Questions tagged [power-supply]

An electronic device which supplies electrical energy to a load. Can be AC or DC input. Typically DC output.

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Can I attach micro usb adapter at the end of cat6 cable?

I am installing underground cat6 cable everywhere in my house - for internet, cctv and telephone. I want to keep the option of replacing my cctvs with a wifi based camera (like mi camera) at a later ...
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Sanity check ±12V/+5VPSU PCB

I'm building a small Eurorack switching PSU using DC-DC converter modules, and before pulling the trigger on the PCB I'd love to have someone sanity check the board. Schematic is pretty ...
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Control problem when changing voltage conversion ratio

If you have a DC/DC converter and, for example, the voltage conversion ratio is M = 1/D with D < 0.5 and ...
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What should I know about safety when assembling a power bank from scratch? [closed]

I have a power bank module for 18650 battery cells which I want to use to assemble my custom power bank. What should I know about 18650 Li-ion cells to protect myself from electric damage (e.g. ...
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How to throttle / load balance between utility and battery power supply

Basic queation - What kind of circuit allows me to throttle the power draw from two different supplies? i.e. 80/20 from a battery bank and utility power, respectively? Or 60/40, or 100/0? Main idea - ...
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Can a 12 V/24 V device work on 13.6 V DC? [closed]

I have a Dometic CFX3 45 portable fridge that I want to run from my EcoFlow RiverMax Portable Power Station. I want to charge the fridge via the DC port on the EcoFlow but it doesn't seem to work all ...
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2 answers
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A question about 78XX power supply design

I want to get 12V and 5V from a 24V power source. 12V drives a MOSFET H bridge and a cooling fan. 5V is for a microcontroller. I have already damaged a microcontroller due to a failed 7805 regulator. ...
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I have a design for powering four motors, could someone verify that it will work as I planned?

My question: This is a simple design that I have created using everything that I know about electronics so far. Is there anything missing in my design or are there any concepts which I have ...
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1 answer
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How do I prevent my WS2812 (NeoPixel) LEDs from drawing power parasitically through data line of Arduino?

I plan to power some WS2812 NeoPixel LEDs via an external 5 V wall adapter and use an Arduino Nano for data only, but Adafruit (NeoPixel vendor) mentions: If powering the pixels with a separate ...
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How can I keep the output voltage of my MPPT buck converter in my PV system constant while connected to the load (battery)? [closed]

I've designed a PV based solar charger controller using the MPPT algorithm to charge my 12 V tubular battery for a DC load. I need to keep the output voltage constant at 14.5 V to connect a 12 V ...
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Turn on a LED for 15 s, then off, sample way [closed]

I want when a user pushes a button the circuit turns on a LED for 15 s, then turns it off. I just want a sample circuit with a small microcontroller.
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Why would a 10 A buck converter only output about 320 mA? [closed]

I bought this buck converter module a while ago and used it for small current applications for a while. It works fine adjusting voltage and current until I just tried to use it with 2 A DC brushed ...
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1 answer
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Power system question: How do you derive the reactive power transfer equation?

I'm reading the EPRI Power System Dynamics Tutorial textbook. On page 3-12, it defines the reactive power as $$ Q_{S}=\frac{V_{S}^2}{Z}(V_{S}X_{L}-X_{L}V_{R}\cos\delta+RV_{R}\sin\delta-\frac{V_{S}}{X_{...
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I need help figuring this thing out [closed]

`I work as a manager for a grocery store chain. This equipment has been sitting in the compressor room for years now after being replaced. They were gonna throw it away, so I hauled it home. Its an ...
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Questions about center-tapped transformer for tube amplifier (MC 275)

I have a question about the center-tapped AC transformer used in the attached figure and its bias voltage generation. Mainly, my question is how to generate DC supply voltage for the 12AZ7 (V4) plate (...
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PCB design noise issue: multimeter probing induces noise into PCB which causes noisy shift registers

Introduction I am developing a PCB which has a 12VDC unregulated power supply connected to an LVR L7805CV from which a couple of shift registers(74HCT595) are being powered. The problem I have is that ...
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Can the output voltage of this variable frequency drive (VFD) be varied?

