### conversion ratio of kva : watts?

Asked by lokoboy 8 years ago

How can i (step by step) generate 4000 watts and 220volt from a car alternator ?

Asked by nicobotha12345 9 years ago

Hello, forgive me if this is not the right blog to post i was just not sure where to ask. i have a 5w led that came off a flash light i would like to either do my own flash light or install it in my house as a light, how can i do that and what do i need to power it, the only thing i know about the flash light is that is a 5 watt. also i dont know much about leds so if you guys can help that will be really cool. thanks

Posted by Nelson_Yepez 7 years ago

I would like to get a few of these for a project. It would be nice if there is a ebay seller that can give a deal. there was a guy that found this out, but that was a year ago.

Asked by JZ Price 9 years ago

Hello, forgive me if this is not the right blog to post i was just not sure where to ask. i have a 5w led that came off a flash light i would like to either do my on flash light or install it in my house as a light, how can i do that and what do i need to power it, the only thing i know about the flash light is that is a 5 watt. also i dont know much about leds so if you guys can help that will be really cool. thanks

Posted by Nelson_Yepez 7 years ago

so as I said I have 2 questions. First: Is there a device that can measure the watts of an appliance? I just got a hold of a cheap generator (900w normal 1000w peak) and need to find out the wattage of some appliances. (None have stickers/plates on them at all to help me calculate it.) Second: Can anyone direct me to an instructable on motorized rotating camera mounts or anywhere that can show me how to build one? I want to be able to watch the sky from inside we get some nice weather here but hard to watch it from inside hehe.

Asked by BlueSuneLIght 6 years ago

The power supply i'm using for a circuit has a higher power rating than a bunch of resistors i bought. What would happen if they are all wired together in one circuit?

Asked by hmddeen 9 years ago

I made the Ruby amp by runoffgroove (http://www.runoffgroove.com/ruby.html) and it's hooked up to a pc speaker with an 8ohm impedance, how would I go about finding the output wattage? And while you're at it if you have any amp-building knowledge to impart or good places to learn about amp circuits I'd appreciate it.

Asked by OptimumAlliance 3 years ago

I know how to use ohms law to calculate what size resistor I need but what I really need to know is how to tell/calculate what watt rating I need to use whether it be 1/4, 1/2, 1/8, 1,10 and so on.

Posted by pattyshaw 6 years ago

Alright, in my cold fusion set up I need to measure the watts going in and the watts going out. How can I do that?

Asked by Kalrag 7 years ago

I happen to have a set of 8 ohm speakers (which say 20 watt max) and wondered about using them so I can listen to my mp3 player in the shower.

Asked by Andale_The_Great 7 years ago

I've worked with 12v and 5v a fair amount, and I've got a good understanding of Ohms law, series and parallel circuits, etc. But, I get a little sketchy when it comes to wattage ratings, KWHs, etc. and their relation to (now) my electric bill, (but hopefully soon to my off-grid, alternate power sources/power banks) and what I can handle as far as power consumption, etc. Any theory, links, book suggestions, practical examples, etc. will be GREATLY appreciated. Thanks so much in advance, everyone!

Asked by sykotik 9 years ago

I was out buying the parts for the free electricity from telephone port in wall, but the resistors have no wattage posted. The man at the electronics store said he needs the wattage for the correct resistors.

Posted by 3l3ctr1cman 10 years ago

I have a transformer with 13v input can i give it 240v without it melting and can you please tell me the math of transformers am new and any information helps

Asked by mohamed amin 2 years ago

I have both inverters and they both still work. Instead of going to buy an expensive 1000 plus watt inverter I'm looking for a simple way to just combine the two I have to handle the wattage I need them for. I go camping a lot and I like having hot coffee in the mornings, so I need an inverter to handle a coffee pot. I could stoke the fire and put a perculator over it or crank up the generator and plug in the pot but I'm a simple guy who likes simply plugging in the coffee pot to my truck!

