Questions tagged [watts]
The unit of measurement and SI unit for power, named after James Watt. It is equivalent to energy flow per second or Joules/Second. In electrical terms \$ W = IR = I^2 * R = V^2/R \$
265
questions
0
votes
1answer
10 views
How to calculate check practically POWER of SMPS required for desktop computer
How to calculate check practically POWER of SMPS required for desktop computers
I have 10 desktop pc in one PC i have a high end gaming gigabyte motherboard with AMD processor graphic card and ...
1
vote
1answer
54 views
How long can this motor run?
If I have a 48v 20Ah 1000w lithium ion battery, how long could it continually run a 48v 33Amp 2000w motor?
Also, how big of a battery would I need to have it run for 45mins at least?
0
votes
1answer
22 views
Measuring the instantaneous power consumption of phone
We can get the instantaneous current consumption and battery voltage via Android's API. So if we multiply those things, can we get the instantaneous power consumption of device? (P=V.I)
0
votes
1answer
60 views
How much power is needed to run these speakers?
I have couple of loudspeakers. Each is rated for:
RMS Power 60 watts
Power 75 watts
vc Imp 16 Ohms
I am going to build an audio amp for those but not sure how much power is needed.
I'm concerned ...
0
votes
1answer
30 views
Dynamic residential power system
I have a farm with solar panels. Right now, it is powering the house, and excess gets sold to the electric company. I was thinking that instead I could have the excess power bitcoin mining equipment. ...
0
votes
3answers
69 views
How do I calculate the total wattage of a dc to dc circuit?
I am trying to figure out the total wattage of the below assumed dc to dc converter circuit block diagram.
Can I get it simply by just multiplying the total SUM of the system output voltages by total ...
0
votes
4answers
72 views
How to know how much energy storage has powerbank? [closed]
I just looked to this question and I don't understand how to know how much Wh this powerbank has (click "Specifications" tab), because it has different output voltages and I don't know how to ...
-6
votes
1answer
102 views
Is it possible that the ampere high than the volt? [closed]
Is it possible that the ampere high than the volt?
for exemple if i have 5v and 6A
and how its possible that there is 30 watt and 5 volt charger?
0
votes
2answers
44 views
Wireless fast charging in car
For my phone I want to wirelessly charge my devices as fast as possible using the cigaret socket (Automobile auxiliary power outlet).
I bought a wireless charging pad which on the back states.
...
0
votes
3answers
93 views
How will I know the power [dissipation] of resistor when buying resistors?
It is very basic question for many people. It is very easy to predict the resistance of a resistor with multimeter, but sometimes it comes with resistors which are slightly larger in size, such as, ...
0
votes
2answers
79 views
why volt is needed for calculate watt? [closed]
hello i dont sure what is the difference between voltage ampere and watts.
voltage is only the potential difference between points high voltage will not cause to the electrons to move faster
so why ...
1
vote
1answer
106 views
How to find how many Amperes does a equipment use? [closed]
In the specification of this miner https://www.asicminervalue.com/miners/bitmain/antminer-s9j-14-5th it says it uses 1350W power with ...
0
votes
1answer
72 views
At what point a battery becomes a load
This has probably been asked before but I don't know how to search for it.
In a circuit where there are a battery and a variable power supply, what conditions have to be met in order for the battery ...
-4
votes
2answers
88 views
calculating Power
I wanted to ask, if I have a electrical component with a power rating of let's say 5W does this mean it would dissapate 10W after 2 hours and 15 W after 3 hours?? or is it correct to say it dissapates ...
1
vote
1answer
54 views
Wheelchair battery life calculation
Apologies because I'm sure this is an incredibly basic question and I've tried to work out the answer myself but I'm getting nowhere with it! I'm looking to get a powered trike attachment from my ...
2
votes
2answers
64 views
Why can a charger handle more watts at a higher voltage?
Why is it that my charger that has a rating of 100-240 volts and 1.3 amps can handle/input more watts at a higher voltage when doing the formula watts=volts x amps?
In addition, why can't it, at a ...
0
votes
2answers
42 views
24V LED Strip Circuit - Switch, Breaker & Wiring Size Requirement
I am running a long LED strip (24V, 21 meter, 0.6A per meter, so technically 13A).
The 24V PSU supplying power to the strips is to be connected to a switch that is rated 240V, 10A & 2400W.
...
