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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Do computer/datacenter power supplies utilize regeneration (like in motor control)?

In a PC power supply I have, it implements a synchronous buck converter that uses two active switches without a diode. I found a picture of the schematic online, whose link is below: https://e2e.ti....
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Failures with MAX16127 chips

Recently I have started using the MAX16127 chip in my designs to protect against overvoltage conditions (Do-160G, Section 16.6.2.4 Category Z, for a very specific condition I am trying to survive, 80 ...
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Battery and USB as power supply

I want to prevent the +5 V from USB to reach the output (VO) of the 5 V-regulator of my 7.5 V battery. I tried to use a MOSFET (PNP) as shown in the image below but its not working. Any ideas?
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Circuit board with power but not responding [closed]

You can see it light up but I got no response when I press the buttons or the remote. I’m clueless so sorry for my dumb questions. What should I do? Replace it? Replace just a cable?
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PSU terminal voltage drop when e-load is set in CC mode

I'm using a KIKUSUI PSU and a KIKUSUI electronic load. I'm driving 5 V and 1 A and setting 0.5 A on the e-load to sink, but my terminal voltage is reduced to 3.8 V. Is this drop acceptable?
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9 V supplied to 12 V piano [closed]

I used 9 V to power my 12 V piano. It worked for a while, but after a week my piano wouldn't turn on anymore. Is my piano already damaged? Or will it be normal again if I power it on at 12 V?
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What is an intuitive explanation of using a boost converter for power factor correction?

By theory, a bridge diode and a capacitor bank can convert an AC sine wave into a DC signal, but the source current would appear spikey, having a power factor much smaller than unity. In order to ...
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How to bring down the output voltage of a 2 x 25 VAC 6 A transformer? (Around 35 VDC after rectifiers)

As above 2 x 25 VAC, 6 A is an off-the-shelf 300 VA transformer. The ideal transformer secondary is 2 x 22 VAC, 6.8 A but it's not available without going custom and that's beyond my budget. Things I'...
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Module works, but IC becomes extremely hot

I bought a Bluetooth-FM-LED Display-MP3 module and the PCB has a 64-pin TQFP IC. From a 5 V, 1 A adapter I supplied power through the connector on the PCB and it worked fine. Later I connected the USB ...
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Double insulated PSU to replace batteries

I am building a small power supply with a linear regulator that can be used in place of 9 V blocks. Like a battery, it needs to be floating and hence I want to build it according to double insulated ...
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How safe would it be to build your own 15 kW, 3-phase generator?

I need to get a petrol/diesel generator for my house with a power rating above 15 kW. It should be a 3-phase generator. The prices of such generators are extremely high. I have a working 2000 CC car ...
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What are the use cases for the earth ground terminals in a bench power supply?

When I use bench power supply such as below: I use the red terminals as (+) and black terminals as (-) and also as ground. But the green terminal I never use and it is connected to mains earth ground....
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Switch to battery when the power supply turns off, operate fan for 2 min and then all [closed]

How to switch to battery when the power supply turns off, operate fan for 2 minutes and then all turn off battery power supply?
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Why is my DC-DC buck converter consuming 8mA of current with no load connected?

I am using a TPS5430 buck converter on my PCB which is converting 12V to 8V. If I shutdown the buck converter using the enable pin it consumes only a few micro amps but if I leave it enabled with no ...
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1 answer
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Shortening turn off time of a PSU output

I have 15W 5V power supply (Meanwell HDR-15-5) which I use it to power an STM32 Nucleo board through its E5V and GND pins. The Nucleo controls an OLED and a current sensor ect. But I noticed the when ...
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Series capacitor buck converter small signal model

Does anyone know how to do the small signal model of the series capacitor buck converter? I can't find a related paper talking about this one. I think the small signal model is not the same as the ...
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Trying to control a solenoid using PWM generated by a esp8266 Wifi Mod [closed]

I have three inputs: idle mode: 3.3 V to 3.6 V (solenoid is stationary) Splicing mode: 3.8 V to 4.2 V (solenoid is at its max) Operation mode: 4.4 V to 5 V (solenoid is running normally) The input ...
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How to run a 12V device with a 5V supply? [duplicate]

I have a fairly low-power 12 V device which I'd like to power from a 5 V Li-po power pack. Assuming my 5 V source has enough total power, is there a simple converter I can connect between the device ...
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Can I combine voltages of the power supply?

