew computer" with a Motorola 68000 and other various vintage computer parts. How can I learn how to design a computer with this processor? I would just like to make a simple vintage style computer with some color graphics and sound.

author: Prime73
author_rank: Regular Contributor
timestamp: July 27, 2014, 03:14:15 am
content: well google could be really helpful...take a look at this site to start with:http://www.ist-schlau.de

author: billybobpickle
author_rank: Newbie
timestamp: July 27, 2014, 11:24:41 am
content: Thank You!I understand how to design a homebrew computer now!

author: andersm
author_rank: Super Contributor
timestamp: July 27, 2014, 12:30:03 pm
content: Try finding a copy of"68000 Microcomputer Systems: Designing and Troubleshooting". It goes over the process from the ground up.
Designing a 8A 60V adjustable current & voltage regulated power supply - Page 1
Forum section: electronics / projects

author: CircuitryLab
author_rank: Newbie
timestamp: December 10, 2014, 07:46:10 am
content: I plan to make a 8A 60V adjustable current & voltage regulated power supply.What I found similar to thishttp://users.belgacom.net/hamradio/schemas/6-20amps_regulatable_powersupplies_on6mu.htm.Image:http://users.belgacom.net/hamradio/schemas/6amp_reg_powersupply.gifThe amp is ok it can reach 6A/8A, the voltage is 28V max, how can I increase it to 60V? Do you know how I can make this project I found to meet my specifications for a 8A 60V adjustable current & voltage regulated power supply?Continue reading, there is a part that mention "Less maximum output voltage needed?", for my requirements I need to increase it to 60V, LM317 does not meet that output(60V). So replacing it with a higher rating transistor will produce the values I need?Such as this user(quote below) used a OPA549 for a high current power supply. Checking the datasheet, OPA549 single supply can output +60V, just what I need. What do I need to do to integrate it with the 6/8A 0-28V regulated power supply project?Quote from: Psi on April 06, 2013, 01:36:15 amAny better suggestions is much appreciated, thank you.

author: oldway
author_rank: Super Contributor
timestamp: December 10, 2014, 08:40:47 am
content: Power dissipation of the series regulator would be 65 x 8 = 520W.That's far too much.You will have to use taps switching of the secundary or a pre-regulator.The pre-regulator can be a triac control of the primary or a chopper in the secundary.Another solution is to project a SMPS.

author: CircuitryLab
author_rank: Newbie
timestamp: December 10, 2014, 12:02:03 pm
content: Basing on 60V 8A;which would cost less? triac control? or SMPS?Easier build? triac control? or SMPS?Switched Mode Power Supply, can I just salvage a PC power supply with right wattage and convert it for my use? To lower the cost.

author: oldway
author_rank: Super Contributor
timestamp: December 10, 2014, 01:30:19 pm
content: A big 750VA mains transformer is expensive, so a SMPS (forward converter) would certainly be cheaper.But a linear power supply is generaly prefered as laboratory power supply.To project a 480W SMPS is not an easy task, better you have experience in this field.A very interesting solution:A mains transformer with one or more secundaries, bridge rectifier(s) and filter capacitor(s).The voltage is then reduceded by a chopper (step down "Buck" regulator) so that voltage drop upon the serie regulator stays around 5V.The max dissipated power is then limited to 5 x 8 = 40W.Highest output voltage of PC power supply is 12V, not 60V.Perhaps a SMPS for telecom system...

author: dannyf
author_rank: Super Contributor
timestamp: December 10, 2014, 02:38:20 pm
content: You may want to look into using audio power amps, particularly class D amp. They are naturally voltage controlled and it is not difficult to add a current control loop.
designing a biasing network for my tranciever  - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: August 10, 2025, 07:57:10 pm
content: Hello, In my tranciever there is TX and RX chains, in which I need to bias or controll a switch.In Tx chain:1. 5V 16mA2.3V 2mA3.-5V on switch4.10V 350mA5. 5V 72mAIn Rx chain:6. 5V 95mA7. two amplifiers 5V 108mA8. two amplifiers 3.3V 10.5mAsuppose I will have +-12V input .What is the best way to convert voltages so it will be as less noisy as possible?Also current consumption is a dinamic thing ,I was told that a suden drop in current consumption in one device can change the current flowing into other devices.Is there some intution I can use to make sure I dont have current issues such as this?Thanks.
Designing a binary output current sensor - Page 1
Forum section: electronics / projects

