Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.
0
votes
1answer
76 views
Is it possible to increase voltage from a power supply without incuring great current lose
I have a 24V 4.5 amp(108 Watt) power supply. I know most Voltage regulators take a higher voltage and regulate it to a lower voltage.
Is there a way to increase the voltage of the 24V 4.5 amp(108) ...
0
votes
1answer
108 views
Why is using a single phase device across phases of a 3 phase outlet OK?
My friend connected two wires to two "non-earth hole" in a 3 phase outlet (208V) to run a 220V single phase blower (Note: the outlet has four holes, one of them is earth). Basically, he used the ...
4
votes
4answers
159 views
Why should any unit be used instead of the watt (W) as a power unit?
I am taking a course on AC circuits and so far I have seen that for the different types of power (read real, reactive and complex) different units are used.
For the real power, which is power in fact ...
6
votes
2answers
159 views
Switching Between Two Voltage Supplies
I have been trying to work out a circuit something like the following:
simulate this circuit – Schematic created using CircuitLab
I want VOUT to be 3V when the switch is open and 5V when ...
-3
votes
0answers
33 views
Error in implementing particle swarm optimization in power system using MATLAB [closed]
I'm trying to get the solution of economic load despatch using particle swarm optimization. I've written the code but during updating the velocity and particle position in the second iteration, it ...
1
vote
2answers
75 views
Static power of Xilinx FPGA
From the results given by power analyzer, I find that the Xilinx FPGAs always have a high static power consumption no matter what your design is, although it will vary if your design utilize different ...
0
votes
3answers
60 views
Switching / dimming a high power mains heater
I need to make an adjustable power controller for a 3kW heater that will run off single-phase 240V AC power.
How should it be done?
Maybe a triac circuit similar to that used for dimming lights. ...
-4
votes
1answer
77 views
I bought a used surge suppressor. When I plugged in my laptop, I heard a “pop”. Why? [closed]
I bought a American Power Conversion Corp. surge-protecting power strip today. It's a seven-outlet model; I found it at the thrift store for $4. It appeared to be in decent condition, though I did ...
0
votes
1answer
40 views
How can I isolate a power well to reduce noise
I am designing a digital board which will drive a very coarse (simple on-off) high[er] current speaker. I am worried that the switching of the speaker will cause noise in the power supply driving it. ...
0
votes
1answer
44 views
Frequency and magnitude of power variations in a DC circuit.
I have a 5 V 5 A power source which is connected to a simple development board with a processor that draw current dependent on utilization. I use a multimeter that measure 1000 samples / s to measure ...
-5
votes
2answers
55 views
What is the range of a 2dB usb wifi dongle? [closed]
For a home robotics project I need to connect my laptop to my robot's Raspberry Pi using wifi. For this to work I want to buy a simple usb wifi adapter to plug into my Raspi. I will need a range of ...
2
votes
1answer
56 views
Frequency Scaling and current draw
I am trying to power a RPi of 4 AA's, and my mobile power device can only output limited current (500mA), but I can underpower my RPi by frequency scaling. Is frequency scaling and current draw a ...
1
vote
1answer
80 views
Electrical saftey of metal panel-mount DC jacks
Context:
I have a robotic arm with a series of servo motors, that together draw up to 3A from my bench supply (depending on the load on the servos). To make it easier to transport the robot around, ...
-5
votes
0answers
20 views
power rating source for modem 2 wire 3801 hgv from back-up to outlet [closed]
i need to replace a power supply for my modem from a back up power source to a dc current.i have the manufacturer power rating which is external PSU 12V,3A.do you know where i could purchase this ...
1
vote
1answer
21 views
Power delay profile and broadband bus
I came across the following solved question, but I have trouble understanding part of the solution. If anyone could shed some light into this I would be really grateful since this problem has been ...
5
votes
4answers
164 views
Arduino Uno R3: Directly supply regulated 5V to 5V pin?
I'd like to use an Arduino Uno R3 battery powered a datalogger. I want do supply it directly with a Step-Up regulated 5V rechargable battery powersource at power ...
