Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.

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1answer
43 views

Hooking audio compressor to mains without chasis

I am nearing the completion of my DIY compressor project, and I have a rather seemingly basic question.. Once I hook up my toroid and everything, since I don't have my 19" 1U rack enclosure yet, but ...
0
votes
2answers
72 views

Is possible to build -168 dBm amplifer?

we know that GPS receiver can reach sensitivty of -168dBm, and also it is possible to make receivers with similar sensetitvity can operate at another bands/frequencies . but I just want to know if ...
0
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2answers
68 views

High voltage power lines

Why are high voltage power lines used? Electricity is generated at 11,000V...so is that a potential at the generating station or potential difference across the ends of the power line? And if it is ...
1
vote
1answer
41 views

Inverter constructed using LDMOS transistors

I have the following question: is it possible to construct an inverter using LDMOS transistors when HV power supply is equal to 30 V and maximum VGS for LDMOS transistors is 5 V? Moreover, lower MV ...
2
votes
1answer
280 views

What is an antenna amplifier ? How does it add gain?

I don't know what exactly does antenna amplifier mean. Is it possible to increase the gain of a Tx antenna ? Where do I connect the antenna amplifier to it ? If, for example, the Tx has a power of 20 ...
0
votes
2answers
42 views

Can I use a 250 VAC socket for 120V power?

I live in canada and I'm trying to build some DIY audio gear. I'm using a toroid http://www.digikey.com/product-detail/en/VPT30-830/237-1326-ND/2090064 (115, 2x15v) And this socket to go with it ...
0
votes
1answer
62 views

Just I want to understand gain, power, link budget

I am a beginner, I am confused about calculating the nessecary gain and power and sensitvity to overcome path loss at certain distances. the first thing what does gain mean ? I am not talkink ...
0
votes
1answer
45 views

If I connected N numbers of amplifiers each have X gain 'dB“ and Y power ”dBm", how to calculate total gain and power?

sorry for bad description, I am a beginner. my question is just for knowledge and I did not test anything. If I connect for example 3 amplifier , each one has 60 dB gain and 15 dBm power. can we ...
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votes
1answer
58 views

240 volt cheaper than 120 volt? [on hold]

We just installed a 6' 240 volt baseboard heater (hardwired). Will electrical consumption be less that using the plug in 120 volt electric heaters we used to use?
5
votes
3answers
401 views

What should I use for powering a Raspberry Pi at near space altitudes?

I'm planning a high-altitude weather balloon project (to around 100000 feet) some time down the line to take video and pictures of near space altitudes and I have some questions I need to ask before ...
0
votes
1answer
73 views

Chattering relay on microcontroller power supply

I am working with a device that has a relay on the 12v power supply to the micro controller that runs the device. Under certain unplanned circumstances this relay can chatter. What is the potential ...
0
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0answers
25 views

Can we use magnitude of C parameter (ABCD parameter) as admittance and B parameter's angle as impedance angle in numerical problems?

I read they can be approximately treated like this in analysis because C has unit of admittance? Can we consider like this?
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2answers
133 views

Where does radiated power come from?

I've had electromagnetism classes back in uni, but I'm having a hard time linking them with that matter: Take a car antenna -which I assume is simply a wire, coiled or not-, and apply a voltage ...
-1
votes
1answer
32 views

maplin xm22y power supply [closed]

I have A Maplin xm22y and the main power transistor blew. I ordered a replacement transistor (tip3055), but wonder that since the transistor is broke I now have a 23 vdc reading. Is there a way on ...
0
votes
0answers
31 views

Energy Monitor IC with built in Hall Sensor

I have looked at a couple of IC's which provide energy measurement(real power,apparent power), however these need to interfaced to a current transformer or a hall effect sensor since they cannot ...
-3
votes
0answers
32 views

Are there any talking prepaid electricity meters? [closed]

an prepaid-meter that measures electricity consumption and provides voice messages to alert the consummer about the status of his or her consumption
0
votes
1answer
53 views

Relation between C-rate and power of a battery

I'm a non-engineer, but I need to understand the function of a battery. I hope you can help me! For example, I have two bulk storages. 5MW (power) 5 MWh (capacity) 5MW/10 MWh So the definition of ...
1
vote
1answer
83 views

Combining LDOs in an effort to increase current

Is there any way to combine 2 (or more) similar LDOs with fixed output voltage so the total output current would be increased? Buying another LDO is possible but I have a large stock of 1A LDOs and I ...
1
vote
1answer
59 views

Leakage current during sleep mode?

