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

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42 views

Noisy Voltage Rails (Vcc, Gnd) - Noise Isolation for Automotive Circuit

I have an audio (mic, speaker) circuit that I am currently powering off of a 12V car adapter that is fed into a 10V switching DC regulator to power the rest of the circuit. I have noticed a horrendous ...
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0answers
46 views

Why am I getting low power from my circuit after replacing the rectifier?

I'm working with a motor and a speed control circuit scavenged from a neck massager. I accidentally fried the rectifier rated at 400V rms while wiring it up to a switch. I replaced it with another ...
0
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1answer
47 views

Primary power selection and cutoff circuit

In my circuit (shown below) I want an output voltage to be provided which is the greater of two sources: a 9V battery, and an external 12V source provided by a wall wart adapter. The circuit should ...
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1answer
45 views

50 Hz noise problem in isolated AC-DC power adapter

I have a circuit which is powered using AC-DC 12V wall converter. One of the power supply adapter has ground pin (3 pins) in its input and the other doesn't have (2 pins). The ground pin in the first ...
3
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0answers
60 views

Multiple nrf24l01, shared power, ripple/interference, DSO screenshot provided

I've got this circuit with 3x atmega328 & nrf24l01+ running off shared power supply, either 2x AA battery or 3v3 reg. It acts as a repeater, and depending on the origin of the message and the ...
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3answers
67 views

Splitting DC power supply risk?

I am looking into taking the power supply 12V output of my PrintrBot and plugging a very simple parallel circuit with some LEDs. I know I can connect a parallel circuit similar to this Splitting a ...
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1answer
66 views

Supercapacitor question - dc boost [on hold]

I like to know two things What is the formula for calculating total current out of a supercap, is it capacity*voltage/3600? Many supercaps are like costly, so if i buy like one rated at 500F, 2.7V ...
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3answers
421 views

Automatically switching from 9V battery to DC wall adapter on insertion

I have a simple circuit that runs off of a 9V battery. I'm re-designing it so that it can also run off of an external 12V DC source (ie: a wall adapter). I want to design the circuit so that if both ...
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0answers
61 views

Servo shaking when GSM module starts transmitting

I have a project which uses 2 Arduinos which is communicated with my phone by a GSM module, and that one of the Arduinos is driving two servos. The question or problem is that my servo is shaking ...
0
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1answer
46 views

Decoupling pair of microphones using noisy power source

I currently have a high quality microphone that I am powering from a relatively noisy 8V source, like that shown below. It has a built-in amplifier, and doesn't require any amplification. It just ...
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2answers
107 views

Powering 3W LEDS

I'm looking to power 50 3W red leds as cheaply as I can. I have a 100W LED COB that I powered with an old laptop power supply (19.5V@4.62A), connected to a 150W DC-DC step up. This is a constant ...
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2answers
42 views

Setting the absolute potential of an isolated DC power supply

I have a circuit that, for reasons out of my control, is powered by an bipolar +/-4V supply. This circuit includes instrumentation amplifiers and so forth that have input headroom requirements of over ...
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2answers
118 views

Combine 9V and 1.5V power supplies to make a 7.5V supply

To save on cost, I wish to buy a 9V DC and a 1.5V DC power supply and connect the positive outputs together to create a 7.5V 200mA supply my Plantronics headset needs. That is, 9 - 1.5 = 7.5 across ...
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3answers
71 views

What LA4282 stands for

Can somebody explain me the numbering system for integrated circuits. I need an explanation for : LA4282 (not what it is, I know what it is), what each character stands for. The one I need to ...
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3answers
42 views

Power, Voltage, Current Supplies

I am confused by the use of these three terms in conjugation with supplies. I read somewhere that the prime objective of the circuit is to provide power rather than voltage? What exactly does that ...
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1answer
27 views

Help understanding onboard power supply measurement test connections

I recently came across this circuit for measuring the output of a TPS54620 switching regulator (12V->3.3V). I'm not a power engineer, so I'd like some help understanding the parts in red boxes ...
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1answer
69 views

Help me hack this other speaker: Where would I introduce two different DC voltages?

