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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What is the best starter adjustable power supply for pretty cheap (preferably ac/dc) [on hold]
Please I am just a kid no $8953739857239875 power supplies. Btw I am an inspiring electrical engineer and I'm 10 so I need a bit of help so I don't how do I put this nicely, ahem trip the breaker if ...
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1answer
31 views
Is it safe to externally power a net normally powered by a SMPS (3.3v buck)?
I have a board which has a microcontroller powered by a 3.3V buck and I need to know if it will harm the buck to power the net that the buck usually powers with a bench-top power supply.
A bit of ...
4
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1answer
64 views
I need help to identify this old SMD device
I'm working on a circuit and I can't find information on this component (see picture).
This hybrid circuit is part of an old industrial PSU. It is a PFC circuit based on UC3854 but I don't know if the ...
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0answers
29 views
Cellphone charging issue [on hold]
I own a Le1S cellphone. Bought it on 2016. Today its showing weird issues. When I charge the phone from the regular domestic supply, it is working inappropriately. I would type "CHAT" and it spells ...
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1answer
42 views
Converting 5V to 3.3V with 100mV ripple max, preferably without board
I am working on a project in which there is an existing enclosure, an existing power supply board and a bought board that I need to interface with.
The board I need to interface with needs to receive ...
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4answers
44 views
Does the switching frequency and ON/OFF time duration of LED affect the power consumption of LED?
I want to drive the electronics consisting a controller with different peripherals on its I/O pins, one of which is LED, with 3V coin cell battery supply.
I want to determine if its switching ...
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1answer
75 views
Most cost effective way to power a bunch op amps +/-12V supply rails from +5V
I'm searching for the most cost effective way to supply +/-12V for 12 TL084 op amps. Reading in the datasheet, it seems they have a typical current output (with load) of about 20mA. So, 12 * 20 = ...
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1answer
33 views
Single battery for different voltage components
So I have a 12V DC motor and a 6V stepper motor. Ideally, I would like both of them to draw from the same 12V battery pack (due to build constraints). The DC motor will be fine but the extra 6V ...
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5answers
64 views
Power NMOS used as voltage switch
I've designed a PCB schematic that uses a MOS device to switch one of the higher power rails. I've looked through the datasheets many times, and believe it should work, according to the Current-...
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1answer
31 views
DC-DC step down 12V to 5V source versus straight 5V source
Here is the scenario: I have a project needing 3 supply powers:
3.3V to run the microcontroller (max 100mA)
5V to run a bunch of adressable LEDs (max 8A, the most current intensive)
12V to supply op ...
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2answers
34 views
Operating Voltage Range Question
Almost certainly a neophyte question. I'm trying to understand the difference between nominal voltage and operation voltage range. My intuition was that, for a given power supply, it would hold a ...
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0answers
67 views
How to find out which voltages a power supply outputs? [on hold]
My TV recently broke down and I am trying to repair it. Parts and traces of the Power Supply are damaged so I had the idea that I could replace the internal Power Supply with an external one. But I ...
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1answer
44 views
Audio jack detection to turn on device without power loss
I'm trying to make simple headphones amp and I wonder - is there any way to use stereo jack connector with N-C switches like this:
to turn on the amp so the battery is mechanically disconnected?
I ...
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0answers
31 views
Capacitor value for power supply [duplicate]
I am designing a power supply that will take a standard wall outlet 120 VAC 60 Hz main and using a 12:1 transformer to step down the voltage to 10VAC. Then using a bridge rectifier and LM7805 to ...
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1answer
24 views
Searching for a transformer for the power board of an Equipe 2400 studio blitz Power/controller
This is for a photographer friend, feel it would just be too bad to let this beautiful equpiment stay in the closet because of, as far as I can tell, one blown transformer. The unit is made by Bowens ...
3
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1answer
52 views
Integrated 5V uninterruptible power supply (UPS) with a lithium cell?
I'm trying to figure out the best way to implement a UPS for an embedded system that runs from a 5V supply.
Essentially the system has a 48v to 5v, 1.2A output DCDC converter that powers my system. ...
