Boss pwede poba mka hingi ng PDF nito sayu tga cagayan de oro po ako Mindanao fix na poba ito boss wla na pobang kailangang e adjust...ito email account ko boss jaylordbalabat123@gmail.com pwede po ba mka hingi ng contact number boss
very nice very interesting technology Class D I have been designing guitar amplifiers for professional musicians for 30 years, this pulse width modulation and low pass filtering is very clever
So much patience you gave in to this project, For a diy I can't do it or instead I'll order a ready to use class D board from you if ever... or maybe I'll use a PwM Car amp mosfet - less hustle
great video, can i use T200-2 core for this project? that is what i have for now and also i have 110-110v ac transformer what component should i change in the circuit if i want to use such big voltage
Nice. Perfect and very strong. Good amplifier very nice strong you is good. Congratulations my brother this amplifier is number one very very good i love, i like this sound is very very good. Tank you.
Nicely done video, When testing audio amplifiers, always use a widely known basic music or a song, with high and low frequencies clearly understandable. But class AB is the BEST
I ordered same PCB but audio not came out plzz suggest me what I do Aur one more thing is that Mur460 near led glow and light down not in regular glow shown as vedio
@@WahyuEkoRomadhon friend, please tell me, why can't you connect it in 1 ohm? I just do not really understand what will happen to the amplifier if you still connect it to 1 ohm? This is a class D amplifier, what needs to be done with the circuit so that it can operate in 1 ohm?
, nice job, those digital class d amplifiers are nice. they run cool, do not need a fan & have clear sound. I have several of them. mostly SMSL. I like SMSL because of the quality & the fact that they are one of the only companies that includes the proper power supply which is critical to the amplifiers output. I have the 36 pro, and the super high power 98 model which is 160 wpc. I use that one with my KEF 150s. very very good sound, of course I'm using a subwoofer also. but not turned up to loud, just enough to fill in some bottom end below 40 Hz.
Ingeniero Buenos días una pregunta al mandar a fabricar el pcb del amplificador en jlcpcb al cargar el archivo se pone en Advance PCB/PCBA. en ese concepto está elevadísimo el precio no hay detalle si lo pido en 2 capas en Standard PCB/PCBA gracias.....
Hola amigo ,, un saludo ,, desde este humilde lugar , te hago una pregunta este amplificador trabaja en 2 ohm, ??,, así como esta configurado,, gracias
@@kka10001 conditioning input power is standard in musician grade gear, why the public thinks it's immune to this i have no idea. A conditioner/surge protector should be mandatory for anything g you intend to keep...
Hi! The capacitor of 220uF/16V next to input signal is reversed on the PCB. Is the filter capacitor for TL071. It should have the negative lead to the edge of the PCB. If you look in the schematic is correct placed since it has the negative rail trough R7 6k8 ohm and R6 10 ohm and the positive rail trough R8 6k8 ohm and R5 10 ohm. Just an info for whom wants to build it. For long term it will leak and maybe explode in long term use.
Mau tanya soal power class d 4K5 klw main 1ohm aman gak? Sya punya 2 speaker sub 12inch embassy 309d 1 speakernya main di 2ohm dan ingin sya pararelkan.
if its running +- 90Vrms, at 20 amp peak, for simple calculation P = V*I , so power in watts calculated, in this cases , when using rails +-90 so total voltage is 180v, so u can calculate 180v * 20 amp = 3600wrms. clean.In other cases when voltage drop, ampere drop it will not reach that peak, maybe arround 600-1000Wrms.
Really nice work! Can you tell me what is the switching frequency roughly? I would be interested in an amp with high frequency for full range and very high power :)
I bet your output inductor gets extremely hot, if it works well at all. That material has high permeability judging by the very few turns you have. To use correctly as an output filter you need powdered iron or a gapped core or some type of low permeability material, which would yield 60 to 120 or so turns for 18uh to 26uh respectively for a 48mm core. Those are just lose numbers. Your core is gonna saturate and overheat possibly short out the fets.
