Questions tagged [electronic-load]

An electronic load (sometimes called an "e-load") is a device which simulates an electrical load, often as a way to test a circuit's behavior under various load conditions. Many e-loads can be programmed to act as a constant resistance, constant current, constant voltage, or constant power load.

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Substantial voltage drop when connecting battery to DC load

I wanted to test the battery from an e-bike. I have noticed quite strange behavior. The first thing I did was to measure the voltage. It was 66.1V which is fine for a 60V battery. When I connect the ...
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Trouble using PNP as a switch

I simulated a circuit as shown below and it works as expected when the switch is closed or opened. I later change the 2n2907 to FMMT591A due to availability, continuous collector current and size. I ...
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How can I make a 50mH inductor/coil that can stand up to 3A current to be used as a DC inductive load?

It will be used to simulate an inductive load for a DC output.
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3 votes
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Fixing overshoot in current regulation of AC electronic load

My AC electronic load (previous question here) shall have a constant-current mode. It is being simulated in LTspice. @devnull helped design the circuit for AC loads, but for simplicity's sake in the ...
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Electronic load for AC - regulating current in both directions

I'm trying to design an electronic load that will take DC or AC (up to 20kHz, for audio amplifier or bench power supply testing) and show a constant (but adjustable) resistance. I'll be using N-FETs ...
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Why is the capacitor filter in parallel with the load and the choke in series in a choke input filter?

What will happen if we interchange them? In a capacitor filter, the capacitor discharges through the load, it was connected in parallel to load. From what I have concluded, if the capacitor is in ...
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How is the peak inverse voltage of diodes in a center tapped rectifier twice than the bridge?

I am not able to understand how the PIV becomes twice in case of centre-tapped rectifier. PIV is the maximum inverse voltage that a diode can handle before having a breakdown. For a half wave ...
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Two stage operation amplifier using MOSFET: How to increase the cut off frequency

so I'm trying to design a two stage MOSFET op amp and I'm required to get a gain bandwidth of more than 260Ghz. I'm biasing the first stage with Vb1 around 2.1 V, 1.9 for 2 and 2V for Vb3. With Vdd =3....
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Heatsink size calculation

Let's say I found a random heatsink with no name or model or anything else from which I can find a datasheet and get its thermal resistance. Therefore, simply by knowing its sizes, how can I calculate ...
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2 votes
1 answer
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Do you think this circuit will work?

I searched the internet and made h-bridge circuit: By combining resistor R5 and R7 are connected to, when I give the pin HIGH, it will rotate counterclockwise when I give it LOW in the clockwise ...
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Why are the electrons coming back with 1V?

The current is in conventional flow , it enters the battery. Is it possible that the electrons that go out of the current source come back to it with 1000mV?
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4 votes
2 answers
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MOSFETs in parallel, combining heat-sharing and ballast resistors? [closed]

In a circuit like this: simulate this circuit – Schematic created using CircuitLab If each 3 MOSFETs be next to each other and on one heatsink, is current sharing balanced? If MOSFETs have TO-...
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2 answers
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Problems with over/undershoot in voltage-controlled MOSFET current sink

I'm in the process of designing an electronic load for testing batteries. The goal is to control the load current in the range of 0 - 10 A with a 0 - 1.2 V signal from a DAC. For easy calculations and ...
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Potential DC protocol / load detection preventing battery pack from working?

I have a slew of Makita 18v Tool batteries and was considering other ways in which they might be repurposed. I know the Makita range of BL18XXB batteries from teardowns on the internet uses internal ...
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1 vote
1 answer
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What test equipment can simulate the inductive load of a DC motor?

I am working on a power supply circuit designed to drive DC motor. Currently, I am testing using the actual DC motor, but I would like to start using test equipment instead. There are several options ...
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Buck regulator transient response explanation

I am using TPS5450 buck regulator and trying to measure the transient response but seem to see a weird triangular adjustment before it settles. I can't see anything in the datasheet that would explain ...
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How to find transfer function of this filter?