This is an assignment question: A system is operating at 325VDC input, what is the required static leakage current during sleep mode in order to achieve Zero power? I know there may be a lot of ...
0
votes
2answers
69 views

Do I use a 5V 2A or 3A DC adapter to power my 2m (6.5ft) WS2801 LED strip?

(Please excuse me if my English is bad) I recently purchased a 5m LED strip, but I only need to power approximately 2m (6.5ft) of the 5050 RGB LED WS2801 strip, but I'm afraid that a DC power adapter ...
-5
votes
4answers
85 views

Please give the simplest explanation of what electricity exactly is

Nothing technical, no mathematics. Just an explanation of what electricity is. I am having a time understanding the whole idea of how electricity works because I don't understand what electricity is. ...
0
votes
2answers
61 views

Can I use the 12V line of a computer PSU to power my circuits?

Or is there any issues I should be wary of? I need at least 7A on a 12V line, but I've found that a computer PSUs are significantly cheaper.
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votes
2answers
77 views

Design help for my 1A variable power supply

In a 1A Variable Power Supply circuit given below is it possible to use a 2A transformer and 1A bridge diodes.
2
votes
1answer
59 views

Finding the Power developed by the Nominal Frequency in FM

Question The sinusoidal signal \$f(t) = \cos(2 \pi f_m t)\$ is applied to the input of an FM system. The corresponding modulation signal output for \$f_m = 1kHz\$, is $$Q(t)=100 \cos(2 ...
0
votes
1answer
64 views

Why monitoring power and energy in energy usage meters?

This time my question about the how power companies monitor usage. We get electric usage bill in [Kilo watt hour]/Energy. What should be looked up on for monitoring the usage the instantaneous energy ...
1
vote
1answer
27 views

What is the minimum voltage for general loads and peltier units

I am confused with "power ratings" on devices and electrical components. First, what is the power rating on a home appliance or a electrical component saying when it is 12V? Is it saying "we would ...
0
votes
0answers
48 views

What is the power or torque I need to rotate a propeller with 57 lbs of force acting on it [closed]

I am looking for an AC motor with the proper specifications, in particular torque and power, to rotate a propeller with 57 lbs of force acting on it. The RPM is going to be slow (between 20-30 RPM). ...
0
votes
0answers
21 views

Piranha LED board connected to USB charger [duplicate]

Can I use this Piranha Light board to connect to a 5v power source like a USB charger? Do I need something extra (more than an USB-cable)? And can I connect more boards to the same circuit? (New to ...
2
votes
1answer
77 views

Power Mosfet design issue

My schematic The components BSN20 is a N-channel enhancement mode field-effect transistor (datasheet) IRF7416 is a HEXFET power MOSFET (datasheet) This is a part of a project in which the line ...
0
votes
0answers
33 views

High voltage distribution line fault current

On a conventional 7,200 volt distribution line, what would be the average fault current in a scenario like the one shown in the video below? Video Specifically, I'm wondering what the power ...
3
votes
4answers
135 views

How do I find the voltage range for an unknown DC motor?

I have a small unmarked motor with a burned out speed controller board. I'm able to figure out that the motor is a DC motor because it has two wires coming out of it and there's a rectifier on the ...
0
votes
1answer
73 views

Amplify a 12 MHz sine wave

I need to take a 12MHz AC sine wave, from around 3.3V - 10V @ 10uA, output 50V, @ 1A (or more). I have the signal generator for signal input, but I am not certain what I need for a circuit to step ...
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vote
2answers
50 views

What's a probable VA rating for this?