5
votes
1answer
397 views
An overseas company is making a machine for me and they need to know whether I want 1,2 or 3 phase and what voltage
I'm in Quebec and the company making the machine is in China. The machine is an industrial sized T-Shirt sublimation machine that does two sided printing. So there's a large heated plate that is ...
2
votes
3answers
1k views
What does the power rating of 10W mean?
When hair clippers or similar appliances are rated at, for example, 10W, does that mean 10W per hour or second? I'm trying to determine power of various hair clippers.
0
votes
2answers
121 views
BLDC Motor max load
Hi i have a BLDC moter https://www.banggood.com/350W-48V-DC-Brushless-Motor-Geared-Ebike-Tricycle-Kit-Engine-Electric-Scooter-p-1419702.html?akmClientCountry=NL&rmmds=cart_middle_products&...
-1
votes
1answer
54 views
Wattage in US vs AU/EU household appliances
This oven is listed in both the US and Australia. You can see that it's the exact same model (BOV845). Yet if you open the specifications, the only difference is that the US model uses 1800 Watts ...
0
votes
1answer
42 views
Batteries Spike in Watts and Amps Pulled with less than 50% Life
To give a background on this, I have been running tests to determine the actual lifespan of a 3 cell pack of some Samsung 18650s and Tesla 2170s at just above freezing. The Samsungs are INR18650-35E ...
0
votes
2answers
79 views
If a 110 volt motor asks for 4W does that mean I will have to change the wall power? [closed]
I am new to electronics like motors so help on how to set this up would be awesome.
0
votes
1answer
108 views
Ammeter scale, not sure what my amp reading is
I have a basic multi-meter that I am using to measure amp on a load.
I am trying to figure out how much amps my small entertainment system draws. (LCD TV, PC, speakers.) I want to build a small DC ...
2
votes
1answer
130 views
How to replace push buttons on an intercom?
This is the intercom panel in my apartment, it's 30+ years old and I want to give it a face lift. The push-buttons are momentary, and I want to replace them using modern ones like these, but I'm not ...
0
votes
1answer
82 views
built in charge controllers take amps they need?
Many devices have built in charge controllers that stop charging when battery is at 100%. I read several places that you can charge devices with the manufacturers recommended voltage and that higher ...
2
votes
3answers
965 views
heat dissipation in watts of equipment in a box
Here is the situation, some electrical equipment will be in low ambient temperatures and I need to make it warmer so that there is no damage to it.
I want to calculate how much power in watts is ...
1
vote
5answers
81 views
When charging rechargable battery, should we care about watts and ignore voltage and current?
I know this might be a silly question, but it's from a beginner.
Let's say I want to charge a rechargable lithium-ion battery, so when I charge it should I only check the watts and ignore voltage and ...
0
votes
1answer
81 views
How can a 12V 80Ah Battery be 1800W? Shouldn't it be 960W?
How can a 12V 80Ah Battery be 1800W? Shouldn't it be 960W?
I was looking for 12V 80Ah Deep Cycle Batteries on Amazon and most of them were 1800W.
Like this one: https://www.amazon.com/Cycle-Battery-...
0
votes
1answer
65 views
Transistor Inverter - when does excessive small wattage become a problem?
I'm trying to choose the best values of resistors given the stock I have so that I can deliver sufficient power and current to an HM-TRP radio module.
In this circuit, I used the 100K resistor ...
0
votes
1answer
299 views
What defines Volts, Amps, Watts and mAh?
My current understanding is as follows:
Volts: Speed of electron flowing.
Amps : Number of electrons flowing.
Watts: Amps x Volts measured for "some" time. mAh: Very confused to
come up with ...
0
votes
1answer
287 views
How does a Hall-based wattmeter work?
I read about the Hall effect and understand its usage in sensors like speedometers, but I also read it can be used as a wattmeter. How can it happen?
In order to calculate power (P) we need to ...
0
votes
2answers
78 views
Soldering station: power confusion
i wanted to ask what the different power/watt indictors for a soldering station actually mean in terms of the performance of the station or whether the number is just some marketing term.
Some ...
1
vote
5answers
182 views
A basic question about amps, watts, and charging batteries
Why do we speak of watts (and not amps) when we refer, for example, to the "7.5W Wireless Charger for iPhones," but when we talk about cord-based USB charging, the specs typically refer to amps (and ...
