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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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3answers
45 views

What current should I choose in bench top DC power supply?

Most of the time while I'm doing my university projects, I find that only voltage requirements are given for building a circuit, and how much current I should supply from a bench-top DC power supply ...
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0answers
26 views

Limit 540 mA CC driver to 300 mA?

I have five 10 W, 34 - 38 V, 300 mA LED COBs I'm wanting to run these in series but to reach the voltage and watt range in the driver, I can only find a 540 mA constant current dimmable driver. I want ...
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1answer
34 views

5 V from power bank not constant when supply circuit

Now I'm working on my project which contains Arduino, LCD, electromagnetic lock, 6 channel 5v relay and 500V isolated converter. My project was designed to power by using a power bank. Now I use eloop ...
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1answer
22 views

Exceeding voltage on STM32 Vbat pin

I want to power STM32F429 Vbat pin with an existing Lithium Ion battery on board. However, the maximum voltage on the discharging curve of this battery is 4.2v which is above the maximum operating ...
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0answers
14 views

+24VDC to 5v converter - does the positive make a difference? [migrated]

I have a fairly general question, but cannot seem to find an answer to confirm my thoughts. I have a garage motor door, and on the top has 4 terminals - 1 and 2 for a switch button to open and close, ...
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0answers
9 views

16-Channel 12-bit PWM/Servo Shield check if it is powered by adapter [migrated]

I'm using Adafruit 16-Channel 12-bit PWM/Servo Shield with Arduino Uno controller In setup() I have a number of default positions ...
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0answers
48 views

small party without power [on hold]

I am considering throwing a little party during my vacation however this will be in a place without direct access to power... My goal is to use my laptop, a pioneer dj controller and 2 krk rokit 5's ...
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0answers
64 views

Why does a motor not work after the power supply?

I have a fairly cheap breadboard power supply and a motor. Now if I touch the wires from the adaptor (the thing that plugs into the power supply to provide it with electricity) the motor works fine ...
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1answer
2k views

Digital voltmeter ammeter wrong reading

Hello! I've built a small adjustable PSU with a buck converter (XL4015 module) and a cheap 10A digital voltmeter and ammeter. It worked fine for a few minutes but after that the voltmeter started ...
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2answers
29 views

Does ESP8266 deep sleep make sense while on the power supply?

If ESP8266 is powered via a dedicated power supply 220V AC → 3.3V DC. Is it worth it to put ESP to deep sleep in order to reduce power consumption? For example the indoor weather station, which ...
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2answers
42 views

The pros and cons of tantalum and ceramics in AMS1117

Task: Make a reliable power supply for sensors and an RFID card reader. Specifications: Total current consumption: up to 0.7A (700 mA.) Elements supply voltage: 3.3V Input voltage: 5V Working ...
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3answers
1k views

2.2K ohm resistor in series with 1A power linear supply circuit, is that right?

Here's right after the bridge there's 2.2k resistor in series with the regulator. This circuit is supposed to provide 1A current to the load! is that correct?
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1answer
248 views

How to generate highest voltage possible without sparking?

I need to precisely control high voltage in order to maximize the corona discharge zone while preventing arcing for a physics apparatus. The actual voltage when the corona breaks down will vary ...
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0answers
17 views

Solar Panel (5v/500mAh) charging USB Power bank (5v/1a)

I've been trying to find information on this but haven't found an accurate answer. I have a USB Power Bank that has a max charging input of 5v/1a and a 5v/500mAh solar panel that can output up to 5-...
2
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1answer
240 views

Can I use a twisted pair cable to send power to a device that uses a micro-USB jack?