Im am looking to buy a Cutler-Hammer "Adjustable Frequency Drive" AF91AGO BF25D. I’m a bit confused even after going through its datasheet. Can the output voltage of this VFD be varied from ...
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Using fast charger with power bank not supporting fast charge [closed]

I bought a power bank that does not support fast charge (both USB-C input and USB-A output parameters are 5 V, 3 A). It came without a charger. Therefore, I would like to charge it with my USB-C phone ...
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Connecting multiple Raspberry Pis to the same power [closed]

I am trying to make a smart fridge. In the fridge, I have 4 shelves. Each shelf has a Raspberry Pi 4. I don't want a mess of cables in the fridge. Because of that, I want to make a power module (or ...
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4 votes
2 answers
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What is this ringing in the inductor current?

I am working on a buck-boost converter and I see this ringing in the inductor current. It happens on turn on of the high side FET (See attached Image). First of all is this ringing normal? Is there ...
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Picking the right boost/buck converter to power LEDs from 12 V battery

I'm looking to run four 3 W high-intensity LEDs in a series circuit using a 12 V battery, for an outdoor lighting setup. My intention was to use an adjustable buck/boost converter, as I've used to run ...
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EMC surge protection

I have a product being EMC tested. It passed all but the surge test per IEC 61000-4-5. For mitigation, they have suggested the addition of some type of surge protection circuitry like MOVs. The ...
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What is this (broken) component in the mains side of an amplifier power supply PCB?

I'm debugging/repairing a broken Logitech Z623 2.1 speaker system that I received in a broken condition (doesn't power on at all.) I have pulled apart the subwoofer/amplifier unit, and after removing ...
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STM32F038x6 Vdd and Vdda Relationship

I am trying to design a breakout board for this STM32 Microcontroller https://www.digikey.com/en/products/detail/stmicroelectronics/STM32F038G6U6/5051266 I'd like to use the ADC's and I'm trying to ...
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2 votes
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Total voltage of six 12V batteries in line

Total voltage of six 12V batteries in-line A golf cart has six 12V flooded batteries in line. Each battery has six cells (six flooded holes for maintaining levels with distilled water.) Each hole or ...
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1 vote
2 answers
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Two similar voltage sources equidistant from a load in opposite direction

I have two 52 VDC voltage sources, each an equidistant of 200 m from my load. For this purpose, take it as one voltage source is coming from the east and the other from the west. Along the 200 m path ...
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Trying to replace battery pack with dedicated power supply

I have a touch sensitive sink faucet that runs on 6 AA batteries. I'd like to replace the AAs with rechargeable 18650 batteries and also connect a power supply to power the faucet, but also keep the ...
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2 votes
0 answers
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Sinusoidal voltage on CAN bus signal wires when powered from 3 phase switching power supply

I am using CAN bus to communicate between this BLDC motor with a built in driver and a real-time control computer which uses a galvanically isolated Microchip MCP2561FDE/SN CAN transceiver. ...
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-1 votes
0 answers
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Xbox 360 slim: power brick stopped working [closed]

I have an Xbox 360 slim but recently its power brick stopped working. I also have an Xbox 1 Chinese power brick. Can I switch the end connectors of each to make the Xbox 1 power brick have the Xbox ...
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Minimum load current on boost converter

I was hoping to use the LM2731Y boost converter to step up 3.6V to 7V, but I'm unclear if this will work for my load requirements. I will likely have a fairly low current draw (<50mA) and there is ...
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Why is there continuity between the output terminal of my DC power supply and input terminal of RAMPS 1.4?

I have a 12V, 15A power supply. Using a multimeter I found that there is continuity between the output terminals (2 positives and 2 negatives) of my power supply. Also, I did the same test on my RAMPS ...
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Sensing presence of 220 Vac for MCU

I'd like to use an HCPL3700(M) (datasheet) to sense if a 220 Vac mains is present. In my application, the device needs to raise an alarm if the mains voltage is lost. Backup power will be provided by ...
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1 answer
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12 VDC to 6 VDC to power a radio [duplicate]

I have a Grundig radio that requires 6 V and 500 mA negative center pin. It is very sensitive to noisy wall warts, so I want to power it from my very noise-free ham radio 12 V power supply. Can I use ...
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Does capacitance value affect ripple voltage, or does something else?