0
votes
2answers
34 views
Lower wattage of IR bulbs permanently
I have two 90w/12v infrared IR bulbs which is put into a r7s sockets. From thes socket goes in total four wires which is connected to our power supply. We have set two of the wires in serial so they ...
0
votes
2answers
113 views
Why does curling a wire decrease its amperage/wattage? [duplicate]
I picked up an extension cord today, and I noticed that it had a different value for its wattage and its ampage, based on whether the cord is wound around its base or not.
(I apologize that the ...
0
votes
1answer
62 views
how do LED controllers work
I’m trying to find out if a device only draws the watts it needs to run or if it takes all available
For example
I have led light that’s says max 0,75 watts and the led controller says output 144 ...
0
votes
2answers
68 views
Electrical Power Question
I am trying to compare watts exiting the battery vs watts being consumed by the bulb.
I have set up a test circuit shown below.
Should not A-B watts match C-D watts??
Sorry for such a basic ...
-2
votes
1answer
61 views
Are watts consumed in wireless electricity? [closed]
If I put a transistor on a coil of wire connected to a 120v AC circuit, and made it so my toaster was now wirelessly powered, if I turned the toaster on would it consume watts that are able to be ...
-3
votes
2answers
191 views
Why does my phone charger consume more electricity (watts) when delivering less amps (slower charging)? [closed]
As far as I could understand, the charging speed is measured in amps. Like, if I use Ampere, it will tell that it charges in 2.5 amps, or 1.5 amps. I hope I got this right. Amps is the only ...
-1
votes
2answers
138 views
How can I measure an induction cooker’s power with an oscilloscope?
I have to measure the current and voltage of a coil with an oscilloscope.
In this case, does P Watt = Irms*Vrms?
The induction cooker writes that the maximum Watts is 1.2K, but I measure it over 1.2 ...
0
votes
1answer
90 views
Is it okay to run a Mercury Vapor Lamp of lower wattage (100/150/175W) on a 400W MHL/MVL ballast? Also can a 60Hz ballast be used in 50Hz?
So, I have this RAB BMHH400PSQ Metal Halide Pulse Start Ballast 400W ,M135/M155 MULTI TAP 120-277V with me. Since the MVL are being phased out it has become quite difficult to get a ballast for one of ...
4
votes
2answers
1k views
Alternatives to High Wattage Resistors? (Do multiple low-wattage resistors equal a single higher wattage resistor?)
I am a beginner, so I may have made a horrible mistake in my diagram, but I am trying to learn.
According as I have figured it, I am having an issue wherein I need a resistor rated for a minimum of ...
0
votes
1answer
61 views
How can I interpret the readings of a USB voltage tester considering the input voltage is 5V and I am charging a 3.7V battery?
I have this USB voltage tester that I place between my usb wall charger and a USB charging cable. This device gives me the total current that went through over a period of time. Let's say after 2.5h ...
3
votes
1answer
2k views
Motor current consumption and power do not match
I am working on a design and need to calculate the energy consumption of this motor:
https://www.maxonmotor.com/medias/sys_master/root/8825428410398/17-EN-256.pdf.
(Part No. 339252)
The ...
0
votes
1answer
104 views
How to properly read Watt of a bulb power?
I'm confused about reading the terms Watt, Wh, and Ws of bulbs. Here is the quoted text taken from an electrical book that I'm currently reading on :
Now I'm take out some points from the remarks ...
-3
votes
1answer
60 views
A question about my refrigerator [closed]
it's written on my refrigerator 500watts..
I want to know how much it consume watts per month.
let's consider that the compressor of the refrigerator works 10 hrs per day.
1
vote
1answer
818 views
12 Volt vs a 24 Volt Motor
I have read that using a higher voltage motor would need less current to get the same power. I understand that P = IV and how that works. My question is if the 24 V motor would get half of the current,...
0
votes
1answer
38 views
why does a potencial coil in wattmetter influences the pointer rotation
can somebody tell me,
why does a potential coil in wattmetter influences the pointer rotation.
if the ideal potential coil doesn't have current, it would not generate a magnetic field and it would not ...
-1
votes
2answers
1k views
12 v watt heater with nichrome coil [closed]
i am new here. First of all I am sorry for my bad english.
I want a help from those who know about nichrome heater coil. I want to make a 12v dc incubator using nichrome wire as heating element, all ...
