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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Interpreting rating label of DC power supply - supposed to be a constant voltage source or a constant current source?
Link to product store page
Hi all, bit of a beginner question here. According to the output section of the label, this is a 12V, 1000mA power supply. This is confusing me a bit. Is this device meant ...
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0answers
21 views
Chromebook power circuit: Surface mounted diode or resistor? [on hold]
I recently enjoyed finding out a mains power short (was working onsite project) has dislodged 2 surface mounted components from my device's motherboard.
Thought it would be interesting to repair ( ...
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0answers
37 views
Boost converter output voltage error
I'm using LT3494a to generate 37v from 6v input. This is my circuit.
According to the datasheet, this chip can provide up to 40v output, so it should be able to generate 37v. Also, the simulation ...
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0answers
32 views
high voltage input low output regulator
I need to voltage regulator for supply of microcontroller.Regulator details should be as:
input voltage range of regulator: 3v-200v
output voltage range of regulator: 2.7v or 3v or 3.3v (for supply ...
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2answers
51 views
I want to make an auto power cut off for my battery charger
I have a charger for a 12v battery but it is without auto power cut off.
I know I need a circuit consisting of a comparator and a relay and I drew the circuit but I don't know if there is something ...
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2answers
35 views
Isolating A Noisy Component In A Circuit
I've been working on a project the past couple months or so and I am incorporating an lcd touch screen as an interface for it. The device is a small digital synthesizer. The problem I am having is ...
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0answers
37 views
Routing the main power supply across a PCB and choosing vias for it
I have a board that uses several different switching converters with 33uH ferrite beads that take up a fair amount of space. I'd originally intended to keep them all at the top of the board (not top ...
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1answer
37 views
Monitoring Health of VFD [on hold]
Good day,
Is there any method or external measuring tool that can be used to monitor the health status of a VFDs perdiodically?
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0answers
35 views
DIY ATX PSU turns off when attaching load on 12V rail
I want to convert my old ATX power supply to a simple bench supply for 12V devices. On the label it says it's a 300W PSU where I can use 264W on the 12V rail (see image below).
https://imgur.com/...
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2answers
60 views
Is my radio pulling more current than it should? [on hold]
I have an FT-747GX radio that I am using as a RF generator for a plasma cleaning machine.
In the operating manual on page 3 it states:
I have a power supply connected to this radio which outputs ...
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0answers
59 views
High voltage low current PSU, newbie question
I need two different power supplies, one 600vdc with a limited current of 500uA (micro ampere), the second 300vdc - 500uA. For laboratory work that requires high voltage and low current.
I do not ...
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2answers
166 views
Why do engineers usually short ground and negative ports on a DC power supply?
I'm fairly new to electrical engineering, and have seen many DC power supplies where someone has shorted the ground (green) port with the negative (black) port. From my understanding, the ground is ...
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1answer
53 views
Measuring USB power adapter quality using multimeter
I have heard horror stories about poor quality USB power adapter. I have a collection of no less than 20 USB power adapters, most are from cell phone manufacturers and some from small projects.
I ...
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0answers
36 views
Parallel resonant induction heater
I implemented a parallel LC induction heater using theory. I made a simple square wave Inverter providing a frequency of 20kHz to the tuned LC circuit. The problem I'm facing is that my tank is not ...
0
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1answer
25 views
Keypad controlled variable 18Vdc power supply [on hold]
I have design a mains operated 18 VDC variable power supply.
However the on/ff and voltage setting is currently controlled by a switch and knob.
I would like to fit a keypad with 3 "buttons" to ...
1
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2answers
37 views
Difference between input current and supply current?
I am reading and trying to understand datasheet of ICs.
I am reading this datasheet now : http://www.ti.com/lit/ds/symlink/sn74hc00.pdf
In the table 6.5, there are two parameters namely Ii and Icc. ...
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0answers
41 views
Voltage reduction issue in circiut
I have two electrical network which I want to power using a single power source.
I am using a 3 cell lithium polymer 8000 mAh 30 C for it. One of the network consume 40 A current and the other ...