-6
votes
0answers
43 views
What is the value of R for which maximum power is transferred from circuit A to circuit B ? (Assume both the voltage sources are in phase) [closed]
What is the value of R for which maximum power is transferred from circuit A to circuit B ?
-1
votes
3answers
64 views
How does P and Q vary with increase in frequency ? Does the reactive power Q increase with increasing frequency ? Assume L & R are constant [closed]
In an electrical circuit consisting of R and L, the active power is \$P=\frac{V^{2}}{R^2+(\omega L)^2}*{R}\$
and the reactive power is \$Q=\frac{V^{2}}{R^2+(\omega L)^2}*{\omega L}\$
How does P and ...
-3
votes
2answers
81 views
Free space model (wireless communications)
The received power at a given distance = 1km is 1nW .
Find the received power at a distance of 5km from the same transmitter , using the Free Space Model.
Suppose that frequency is 1800Mhz, ...
6
votes
4answers
187 views
Protecting Microcontroller Input Pins from Soft Power Switch
I'm working on a soft power switch for a microcontroller where a momentary switch can turn the circuit on (including microcontroller), and then when the switch is pushed a second time, the ...
10
votes
3answers
3 views
How much current can I draw from the Arduino's pins?
What's the maximum amount of current which I can draw from each of the Arduino's pins without tripping any of the internal fuses? Is there a limit per pin as well as an overall limit for the whole ...
0
votes
1answer
34 views
What is the analog pin for on a Phidget 3051 Dual relay board?
I recently purchased a Phidget 3051_1 Dual Relay board with the intention of using it to switch on and off flourescent lamp ballasts (20W tubes) over a fish tank by connecting the relays to 110VAC and ...
-4
votes
0answers
33 views
power transistor [closed]
I need to test a darlington power transistor with serial number sqd400ba60 and if there is a method to test three one connected in parallel as they are installed together in ups system and ...
0
votes
3answers
81 views
Serial and parallel circuits and power
If I have 12V of power, and wanted to power LEDs with a forward voltage of 2V, could I only power 6 of them? Would I connect the cathode of one to the anode of the next, creating a kind of serial ...
0
votes
1answer
51 views
power loss calculation
I was reading StevenVH's response to the post How long will it take... and he brought up something I was completely unfamiliar with; the power loss associated with the large volt difference between ...
3
votes
2answers
118 views
Measuring an Arduino's power source voltage using Analog In
I am powering an Arduino using a 5v battery, and I need to measure the voltage. Let's say the battery delivers high current, is it safe to measure the voltage via Analog In? As in this:
The reason ...
0
votes
1answer
101 views
3-phase power calculation when phase to phase voltages are different
I have a 3-phase power supply rated at 230VAC per phase. However, the phase to phase voltages are not equal. Suppose \$V_{RY}\$, \$V_{YB}\$ and \$V_{BR}\$ be the three phase-to-phase voltages between ...
5
votes
2answers
125 views
How do these modern power buttons on devices work
In the older days and still now we have buttons where one way is off and the other way is on, its mechanically built to connect or disconnect an electric path physically.
On modern devices like ...
-2
votes
0answers
23 views
Where can wireless force and speed recording sensors and digital readout equipment be found? [closed]
I am trying to find a supplier of small, no larger than about 1 inch square wireless sensors that can measure the speed and force of a boxers punch. In addition, I would like a digital display, or an ...
3
votes
1answer
75 views
ATX PSU 5VSB + 5V
Is it possible to connect both the 5VSB and 5V pins of an ATX PSU to provide +5V?
I would like to be able to initially boot using the 5VSB, which is always enabled. Once I've completed setup I would ...
3
votes
2answers
88 views
Why are the power transmission/distribution systems AC and not DC?
Is there a good reason why we are not in the process of completely converting our electrical transmission system to DC? The main reason for using AC on the grid (no offense Tesla, I love you man) was ...
1
vote
1answer
82 views
Arduino Nano: This schematic would work?
If I used this 9v battery, and a 6v battery pack(AA battery), would this combination work.
I want to it run disconnected from the PC.
Sorry my bad english.