@@WahyuEkoRomadhon Could you share your construction details with me about the inductor? Type of material, manufacturer, your target gauss? Curious if I missed some good toroids to have on hand for output inductors. Thanks
i received JLCPCB boards using you gerber files the 555 ic does not send any signal to IR2110 . why does this not work please send correct circuit diagram that is for circuit on the video that you build, your 1200watt amp has a mistake on solder mask, it works perfectly when mistake is found, i found that mistake. what is mistake on D4K5, im using JLCPCB professional made pcb from your GERBER file on this channel. please help . thank you
Hay!if you let music signal in that amp it can deliver 1200watt rms on 2x90v dc on 2 ohms speaker.but,can it take more, 2x130volts dc and play music signal and how much watts can it deliver on that voltage?or,how much voltage power suplly need to be for this amp to get the maximum power from this amp?thank you!
I see where the DMM shows 184V, so plus/minus 90V. It is a BTL amplifier, so the speaker can be exposed to 184V across the terminals. If it is a 4ohm speaker, 46A can flow. I know the amp clamp only shows 15A, but we don't know the duty cycle of the signal used, so cannot quite trust the meters. I would have used a scope on both the voltage and the current channel. Either way, in theory, that set up can easily deliver more than 4kW of energy to the speaker.
You are right. I assumed it was. Now the power claims are a lot more suspect, I agree. I found the schematic. drive.google.com/file/d/1LQH2L35j55IrUQEPinwgX9cr5OR8Y21c/view
@@Daaremikkel OK I have your attention :) According to the website he meant the power with 2 Ohm load. Which would still need 135V supply, not 100V. Which, I don't know. His MOSFET have 0.05 Ohm load impedance, which means three on parallel, total 0.02 Ohm. Derated for possible heat and switching phase let's say 0.04 Ohm. That is 1/50th of 2 Ohm, so just about 90W loss, spread among 6 MOSFET. 15W each. If I'm more generous, best case 8W. I don't think you should be running more than 1 kW through the thing. Which granted, is a scary amount of power too. Scary.
HI SIR HOW ARE U SIR I HAVE SOME DOUBT WHAT MEAN BY PASS SHIFTIER PLS EXPLAIN SIR ITS MY KINDLY REQUEST AND HOW TO FINDE PHASS SHIFTIER PLS HELP ME SIR
What is the maximum dual PSU that can be used, the fets are 200v devices. i have an amplifier that has +100v 0 -100v PSU using SJ 1058/162 200v fets and it keeps blowing. the fets on d4k5 are also 200v will d4k5 amp handle +-100v PSU
Wahyu Eko, i have a question, would you build amps for my line of self powered subwoofers ? not just a typical offer i would hope that you could get back with me, i'd love to discus what i have in mind.
Good day sir. Why does the Lf coil of 22uh heats up sir with only load of 4 ohms average voltage output of 25ac. Is this normal sir . Im new with this class d's pls give respect
Hello Brother I want this Circuit board please tell me price i can't build it because I don't have equipment and component and i don't have knowledge about it please tell me the price i want one to connect it with my upcoming marQ 120w home theater in future
Até hoje não entendi esse site,se tem que mandar o esquema,se tem que mandar o ley aut ,se eles mandam as peças,se só faz a placa.esse site teria que ser mais simples
Sr plz tell me cd 4049 ic pin 3 pcb in work but Systematic in pin 3 open. Nd pin 12+13 in pcb. But systematic in open Nd ir2110. Ic. Pin13 in systematic open. But in pcb use plz. What's right
Ya begitu mas kalau membuat tutorial langsung tes kasih bunyi seperti ini tendangannya betul"kelihatan daun spikernya tapi kali uji dengan alat nda tau itu bagai mana kekuatannya itu mantap yg itu saya mau tanyaka jenis itu harga brapa bos
![[DIY] 1000 watt High Power TBM Amplifier Board Using 2SA1943 & 2SC5200 Transistors #cbzproject](http://i.ytimg.com/vi/zXyC22Wvbrg/mqdefault.jpg)
![[DIY] 1000 watt High Power TBM Amplifier Board Using 2SA1943 & 2SC5200 Transistors #cbzproject](/img/tr.png)
Class D fullbridge ua-cam.com/video/FLq5w_r1aKE/v-deo.html pcb tersedia single layer.
Beli jadi ada nggak om
Beli jadi ada gak mas?
@@Amira_2721 ada mas
@@WahyuEkoRomadhon .di BL gak ada mas?
Adakah nmr w.a ato grup buat jual jadi?