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0answers
28 views
2 MOSFET DC to AC Inverter Design (Wireless Charging)
For one of my projects, I am trying to create a wireless charging station for a LiPo battery. For my input, I'm taking the standard 120 Vrms, 60 Hz voltage source I get from a outlet. From initial ...
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0answers
37 views
Diagnosing shorts in circuits involving power supplies
I was using a dc power supply connected to a wall outlet with a neutral and live wire. (https://www.amazon.com/gp/product/B074YHN8D1/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1). This was on first ...
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1answer
145 views
What does 1 and 0 mean on this power supply?
I have a Shaw Scientific power supply. On the front there is a switch to set the voltage from 0 to 12 volts. There is an on/off switch. There are connections for ac and also for dc. Then there is a ...
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0answers
25 views
Broken MSI Charger [closed]
I've recently broken an MSI Leopard 2pe gp70 charger, the rubber sheathing cut open and the wires became exposed, hot and started sparking. I've ordered a new one and it hasnt arrived soon, so to the ...
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0answers
43 views
Electrical engineering on motor [closed]
Please help me in finding the solution of it and i am very various for it.
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1answer
65 views
What nichrome wire voltage/amps is required to heat 1 meter [closed]
How can I work out what voltage and amps are required to heat nichrome to:
Temperature: 220 F
Length: 100 cm
Gauge: 20 (0.85 mm diameter, 1.62 ohms per meter)
I think I need 7 volts and 3 amps.
I ...
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1answer
37 views
Choosing correct relay for LED power supply rating
I have a 500W 24V power supply for running 24V LED strips. The power supply says it's rated for ~21 amps (500W / 24V). Assume input is US 120V household power.
I want to control the 120V supply ...
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0answers
33 views
XBOX 360 PSU for walkie-talkie chargers
I'm in the process of modifying a 360 power supply to power a 6 unit Motorola radio charger. I've got the +12v and the ground wired to live and ground on an NL-2 connector; and I've jumped the blue ...
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1answer
33 views
Amperage discrepancy on computer PSU
I have a 500W PSU that has both 12v and -12v supply rails with the dual +12v rails rated for 360W (20A each) and a single -12v rail rated for 9.6W (0.8A).
My question is; if I was to power something ...
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0answers
18 views
How long will this power bank last? [duplicate]
I'm new to electronics, so I apologize if I use some terms wrong.
The device I want to power needs 300mA.
The power bank I have is rated at 2000mAh.
How long will it last? I am not sure whether I ...
1
vote
1answer
45 views
How to connect a CR2012 coin cell battery with a PCB?
Im trying to build a flat, battery powered PCB assembly that fits into a small gap of approx. 2mm. I have found the CR2012 coin cell with a thickness of 1.2mm, which would be a good fit in terms of ...
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0answers
19 views
Singular Matrix: Check node warning
I'm trying to design a regulated power supply. When I try running the following circuit in LTSpice, I get the following error message:
...
3
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1answer
101 views
Powering 9216 leds @5V, @24V with converters
I am struggling with a power supply question. I would like to power up and control 9216 LEDs -- strips of 144 LEDs/meter (WWA SK6812 - just like the RGB kind).
These are powered at 5V and draw 43.2 ...
3
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2answers
119 views
Powering 30m of RGB LED strips?
I'm currently interested in following this tutorial which explains how to create a homebridge (ESP8266) controlled 12v RGB strip which is exactly what I've been looking for. However, whilst I do ...
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3answers
105 views
What is this component on circuit schematics? [duplicate]
It's a resistor like coloured 2 pin component from a power supply board of a home theatre, with a glass-transparent aspect. I'm a hobbyist and not into complex circuit till now... looking for an ...
4
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1answer
48 views
Diagnosing power supply issues?
I have a workstation that's becoming a little long in the tooth, as it were. It's a rock solid system, but about a year ago it had a faulty power supply that I replaced. During the past 11 or so ...
3
votes
1answer
68 views
How can i add voltage regulator to unregulated DC adaptor?
I would like to add L7809 voltage regulator to an unregulated DC adaptor,as
it is shown in the photo.
In the data sheet,there is a figure for application circuit that included 2 capacitors(bottom ...