Asked by WildBill76 8 years ago

Hey guys, So I've recently gotten into making DIY speaker systems, but I'm having trouble understanding the whole ordeal about wattage and ohms. I have four speakers I managed to salvage from some old speaker systems that I got from an old thrift shop. I have two 15W 4ohm speakers, a 20W 8ohm speaker and a 2W 8ohm speaker (but I don't think I'll find a use for that one, I'm not sure) I plan on buying the Lepai LP-2020A+ amplifier, it's a two channel amp and delivers 20W/ch with impedance of 4-8ohms. What I want to know is what set up would be best with what I have? Can I run the two 4 ohm speakers on 1 channel even though they would draw 30W of power? I'm a bit new at this, and my understanding is still a bit unclear so if anyone could please explain, I would very much appreciate it :) Thank you

Asked by VoicesOnAir 4 years ago

Morning Guys Need a bit of help with the maths. Hoping to run a fridge on a inverter / battery / solar panel. If it has a energy consumption of 0.43 KWH, I think it would be about 43 watts not sure here. What size battery and solar panel would I need? Big Love Chris

Asked by Handyperson1 2 years ago

Ok, I need a charger for my motorolla two way radios. I have the dock, only need a DC power supply. on one of them it states "18Volts DC +/- 20%, 15.3 watts" .Lets say I get 18VDC 1amp power supply, that's 18W,it means it's an overkill? or 15V 2Amps? As I understand, usually amps don't matter, as the item draws as much as it needs, but since it is a charger.. Cheers for the teh help!

Asked by zhgutas 6 years ago

Hi guys, i recently bought a mini compressor for cake decorating. Its a "ABD TC-20" and i bought it at TCPglobal. Problem is, i dont know how many Watts it uses! You see, i bought it as a pressent for my wife. "Nice? Yes!" "Bought with my nose and not my brain? Yes! Im living in Holland, and our network works on 220volt at 50Hz. The compressor i bought works on american standerd, 110volt at 60hz. So i need a converter to make the machine work without frying its circuits... If i buy a converter specificaly for this machine, it has to have the right amount of Watts. i know, i can buy a converter that handles Watts in the range of 1000Watts, cuzz more watts on a converter is better, but than i'd have to buy one thats quite expensive. Because if the compressor only uses, lets say, 50 watts, i could buy one that has a max of about 100 / 150 for a waaaay lesser price than the one thats more powerfull. It would be 50EU for the smaller converter against 200EU or more for the bigger one. So, if you happen to know something on this subject, i would be more than happy with any info you've got ;-) greets! P.S. At the moment i wrote this, the package is stil on its way from america to my house. So i dont have a box or machine sticker to sneak the info i need from...

Posted by AriedeB 5 years ago

Dumb question. Have a heating plate that uses 1100 watts and runs on 120 volts ac. if 1100 watss / 120 volts = more or less 10amps, Could I safely use a 10 amp rated ssr aka solid state relay or use something higher.

Posted by Computothought 3 years ago

For a project powering red, blue, and green LEDs, with a common positive, I am hoping to power around 250 LEDs with around 5 amps. This means that each wire needs to be able to handle 5 amps of current at 12 volts (or 60 Watts), with the other three wires acting as grounds. I've looked at PC peripheral molex connectors, capable of handling around 5-8 amps however that is over all four wires. I need something stronger, most molex connectors use 20 gauge wire (which handles 1.5 amps), while the national electrical code suggests a 14 gauge wire to handle 5.9 Amps. It doesn't matter to me what the connector is supposed to be used for, if it's an audio plug, power plug, or whatever, this project will be very jerry-rigged. I would greatly appreciate any suggestions for a suitable plug.

Asked by QuackMasterDan 9 years ago

Is it true? 2 watt led has 1 diode, and 3 watt led 2 diodes? or can a 3 watt 700ma have both?