2
votes
1answer
65 views
Doubts related to the Arduino Ethernet with PoE
I implemeted a system by using the Arduino Uno and the Ethernet Shield without PoE. Now, I am thinking to use the Ethernet with PoE but I have following doubts, even if I read the Official ...
1
vote
1answer
116 views
Power consumption and frequency
I am making a small, mobile device with the Raspberry Pi that depends on batteries, so power consumption is an issue. I have scaled the "arm_freq_min" (unsure if clock or instruction cycle frequency) ...
3
votes
2answers
81 views
Power switch for a dive computer
I am creating an open source dive computer (www.diydivecomputer.com) and I am having a little bit of a problem trying to figure out how to power the device on and off. The problem is that the device ...
4
votes
1answer
66 views
2 full bridge with 2 secondary winding in series… is it possible?
simulate this circuit – Schematic created using CircuitLab
Is this possible? Think of the center tap transformer as a 2 winding connected in series
1
vote
3answers
82 views
How is current lowered as Voltage is increased in AC power transmission
I was reading about power transmission on wikipedia and came across the explanation of the efficiency of AC power transmission that said power in the load = (I^2)* R while power transmitted= IV. The ...
2
votes
1answer
129 views
Mixing AC and DC power in a circuit
This is likely a noob question, apologies if the answer is obvious.
I'm trying to control a furnace using a 3.3V microcontroller. The furnace operates by connecting a common 21V AC "hot" line to one ...
2
votes
2answers
102 views
Power Electronics for 3.3v or lower MSP430 + 10v sensor
After asking around I realized that switching regulators should be used to regulate the power going to the MSP430. I'm wondering (I'm not very informed in the topic of power electronics) how can I ...
-8
votes
0answers
59 views
grounding system simulator [closed]
hi all dear members…
this summer i have a final year project to graduate as an electrical engineer …
my topic is to design and implement a simulator of aprotective grounding system that contains the ...
3
votes
2answers
125 views
How can I break one circuit when another one's current draw is high?
A layperson here. I own a small RV park, as well has a nice large Motor Home. Most of my guests have the same set up in their Motor Homes as I do. The Microwave and the Hot Water Heater are on a ...
0
votes
1answer
35 views
Xilinx Xpower Analyzer: Expected scope definition in VCD
I use a VCD file to evaluate the power of my design. The VCD is generated using the following command in the testbench file.
...
1
vote
1answer
106 views
AC Adaptor converted in USB charger, is it safe?
Is it safe, or maybe I should I say "logical", to take an AC adaptor and splice the wires, reconnect them and solder together with a USB cable to power a device?
I had an old gameboy advance sp ...
2
votes
0answers
60 views
Large power-systems for power-flow study
I have just been started on a research project which involves finding ways
to speed up the solution time of the power-flow problem
which is basically calculating voltages at each of the buses of a ...
-4
votes
0answers
57 views
What is the responsibility of the department “Power Quality”? [closed]
I am momentarily busy with a research on how an ideal power company should be structured.
I came up with a few departments and the structure. I have 5 departments of which I do not quite know what ...
-3
votes
0answers
33 views
calculation in power system [closed]
May i know the simplest way to simplify one-line diagram into impedance and reactance diagram.
can you explain me about complex power in single phase AC circuits.
how to understand the calculation ...
0
votes
1answer
67 views
Power analysis of a simple circuit and battery lifetimes
I only do electronics stuff as a hobby so forgive my simple question.
I have a simple IR LED/photodiode detector circuit hooked up to an arduino microcontroller. It's not important but the purpose is ...
2
votes
3answers
79 views
Find current and power factor in circuit
This is a picture of a homework question that I do not understand all too well. The question is below:
The power supply in Fig. P9.59 generates 50 kW
the line impedance is 0.095 . If the load ...
1
vote
1answer
44 views
Values in a solar array
My dad had just bought a solar array of 4kW together with an inverter, a kaco powador 4400.
The array is now running and generating electricity. I am trying to understand how it all works, but ...
1
vote
0answers
68 views
Why does my bluetooth dongle use more current when paired then when idle?
I have a bluetooth dongle which is connected through USB to my PC. I wanted to measure the current drawn and hence I connected an ammeter in series with the 5V line and am measuring the current. I ...