Super entry level here. Forgive my very basic question. I have this starter circuit: I'm sure you're all familiar with this one, in which I set up 5V on the left jumper, and 3.3V on the right jumper. ...
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Purpose of capacitor connected across AC input in a smart bulb?

I recently had an IKEA smart bulb (TRÅDFRI, E27) go bang, but it continued working. After disassembling it, I discovered that only a single capacitor had failed. The capacitor is connected directly ...
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Why have a 2.2Meg resistor connecting DC common of bridge rectifier to 120VAC?

I have been working on electronics for over 35 years and never seen anything like this. While going to repair a JC Penney AM/FM Stereo/Cassette/Clock Radio Model 680-3796 Catalog # 850-1793 FCCID:...
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What is the viability of using telecom DC-ATX converters for a standard desktop computer?

I have gotten mixed feedback about using non-isolated power supplies for a desktop computer. On one hand, the average engineer reaction is "Oh you can't use a non-isolated power supply because ...
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Powering multiple components with different power requirements from a rechargeable battery

I'm building a toy for a baby that basically runs an ESP32, 2 class-D amplifiers, an SDCard module and a NeoPixel (a single one..). It has to be battery powered and so far I've found out that it's ...
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TL494 with synchronized output rectifiers for push-pull converter

I want to build a push-pull converter with synchronized output MOSFETs using a TL494 IC which has two outputs that can directly drive only two transistors. The output of the push-pull converter is 12 ...
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Activate 4-pin RGB LED Strip-light 5050 to micro switches [closed]

I’ve Checked everywhere for a solution to my issue. Hopefully you guys can help out a novice. My goal is to activate my 4-pin RGB LED strip light(s) (5050) with a micro switch(s) when the force weight ...
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What adapter do I need to replace 4 AA batteries?

I have Yale Linus lock installed at my home. It has 4 AA alkiline batteries inside, and it grinds through them like hot knife grinds through butter. Therefore I want to convert it to an AC powered ...
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3 answers
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What happens if 3 V of AC power is sent to a 1.5 V motor but the motor is stuck?

I have a demo product box that has a 1.5 V motor, and the power source is an AC/DC adapter that I plug into the wall. Sometimes the motor is stuck due to another part. The motor is still on (yet stuck)...
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How do I hook up my power supply to an outlet? [closed]

I bought a VGD-75-D524 power supply for an Arduino project (since it had a 24V, 2A option) which is what I need to power my Nema 17 stepper motor. I'm unsure how connect this to my home's 120 V outlet....
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USB Charger (Samsung/Apple/Dedicated)

I have read a lot of lines about D+/D- Voltage when using different devices. Also the Article from maxim integrated. The conclusion is: I test it with iPhone X(iOS 15.6.1) and i found something ...
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Converted PC power supply producing too much voltage

I have converted two ATX PC power supplies to 12V bench power. They have worked flawlessly for the past 5 years. Suddenly, both are providing 17V+. What could be causing this? I have a 10ohm ...
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LED 12 V, 30 A power supply blinking and 0 V output

I bought a 12 V, 30 A LED power supply for a chemistry experiment (electrolysis). The power dropped to 0 and the onboard LED in the power supply started blinking when the anode and cathode were in ...
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Induction motor control panel circuit

Updated Again: I have been working on this project for a few weeks now, with an end goal of having a control panel to power our two 120 V induction motors and 6 lights on the control panel using two ...
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1 answer
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Can you calculate equivalent capacitance across a MOSFET if you know the rise/fall-times and voltage across it? [closed]

In my high frequency supply my MOSFET VDS signals seem to be falling/rising at much slower rates than the data sheet would suggest for a Gallium Nitride switch: https://www.ti.com/lit/ds/symlink/...
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What is the Idc to Iac(rms) multiplication factor for these two power supply configurations

For each linear dc power supply configuration, when designing the power supply, in order to size the power rating of the required transformer correctly we need to know the supply's dc output current ...
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How to choose the right type of capacitor?