I already asked a question about a similar speaker. I am also trying to convert a larger speaker in the same fashion. I open the speaker, and can identify the power supply and rectifier (I believe) ...
3
votes
2answers
60 views

What parameters are important in inductor when used in power supply

I interface an image sensor, and the design schematic for power supply is: How do I choose one from the available 3uH inductors based on the specs? I figured the maximum current and dc resistance ...
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2answers
110 views

Bypassing a switching regulator

I am trying to design a power supply for a 3.3 V / max. 340 mA system. It should provide the possibility for 5 V-12 V input as well as directly providing 3.3 V. Even though it is not intended to ...
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3answers
154 views

What causes old power supplies to start humming?

I have a number of mains-powered devices that have begun humming (I assume at 50Hz, though I haven't measured it). These include clock radios, a speaker system, a lamp (20W halogen with a transformer ...
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0answers
61 views

How to determine input voltage of something with no possible specs? [closed]

The question is somewhat unclear, but what I am in is the predicament of I have an electric train table that my late grandfather has designed himself, but unfortunately he didn't leave any diagrams or ...
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1answer
33 views

Battery discharge rates and current limiting

In a project I am building, I have a CVCC to control the current and keep it where I want it. (The circuit would definitely use more current it I didn't use the CVCC.) The problem arises because when ...
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2answers
82 views

How to separate two DC voltages in s dual power supply?

I have a dual power supply (Lacie ACLG-51) that supplies both 12V DC and 5V DC with a common neutral (3 wires) I have used it to drive a little system composed of a Raspberry Pi (5V), USB HUB (5V), ...
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1answer
38 views

Phasors of power supply Vs1 in one example

I read one example in my note: If \$V1=1=+j2\$ and \$V2=12+j12\$, phasor of power supply Vs1 is: \$29+j59\$, but I couldn't get it. I think it's wrong and the solution is \$29+j57\$. Could anyone ...
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1answer
79 views

Dual power supply: two secondaries or series regulators?

I am going to create a simple dual voltage power supply for powering logic (5V) and some stepper motors (12V). What would be a better solution: Would it be to use a transformer with two secondaries ...
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53 views

Modifying LED driver

A friend of mine gave me an LED driver that drives 30-36V and 3 amp in the output. Is there any way I can modify that to get 20-22V and 4-4.4 A to power a new LED I got? I live in Argentina, and ...
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0answers
36 views

Safely shutting down 19V mini PC when power fails

I am adding an Intel NUC (4"x4" i5 PC, 12-19V, 10A@19V) to my guitar effect pedalboard for all kinds of fun signal processing with Ableton Live and Max/Msp. I'm building a 12V 20A power supply using ...
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0answers
35 views

iPhone charger(wall) adapter [closed]

i have been wondering on internet from many days to get information iPhone charger. i am from india. one day my iPhone was plugged in then suddenly i noticed my rooms tube light shined more than usual ...
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1answer
99 views

Help me hack this speaker, where would I introduce DC voltage

I have a speaker that runs off of AC (there is a switching converter within the speaker) I'm attempting to convert it to battery power, From my understanding the speaker runs off of 5V (someone else ...
0
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2answers
64 views

Looking for efficient battery supply to power 3.3V circuit

I have been searching everywhere for the best way to power my circuit and I can't find straight forward information. My circuit needs 3.3V and the maximum current it draws is 50mA. It will run at ...
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3answers
102 views

What is the significance of 0V output from a regulated power supply?

I am mainly interested to know the application of 0V output from a lab power supply. Which linear regulator IC one can use to get 0V output? Edit:The LT3080 datasheet says that it is adjustable to ...
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4answers
108 views

Can voltage be controlled in a fixed DC circuit?