I purchased a Google Home Mini that according to the specs this requires 5V, 1.8A. The OEM power cable has a transformer that plugs into AC and has about 3 feet of cable terminating at a USB micro ...
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0answers
110 views

Free energy from spark plugs and speakers [on hold]

I just saw a video where someone uses two speakers, 3 spark plugs, a coil made from insulated wire (and terrible soldering) and manages to turn a lamp on and off just by touching the speakers together....
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2answers
250 views

Chassis grounding for multiple daisy-chained units

I'm designing a system that provides power/ethernet/serial for up to 5 daisychained units. All of the boxes will be metal and my initial plan is to run power and signal ground through the 14 pin ...
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1answer
95 views

6v/12v Dc motor runs and stops for 0.5 seconds (cycle repeats)

although am an electronic hobbyist,but i have pretty much just the basic knowledge about electronics and here's a problem that I am facing. I am using a toy dc motor that runs on 3v/6v/12v. It runs ...
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1answer
52 views

schmitt trigger causes noise

I am trying to get a 74HC14 hex inverting schmitt trigger to work. First thing I did was connect it to a power supply. When I connect the Vin and Ground ports to my bench power supply (5V), some ...
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1answer
46 views

Using a Computer PSU for its 12V output for high wattage loads [on hold]

I'm looking to install some LED light bars (primarily designed for use on off-road cars) as fixed outdoor lighting on my property. I see they have models that use up to 700+ watts of power (for crazy ...
0
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0answers
21 views

SMPS 5V without load, fluctuation on load TOP258PN

I am using PI Expert Online (this) to design a smps circuit for 5V, 2.5A output. I already have TOP258PN IC with me so built circuit for that. Change from schematics: I am not using choke and using ...
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3answers
2k views

Should I twist DC power and ground wires from a power supply?

Is it beneficial to twist the red/green power/ground wires from a low-voltage (~5V), relatively low current (1 to 5 A) switching, desktop power supply? This makes my wire bundle on a desk less ...
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0answers
32 views

Is there a power supply dropout time rule of thumb for router modems? [on hold]

This question arises because I don't want to get too lost and over engineer a solution. I do understand a UPS could be placed ahead of the circuit, but I'm wondering if a little ingenuity can be ...
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2answers
79 views

High frequency reduces power on circuit

I am not expert in electronics so there must be many errors that I am not considering. I designed a simple half wave rectifier that gives signal to a LDO voltage regulator of 3V3. In the input I have ...
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3answers
53 views

DC Power Limiting Circuit

I would like to know how to build a power limiting circuit. The goal is to be able to combine two PSU's with the same voltage in parallel in order to increase the Power output. From what I've tested,...
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0answers
38 views

Buck/Boost converter TPS63070RNMT is not working properly

I am working on a Buck/Boost converter design which is based on Buck/Boost converter TPS63070RNMT. Below is the schematic design. All the selected components are as per the Section 9 of the datasheet. ...
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2answers
292 views

MC34063 with external FET. Why?

Follow on from : earlier post Below is an LTSpice simulation of an MC34063 step up (5v to 9v) circuit. As you can see, this particular circuit is working correctly, and delivering about 300mA. The N-...
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1answer
97 views

TP4056 doesn't work without power source connected [on hold]

I have a problem with my TP4056 circuit. My goal is to (solar)power a NodeMCU V3 with the TP4056. I simply connected the output from the TP4056 to VIN and GND from the NodeMCU board The TP4056 ...
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4answers
1k views

How can I safely determine the output voltage and current of a transformer?

So I am building a Tesla coil with my partner for a senior design project. We safely ripped out a transformer from a microwave oven. However, after a good amount of research, we were unable to find ...
13
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5answers
39k views

24V 3A from ATX power supply?

I am looking for a cheap way to get +24V DC max 3A from computer power supply. I prefer easy soldering solution like DIP, and standard components that do not need to be purchased over internet. Any ...
1
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1answer
1k views

Eagle PCB supply symbols in a multi-voltage system

Supply symbols signify vdd and gnd and perhaps vdd, gnd and vss in dual supply system. However, in a situation where one has +5V, -5V, +3.3V, 1.8V, Analogue ground and Digital ground, what should one ...
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1answer
55 views

Would this switching power supply work?

I'm trying to design an integrated power supply to use in IoT projects that I'm working on, some including microcontrollers like the ESP8266 or ESP32. In previous projects I've made, power supply ...
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2answers
86 views

How to obtain 360vdc from 240vac for audio use without a transformer?