I was reading TI's Designing an LLC Resonant Half-Bridge Converter when I came across this paragraph: Does the actual capacitance value not really matter, or is this just the case for the LLC half-...
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2 answers
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How to properly wire a power supply to a remote control [duplicate]

I have a remote control for an RC helicopter that I want to hook up to a power supply. Each battery takes 1.5V and I need 6 total. The power supply has a positive and negative terminal. Basically I'm ...
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Adding coolant to consumer PSU brick?

Delete if repeat of What dielectric liquids can be used as coolants?. I got a cheapo 42v PSU to charge my skateboard. It gets quite hot, and I was thinking of injecting some Vasaline in there. Is this ...
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Arduino board consumption benchmark

I know consumption depend of the type of application, but I would like to know if a comparison of average consumption exist between arduino and similar boards (Teeny/Dfrduino...). The board I am ...
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Detect if PC power is on/off then turn a TV on/off using an Arduino

I'm building an arcade cabinet using an old PC and an old(ish) Bush LCD TV as the monitor. The TV is connected to the PC graphics card via HDMI and all is good. However, the problem is that I want the ...
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1 answer
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Battery Charger and power supply DC-DC with noisy input

I have sort of a weird question I'm hoping folks here can help with. Have searched other questions but not found a similar-enough one that applies. I have a large mechanical system which travels over ...
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Delivering power by USB C - Magnetic Framework Laptop Extension

I'm trying to build my own magnetic extension card for the Framework Laptop, and am trying to figure out the least number of pins I need. I have this YouTube video that says the USB C PD spec needs ...
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1 vote
2 answers
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ESP32 restarting when relay is turned on

I am designing a PCB with a 5V relay that controls an external DIN mounted latching relay (red line with the "1."): The problem I have, is that the ESP32 often restarts after turning the ...
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0 votes
1 answer
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What's the simplest way to produce 150VDC for activating my piezo stack?

I recently bought a piezo stack for research purposes. To activate the piezo stack and get the maximum stroke I have to supply 150VDC. I want to use the piezo stack in two states only: 0V and 150VDC. ...
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1 answer
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Buck converter load voltage drop

I'm creating a buck converter from a NE555 and LM358 (feedback loop) for powering a tablet motherboard. (This is a learning experience for me, don't want to use an off-the-shelf board.) Here is the ...
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Can AC/DC converter be fed with input voltage below its specified voltage range when it is supposed to be off?

In a bathroom there is a 4 x 2.5 mm power cable. One hot conductor is for powering the main light, and the second one for powering the AC/DC converter for the LED strips. However, when the main light ...
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Working of a LILO

I have a question regarding the working of LILO. Attached is a diagram showing the working of a LILO: In the above diagram let's say 132 kV is coming into the substation. My question is that in Line ...
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1 vote
2 answers
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What type of connector is this - Barco/Philips TSM12PHC

I have a Barco TSM12PHC also known as Philips TSM12PHC from a cardiology. Unfortunately, I am missing the power supply. I know that the display takes 24V at 0.8A. The first three pins are positive and ...
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Coil near the DC output side of a power supply

Does anyone recognize this cased component? It is located near the DC output of a power supply. Could it be a choke, an inductor, or a transformer? I couldn't read the markings on top of the PCB. I am ...
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3 votes
1 answer
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How can some power supplies run on different input voltages (110/220V)?

Some power supplies can operate under either 110 V or 220 V input, with different rated power though. What enables this behavior? Are there relays to react depending on the inputs and lead to ...
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5 votes
2 answers
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Why do power supplies get less efficient at high load?

Many PSUs follow the 80 PLUS standards, and it shows efficiency peaks at intermediate loads. Power supplies are less efficient at low loads due to quiescent current. But why are they also less ...
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2 votes
2 answers
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Can a 3.3V 170mA (peak) device be reliably powered from only 2.5V?

I'm upgrading/hacking a broken device for a hobby project, so pretty academic and mostly out of interest. The case has a battery compartment designed for two C batteries in series (providing 2.5V to ...
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