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0answers
15 views
Ideal voltage multiplier design to run a VFD from a battery
I'm looking to run an IV-21 VFD tube off of a low-voltage portable power supply of 4-8 VDC. I've been looking at various voltage multiplier designs to supply the higher voltage needed for the anodes ...
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1answer
83 views
microcontroller is “hanging” when it is feeding PWM to a DC motor controller
I am using linear potentiometer to control the speed of a DC motor. I am using the following schematic.
An ATmega328P receives the value from linear potentiometer via analog read. This ATmega328P ...
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1answer
27 views
What is the reference for High side IC with internal mosfet driver
In the schematic below (like many other) the IC (switcher) is on the high side.
I was really curious how the internal circuitry of such an IC is referenced to.
My first thought was that everything ...
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1answer
44 views
Tumble dryer heater element [closed]
The heater element on my tumble dryer died, ordered a new one using my model number etc. The problem I have is that the original element is rated 240 V and 1050 W, the replacement sent is 240 V and ...
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2answers
47 views
Do “standby switches” consume energy?
Suppose I have a TV plugged in and it is connected to a power outlet which is also turned on. This appliance is "turned on" and on "stand by mode". It consumes energy I think just to light up that ...
1
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1answer
47 views
Why are input MOSFETs in Laptop power supply always in pairs?
For example, on https://youtu.be/CW87dyYIimE?t=340 (and related work on motherboard), it says the managment chip uses two MOSFETs as a switch (as overheat protection, emergency poweroff on 10-second ...
3
votes
1answer
70 views
5v power switcher: Uninterruptable power source
I know there are a few other questions similar to mine, but after looking through the answers, it does not seem like it's what I need. I've also looked at the Arduino Due/Uno circuitry, and they aren'...
1
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1answer
44 views
Low Voltage AC as power source for Audio Equipment?
When might an AC (not DC) voltage be used as a power source for an audio device - most every guitar pedal I've ever owned converted line voltage - 120VAC to some lower DC voltage - often 9v or 12v DC. ...
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0answers
35 views
Powering both sides of an opto-isolator from the same power supply rail
I have an opto-isolator circuit to drive a 12v relay coil that controlled by a microcontroller. The microcontroller power supply is 3.3v that generated from a 12v power source (using voltage regulator)...
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0answers
42 views
Repairing DC Jack - What are all the things I'm doing wrong here?
I have a Lenovo Ideapad 110s as a beater, around the house laptop. It's a very low-spec computer, but I run Xubuntu on it and it does its job well.
Several months ago, the positive pin connecting ...
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1answer
38 views
Is there any criteria to call a load inductive for switching applications?
I was hesitating to ask this but in many applications such as the ones with electrical machines or relays we always read such precautions or considerations: “If the load is inductive do that don’t do ...
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1answer
78 views
What is the simplest design to replicate Oerstead's experiment at home?
I want to demonstrate what Oerstead did several centuries ago. He demonstrated that there is magnetic field near a current carrying wire.
I have a compass that is sensitive to earth magnetic field of ...
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2answers
49 views
How do SMPS work on such a wide range input voltage?
I have a 5 V 3 A SMPS which says that it can take input voltages between 100 V and 240 V AC and frequencies between 50 Hz and 60 Hz.
How do these work?
How can they take ...
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1answer
42 views
Dual DC output voltage power supply made from two power supplies?
I need replacements for power supplies which output two voltages. For example, a Nintendo 64 needs 3.3V DC 2.7A and 12V DC 0.8A. There are readymade options but they seem to be of questionable quality....
2
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1answer
83 views
5-10 second backup for wifi router during power cut
In India power cut is often. And most houses are installed with Inver-battery, for backup till the power comes back. But since all inverters don't behave as ups, there occour a little gap between the ...
1
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1answer
35 views
Does Reactive Power flow between Energy storage elements in a three phase system?
I noticed that unlike the single phase ac power sources, the power in three phase is constant which means the instantaneous power is the same as the real power which is $$3V_{rms}I_{rms}\cos{\theta}$$ ...
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0answers
31 views
Drone Ground Control Station Switchable Power Supply
My drone ground control station will be able to run off of a 12v power supply, or a 12v car battery. I want to make it so that if the power supply is plugged in and providing power to the load while ...
