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

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2answers
34 views

How to calculate power supply for 100x loads @ 3V 700mA

I'm currently designing a setup using 100x loads that requires a 3V 700mA supply ea. The loads are connected in parallel with the main power supply. I'm a bit doubting about my power supply dimension ...
1
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1answer
42 views

Did ESD fry my REF200 current source circuit?

Last summer I built a current source to power a custom-made pressure sensor. This source uses a REF200 IC and is powered by a wall wart that outputs 5V. The whole circuit is encased in a plastic box ...
0
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2answers
47 views

When replacing a PS, how do I know I'm safe if device doesn't list current? [duplicate]

I recently acquired a Lantronix UDS1100 telnet-> serial converter. It came without a wall wart / power supply. I have an extra power supply from an old modem that I think might work, but I want to be ...
3
votes
1answer
40 views

Measure Power Supply Noise Rejection at MHz and GHz

I'm trying to characterize the performance of a power supply module, one of the criteria being power supply noise rejection, in particular at different frequencies. For testing 10Hz to 100kHz, I was ...
0
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2answers
61 views

Connecting phone chargers in parallel

Could we connect two 5 Volt phone chargers of different ratings in parallel for quick charging with a diode as shown(rectangles being the chargers) Please excuse me for the drawing I made..
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1answer
23 views

Sharing negative terminal (“ground”) between 2 LiPo batteries and UBECs / paralleling 2S LiPo packs

One of my projects require a hefty amount of amperage - and as such I want to use 2 LiPo 2S batteries, in parallel. In addition, I am regulating the voltage using multiple DC-DC step down converters ...
0
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1answer
39 views

ATX-PSU to supply PC and RaspberryPi

I want to integrate a RaspberryPi into the case of my desktop PC, that has an ATX-PSU. I want the RaspberryPi to keep running, even if the PC is shut down. It would be nice to avoid the additional ...
1
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1answer
38 views

Supply voltage of stepper motors

I'm going to use the following stepper motor drive chip: http://www.st.com/web/en/resource/technical/document/datasheet/CD00255075.pdf And I have choosen the following AC/DC converter: ...
1
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1answer
56 views

Aluminum winding in inverters

I am planning to buy inverter. I finalized one model; however, I was told that it uses aluminum windings whereas the other model has copper windings. They recomended I should buy the one with copper ...
2
votes
2answers
53 views

How to power a Arduino Yun with a 6V battery?

I would like to power my Arduino Yun board with the following battery: Arduino Yun has a VIN pin that represents the input voltage to the Arduino board. The official documentation says: Unlike ...
0
votes
4answers
127 views

heat air with nichrome wire

108 rows of grapevines, each row 650 feet long. Suspend a nichrome enameled wire along each row in order to raise the temperature of the air within 18 inches of the wire 6 degrees Fahrenheit. What ...
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votes
2answers
64 views

SMPS with two outputs ,12v 3A(max) , 24V 2A(max)

Hi all , I am new to designing circuits. I am building an SMPS using the fairchild Semi FSGM300N Power switch. here is the datasheet http://www.farnell.com/datasheets/1526530.pdf they have given a ...
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3answers
124 views

Can I use one battery to power up two circuits?

I 'm planning to use a zinc–carbon 9 V battery to power up two circuits (the one that battery belongs and one more). I 'm thinking of using a breadboard in order to achieve this. The second circuit ...
1
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2answers
78 views

PMOS Inrush Current Limit - Where to place Capacitor

In order to reduce back-EMI of a Buck converter a LC input filter is to placed in front of the converter. To limit the inrush current when those caps are charged I consider to use a PMOS with a RC ...
0
votes
1answer
46 views

Debugging power on issue [closed]

First off I don't know if this is the correct fora, for this kind of question. My personal Acer Aspire 5745G has an issue, namely that it usually has issues powering on. The issue is that when the ...
1
vote
1answer
82 views

Voltage on circuit input different than on power supply

I'm using a really good 5V-35A switching power supply to power some mini PCs (Cubieboards if that matters) as below. simulate this circuit – Schematic created using CircuitLab The weird ...
0
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1answer
57 views

Reduce discrete linear voltage regulator dropout

I am investigating the following circuit taken from here which works fine in simulation. However, while Vout rising linearly with Vin it shows a ~800mV dropout, which I don't quite understand. ...
0
votes
1answer
67 views

High voltage drop across H Bridge [closed]

I have a circuit built with the schematic below. When I connect it to the motor and turn on the power supply, the voltage drop is big. My power supply voltage is set to 12V but when it is turned on, ...
0
votes
0answers
73 views

What kind of circut is needed to wire multiple 12 volt power supplies in parallel?

