Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.
6
votes
5answers
141 views
Can we measure reflected power in a transmission line?
This is a question related to radio transmission, I hope this is the proper forum to ask it. It relates to transmission lines connecting a radio transmitter to its antenna.
In his book "Reflections", ...
0
votes
0answers
20 views
i am trying to match a power supply to a computer but cannot get the exact volts /amps/ power in a standard psu [duplicate]
As I said above, i cannot get an exact match for the computer I am trying to repair. Which is 12v @ 6.7 amps approx 80 watts. The closest I can get is a 14v -17v unit. is this higher voltage likely ...
0
votes
1answer
48 views
Average Household Power Usage - Distribution Spread
I'm trying to compare energy savings of solid state electric meters over older style electromechanical meters and am trying to find information on how long the average US household spends at each ...
3
votes
1answer
105 views
Safely extract power from USB
I am upgrading the lighting in a model with simple circuit which has 17 LEDs (approximately) plus one or two 555 timers. Presently, everything is powered by 3 AAA batteries. It drains between 150 and ...
1
vote
1answer
81 views
Transmitting power and PWM signal through the same cable
I am working on an Arduino based project, which required to supply 24VDC at 2A and 3 PWM outputs from the main board to the other board. The 24VDC is for powering the LEDs, and PWMs are for dimming ...
0
votes
1answer
47 views
Powering several amplifiers with one power supply
I need to power 5 industrial amplifiers for a project but I am not sure I can use one power supply for all. Here is the amplifier model I will use:
http://www.hbm.com.pl/pdf/a0114.pdf
And manual says ...
-1
votes
0answers
31 views
Are all 12 v dc batteries the same? [closed]
I have this pool skimmer that has 2 motors on a floating boat thats skims the top of the pool as it cleans. It uses a 12 v NiCad rechargeble pack. When it died I bought a 12V Lithium ion batter pack ...
0
votes
1answer
46 views
Frequency of fluctuations in power in an input power design circuit
I am thinking about the following power design circuit in section 6.1 : http://www.arndaleboard.org/wiki/downloads/supports/BaseBoard_Specification_Arndale_Ver1_0.pdf
Is it possible to calculate how ...
3
votes
1answer
36 views
SD Comms Resetting Processor
I have implemented an SD/FAT combination on a Renesas RL78/G13 processor. The SD card is being driven using SPI.
The code has been proven to work on two custom target boards using a 2GB card - the SD ...
0
votes
1answer
53 views
How to Calculate the charge/discharge power of a battery?
I need to measure the discharge power of a battery in general.
At the end i want the maximum charge/discharge power as a function of the state of charge(SOC).
So i need a curve that looks like the ...
-2
votes
1answer
64 views
Power supply for my c-pap [closed]
How long will my truck equipped with dual 750c.c.a.batteries power my c-pap machine that draws 90 watts using a portable power inverter and say a 50' extension cord. Thank you so much in advance of ...
1
vote
1answer
77 views
Linear useage of excess power generation
A friend of mine is fortunate to have moved to a very warm and sunny country, and has installed a photovoltaic system on his property. This is grid tied and any excess that he generates flows into the ...
0
votes
0answers
26 views
over temperature and current limiting question about a power switch: BTS5235
I am designing a cuircuit with BTS5235-a smart power switch from infineon.this is the datasheet of BTS5235
I get realy confused about its datasheet.
1.problem about VDS(Voltage at power transistor). ...
9
votes
2answers
401 views
The electricity grid: what keeps small power generators from being 'driven' by large ones?
This is a two part question and pertains to power generation:
What prevents a larger plant (say nuclear) from turning an itsy-bitsy gas generator into an electric motor and drive current through it? ...
-2
votes
0answers
45 views
power led to monitor plugged device [closed]
I am trying to create an experimental circuit to handle groups of HDDs (SATA) for multiple PCs. (e.g. I can swhich which PC control which group without having to move cables).
The thing is, I would ...
1
vote
1answer
48 views
How to understand synchronism?
In my job, I frequently compile a rough rundown of the power consumption of simple industrial plants. Here, you always encounter a "synchronism" factor, besides how many motors of which power and ...
0
votes
1answer
83 views
Is it important to have common ground between you microcontoller and high-power devices on the same PCB?
I noticed that there are more N-channel mostfets than P-channel mosfets on the market.
Then I realised that probably in many applications, the high powered device runs on a higher voltage and ...
3
votes
2answers
112 views
Splitting a power supply between two circuits
I have two separate circuit boards (clock & radio) that I'd like to place within the same enclosure. One takes 12V, and the other needs 3V. How can I utilize one AC adapter to power both boards ...
2
votes
2answers
76 views
Best practice to switch +V or GND connection?
Consider LAMP1 and LAMP2 in the simple example circuit below:
Which is the "better" practice, using the switching component ...
-1
votes
3answers
66 views
Interpreting the power rating of the refrigerator [closed]
My refrigerator is rated as 130W of power. I need to know how to interpret this. Does that mean if the compressor works for a whole hour then only it consumes 130W? Or is 130W the average power ...
2
votes
2answers
101 views
Wireless transmission of energy through a layer of non-conductive material
Is it possible to effectively transmit energy by electromagnetical induction?
I have a plate of nonconductive material (5-10 mm) and I would like to transfer electrical energy from circuit on one side ...
0
votes
0answers
77 views
Account for electron spin [closed]
I bought a pinball machine from New Zeeland. Before I connect do I need to reverse the wires? I live in the Northern Hemisfear so I think electron spin will be reversed?