If resistance is fixed in a DC circuit, can voltage still be controlled and changed from one value to another? Imagine this circuit, that has a fixed resistance of 1 Ohm, and the desired current is ...
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1answer
47 views

Elongate the power supply p4 connector [closed]

I've got pico-psu, tiny little power supply for computers. Recently I've moved onto a new motherboard, connectors on this mobo are located further than before. So I had to elongate psu-p4 connector ...
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votes
1answer
44 views

19.5V, 5.13A power supply to replace 19.5V, 7A power supply? [duplicate]

I have this laptop: http://www.newegg.com/Product/Product.aspx?Item=N82E16834233058 It came with a pretty large and heavy power supply, so I am trying to replace it with a smaller one. The reason ...
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1answer
89 views

Expressing a circuit in the form of block diagram [closed]

I am doing an electronics project for 12th grade in electronics.This project is about water level controller.I have component list along with the description and I have soldered the circuit as told.I ...
0
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1answer
96 views

What caused my servo to burn out?

I'm working on a servo project. I connected 12 servos to a single Adafruit servo shield and plugged in a 5V 10 amp (http://www.adafruit.com/product/658) switching power supply to the shield. ...
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0answers
46 views

at89c51 power supply [duplicate]

I am making a project using at89c51. I used my mobile charger (output: 5V, 1A) as the power supply. Will my IC get damaged due to the high current? I asked cause, without loading the program I ...
0
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1answer
55 views

Power supply for Raspberry Pi

Before you tell me that the question has already been asked, only similar things have been asked. I need to power a Raspberry Pi with some electrical equipment attached to it. The Pi needs to run ...
0
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1answer
33 views

Repairing (possible) earthing/ground issue in computer PSU? [closed]

I've got a computer that will no longer power on. It used to be willing to power on quite randomly, and ran fine when it did. I'm not an electronics savvy person, but i've done a manual check on the ...
0
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1answer
63 views

Prevent EPROM powering from IO pin

I consider using a cheap Microchip 3-pin EPROM with single bidirectional data line as ID storage on various daughter boards. Since I don't want to waste daughter board connector pins on a device ...
0
votes
3answers
118 views

Boost regulator from 3V to 14V; then two LDO to make a +5/-5 power supply?

I am designing a mixed signal circuit and I need +5/-5 dual supply for my opamps. Could the following configuration work, else what are my alternatives? ...
2
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2answers
137 views

BeagleBone Black - power supply sensitivity

I've bought a AC/DC adapter which per its specifications should output 5VDC and deliver 3A. I was going to use this adapter to power my BeagleBone Black (BBB) with. However, when I'm measuring the ...
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2answers
67 views

How to Mount Power Supply to PCB

How can this 5V 3W power supply board be mounted and electrically connected to a custom designed PCB? Or will it be better to get this power supply board instead due to the right angled pins ...
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3answers
124 views

Why do most batteries or circuits use a 12V supply?

I have seen most of the circuit using 12V supply, is there any reason behind this? Is there any reason to choose 12V in all systems like battery-powered devices?
1
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2answers
88 views

Changing the voltage of a power supply

I have an old laptop power supply which provides 3.5A at 20V. I want to re-purpose this for another project for which I require 3A at 5V. If I cut the output cable I'm assuming I'll find a +20V wire ...
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2answers
56 views

Running up to 40M (130Ft) of WS2801 IC LEDS

After many hours of searching the internet for information and gathering what I could, I have run into my final problem that I am having trouble finding an answer for. I have 40 Meters (130) Feet of ...
2
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3answers
195 views

Is my PSU design safe, what should I change?

Normally I would just go and breadboard the design out, but since this is using mains power, I would rather ask experienced people first. I want to build a desktop 170V DC power supply to fiddle ...
2
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2answers
130 views

How does R5 bias the zener in this SMPS circuit?

In the description for the circuit below from this data sheet for TNY268 off-line SMPS switcher, it says R5 is used to ensure that the Zener diode is biased at its test current and R6 centers ...
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2answers
91 views

Power supply for 144 LEDs in parallel?

I appreciate any help as I try to figure this lightbox project. I need to wire up to 144 3V (built-in resistor) LEDs from flickering tea lights (normally battery powered). Not sure how many to wire ...
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2answers
118 views

Could a modified sine wave inverter destroy/damage the AC adapter for a laptop?

I recently encountered a scenario where I attempted to use a Energizer EN500 modified sine wave inverter to provide power to a Dell 180 watt AC adapter. The circuit powering the inverter was 12 volt, ...