Questions tagged [inrush-current]

The high current, that often occurs when first plugging an appliance in the power supply.

38 questions with no upvoted or accepted answers
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4
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1answer
203 views

Energy efficient inrush current limiting

Short version: looking for simple and energy efficient way to limit capacitive inrush current. Primary design goals are to minimize radiated heat and current draw during normal operation. The ...
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0answers
213 views

Inrush Current problem?

I have a 360W 36V Switch Mode PSU which I am using in a garden lighting system I have designed. I'm in the UK so it's running off 240V therefore can supply about 10A. Each section of the ...
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0answers
330 views

24-60V Precharge schematic critique

I'm looking to design a soft-start precharge circuit for starting up circuits with substantial input capacitance (~1.5J @ 24V). The main requirements are: 24-60V compatible Constant current pre-...
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1answer
198 views

5V Switching Regulator Problems

I have a circuit with two supplies. A 19v supply for stepper motors, and a 5v supply for driving the ATMEGA644, 3 stepper motor driver daughter boards, a bluetooth LE daughter board, and 2 ws2812b rgb ...
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0answers
230 views

How to prevent large inrush current without a reset-fuse

In another question (DC-DC booster fails with lead-acid battery source) I described a problem with a DC-DC booster that destroyed itself by dragging a large current when its output was disconnected. ...
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0answers
420 views

Bridge rectifier protective resistor selection

I have a device with a supply voltage range requirement 12-24AC. The B80S bridge rectifier I am using recommends a 3.5 Ohm series resistor to limit inrush to acceptable levels. Initially I decided to ...
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1answer
56 views

Why would a multimeter (ammeter) connected in series prevent the instrumented device from powering on?

I'm trying to measure the current used by a 3.5" hard drive in an external enclosure. I connected my multimeter in series with the positive 12V power supply, but in doing so, the hard drive ...
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0answers
56 views

Limit inrush current after emergency stop relay

I have a power board with an emergency stop (using a mechanical relay). The input voltage is 24V and on the power board I have multiple DCDC converters, some before the emergency stop and some after. ...
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1answer
95 views

Voltage drop on lithium batteries

Is there a difference between having one big battery vs 2 batteries in parallel? I am building a "fan controller" and want to power a 12V fan with a lithium ion / polymer battery. The ...
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0answers
60 views

SMPS powered DC motor inrush current problem

I stumbled upon a problem when connecting a DC motor to a SMPS. It's a 20W AC/DC converter with an 12V output that powers some 12V DC motors the processor and some LEDs. I needed to speed up the most ...
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0answers
80 views

DC-DC boost converter resets mcu

Edit: A p-channel mosfet to keep DC boost circuit separated from main circuit until its charged worked like a charm. I'm trying to build a DC-DC boost converter, controlled by a 200kHz PWM signal ...
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0answers
47 views

Zero crossing solid state relays

For zero crossing relays, does the switching at zero current only limit voltage spikes, or does it also reduce inrush current?
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1answer
81 views

Need help understanding the mosfet trailing edge Dimming

I am working on a circuit to control AC loads up-to 1.5KW by using Mosfets(FCHD125N65S3R0-F155) Circuit is I have few concerns The current is flowing through the body diode of Q2 for positive half ...
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1answer
40 views

Energization angle of a transformer

I am trying to understand transformer behavior for a project that i am currently doing. I am trying to simulate characteristics of transformer using simulink models. In the various papers that i have ...
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0answers
63 views

How to choose a DC-DC Converter for a motor with inrush current? (Theory)

I am wondering how to choose a DC-DC converter for a motor. This is a theoretical question for understanding. For example, if I have a converter that can output 5V with a maximum current of 1A. ...
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2answers
955 views

Limiting inrush current in N Channel MOSFET power switch

I have a N-MOSFET as power switch like this: I want to add a fuse on the power line but I have few capacitors on the across the load and I am worried that the inrush current might blow the fuse off....
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0answers
140 views

Inrush current limiter circuit for filament bulb - comparison

Context: A 12V power supply is switching on externally connected 12V filament bulbs. The power supply's load switch implements an electronic resetable fuse (13A/τ=15ms) in case of an external short. ...
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0answers
159 views

How to limit starting current of a SEPIC based LED driver?