Emang butuh kepandaian kalo melihat org2 pandai....pokoke sabar dan tetap berkarya. Mugo wae iso ketuku ......jossss
Editing videonya joss 👍
Salah satu yang terbaik utk chanel elektronik lokal mnurut saya.
iya
I build that circuit and
my power supply is 100volt 30 Amps
100% Works Thanks
@Whayu Eko Romadhon
Hi are you Indian?
Nope I'm Philippines
Okay thanks
musta boss performance?
Boss pwede poba mka hingi ng PDF nito sayu tga cagayan de oro po ako Mindanao fix na poba ito boss wla na pobang kailangang e adjust...ito email account ko boss jaylordbalabat123@gmail.com pwede po ba mka hingi ng contact number boss
very nice very interesting technology Class D I have been designing guitar amplifiers for professional musicians for 30 years, this pulse width modulation and low pass filtering is very clever
super amplifier brother well-done
So much patience you gave in to this project, For a diy I can't do it or instead I'll order a ready to use class D board from you if ever... or maybe I'll use a PwM Car amp mosfet - less hustle
Edifier Bass
respek sama om eko daripada yg bilang dibully bule tp dia ga ada bukti kerjanya .... salute mas eko
Mkasih mas saya akn sllu sajikan video yg terbaik. Penyemangat 😁
man, you must be some kind of electronics genius to put that all together. and know how to measure everything.
not 4500 watts, but a good push of power though, i bet its around 400/600 if you was really playing it at full power in the vid
if use +/-90V?! ... max 1800W/2ohms 10%THD. but weery, wery good
great video, can i use T200-2 core for this project? that is what i have for now and also i have 110-110v ac transformer what component should i change in the circuit if i want to use such big voltage
Nice. Perfect and very strong. Good amplifier very nice strong you is good. Congratulations my brother this amplifier is number one very very good i love, i like this sound is very very good. Tank you.
Yes its good amplifier
Hands down the most words I've ever seen someone use to say so little
@@blakebooth1982 It almost sounds as a joke
dia berulah lagi..👍👍👍
mas etalase Bukalapak nya di tambah dong.
Ad kok mas
nama toko nya apa
@@WahyuEkoRomadhon nama toko lapaknya apa nggih mas? Maturnuwun
Nicely done video,
When testing audio amplifiers, always use a widely known basic music or a song, with high and low frequencies clearly understandable.
But class AB is the BEST
Like class D
Whatever you do, I feel very good.
Is this amplifier more powerful than my Marantz SR 5012 7.2 channel AV receiver which has big transformer and many power transistor?
Alhamdulillah, the visuals are good
Thanks bro :)
Mantap . Kerja keras yg bagus salute kpn sy ada wkt buil ampli ini
Brother you should sell these amplifiers to mass produce and sell them to the world and you become an entrepreneur!
Yes this amp is super, maybe in next dream bro.
Wahyu Eko Romadhon bro can you please provide a way to get all the components used in this circuit in one place so everyone can buy it...
Agreed with u
@@WahyuEkoRomadhon hay what is maximum voltage of power supply for this amp?it can play on 2x100v maximum or it can go higher vith voltage?thank you!
sir plzzz tell where i can buy all components
I ordered same PCB but audio not came out plzz suggest me what I do
Aur one more thing is that
Mur460 near led glow and light down not in regular glow shown as vedio
Excellent project
Hello friend. This amplifier can use in 1 ohm load? We say that this amplifier can get 400-500w this is 4 ohm load? In 1 ohm was approximately 1000w?
No it cant.
@@WahyuEkoRomadhon
friend, please tell me, why can't you connect it in 1 ohm? I just do not really understand what will happen to the amplifier if you still connect it to 1 ohm? This is a class D amplifier, what needs to be done with the circuit so that it can operate in 1 ohm?
Waaoo...Amazing work..
, nice job, those digital class d amplifiers are nice.
they run cool, do not need a fan & have clear sound.
I have several of them.
mostly SMSL.
I like SMSL because of the quality & the fact that they are one of the only companies that includes the proper power supply which is critical to the amplifiers output.
I have the 36 pro, and the super high power 98 model which is 160 wpc.
I use that one with my KEF
150s. very very good sound, of course I'm using a subwoofer also. but not turned up to loud, just enough to fill in some bottom end below 40 Hz.
Very cool brother
@@WahyuEkoRomadhon I am interested, how to order please?