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0answers
14 views
Heathkit IP-27 bench PSU min. stays at 0.18V and there is a +0.1V for all the readings?
I've recently acquired a Heathkit IP-27 bench power supply. The supply itself works quite fine except that the minimum voltage it can be turned down to with the coarse adjustment is only 0.18V, doesn'...
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0answers
65 views
Power switch - IN and OUT connected all the time
A while ago, I asked about detecting whether a power jack is connected or not, in order to select power source from USB or DC jack.
You can see the question here: Power selection circuit for USB or ...
0
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1answer
85 views
raspberry pi power [on hold]
I have a VEX 393 motor and was wondering if there was any way that I could hook it up to a raspberry pi and if so how many extra voltage is needed to add to the ground prong (provide diagram if ...
1
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1answer
70 views
Cuk converter implementation
I have come across this article:
https://www.powerelectronics.com/power-management/step-down-dc-dc-converter-eliminates-ferrite-cores-50khz-enabling-power-supply-chip
That describes the Cuk DC/DC ...
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1answer
41 views
Controllable power source (current) with one transistor and one resistor
I have this circuit:
It should be a controllable powers source for current. Is that right?
1) What's the name of this circuit?
2) What does the resistor and how can I calculate it?
Thank you!
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1answer
48 views
Designing a step-up transformer [closed]
I'm designing a new transformer for a project I'm building. I trying to design a new product the primary produces has 2 connections and makes 0.8A. I want to step-up to one coil and need to produce ...
0
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1answer
31 views
Dual supply PCB layer stackup
My PCB is powered from USB port and includes Recom RKZ0505D for powering dual-supply OPAMPs. Recom gives +5V and -5V outputs. So I have:
Top signal & components
Bottom signal & components
GND
...
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1answer
1k views
What are these obscure components?
I'm having difficulty identifying these components. I salvaged them from a diy power supply enclosure from a garage sale. Each of the black leads in the image attached to female connectors on the face ...
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1answer
56 views
How to modify a small power supply to not require a 20W load to turn ON? [closed]
I have a couple of obscure german “AT60” power supplies I scavenged from some designer lamps. They’re small, and don’t get hot even under ~30W load — but for my purposes, I need them to be always on, ...
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3answers
41 views
Power determination for resistive load
I am a mechanical engineering student and i need to measure electrical output. I have some voltage and current measuring instruments. I used them to measure the voltage & current of a blower(...
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2answers
62 views
How does USB port on a power strip detect the optimal current output?
I am looking to buy a power strip with USB ports and came across this one online.
The description says "Top-notch USB smart charging technology which can detect and deliver optimal current output up ...
7
votes
3answers
1k views
Why would you need an op amp for reference voltage when the voltage divider does the trick?
Is there a reason this schematic uses an op amp (AD8031) for the reference voltage of the op amp (AD8544) filter when the voltage divider already brings down the voltage anyways? Can the AD8031 op amp ...
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0answers
53 views
Protection and isolation of 4-20 mA receiver [closed]
What are the possible solutions to isolate a 4-20mA receiver circuit from an industrial point of view? What care can I take for the protection of that receiver?
The sensors are basically environment ...
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0answers
41 views
Negative voltage supply
I've been trying to make a active load that would use a very small resistor, around 10mOhm as a shunt resistor. I've figured out how to make it, it's a common circuit, however since I need to use ...
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2answers
110 views
Can I use any HV Probe for a Voltmeter/Ampmeter gauge?
I purchased the multimeter pictured below for a high voltage power supply I'm working on. It's rated for 100V DC and 10A, but I hope to measure several thousand volts. Is it possible to use a HV ...
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1answer
73 views
RGBW Cree XM-L LED power circuit HELP!
I have 10 Cree XM-L RGBW LEDS and I would like to power them from a 12V power supply. I came up with this idea:
A 12V 30 amp power supply powers 3 different step down buck converters (10 amps each ...