I would like to build a circuit to allow multiple 12 volt power supplies to share a load. Each supply is rated for up to 100 Amps @ 12 Volt output what kind of circuitry do I need to achieve this ...
-1
votes
2answers
67 views

Documentation on Apple's USB Chargers? [closed]

I'm worried if someone charges my single-cell lipo with an Apple USB power supply that it'll get damaged. Is there documentation on Apple's USB chargers? I'm imagining I want to be able to support ...
1
vote
1answer
52 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
3
votes
3answers
525 views

Powering a Raspberry Pi from 12 V DC

I new to electronic engineering and am trying to learn electronic engineering by creating little projects. I have a few questions about powering my Raspberry Pi (5 V DC @1000 mA) from a ...
0
votes
1answer
34 views

Calculating capacitance required for a pulse duration of time T using a class AB amplifier

Firstly I apologise if this question is similar to another one I asked a while ago. But, as you will see, this is question is slightly different. I have an amplifier which is a common emitter driving ...
2
votes
1answer
44 views

How do variable current limiters work in power supplies?

Bench top power supplies often enable you not only the set the voltage, but the maximum current. How do these bench supplies provide this variable current?
1
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1answer
104 views

Do N-channel MOSFETs require a pull-down resistor?

I'm using an N-channel mosfet to supply power to a servo. The problem is that even with the gate set at low, I'm still getting some amount of voltage (~0.9V in a 5V system) coming through. Do I need a ...
0
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2answers
86 views

Stepper motor causing Arduino brownout?

I'm trying to build what amounts to a single-axis CNC machine running off a 12v automotive type electrical system. Here's a basic description of the build: Arduino Uno Just for testing, I'm using a ...
0
votes
1answer
60 views

How to charge double cell lipo battery with single cell charger?

My setup is simple: I have this bluetooth module with a built in single-cell Lithium ion/polymer battery charger. I have this double cell LiPo battery and I also have an arduino nano that I will have ...
0
votes
1answer
95 views

Decoupling a power supply

I'm building my first biped robot, using a Raspberry Pi as the brain. My problem is, I want to decouple the battery before I use it to power the Pi. The reason I want to decouple the battery is ...
1
vote
1answer
142 views

Getting 9V and 400-500mA out of a 24V power supply

I recently bought this power supply to power a microstepping stepper motor controller (which requires an input voltage of 24V). My project requires the ability to dynamically turn on and off an ...
1
vote
2answers
67 views

Can i use a power supply that supply slightly higher current than the rated current from my dc motor? [duplicate]

I got a 12v ,0.9A dc motor.Currently i got two 12v dc supply which borrowed from my friend.The current of the 2 dc supply is 1.0A and 0.5A. Is it safe for me to use the higher current supply from 12v ...
0
votes
3answers
79 views

Current flow due to capacitor in a basic power supply circuit

In a basic power supply like this one below, for a positive half-cycle the capacitor is charged up along with the rectified load current. For negative half-cycle diode is "off", so no conduction from ...
0
votes
2answers
69 views

Arduino overheating with 5V addressable LED strip

I've got one of those 1-meter addressable RGB LED strips from Sparkfun (link) connected to an Arduino. The Arduino is powered by the recommended 9V DC 650mA power supply through the barrel jack. ...
1
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1answer
58 views

Power Supply for LED Project

I am working on a project where I have to power a 5 meter long LED strip (https://www.sparkfun.com/products/12022) and 54 3.4V 20mA LEDs and control them all from an Arduino. My current idea was to ...
0
votes
1answer
58 views

How to power servos externally in Arduino

I tried to control 2 servos with my arduino. It worked fine but if I try to control 5 servos with my Arduino, it doesn't work. I want to power up the servos externally but I don't know how to do it. ...
0
votes
2answers
70 views

5V wallwart to 4 USBs and 3Pin fans

I am working on a small Raspberry Pi cluster that I am going to use for web hosting, home automation, cloud storage, VPN, and so on. I plan on using the 3D printer and laser cutter/engraver at my high ...
4
votes
1answer
142 views

Why would this logic gate use negative voltages?

