Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.
0
votes
1answer
45 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
35 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
49 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 ...
-1
votes
1answer
59 views
Power supply for my c-pap
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
75 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
25 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). ...
7
votes
2answers
311 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? ...
-1
votes
0answers
44 views
power led to monitor plugged device
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
106 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
71 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 ...
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
65 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
53 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
48 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
382 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
64 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
57 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
195 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
72 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
87 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
102 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
104 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
127 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
140 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
106 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
146 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
191 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
86 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
127 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
167 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
171 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
44 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
83 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
70 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
81 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
44 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
50 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
81 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
58 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
85 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, ...
1
vote
1answer
26 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 ...