Asked by MistaMasta 5 years ago

I am trying to run a sign off of solar power. The sign has 40 LED modules. Each module has 3 individual leds. The specs for each module are 12v, consumes .7 watts, and 50 mA. Multiplying watts and amps by the number of modules you get 28 watts and 2 amps. I'm looking at solar panels from walmart and they come in 10,15,20,30 ,60 watt panels. If the sign is ran 12 hours a night(6pm-6am), That means 28 watts x 12 hours = 336 watts used per night. If the solar panel gets 8 hours of sunlight to charge(8am-4pm), that means 336 watts/ 8 hours means I need a 42 watt solar panel? Also, how big of a battery do I need? 2 amps x 12 hours = 24 AmpHour battery? EDIT: I'm going to use a 12V timer relay so I can run the LEDs from 6-11 pm and 5-7 am. This decreases the on time to 7 hours and 196 watts. With 8 hours of sunlight, that means 25 watt charge. Also 2 amps x 7 hours = 14 AmpHour battery.

Asked by tallemertes 2 years ago

Let's say I need to have a resistor in a circuit rated for 10 Watts. If I had two resistors rated for 5 W, could I wire them in parallel to make the equivalent power rating 10 W? I know my resistance will be different but I'm not sure how the power rating would differ.

Asked by ishmal1103 4 years ago

Is there any relation between farads, watts, and amps? can the energy stored in farads be translated into watts or amps?

Asked by mazedicer 1 year ago

I am trying to build an AC arc welder from transformers. I need to know how many amps, volts and watts a normal microwave transformer outputs because i am trying to use different transformers, as i don't have two microwaves on hand. -Thank You

Asked by shammallamaman 9 years ago

I have recently been talking with another person on instructables about converting 33 megajoules into a standard comparable electric unit, watts. Now the formula for joules just so happens to be watts times seconds, but he still thinks this is wrong. He says I can't just assume time. Now I can assume any amount of power for any amount of time I wan't to as long as it adds up to 33,000,000 joules in the end right. So if I wan't to consume one watt every second, then I have to set the amount of time as 33,000,000 seconds or roughly 9,166.7 hours. This all seems fine to me right, because one watt for 33,000,000 seconds is equivalent to 33 megajoules. Now I originally didn't understand all of this so I just fumbled around and ended up converting to hp and got roughly 12, which is very close for being a rounded off number. It comes out over one hour to equal just over 32 megajoules. I can't seem to understand what the problem is, the DEFINITION OF ENERGY/WORK IS POWER *(OR OVER THE PERIOD OF) TIME Is there really such flawed logic here that "joules could be converted to cubic meters?"

Asked by jj.inc 6 years ago

I just bought a rock tumbler off ebay. the brand name is "chicago power tools". its a basic 3lb capasity rock tumbler/ lapidary rotary tool. now, because i live in australia, i have a problem, my power outlets produce 240v , and the rock tumbler can only take 120v, and so when i pluged it into a power adaptor (us-aus), the transformer gegan to work, then overheated and produced smoke, fortunately it still works . now, i am going to go and buy a stepdown transformer and have learnt that if the device is using more than 90% of what the transformer supplies, the transformer will overheat or break or something. now, on my tumbler, and everywhere a description for it is put, it mentions nothing on wattage consumption, and so i am asking , how many watts will it use so i may accordingly select a stepdown transformer for it.

Asked by oldmanbeefjerky 7 years ago

1.As you can see in the diagram i have eight 4.5 AH SLA batteries joined together to make four 12 volt 9 AH batteries. how would i incorporate my bigger 7 AH 6 volt SLA into this? 2.Is my math correct that i did up in the corner? 3.Does an amp an hour storage in a battery mean it will supply one amp for one hour? 4.If so and my math is correct i would have 516 watts of power for one hour stored in these batteries?