I'm reading a data sheet for a hex buffer with enable- a pretty simple logic DIP. Here's the logic diagram and pin assignment: This all makes sense to me until I look at the electrical parameters. ...
6
votes
2answers
377 views

What type of power supply is this and how does it work?

I am evaluating a new controller and see a circuit I do not quite understand. I've built the circuit and I see the following (see image), but not understand why. Can someone please give me the name of ...
12
votes
4answers
1k views

What is the usage of the negative voltages on a PC motherboard?

What is the usage of theses negative voltages? Are they there only for backward compatibility? In nowadays PC power supplies, we have: +12V +5V +3.3V but also: -12V -5V But the current rating ...
1
vote
1answer
61 views

Power ATX motherboard from JAMMA

I have some arcade cabinets with computers in them, and I'm using a regular PC PSU for them, which sucks because it takes up so much space. I know there are pico-psus on the market, but I don't ...
3
votes
2answers
323 views

What's the rationale behind “wall wart” plugs? [closed]

It's more of a curiosity question than a real problem, but since I've run out of wall sockets again, I'd like to ask you - is there any particular reason or use case in which "wall wart" AC adapter ...
0
votes
1answer
53 views

ADC Analog & Digital Supply?

I'm working on a circuit based on ADC and DAC. I understand that keeping ground plane of analog and digital section different is crucial in many applications for reducing digital noise interference ...
0
votes
2answers
79 views

What is the maximum safe voltage for 1.5V and 3.7V gadgets of consumer electronics?

I know that most electronics for 1xAA battery accept at least 1.1-2V and for li-ion 3.5-4.3V. But what is probable safe maximum? Can I use li-ion with 20ohm resistor or even without it for supply 1xAA ...
10
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7answers
1k views

Is there a constant power supply?

A voltage source is a device that produces constant voltage, but allows amperage and power to vary, in accordance with the laws of electricity. An current source is a device that produces constant ...
0
votes
0answers
9 views

Will a spike protector work in reverse? [migrated]

Will a spike protector work in reverse? Protect the circuit from an appliance? My attic lights' blubs blow 10x faster than any other bulbs in the house. I think it's because everything in the attic ...
0
votes
1answer
78 views

Li-ion battery choose question

I am new to this forum and I hope you can help me with this. I want to build a small circuit that will have: an ATXMEGA ucontroler that uses all of its 5 USART and one bluetooth module. This circuit ...
2
votes
2answers
80 views

What is “current rating” in a battery implied by?

How battery limits current to the maximum level that is indicated in its specification? If V/R value is greater than maximum current rating then current through the device will be V/R or maximum ...
0
votes
3answers
117 views

Regulated +5V drops when relays are switched on

A regulated power supply RAC02-055C/277 provides 5V to an Arduino driving 2 relays. The power supply is rated to provide 2W of power. Connecting a multimeter between one of the leads of the power ...
10
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5answers
2k views

To what extent are “pure sine wave” power supplies marketing spin?

Recently, I've noticed a trend in power supply manufacturers touting their PSUs (generator or battery inverter etc.) as having a pure sine wave output. I've also seen people saying that warranties ...
1
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4answers
126 views

What would be the input current of buck regulator

I have a basic question about measuring input current. The buck regulator I have chosen is rated to deliver 3.3V/2A from +12V input. My question is - Is the input current 2A (load current) + few mA ...
0
votes
1answer
34 views

Powering an iComSat GSM Shield and a Gear Motor with LiPo Battery

I have an iComSat GSM Arduino Shield (based on the sim900) and a gear motor that I am planning on using with a Teensy 3.1 microcontroller. I'd like to power the whole rig using a 2000mAh LiPo Battery ...