Questions tagged [inrush-current]
The high current, that often occurs when first plugging an appliance in the power supply.
278 questions
0 votes
2 answers
80 views
Query about PMOS based pre-charging and voltage soft start circuit using LTspice simulations for hardware implementation
I have to charge a bulky DC link capacitor (3000 µF, 400V). I am trying to limit the inrush current and ramp up the voltage in a soft-start manner by using a pre-charging circuit centred around a ...
- 390
2 votes
3 answers
134 views
Inrush current and voltage soft start
I was trying to understand inrush current and soft start voltage specifications. I am designing a unit which gets power from another unit. If inrush current and/or voltage slew rate needs to get ...
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2 votes
2 answers
310 views
SSR inrush current Issue
I am using the AQ10A2-ZT4_32VDC SSR for a circuit. Its datasheet mentions a maximum input current of 20 mA. I added a series resistor of 550 Ω and tried to drive the input coil from a digital power ...
0 votes
2 answers
79 views
What is a systematic way of handling DC inrush currents?
Let's say I have the following setup: 24VDC PSU → PWM Dimmer with 5A outputs → Incandescent 24V 40W bulb While the 40W bulb consumes only ~1.5A, its inrush current is about 10A. The PWM dimmer has no ...
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1 vote
1 answer
57 views
Startup current vs LDO capability
I’m designing a small board with a external IMU that requires 3.3 V ±7%, nominal current of about 0.1 A, and a max start current of 1.5 A according to its datasheet. I have very limited space, so I’d ...
- 553
0 votes
1 answer
42 views
How to size the mains switch for multiple SMPS in this scenario?
I want to turn on a system power by an IEC switch where the system will be inside an enclosure but having four different SMPS powering different units. So the switch will turn on the power supplies in ...
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0 votes
2 answers
127 views
Relay welding: what time scale is relevant for capacitive inrush current welding?
As a follow up to this question about relays welding, I'm now trying to characterize better my loads, in order to find out if they are capacitive and/or inductive, and how big the inrush current at ...
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0 votes
0 answers
80 views
Capacitor Inrush Current adding
I am currently developing a filtering and protection circuit for a railway application, and I would like to know which capacitors would need inrush protection, the circuit is currently like this I ...
-1 votes
1 answer
85 views
How can I prevent relay arcing when reversing a DC brush motor?
I'm fairly new to electronics and working on a project that uses a 25A 30VDC DPDT relay to reverse the polarity of a brushed DC motor (powered by a 24V battery). The relay has been failing by arcing ...
2 votes
4 answers
516 views
Inrush current limiter
I am designing an input inrush current limiter for an input voltage of 15-70V DC and a max current of 3A. I have simulated the attached circuit in LT spice and all seems to be working properly. ...
2 votes
4 answers
1k views
Understanding DC solenoid inrush current (oscilloscope readings)
ORIGINAL: I'm struggling to understand the behaviour of my system, and would appreciate some advice. I have a 'scope with a current probe. I've included two images of these (both current profiles. ...
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0 votes
1 answer
138 views
Circuit breaker selection and panel design for LED lighting fixtures
This drawing was made for LED lighting fixtures. The fixtures will operate at 230V and have a power factor of >0.95. The current in each branch should be around 2-3 amperes. I don't understand how ...
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0 votes
0 answers
103 views
MOSFET SSR inrush current with capacitive load
I'm searching for a small switch to switch 400 V AC 50 Hz on 11 nF capacitive load. Switch would not be opened and closed often and continuous current would be under 2 mA. 2 resistors were added ...
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2 votes
2 answers
127 views
Oscillation in inrush current load switch
I have the switch in the picture and I've measured an oscillatory behavior while it's switching ON. The idea of the circuit is to avoid the large inrush current to charge the EMI filter by slowing ...
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0 votes
0 answers
78 views
Circuit to supply inrush current
In my circuit, I can drop my 3V3 rail as low as 2.6V without brown outs, but not below. My buck-boost power supply is not beefy enough for the initial power surge of my load (an air quality sensor ...
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