I cant sell this amp. Yoh can order the pcb
wow its loking super cool
Try it
Ingeniero Buenos días una pregunta al mandar a fabricar el pcb del amplificador en jlcpcb al cargar el archivo se pone en Advance PCB/PCBA. en ese concepto está elevadísimo el precio no hay detalle si lo pido en 2 capas en Standard PCB/PCBA gracias.....
Please tell me the name of the track 6:19
ua-cam.com/video/senY85iNmco/v-deo.html
Hola amigo ,, un saludo ,, desde este humilde lugar , te hago una pregunta este amplificador trabaja en 2 ohm, ??,, así como esta configurado,, gracias
Complete insanity, I have faith in you!
Is there a parts list for this?
Visit link in description
Brother how many volts and amperes will it take for this amplifier? I am using irfp260 MOSFETs
Such poor sound quality from these Class D amps. Why even bother.
Why
actually they sound pretty good. Not sure about this one, but my class D sounds really good with proper speakers
With proper high current supply, they sound sweet. Shitty power = shitty sound.
@@kka10001 conditioning input power is standard in musician grade gear, why the public thinks it's immune to this i have no idea. A conditioner/surge protector should be mandatory for anything g you intend to keep...
Hi!
The capacitor of 220uF/16V next to input signal is reversed on the PCB. Is the filter capacitor for TL071. It should have the negative lead to the edge of the PCB. If you look in the schematic is correct placed since it has the negative rail trough R7 6k8 ohm and R6 10 ohm and the positive rail trough R8 6k8 ohm and R5 10 ohm. Just an info for whom wants to build it. For long term it will leak and maybe explode in long term use.
Sdh share mas, di sosmed sy. Sdh kirim email jg, semoga dapat, aamiin. Terima kasih.
Please sir tell me this circuit are 2 ohms supported and how much watt of 2 ohms please reply me thank you
Joss bos ku
Mau tanya soal power class d 4K5 klw main 1ohm aman gak? Sya punya 2 speaker sub 12inch embassy 309d 1 speakernya main di 2ohm dan ingin sya pararelkan.
Nice monno amp
Please tell the complete kit cost and from where can I buy this.
I am from India, I have a small electronic workshop
Bodo amat emang gua pikirin. I
I am also Indian send me your number please My number is 9898831924
if its running +- 90Vrms, at 20 amp peak, for simple calculation P = V*I , so power in watts calculated, in this cases , when using rails +-90 so total voltage is 180v, so u can calculate 180v * 20 amp = 3600wrms. clean.In other cases when voltage drop, ampere drop it will not reach that peak, maybe arround 600-1000Wrms.
Like this mas brooohhhh
Thanks for the link to the pcb and great video. Do you have a list for all the parts and a schematic to build?
visit link in description
Kapan bagi2 pcb nya om😁😁
Cek kmen tratas y mas :)
.
Really nice work! Can you tell me what is the switching frequency roughly? I would be interested in an amp with high frequency for full range and very high power :)
Is about 250khz
I bet your output inductor gets extremely hot, if it works well at all. That material has high permeability judging by the very few turns you have. To use correctly as an output filter you need powdered iron or a gapped core or some type of low permeability material, which would yield 60 to 120 or so turns for 18uh to 26uh respectively for a 48mm core. Those are just lose numbers. Your core is gonna saturate and overheat possibly short out the fets.
No its not hot 😋
@@WahyuEkoRomadhon Could you share your construction details with me about the inductor? Type of material, manufacturer, your target gauss? Curious if I missed some good toroids to have on hand for output inductors. Thanks
Can i win something
Where are you from?
i received JLCPCB boards using you gerber files the 555 ic does not send any signal to IR2110 . why does this not work please send correct circuit diagram that is for circuit on the video that you build, your 1200watt amp has a mistake on solder mask, it works perfectly when mistake is found, i found that mistake. what is mistake on D4K5, im using JLCPCB professional made pcb from your GERBER file on this channel. please help . thank you
а где графики
Hallo sir
@@krishanadhand4078 hi..no include graph rightmark audio analyzer
Hi I like it.i want to build this amplifier.but there is one problem.i want to be high and mid sounds.can you help me? thanks
Sir what is this amplifier impudence?????
Is it can handel 2 ohm load????