I have designed a SEPIC based LED driver which gives 60 V, 350 mA constant output with a good power factor. It is connected with 220 V AC source.Then I have used full-wave rectifier.After ...
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2answers
358 views

Contactor/relay rating for bypass function of soft start circuit

I am designing a soft start circuit for a 70KVA, 70A, 480/230 delta/star transformer, since the fuses kept blowing without. I've been using 3 NTC thermistors rated for 80A in series with the lines ...
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0answers
369 views

Soft-Start Circuit with Premature Loading

BACKGROUND I am designing a board to convert high voltage (~400V) DC down to medium voltage (~30V) DC to provide power to subsequent boards. In its simplest form, my board will consist of the DC/DC ...
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0answers
853 views

How to Reduce Current in Solenoid Coil

First time poster and electrical newbie here. First off I just want to thank everyone for helping create such a great and helpful forum! I've been lurking for years and have learned a lot here! I ...
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0answers
20 views

Duration of inrush current for high pressure sodium lamp with electronic balast

I'm trying to find reliable information regarding the duration of inrush current for high pressure sodium lamps with electronic ballasts. This document states that: "In reality, due to the ...
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0answers
52 views

The right fuse (inrush current problem )?

Hello Electrical Engineers, just a quick question I need to get a fuse between the mains voltage (120V) and the adapter. I know that the load will draw around 30mA and has an operating voltage of 24V. ...
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0answers
20 views

How to measure inrush DC current in PV solar system?

I need to measure inrush DC current in PV solar system. Can I do that with a clamp meter?
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62 views

how to protect a dc-dc converter (LM2596) and an Arduino from Inrush current

I am fairly inexperienced with electronics so please bear with me. I have an Arduino Nano 33 IoT being powered by a battery pack which at 100% outputs 40.2V and at 0% outputs 36.5V Since the Max Vin ...
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0answers
84 views

Opamp output voltage spike and swing due to DC heater

Turning on the heater introduces a voltage spike and voltage swing on my 3.3V regulator and this causes a transimpedance amplifier output to be wrong. Every time the heater turns on my 3.3V regulator ...
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0answers
30 views

What breaker should I use to protect downstream?

I have a 16A supply connected to a junction box to split into a 16A feed and a 13A double socket. The issue is the 16A is connected to a load that will have high inrush current. I have protection for ...
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0answers
43 views

Unsure if motor starter (contactor + overload) is needed instead of normal solid state relay

I am designing a system with several pumps ranging from 0.5 to 1.5 HP (all single phase) and am unsure of what kind of circuitry I need. I researched different motor contactors and overloads I could ...
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0answers
40 views

lt4363 - 2 Surge Stopper: Shutdown / MOSFET Gate and Vout

Good day everyone I am currently working on the board which uses a Surge Stopper LT4363-2. Without LOAD the circuit works fine but once I use LOAD and force a SHDN to low with a Temperature sensor The ...
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1answer
131 views

How to choose NTC thermistor?

I would like to make a siren on an UPS backup. I used this board with an 18650 embedded battery: https://www.aliexpress.com/item/32911096857.html?spm=a2g0s.9042311.0.0.24db4c4dn31JsH And this siren: ...
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0answers
77 views

how to proteus simulation inrush current

i've a reverse polarity protection , i want to check inrush current simulation , but i don't know how . i read this , but i tried but doesnt work How to plot voltage vs current graph on Proteus ...
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2answers
82 views

SMPS inrush time

In the datasheet of the smps supply, I have found that the inrush current of the supply is 40A. But the time period of the inrush current is not provided in the datasheet. Is there any way to find the ...
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2answers
89 views

Why does this current inrush circuit not work well?

I've done some research and tried to implement a resistor and relay combination to limit current inrush for my power supply. How can this be improved as I am still seeing a peak of 85A at the ...
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0answers
118 views

How to prevent voltage droop when discharging a battery?

This is quite an open question, so apologies in advance if you would rather schematics and the like, if you really think this would help I can provide them My problem: boosting from 2x AA Li ...
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2answers
349 views

Does an ac servo motor experience high “inrush current” every time it moves after initial power up

we are currently building a motion platform for an airplane simulator and the linear motion actuators will be driven by 6 servo motors of type: Syntron 3KW AC 380V 130HMB-30100. The datasheet says ...
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0answers
114 views

Capacitor for handling startup current of DC-DC converter shows different behavior

I’m using a 5V DC-DC converter to step-up a coin cell (Nominal Voltage: 3V) to 5V which did not work. I suspected that the high startup current of the converter was causing the Cell voltage to drop, ...
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0answers
130 views

Mains switch arc - multiple smpsu inrush current

I am working on a design that consists of a mains power entry module which is a filtered, fused mains switch. This switches the live and neutral conductors to feed 4 switch mode power supplies. Each ...
0
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0answers
280 views

In-rush current limit MOSFET, resistor

I'm using DC/DC converter LTC3112 to supply GSM module. Battery source is about 12V and DC/DC output is 3.7V. Microcontroller logic is 3.3V powered from other DC/DC converter. The application is ...