I built an AC power supply (we called it a TENG) based on the tribo-electric principle. It can light up about a hundred 3 mm LEDs. Now I want to try supplying the power from my TENG to an LCD ...
7 votes
2 answers
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UPS vs portable power station capacity ratings

I have been looking to buy a dedicated 220V AC offline UPS or portable power station with an offline UPS functionality. What surprised me is that, whereas both are very similar devices, is that ...
31 votes
4 answers
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Why put a 10k resistor between VUSB and GND?

I recently came across Yet Another RP2040 Trinket (the Beetle RP2040.) In their linked schematic something caught my attention: It is R10 below - a 10k resistor ...
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Capacitor to earth in floating power supplies

I'm looking at using two separate, floating supplies in a 20W power amplifier design to generate +24V, 0V, and -24V low-impedance rails. Some research suggests this is doable, and seems much less ...
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Would this power supply modification work to double the voltage?

I would like to replace the existing E-I lamination transformer with a toroid that I have. The original transformer has windings for 48 V phantom power. I was thinking perhaps I could just tap the +/- ...
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Did I fry my DC power supply? [closed]

I'm trying to get my NEMA 17 stepper motor working via Arduino. As a power supply I'm using a 24 V DC power supply adapter, 24 V 2 A 48 W AC to DC converter transformer 100~240 V AC input with 5.5x2.5 ...
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Is the two-wattmeter method applicable for an unbalanced source?

In balanced three-phase systems we can use the two-wattmeter method to measure total power. What about unbalanced sources and/or balanced/unbalanced loads? Can we use it for both delta and wye ...
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why isn't \$P=P_c\$ where \$P\$ is the power that we want to supply and \$P_c\$ is the power lost during transmission

When deriving the power lost during transmission, we use the following two formulae \$P=VI\$ where \$P\$ is the power that needs to be supplied, \$V\$ is the potential difference, and I is the ...
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Heat sink designing for an automotive grade motor controller

I am working on an electric vehicle development project. I am using a motor controller to drive a 3 phase induction motor. The motor controllers' input supply is 48 volts, and they sink a maximum of ...
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Switching between two DC power sources with opposite currents [closed]

I'm running a 24 V DC motor, it allows for a change in direction of current to change the turning direction of the motor. I have two exactly the same DC power supplies, with forward and reverse ...
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Protect a switching source from other electrical devices [closed]

I have the following problem: I have a WiFi electronic device in my kitchen to automate the lights using relays (made by me). It is based on a Wemos D1 mini microcontroller and the PSU is a Hi-Link (...
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Digital and analog supply voltage for amplified half-bridge strain gauge and ADC - MSP430G2995

I am working in a project to extend a pressure transmitter with a second pressure sensor (half-bridge strain gauge). This extension will use an op-amp (MCP6N16T-100) to amplify the signal and a ...
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Looking to find the value of this high-power resistor

I'm trying to find and replace this resistor and I'm having a heck of a time; it seems one of the bands has faded quite a bit. I'm guessing it's the second band because of how the bands are spaced, so ...
1 vote
1 answer
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Multiple AC-DC power supplies: one direct AC wall plug or two?

I'm building a data acquisition system that needs to power sensors and a high voltage contactor at 24Vdc, 12Vdc, and 5Vdc. After reading another post, it seems it is best to use separate AC-DC power ...
2 votes
4 answers
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Why does the L298N schematic supply Vcc to diodes?

I have been studying the L298N motor driver module to re-implement it as an exercise to learn PCB design. Something I am confused by in the schematic of the module is why Vcc is supplied to the diodes ...
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Amplifying electret microphones with wrong bias power

I have an issue. I'm making a device that can switch between two microphones for a two way radio. The microphone that comes with the radio is an electret microphone that gets its plugin/bias power ...

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