Asked by harry88 4 years ago

I want to make my own solar panel (a small one) for a school project, but I also want it to be useful for after the project as well. I need a small light to light something outside, but at night (because, obviously, I can see during the day). So apparently you need a battery to store the energy during the day, and a charge controller is really important. I've found a lot of useful sites and videos (and instructables) that show how to make solar panels, and a few that show how to connect the solar panel directly to a light bulb, but I can't seem to find anything that clearly explains the battery and charge controller part. Please note that I know nothing about the technology of solar panels, watts, volts, etc., and have never taken apart or made even a simple electronic device of any sort. The most experience I had with this stuff was when I made a small circuit with a light bulb, battery, and alligator clips sometime around the sixth grade, but I have no idea how all that works and all the numbers that you need to keep in mind (I did learn the basics a couple years back, but I've forgotten everything), so when I find brief explanations online that say you need a battery, charge controller, and you need to somehow calculate the correct capacity and voltage, I'm totally lost. Can someone please help me out and explain? Or at least provide a useful link or something? I've scoured the Internet, trust me. Unfortunately, I was unable to find anything clear or something in a "How-to" format. Also, I'm flexible on the 10w thing. A 10w light bulb was just the lowest I could find and I thought the lower the better. So what kind of a battery and solar panel (how many watts/volts, etc) would I need? Low cost is ideal.

Asked by a Canadian 5 years ago

Watts = amps times volts, correct? So if I had a laptop that charged with a 60 watt power supply, could I: -Charge it with 10 amps at 6 volts? (that is the same as 60 watts) -Charge it with 6 amps at 10 volts? (that is ALSO the same as 60 watts) -Charge it with 5 amps at 12 volts? (that is ALSO the same as 60 watts) -ect... Watts is just how much 'energy' passes a single point every second (or whatever), so it doesn't matter how you get the watts, watts is still watts? I'm still trying to grasp the whole concept of watts, so yours answers are infinitely appreciated!!!

Asked by nepheron 8 years ago

5000 watts power inverter with the circuit diagram using SG3524

Asked by santos4eva 7 years ago

I'm hoping to build my own electric scooter in the summer once I know more about the motrs, batteries, etc I've found two 500w electric motors on eBay. One's 24v and the other's 48v. what's the difference? why would they need different voltages? I can't remember that particular lesson about electronics from my school lesson lol.?

Asked by JackIsted 7 years ago

I'm fairly new to car audio. I just put in a Pioneer MVH-370BT headunit into my car, and while it is working great right now, it is evident that I'm going to need new speakers soon because the factory ones are not very good. I was looking at either the Kicker 40CS54 2-way speakers or the Kicker 41DSC54 2-way speakers because many people have recommended these speakers. The problem is on the website, the pioneer headunit only says it puts out 14 watts RMS power while the speakers say that they use up to 75 watt RMS. I'm trying to avoid getting an amp because I'm going to be putting the speakers in myself and i don't want to have to drill a hole through the firewall. So, my question is what will happen if I run the speakers with the 14 watt RMS receiver? Will it just not play very loud? Will the sound be very distorted if I try to play it loud? Is this bad for the speakers? Thanks!

Asked by JoeG4 3 years ago

Hi, I want to make a portable speaker as a project, whilst gathering all my components together i realised that my speakers specs had 6ohm and 3watts. Where as my audio amplifier specs are 3 watts and 4ohm and 8ohm (listed on website). does the ohm levels on the audio amplifier have to match the speaker?? Please keep reply simple as i am new to this, thanks :)