I bought a variac at a garage sale a few months ago and I've played with it since then with a 40W incandescent desk light. Now I want to use it for the incandescent house lights in a small theater. ...
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votes
1answer
95 views

How to get power/electricity when the power is cut? [closed]

My power bill is cut and power is out until someone pays it. I was wondering if there are any scientific methods available to create a source of power to charge a laptop and keep it full for at least ...
1
vote
3answers
321 views

Child-Safe setup for ESD protection environment on desk

I need to setup an anti-static workbench in my spare office, and kids sometimes get into it ever since they learned how to pick the locks. My intended approach is to: Lay out an ESD mat on the ...
0
votes
1answer
64 views

Simultaneous Buck-Boost or Flyback Regulator - Help Selecting Chip [closed]

I have been trying to find a switching DC power supply that outputs a constant voltage of 12VDC, given a variable input between 4V and 25V. It's to my understanding I'd need a buck-boost converter, ...
2
votes
1answer
71 views

Can I extrapolate the rated overload spec of a wirewound resistor to a joule rating?

I'm considering using a Vishay FVT series resistor for precharging some capacitors. Capacitance: 3300uF Voltage: 730V Resistance: 500 ohms Resistor continuous wattage: 25W This series, like many ...
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votes
2answers
91 views

I want to operate a DC 9v relay with a small power

Can a lightbulb be switched on using two mobile phones? (Make a call and the bulb switches on) I need this for a kid's school project so the questions like should the bulb keep glowing after the ...
2
votes
1answer
102 views

Boost regulator: Unexpected output voltage

I just finished setting up an LM2577 as a boost converter, and have run into some unexpected issues. For starters, here is the recommended "typical application circuit": My application circuit is ...
0
votes
1answer
73 views

Commanding a 12V DC motor with high power (~20A)

I'd like to control a 12V DC motor but it has very high power, around 20A. I was looking for H-bridges but they all support only low power (around 1A) Do I have to build my own H-bridge with high ...
0
votes
2answers
100 views

Does unplugging a television from the wall socket make it safer? [closed]

Does unplugging a television from the wall socket make the electronic safer (against power surge for example) compared to: Plugged in, button on wall socket is off Plugged in, button on wall socket ...
0
votes
1answer
63 views

Strategies for powering an ATtiny micro controller and 40W peltier from mains

I'm trying to power an ATtiny1634 at 5VDC and a 50W peltier element at 12VDC. The microcontroller will, amongst other things, turn on the peltier via a 5VDC non-latching relay. I want to use an ...
1
vote
2answers
70 views

What is the sign convention for generated power?

Generally speaking, generated power is denoted as negative, correct? If I understand correctly, this is just the convention. Conceptually, I think of it kind of like a force, it has a magnitude and ...
1
vote
1answer
80 views

Stable voltage at high current

I am working on robotics project. The drive chassis is powered by a 3-cell 12V 8 Amps battery (I might also go for connecting two batteries to attain speed as my drive motors work at 24V full power). ...
0
votes
0answers
31 views

How does the impedance of the source effect the positive sequence impedance measurements of distance relays?

How does the impedance of the source effect the positive sequence measurements of distance relays in relation to power system protection? I wrote that increasing the source impedance decreases the ...
1
vote
1answer
48 views

Is it possible to calculate the load resistance in a full bridge rectifier when given only power, inductance, and input voltage?

I'm given a full bridge rectifier circuit with values for power, industance, and RMS input voltage: [P = 380 W, L = 85 uH, Vs = 115 V]. The question states to 'select' output resistance for a ...
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2answers
87 views

Getting 320V DC from 12V DC

I'm a photographer. A friend of mine gave me two big flashes, which I can use without grit. There is a generator, which generates 300-320V DC from 12V DC. This voltage loads the capacitors directory ...
0
votes
1answer
65 views

LiPo protection circuit IC

I'm making a power board for my robot and I am looking for some advice regarding LiPo battery protection ICs. I might need to draw a fair bit of current (9A), though if I get the programming right, ...
0
votes
1answer
46 views

Calculating a voltage and power dissipated in a circuit after creating a supernode

I am looking at this circuit and I am trying to calculate Vx and power supplied by the 1A source. I believe my calculations for node V2 are correct but I am not too sure about my V1 and V3 supernode ...
0
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2answers
69 views

newbie question: can I plug a 250v power strip into a 120v power outlet (and then connect three 120v power adapters to the power strip)?

I'm sorry if the question is too dumb, but I was wondering if I could connect a power strip rated for 250v into my home's power outlet (120v). I wanted to connect 3 power adapters rated at 120v to it ...