How can I find the transfer function of this circuit? Is there any way to find the total impedance? I don't want to use Laplace transform. And can I find the bode diagram for this circuit?
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2 answers
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In-Series current source equation solving

I'm an electronic newbie, i was simulating this circuit on LtSpice and i found the result below, i tried with different methods (Kirchhoff's laws, Millman theorem, superposition) but i failed to have ...
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Why will this circuit not work? I need a perfect reason [closed]

Will this bulb light for nanoseconds?
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2 answers
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Multiplexing 24V signals to DC load generator

(Electronics beginner) I have a DC load generator (TENMA 72-13210 a rebrand of Korad KEL103). I want to use if for testing a custom board designed in-house with 30 outputs each capable of driving 10A ...
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5 answers
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What is the difference between high-Z (high impedance ) and open circuit?

I cannot understand exactly difference between them. I am not sure about this topic. I think high-Z means "temporarily open circuit." Can you explain the difference to me?
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1 vote
1 answer
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Need guidance for building a electronic load using BJTs

I've been studying DC electronic loads and almost all of them used mosfet as main transistor, while researching I find out that mosfets that are designed to work in their linear region are expensive ...
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2 answers
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Constant resistance mode in electronic load

I have this DC electronic load. I am setting this electronic load to a constant resistance mode option - say 100 ohms - and turning the output ON. When I measure the resistance across the electronic ...
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Problems enabling remote voltage-sense Rigol load DL3021 via SCPI

I am automating some tests with Rigol hardware. There is only one bottleneck in the SCPI implementation that I can't figure out: How to enable the remote voltage-sense terminals on the Rigol DP3021 ...
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Confusion on Voltage levels in Digital Waveforms

My question is why Io is in different direction when Vo=H and Vo=L respectively? I really can not understand the underlying mechanism!
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1 answer
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Using Inductor and Electronic Load Instead of a Permanent Magnet Synchronous Motor (PMSM)

I would like to test whether my power board can handle to currents required to drive a 1.5 kW motor. My issue is that the motor testbench is still not here and I have to test it now. I do not have ...
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2 answers
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How to use SCPI over RS232 with a Rigol Programmable load?

I have a Rigol DL3021 programmable load. I'd like to control it as part of an automated test setup, over SCPI from a Linux box. Their programming manual assumes you're on a Windows machine and wants ...
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3 votes
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Battery/Charger Not Reaching Float with Load Attached

I'm trying to add a backup/UPS to a system I have outside with the following battery charger - https://www.meanwell.com/Upload/PDF/ENC-180/ENC-180-SPEC.PDF . The DIP switches are set for AGM mode. My ...
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2 votes
2 answers
248 views

Chrome plating current control

I am an electronics hobbyist and this is my first attempt at an analog circuit of this type. Mostly I stick to arduino and LED stuff or just wiring up kits, etc. This is my first attempt at designing ...
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1 vote
2 answers
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MOSFET gets hot in an Op-amp MOSFET-based constant current load build

I've made this schematic following the circuit steps in this site: and after running the output with just 0.1-1A (which works ok according the input setting and current reading seems correct) but the ...
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Cartridge loading in Rodec phono stage

I saw a very strange design of phono stage in Rodec MX180 consoles. 3 generations of those mixers (mk1, mk2 and mk3) have this phono preamp on board! They have an input filter with 1nF cap then 220 ...
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How to reduce dc 5 volt to below 1.5v by add extra load [duplicate]

I have an USB charger with 5V DC output. I want to use this charger to power a 1.2V DC motor. I think about adding an extra load, like a DC bulb, to this circuit, maybe it could reduce the voltage ...
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2 votes
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TLE2141 op-amp alternative (in DC load circuit)

I recently found a schematic for a DIY electronic load, which I think is based on Dave Jones's EEVBlog old DC load design (attaching the source link: Dynamic DC Power Load (updated), but I am ...
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5 votes
2 answers
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Is it possible to use a Mosfet in switching mode as an electronic load?