I'm in the process of creating a tube guitar amplifier with an output power of ~6w (fender vibrochamp AA764) which requires the use of 360-400vdc. How could I obtain such a voltage from mains without ...
3
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3answers
519 views

I2C communication with different power sources

Will I have some trouble if I try to establish a I2C communication between 2 µC powered from two different source? Both µC run on 3,3v but this voltage is provide from a different regulator (LM317). ...
1
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1answer
95 views

Designing a PCB with multiple supply voltages

I'm in a process of designing a 2 layer PCB for my device. The device is a master control board, and there will be 10 daughter boards. Various peripherals and things will be connected there: I need ...
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1answer
58 views

Power supply module is being powered by the arduino [on hold]

simulate this circuit – Schematic created using CircuitLab i started a project to try and pilot a 28BYJ-48 5v stepper motor with its ULN2003 board from an arduino Nano, along with some LEDs and ...
4
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0answers
59 views

Radio module resetting when fluorescent tube switched on/off

I have a PCB powered by an IRM-30-12 power supply (230VAC to 12VDC). On this PCB, I have a MRF24J40MD from Microchip and a Udooneo to drive it + a 5VDC regulator and the 3.3VDC of the Udooneo. After ...
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1answer
53 views

USB Port Amperage

So I have built a Benchtop Power Supply out of an old computer power supply to power and test misc. gadgets I have created. I would like to attach 2 salvaged USB ports from a junked computer to the 5v ...
13
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6answers
11k views

Why do buck (step-down) switching regulators require an inductor and diode?

So, I understand, at least at a basic level, the method of operation of switching converters, both buck and boost. What puzzles me, though, is why buck converters in particular aren't simpler. Why ...
0
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1answer
97 views

SMPS Flyback transformer selection

I am trying to design a SMPS for a project (I have to make a custom one for integration purpose). This SMPS have universal input (85-265V AC at 50 or 60 Hz) and an output of ideally 53V (but it can ...
6
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8answers
6k views

Can I use an op-amp to supply itself a negative voltage?

For my project, I am using an LM324. According to the datasheet, its power supply can either be +/- 16V or 0-32V (max). The output will range from -3V to +3V (or there abouts), so I realise I'm going ...
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3answers
237 views

Phono preamp, one channel doesn't work

I have built a stereo preamp using this circuit (taken from here Hi-Fi Phono Preamp Rod Elliott - ESP), but for some reason I can't get the right channel to work at all while the left one plays. Now ...
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0answers
50 views

Component 12v to 5v powered USB ports [closed]

I'm trying to fit powered USB ports to my vw campervan, but want to retain a factory look. I've done all the usual searches, but the only ones I can find are the ubiquitous cylindrical ones, with ...
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2answers
41 views

Active Discharge Options

More and more frequently I am faced with a specification that requires the ability to discharge an output capacitance to a safe level X, in time Y. The circuit I am currently working on is 2000uF @ ...
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4answers
409 views

Parallel Power Supplies with Ideal Diodes

I'm working on a project that operates at 5v - and can draw UP to 10 amps. Under normal conditions, it won't be doing that - probably closer to 3 amps, and (if configured for low-power) only 450mA or ...
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2answers
57 views

Understanding DALI power supply

I am working on a DALI system and I came across this schematic for the DALI power supply in a Microchip app note AN1465: It says the power line can be 12-20 Volts but the current has to be limited to ...
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1answer
84 views

Why does my phone pull less current from power bank when the screen is on? [on hold]

While charging my phone (a Samsung Galaxy S5) with a power bank that displays the power output with 0.1 W resolution, I turned the screen on. To my surprise, the power pulled by the phone went from 7....
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3answers
10k views

What power supply do I need to power 4 peltier plates with 5A 12V each?

I need to power 4 peltier plates (tec1-12706) with 12V and 5A for a thermoelectric cooler project. I wish to have maximum cooling. Also I need to attach a few(4) computer cooling fans to dissipate ...
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2answers
365 views

Transient Power Supply with LM317 and LM2576

I have a power supply to power up a 8W LED board and a raspberry pi. I have used a 24VAC (12-0-12V) 2A transformer to feed the bridge. I have also used a LM317 to provide a voltage of approx. 15.8V ...
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3answers
74 views

Stepping down 25V-11V to power 5V micro-controller

I need to power a control circuit from a variety of LiPo batteries 3-6S (12.6V to 25.2V). The control circuit can draw up to 100mA at 5V (atmega328p + other discrete components, LEDs, etc). Choices I ...