Tumbas PCB nya dong mas, 😥😥😥
Boleh
@@WahyuEkoRomadhon beli kita nya brp mas
Sy psang dbklpk mas
Wahyu Eko Romadhon Kata kunci pencarianny ap masbos?
minat pcbny mas
hello friend you tested the 4k5 how did the audio excuse my questions but the charge you 2 ohms?
Im the first to like youre video
Thnks brad
AND THE LAST
Hay!if you let music signal in that amp it can deliver 1200watt rms on 2x90v dc on 2 ohms speaker.but,can it take more, 2x130volts dc and play music signal and how much watts can it deliver on that voltage?or,how much voltage power suplly need to be for this amp to get the maximum power from this amp?thank you!
Electro India punya video, diUpLoad. Coba Cameramu dihadapkan kewajahmu
Mkstnya gmn? Reupload gt?
cah suwong memel ae
Mkan dlu sna mas Swandhy
Re upLoad
@@batik_barangantik3302 d lhat2 dlu mas vdeo sya. Video jg dlhat dgn kualitas HD klo prlu. Dlihat dpcb ad nma siapa 😁
Love power class D jedag jedug di kuping 😂😂
Ptg g dimata mas :D
Wahyu Eko Romadhon
Punya video yang berkwalitas dan berkwantitas. . . . .
Trims supportny mas
But brother ,,, on your website (elcircuit) you have written that it will provide 2000w at 4 ohm speaker
Is not RMS
Editor terbaik 🤜
A great job, and a video of the first one.
I'm doing it to see how it goes.
A question.
How to adjust the 10k adjustable resistance?
Thank you
It's for circuit protection
@@WahyuEkoRomadhon But how does it fit?
Wong madiun pancen uye. Aku emoh ketinggalan video video selanjute. Aku yo pengen ilmune. Aku yo podo wong medione👍👍
Amiinn mas. Nggeh sami mas tiang medion mawon kulo
Wahyu Eko Romadhon madiune sampean pundi mas wahyu??
@@WahyuEkoRomadhon klo pesan jadi brapa harganya.... Juga saya baca bisa pesan di buka lapan.....! Kode barangnya apa mas... Trim
Can you explain how to adjust the trimmer potentiometer to turn off the protection. Thanks
Здравствуйте, собирали эту схему ? Работает ?
I see where the DMM shows 184V, so plus/minus 90V. It is a BTL amplifier, so the speaker can be exposed to 184V across the terminals. If it is a 4ohm speaker, 46A can flow. I know the amp clamp only shows 15A, but we don't know the duty cycle of the signal used, so cannot quite trust the meters. I would have used a scope on both the voltage and the current channel. Either way, in theory, that set up can easily deliver more than 4kW of energy to the speaker.
Thanks
It is not a BTL amplifier.
You are right. I assumed it was. Now the power claims are a lot more suspect, I agree. I found the schematic. drive.google.com/file/d/1LQH2L35j55IrUQEPinwgX9cr5OR8Y21c/view
@@Daaremikkel OK I have your attention :) According to the website he meant the power with 2 Ohm load. Which would still need 135V supply, not 100V.
Which, I don't know. His MOSFET have 0.05 Ohm load impedance, which means three on parallel, total 0.02 Ohm. Derated for possible heat and switching phase let's say 0.04 Ohm. That is 1/50th of 2 Ohm, so just about 90W loss, spread among 6 MOSFET. 15W each. If I'm more generous, best case 8W. I don't think you should be running more than 1 kW through the thing. Which granted, is a scary amount of power too. Scary.
aku malah fokus karo editing video ne. mantep mas pro bangett
Very good, but where it says "Download Gerber file" I only get ads, please help.
Visit elcircuit
Can this amp work on a 120V AC power using rectifiers and a capacitor?
If does, it'd be a great thing to sell!
Is this based on a tripath design?
Great thing to sell to enemies that you want dead, you mean? Also i think resulting 170V dual DC is really too high for the circuit.
Is it enough to power 2 1,200 watts when we do this?
I love your channel but can you give some specs like THD and noise and stuff?
Thanks Video duration its take too long.
Nghe một số ý kiến bảo rằng mẫu này khi mở công suất lớn hay bị ngắt tiếng bảo vệ có phải không vậy
What video editing software did you use to create the video?