author: tmd63
author_rank: Contributor
timestamp: April 24, 2024, 05:28:06 pm
content: I had a design from years ago that had reed switches with a wire wrapped around them. If current was flowing (depending on the wire gauge and number of turns) then the magnetic field would cause the reed to switch on and cold be used to indicate current flowing.This was great but in a high vibration environment, The reeds could still bounce and doesn't help with todays low current LED devices.Is there a simulator that can be used to work out which diodes could provide a 1V Vf for a very wide range of currents If? (Typically 20mA to 2.5A or more)2.5A on a 12V system gives a power of 30W, but it is the very low Vf at If=20mA that is an issue for a single diode.I need to reliably trigger a transistor with a Vf> 0.6V but I don't want a high Vf at higher currents (1V is good enough but 2V is too much)

author: xvr
author_rank: Frequent Contributor
timestamp: April 24, 2024, 06:02:12 pm
content: > Is there a simulator that can be used to work out which diodes could provide a 1V Vf for a very wide range of currents If?LTSpice, but you need accurate diodes models.> Typically 20mA to 2.5A or moreThis is a very wide range for a single diode. Voltage drop will vary.

author: tmd63
author_rank: Contributor
timestamp: April 24, 2024, 06:09:09 pm
content: I tend to use the falstad visual circuit simulator. I had tried different diodes wired in parallel so the lower currents would give a higher voltage but they failed in simulation the currents didn't flow where I thought they would.

author: xvr
author_rank: Frequent Contributor
timestamp: April 24, 2024, 06:38:25 pm
content: > I had tried different diodes wired in parallel so the lower currents would give a higher voltageFor larger voltage drop diodes should be connected in series, not in parallel

author: Marco
author_rank: Super Contributor
timestamp: April 24, 2024, 07:03:48 pm
content: You seem to have power on the other side, so why not a hall effect current sensor? (You can make a few loops of PCB tracks to increase sensitivity.)

author: DavidAlfa
author_rank: Super Contributor
timestamp: April 24, 2024, 08:55:58 pm
content: How about a shunt resistor for small power loss + opamp?A 10mOhm shunt will only drop 100mV at 10A, seems way more than your application requirement, so actual drop will be even lower.A dual 8-pin package op-amp will do the job, 1st stage amplifies the voltage by x100 (For example) as it's hard to compare against millivolts, the second one compares the high level output against a reference (Like 2.5V or whatever), toggling the output when surpassing it.Add a small hysteresis so it doesn't toggle like crazy (For example, switching at 1A, releasing at 900mA).
Designing a class G amplifier  - Page 1
Forum section: electronics / projects

author: Datguy123
author_rank: Contributor
timestamp: June 07, 2025, 07:52:50 pm
content: Hi all, I am creating this topic to ask technical questions and serve as a useful reference to aid others in understanding and designing their own Class G amplifier. The goal is to understand the effect each component has on the circuit by building it up component by componentIn a scaled-down single-ended model of the output stage, I observed that the collector voltage of the inner transistor increases when the input swings negative, only when its magnitude is decreasing. Is this normal, and what could be the cause of this?

author: mtwieg
author_rank: Frequent Contributor
timestamp: June 07, 2025, 11:55:51 pm
content: Consider than when Vin is going negative, both BJTs have their base-emitters reverse biased far past the point of destruction. Everything in the simulation after that point is meaningless IMO.
Designing a frequency multiplier - Page 1
Forum section: electronics / projects

author: eddy66t6
author_rank: Contributor
timestamp: April 19, 2013, 12:11:18 pm
content: Hi, I'm working on a project and found this circuit for a frequency multiplier that could be of use to me. I would be dealing more in the Hz range than the MHz range, and was wondering if anyone can point me in the direction of a good tuitorial or the like for it... What are the drawbacks to such a circuit too?I'd be dealing in audio signals so I'd want to keep noise to a minimum too...Thankshttp://electriciantraining.tpub.com/14181/img/14181_95_1.jpg

author: c4757p
author_rank: Super Contributor
timestamp: April 19, 2013, 12:50:58 pm
content: It's a tuned circuit. It's set to multiply 1 MHz to 2 MHz, and it's not going to do anything but that unless you retune it. It's basically a 2 MHz oscillator being excited by a 1 MHz input. (And you'll need onemassiveinductor to use this circuit in the Hz range.) I don't think this will be useful for you.You might find something like the4046 PLLof more use, though you'll need a bit of extra circuitry, and it's square wave only.