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0answers
43 views
AC voltage at the output of SMPS
We have 230 VAC power supply in our lab.A chemical earthing is done for this power supply. I have connected a SMPS (LRS-35-12) to it. The Output of SMPS is connected to a load of maximum 2A. I have ...
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1answer
36 views
Power supply and pcb connections to ground, earth
I am planning a pcb which is powered by two switching power supplies
LRS-150F-5 (230 V/AC to 5 V/DC)
LRS-150F-12 (230 V/AC to 12 V/DC)
.
The power supplies are mounted in their own metal box and the ...
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1answer
50 views
Identification of power connector
What kind of 4-pin power connector is this, displayed in this (exemplary) image? Are there any specs of the maximum current and voltage it is designed to provide?
(Unfortunately this was the best ...
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2answers
75 views
230vac / 5vdc power supply design
I am making my own basic bench power supply mainly for testing logic gate circuits, relays, flip flops etc, that I can move around to different locations.
The circuit of the entire schematic will be ...
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0answers
17 views
MAX17205 battery pack fuel gauge configuration
I am working on the fuel gauge by MAX17205 for my project.
https://www.maximintegrated.com/en/products/power/battery-management/MAX17205.html
I am able to communicate with the chip using I2C protocol ...
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0answers
51 views
Discrete DC Connector recommendations - 24v 8.3a [closed]
I need a DC connector for a DIY project I am working on, a high powered LED for an aquarium.
I am using a 200 W 24 V power supply in conjuction with 5 Meanwell LDD-H Drivers. I’m hoping to keep all ...
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2answers
76 views
How to diagnose transformer failure or expected output
I have a pcb that takes 5v from a main board on pins 3&6 and takes this current through the T1 Transformer (obsolete, no datasheet S1673305) and should output some voltage (service manual does not ...
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0answers
31 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 ...
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0answers
29 views
TPS562208DDCT current problem
I have attached a PSU design which I have created. The input voltage is between 12 and 24V DC.
The first stage creates an isolated output voltage of 7V that is then fed into the two TPS562208DDCT (...
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1answer
32 views
Power supply design with charging circuit
I am designing a GSM modem power supply circuit.
The circuit requires a 2A power supply.
The module SIM800C itself can be powered directly by Li-Ion or Li-Poly battery power.
I am looking at a ...
1
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0answers
23 views
Can I connect 2 power supplies for 16 meters LED RGB strip?
I've bought 2 sets of 10 meter LED RGB strip (7.2w/m) for a room. Then I've cut them to around 8 meters each to get 16 meters. Everything seemed fine but one thing, because it's 2 separate controllers,...
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1answer
59 views
Arduino 2 power source - auto switch?
I'm planning to switch between two power sources DC and USB with an Arduino like below diagram.
What I'm going to do is cut off the DC V+ wire when I insert the USB jack to the Arduino for uploading ...
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1answer
45 views
Wiring a power supply, arduino, and LED strip together?
I've been researching various websites on all of my questions and have found answers to many of them but I am also finding conflicting answers for some of them. I've read that electricity is something ...
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1answer
102 views
Removing the smallest supply decoupling capacitors in multilayer boards
Hello I want to make PCB for ADF5901 24GHz power amplifier, it says use 3 capacitor for each supply pin, 10pF, 1nF and 100nF. we have about 6 supply pin.
Can we remove 10pf bypass from all pins, If ...
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2answers
108 views
Why do we need a chain of resistors to increase the voltage? [closed]
I did a workshop on SMT today and we made this board attached. However, what I don’t understand completely is the logic: why do we need 3 resistors to increase the voltage (on the boost part)? What do ...
0
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1answer
31 views
Remove PC PSU From Cage [closed]
I am trying to fit a Mini-ITX PSU into a small custom computer case. However with the PSU metal cage it is about 1/8" too tall. I can make it fit if I remove the cage.
It is safe to run a PSU without ...
1
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2answers
117 views
Multiple Step-Down Voltage Rails from a single DC Power Supply
I have one working PCB which has three different Voltage Rails: 3.3V, 4V and ...