I'm trying to use a mosfet as an electronic load to measure the IV curve of a solar cell, but if I use it in linear region it dissipates too much power. I was thinking that I could use it in switching ...
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3 votes
3 answers
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Electronic load, Problem turning MOSFET on

I am trying to make an adjustable dummy load to test a 12V supply, I’m having trouble with the op-amp feedback circuit. Attached is a simplified schematic. I have tried lots of things and stripped it ...
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In building an electronic load with a mosfet and op amp. It adds some benefit to use a mosfet driver IC?

I´m building an electronic load following this schematic. My op-amp is an LM358 or LM324. My mosfet can be an IRFZ44N, and STW45NM50 or a IRFP460. Those are the parts that are in my bin. My ...
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1 vote
0 answers
616 views

Electronic load for negative voltage PSU

I am making a MOSFET based electronic load to test my PSU rails. Below is a simplified version of my circuit with V2 as the PSU that is being tested. I want to be able to test negative voltage rails ...
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Can someone explain this constant current load circuit?

I'm currently a rising junior in EE and I was just wondering if anyone could help explain this circuit for me. The purpose for this is because I need to learn how to build a discharger (constant ...
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1 answer
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Impedance load matching

So I've done this so far, and know one of the components is a 50ohm resistor. However I dont know where to go from here. How do i decide if its an inductor or a capacitor? This is a past paper exam ...
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Using variable resistor to nullify Cap Bank Droop

In a high power application I am charging a cap bank to 800V and letting it discharge into a load of about 2 ohms for 2 seconds. To avoid droop I could overcharge the capacitors and use a buck ...
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Buck Converter Load Regulation

I have attached a schematic of a buck converter circuit I have designed. It's designed using a LMR16030 IC. Input voltage: 12-14V Output voltage: 5V Switching frequency: 1MHz Output Current: 2A I'm ...
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0 votes
1 answer
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Looking for design advice for custom electronic lock

I'm building a door lock that will be controlled by a Raspberry Pi Zero W. Here's a link to the lock I'm using: Electronic Cabinet Lock With Status Reporting (MA1208S-T) From what I understand, this ...
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-2 votes
1 answer
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why in case of dc neither of terminal is at zero potential? [closed]

why in case of dc neither of terminal is at zero potentialpotential while in case of ac ground is at zero potential ,let us consider negative terminal of the dc is at zero potential then why we use ...
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0 votes
1 answer
110 views

High temperature of components to joining & soldering

Please help me to know the best components for the process of welding an electronic circuit to operate it in a very high temperature environment up to more than 600 degrees Celsius? Note: I do not ...
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2 answers
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How can I sacrifice a bit of DC Voltage to transform it to DC current?

I made a project with using voltage doubler(which has input of 12V) which output is 43V(I expected 24V) but current is low when connecting the 150 ohm resistor,its about 150mA,but I dont need so much ...
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1 answer
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electronic devices impedance and drawing current

I have a questions that kind of bugging me for a while. So in electronic devices, it has capacitors, inductors, resistors, transistors and etc. All of these together is the load of the device, which ...
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1 answer
785 views

varistor curve and voltage meaning

Could I get an explanation for these datasheet definitions for a varistor? 1) Max. applied voltage. 2) Min varistor peak volts. 3) Max varistor peak volts. 4) The clamping voltage is known to be ...
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-2 votes
6 answers
203 views

Type of resistors [closed]

What is the difference between 220 ohm resistor-1/4 Watt and 1/2 Watt? Which is suitable to be connected to a LED of FV 1.8V and current 15mA ? Supply voltage is 5V.
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4 answers
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Electronic load MOSFET drain to source current suddenly increases

My questions: Why would the drain to source current of MOSFETS suddenly increases. What can be done to resolve it? I am aware that there is supposed to be an increase in current as soon as the gate ...
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0 votes
4 answers
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Non-mechanical load suggestions for a 12VDC / 6A PSU?

I need to provide a load for the 12VDC/6A power supply. I used a small motor before, but something less mechanical (more reliable) like a light or (anything that's not mechanical) would be ideal.
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