author: eddy66t6
author_rank: Contributor
timestamp: April 19, 2013, 01:26:28 pm
content: Yeah, I thought so, I was hoping for a sine wave multiplier... I shall certainly take a look at the cd4046 though

author: c4757p
author_rank: Super Contributor
timestamp: April 19, 2013, 01:36:45 pm
content: If your specific problem is "doubling a low frequency sine wave", you can use ananalog multiplier, because a sine wave squared is a sine wave of double the frequency. Those specific ones aren't cheap, but you might be able to find a cheaper one.

author: w2aew
author_rank: Super Contributor
timestamp: April 19, 2013, 02:15:46 pm
content: The multiplier is a good route to explore. The typical RF techniques for frequency multiplication can get into unwieldy component values at low frequencies. If you want to learn more about the 4046, you might want to view my video on the basics of PLLs and frequency synthesis, which uses the 4046:
Designing a Low-Noise Power Supply for Precision Sensor Project - Page 1
Forum section: electronics / projects

author: patrickdam
author_rank: Newbie
timestamp: September 04, 2025, 06:38:25 am
content: Hello everyone,I’m currently working on a project that involves precision analog sensors (temperature and strain gauges), and I’ve run into a challenge regarding the power supply design. The sensors require a very stable and low-noise supply; otherwise, the signal drifts and introduces measurement errors.Here’s the situation:The system runs primarily on a 12 V DC source.I need to generate a clean 5 V (and possibly 3.3 V) rail for the sensors and ADC.I tried a few switching regulators with LC filtering, but the ripple is still noticeable in the output readings.Linear regulators help reduce noise, but efficiency and heat dissipation become a concern, especially in a compact enclosure.My questions:Has anyone designed a low-noise power supply specifically for sensitive analog circuits?Would a hybrid approach (switching pre-regulator + low-dropout linear regulator) be the best compromise here?Are there recommended regulator ICs or filter topologies that work well for this type of application?Any PCB layout tips to minimize the coupling of noise from digital/microcontroller circuits into the analog rails?I’d love to hear from those who have tackled similar challenges. Any suggestions, references, or even example schematics would be a huge help.Thanks in advance for your insights!

author: Magnethicc
author_rank: Contributor
timestamp: September 04, 2025, 07:06:35 am
content: You said switching regulator with LC filtering is not good enough but if its ripple that is your problem then why not increase the output capacitance? why not another stage for the LC filter? (just make sure to damp them correctly).You said LDO only solution has a heat concern but what are the losses? you need to provide more information.if you could post your already tried solutions with schematic, values and results that could help you get more accurate responses.If current is low enough maybe you could try the BJT capacitance multiplier circuit to reduce ripple RMS with this clever circuit.LT has some low-noise switching regulations like the SilentSwitcher.Switching Pre-regulator + Linear Regulator is good, tried and tested solution with commercially available products that use this topology to achieve low noise but maybe there is a simpler solutions.

author: Halcyon
author_rank: Unknown
timestamp: September 04, 2025, 07:57:37 am
content: OP is a previous commercial spammer/ban evader. First post made to look legit, but really, just preparing for SEO spam for a dodgy app. Tried to hide their advertising in their signature using a small/white font. Amateur hour.
Designing a power supply for 110v,12v,6v,and 3v - Page 1
Forum section: electronics / projects

author: Jesset1996.5
author_rank: Regular Contributor
timestamp: September 23, 2015, 06:31:21 am
content: So i have decided to make a new psu for my prc 320. It has to have 110,12,6,and 3v dc with no ripple and it cant make much heat. Any ideas on what i could do for the 24 to 110v curcuit?