Asked by RookieSean 3 years ago

Can you rectify the US mains (120vac, 60hz) as it, and used the pulsed dc to feed into a transformer and get a dc voltage out of the transformer? I'm asking this because it would be much much more efficient for high current situations. Here's my specific situation:I want to build a capacitive spot welder and a capacitive discharge cutter in an all in one device. To charge the enormous capacitor rapidly (1.5 farads in my case), I need a very high current power supply. I'm using a modified microwave transformer that was rated at 1kw, and it is now modified so that it outputs 12 volts AC at around 80 amps (probably less because of losses). This must be rectified to charge the capacitor.Assuming a perfect transformer (for arguement), it would have:120volt, 8.34 amp input12volt, 83.34 amp outputthe following is with full bridge rectifiers, assumed voltage drop: 1.4vIf the power was rectified before the primary, the loss on the bridge rectifier would be: 11.67 wattsIf the power was rectified after the secondary, the loss on the bridge rectifier would be: 116 wattshuge differenceso once again, the final question is: Does rectified input of a transformer = rectified output? Does the 120hz pulsed dc (as opposed 60hz ac) matter? Could this setup charge a capacitor?

Asked by guyfrom7up 8 years ago

I want to make a 1 watt violet laser, by using a 1 watt 808 nm laser and channeling the laser through a KTP crystal. Judging from my humble knowledge of second harmonic generation, That should create a 1 watt violet laser beam. Correct?

Posted by Nexoid 7 years ago

Asked by brab 8 years ago

Let's say I salvage a few resistors from an old electronic, how can I tell if it's a 1/8 watt or 1/4 watt etc? I have a multimeter if need be.

Asked by surlistyc 7 years ago

Do they?

Posted by Yerboogieman 9 years ago

I have been working on a small generator and i need a dynamo to generate the electricity so I did a little experiment to find out what motor i had was most efficient at generating power so I know what I should use a in the upcoming project. On each motor which was spun at the same speed by my Dremel all the results were ordinary except for one motor which surprised me with its super high reading. Upon seeing this I thought it might be my multimeter going dead and giving me false readings i changed out my multimeter and got the same exact readings for the motor. Is this because it really can produce 120 watts or am i doing something wrong? My formula for finding watts was V*A=W the motor was producing around 8.5 amps at 14 volts. I'm pretty sure the formula is correct as well. Help would be appreciated greatly thanks. Harry

Asked by harry88 4 years ago

I'm planning on getting a 905nm IR laser that's pretty powerful, and I don't want to spend a lot on the goggles (from my searching, they're normally pretty close to $200). Does anyone know where to get some decent ones on the cheap?

Asked by The Ideanator 8 years ago

Well i was thinking, 5mm LED's take about 1/10 of a watt, correct? and from this calculator found out Cree 5mm led's are .806 lumen's. i assume they are 1 tenth of a watt. well, my calculator states they are 8 lumen's per watt (if i could run them at a watt.) i figure they are 1/10 of a watt because because this 500 led light makes takes about 50W as in the video and led's give less than a lumen of light. so far, it seems leds just last long and emit blueish light. is incandescent light better? with 20 lumens per watt from halogen?

Asked by -max- 7 years ago

Hey everyone i was just wondering how watt meters work. most of you already know the Kill-A-Watt. this is basically what i am looking to understand. Kill-A-Watt may get a little complicated as a device, but i would like to know what the basic idea is behind the meter.is there an instructable on how to make your own simple meter? any help is greatly appreciated. thanks

Asked by mohissa 5 years ago

Hello everyone, My dad bought a new kitchen and he would like to put led lights behind plexiglas to have a light source at the level of the work place , I've searched on eBay for cheap led light bulb 40 watts equivalent , but it's a little bit expansive and after searching more , even if they say it's 40 watts equivalent , it's actually not and it's definitely not bright. Please , may someone help me finding the ultimate inexpansive led light bulb ?

Asked by Anykey 6 years ago

I am currently working on a mini A/C with a TEC that draws 12V and 12 amps and the relays I want to control it with have a rating of 10 amps 120v. not sure if it is as simple as this but 10A*120V=1200 watts. While 12A*12V=144 watts so in my eyes this would work because there is much less power flowing through the relay but I would like to request advice from someone who is a bit more knowledgeable then I. Help would be greatly appreciated thanks a bunch. Harry

Asked by harry88 3 years ago