2
votes
1answer
66 views
Can a linear regulator in shutdown mode have the output in parallel with a switching regulator
I am trying to design an efficient battery powered circuit using a 3.3V microcontroller (NXP LPC1343). One of the requirements is that the microcontroller periodically read a value from an ADC and ...
0
votes
1answer
54 views
Any Ideas for Understand one of the 3 phases has powered
I want to ask you about a situation which i couldnt find the exact solution or better way to do the job.
The situation is i have 3 phase (380V) induction motor and one of the phases to the motor had a ...
-1
votes
1answer
49 views
Using laptop going from USA to France [closed]
My Dell laptop comes with an AC adapter with the following specs:
Input AC: 100 - 240 V, ~1.5 A, 50 - 60 Hz
Output DC: 19.5 V, 4.62 A
Does the 100 - 240 V mean ...
15
votes
1answer
420 views
Does this device which claims to reduce reactive energy from a house work?
I've opened a device that states that it can reduce the reactive energy from a house, by plugin it directly to the power outlet/wall socket. I think it is a con, so I've opened it and I saw this black ...
0
votes
1answer
65 views
High voltage DC power line for batteries
I am planning to install a photovoltaic plant of 1000Wp on the roof that puts into 10×12V batteries in series to have 120V. This way can guarantee a low section of the cable, if I had a 12V power line ...
0
votes
1answer
52 views
power from glitches vs power consumed on pinelining
first let me define glitches as i understand it and correct me if i"am mistaken.
glitches are the propagation of unstable signal through the system it happens when one of the operand arrive to ...
2
votes
2answers
74 views
Using 2 different LDO with the same voltage in the same application
I'm using a Raspberry Pi and have designed an extension board (Like the Pi-face) but I have a question about the power supply. I need 3V3 on my board, but the 3V3 from the Raspberry is not strong ...
0
votes
0answers
63 views
Help designing a power supply using UC3842 (or a similar chip)
I am repairing a device that has a flyback DC-DC converter (48V to 3.3V), but the primary side is no longer working and I cannot really fix it (some components are impossible to identify, ones that I ...
2
votes
3answers
241 views
How do I calculate battery life allowing for duty cycle?
I have a battery rated at 2610mAh.
The device it's powering transmits to the network for 35ms during this time it uses 1.95mA of power. the rest of the time the device draws 0mA. I want to workout how ...
-1
votes
1answer
73 views
Will a 40W incandescent AC bulb operate on a 330V DC voltage?
Will a 40W incandescent AC bulb operate on a 330V DC voltage or not?
3
votes
1answer
88 views
What is the function of a capacitor in a motor circuit?
I read a manual of how to connect a speed controller to a motor. I see there is a capacitor as shown below. My question is what the function of the capacitor is? Thanks
5
votes
3answers
103 views
Voltage supply clipping to <=3.3V
So, I have this circuit which needs <50mA and can be supplied with a voltage between 2V and 3.3V.
I want to supply it with a Li-Ion cell, which has 2.7-4.2V. I don't really want/need the ...
-7
votes
1answer
76 views
Does the anticircuit exist? [closed]
Are there anticircuits like antmatter? Maybe poles are reversed and condensors become resistors and everything else is reverse. I wonder if so if one day things that suck power like heaters might ...
0
votes
3answers
116 views
Three-prong / USB power outlets in wooden desk [closed]
I am trying to mount a strip of three-prong outlets and a strip of USB charging outlets on an old wooden desk. I can handle the carpentry aspect, but I am struggling with the electrical aspect.
I ...
-2
votes
0answers
26 views
Transformer Power Factor [closed]
I have a 24 VA 220/24 Vac transformer connected to a full bridge rectifier.The load connected to the transformer rectifier unit are electronic counters and digital displays. I need to calculate the ...
0
votes
1answer
70 views
Reduce heating in linear power supply
I have a linear regulator in a product which works from 20 to 240VAC: a two stage linear regulator. Stage 1 converts to 18V and stage 2 to 5V. Stage 1 starts heating up as the input voltage increases ...
3
votes
1answer
134 views
Higher current LED driver for persistence of vision display
Project needs
We need an inexpensive LED driver IC that:
Can source or sink at least 15mA/LED
Has an SPI-like interface (not I2C)
Has a separate latch pin
Has at least 256 grayscale intensities
...
2
votes
1answer
141 views
Can enough RF power melt an antenna?
I've heard of someone getting RF burns by touching a high power antenna. If enough power is supplied to the antenna could it melt, or would anything else happen? If so, how much power would have to be ...
4
votes
2answers
107 views
How can charge be determined?
How can software determine the amount of power or charge left in a battery (like an iPhone battery or a laptop battery)?
3
votes
2answers
147 views
Vacuum cleaner power rating does not match line voltage and current rating
I have a vacuum cleaner on which is proudly written:
12.0 Amps
1300 W
Assuming a 120 V (RMS) power supply, how would the power consumption of the vacuum cleaner be calculated given the 12.0 ...
3
votes
3answers
198 views
Oscilloscope noise reduction when measuring IC voltage
I am trying to monitor the voltage of an IC. The supply voltage of the IC is 3.3V and clock frequency is 24MHz.
Here are some parameters for the channel used for measuring voltage:
vertical scale to ...
-2
votes
0answers
55 views
Power line communication in an industrial environment [closed]
I am trying to test the reliability of PLC modems (power line communication) in an industrial environment. This is will be the subject of my master degree work. This kind of technology would be very ...
0
votes
1answer
87 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
128 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
180 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
175 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
45 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
84 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 ...