Adobe premiere
I wonder, how much it costs for all the components
How many 12" subwoofer work on this amp. With 50v dc supply.
HI SIR HOW ARE U
SIR I HAVE SOME DOUBT WHAT MEAN BY PASS SHIFTIER PLS EXPLAIN SIR ITS MY KINDLY REQUEST
AND HOW TO FINDE PHASS SHIFTIER PLS HELP ME SIR
What is the maximum dual PSU that can be used, the fets are 200v devices. i have an amplifier that has +100v 0 -100v PSU using SJ 1058/162 200v fets and it keeps blowing. the fets on d4k5 are also 200v will d4k5 amp handle +-100v PSU
U can use irfp4568 for handle 100vdc
Wahyu Eko, i have a question, would you build amps for my line of self powered subwoofers ? not just a typical offer i would hope that you could get back with me, i'd love to discus what i have in mind.
mas saya mau rakit JBL 1210 (Power Handling 250Wrms, 1000W peak) atau JBL 1224 (Peak: 1100 watts, RMS: 275 watts) ada saran buat power dan amplinya ?
beritahu saya berapa biaya untuk membuat modul indolari dan pcm ditambah suku cadang untuk merakitnya
Good day sir. Why does the Lf coil of 22uh heats up sir with only load of 4 ohms average voltage output of 25ac. Is this normal sir . Im new with this class d's pls give respect
What the coil u used? And value cap lpf filter?
cara beli kit jadi gimana mas ? ada yang class D fullbridge nggak masc ?
Hello Brother I want this Circuit board please tell me price i can't build it because I don't have equipment and component and i don't have knowledge about it please tell me the price i want one to connect it with my upcoming marQ 120w home theater in future
Can i use this in 8 ohm load without overheating it?
Até hoje não entendi esse site,se tem que mandar o esquema,se tem que mandar o ley aut ,se eles mandam as peças,se só faz a placa.esse site teria que ser mais simples
It's monster amp for it's kind, is there a possibility that you can share the diagram and parts used
Please visit links at video description.
Great work!!! Where can i find a power supply for this amp?
Why does your LED blink and generation does not stop? It lights up for me and the sound goes out
Good job mas. What is the osc freq?
Mkstnya mas?
@@WahyuEkoRomadhon , mksdnya, pake frekwensi carrier pwm nya brp?
250kHz it mas.
@@WahyuEkoRomadhon makasi infonya mas
Iy mas
Mono only? Is there a stereo version?
asik bnr sub nya.. pgn bljr class d
There is different schematic hai original PCB
Plzz cheak out
Cd4049 and ir2110 ic related tracks are to many issues
This is subwoofer board or not ???
mas itu catu dayanya langsung colok,atau harus pakai pawer suplay bias dan drivernya,makasih
12v pakai ctu dya terpisah mas
Wahyu Eko Romadhon , kenapa driver yg aku baru aku beli di coba cuma dengung,apa masalhnya mas?
Driver ap mas?
Wahyu Eko Romadhon driber klas d d1k5 mas
Do you have any plan to build 5.1 Dolby digital Prologic Board
Sr plz tell me cd 4049 ic pin 3 pcb in work but Systematic in pin 3 open. Nd pin 12+13 in pcb. But systematic in open Nd ir2110. Ic. Pin13 in systematic open. But in pcb use plz. What's right
how to increase mosfet in mono amplifier please tell me.i have mono amp. in this amp use only 10 mosfet i will increase it 12. how to increase it.
Bhai ye complete setup kitne ka h or kese.order kiya jaa skta h aap de skte ho kya
Inductor core getting over heat what can I do sir. I used ks157 - 125 core
habis berapa duit bikin ini semua..??
hebat lah.. kreatif..
terjun ke dunia elektronik sudah berapa tahun mas? (khusus nya dunia audio)
hehe :)
Klu 2fet normal tidak panas, tapi klu ditambah fet lagi panas dan tidak merata di masing fet kenapa mas??
Ya begitu mas kalau membuat tutorial langsung tes kasih bunyi seperti ini tendangannya betul"kelihatan daun spikernya tapi kali uji dengan alat nda tau itu bagai mana kekuatannya itu mantap yg itu saya mau tanyaka jenis itu harga brapa bos
Sir this can be capable to drive the 15inch 2 top in 750 +750 watt