my home made inverter circuit - Page 1
Forum section: electronics / beginners

author: Nickk2057
author_rank: Regular Contributor
timestamp: March 29, 2013, 02:43:14 pm
content: hello to all the fandom of the electronic field and a BIG hello to the best person on youtube to Mr. Dave himself.. anyways.. my name is Nickk2057.. and i wanted to show off my home made inverter circuit.. and i hope that Mr. Dave can try it himself too....anyways here is the link to it... and hope he can try it and put it on youtube as well since its alright by me for him to tryanyways... here is the link to it from my youtubehope he has fun with the fun time there... it will be a shocker XD

author: RPBCACUEAIIBH
author_rank: Contributor
timestamp: March 29, 2013, 10:10:34 pm
content: Are you driving those transistors with square or sine wave, or with some pwm solution???I was thinking about making an inverter as well, with 2n3055 transistors(I have a few of it at home), and a huge transformer that still remain of my father's inverter which he made about 25 - 30(or more) years ago... He driven it with square wave, and he said that the washing machine and other equipment with AC motors didn't liked it, but it was good for lighting... (They didn't had much current at here in Romania at the time of communism especially at night so he made some...)

author: madshaman
author_rank: Frequent Contributor
timestamp: March 29, 2013, 10:24:13 pm
content: Pretty cool Nick. Do you have a scope yet? If not, keep your eyes out for one, it helps to be able to probe things like the gate and drain on those mosfets for one.Thanks for sharing!

author: Nickk2057
author_rank: Regular Contributor
timestamp: March 30, 2013, 03:04:40 pm
content: well really the inverter is still in working phase.. and i was using an analog scope (hooked up to the input on my computer through a resistor) and also was able to get close to 250 watts output.. which aint bad... the range of the Hz range was about 60 HZ range cause it was doing a double loop through the transformer meaning that there are double the poles in it... one centertap was at 5 volt range and the other was 24 - 0 - 24 centertap from a old home amplifire which aint bad for the first time with these transistors.. and i apologize that i said on that video.. it was NOT mosfets... it was PNP transistors on those.. but still worked great with that project.. but when the power starts draining on the batteries so does the voltage on the output.. and also the amps on the output as well... tho the output aint at a high output yet.. one time i went to try a 500W halogen light and was able to light it up.. which has surprised me quite a bit... but it put quite a straine on the batteries since i was using two of em... but really trying to get to use just one so i can try it in my car so i can have some mobile power to use drills and suchanyways.. hope it answered any of your questions.. i am going to try another methed to make a French inverter circuit which is using a combination of NPN transistors and NPN mosfets... hope i dont blow any uphehe.. anyways.. wish me luck

author: Nickk2057
author_rank: Regular Contributor
timestamp: March 30, 2013, 03:41:10 pm
content: Quote from: RPBCACUEAIIBH on March 29, 2013, 10:10:34 pmand by the way... what transformer is it? cause i was using the one from a home amplifier... but the next on ei am making is a french inverter circuit.. which is using a combination of the NPN transistors and NPN mosfets... also the transformer i am using on that one next will be from an old UPS with a centertap 6-0-6 input... tho i know that on mosfets it will be lower on the output but with a high current.. tho the transformer will be at high watts if i use a proper heatsink on the transistors

author: Nickk2057
author_rank: Regular Contributor
timestamp: March 30, 2013, 05:02:18 pm
content: my FISRT inverter was a first kind i made which has a better version the using 2N3055 transistors.. which was rated for 15 amps.. the audio guy that was in town here told me to try a more powerful version which was rated at 20 amps.. which was much better to use and was more powerful on the output... and also the resistor i used was two 100ohm 10W ceramic resistors and four 2nh3773 transistors which went ok but did not have a high output to run a 100W light bulb.. kept draining out when i turn it on with load... but it went good on it.. tho it DID sound like on it that it will do stuff but nope.. it did not...anyways here is the vid of it

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 01:15:12 am
content: well... i got bad news.. the french inverter circuit turned out to be a bunch of crap... did not do what it says.. and worse... it did not even show a little ripple on the tests... not even a spark... but i DID do another method that worked fantastic.. i will show it in a sec... have to load it up on youtube

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 01:21:55 am
content: The "French inverter circuit" that I saw you post before looked fine. Old-fashioned but fine. Check your connections.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 01:32:54 am
content: i did... and even with a light bulb too... even on the mosfets... but it did not do anything... and the parts i got from radioshack too... i did everything correctly.. soldered all the connections and stuff

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 01:36:19 am
content: plus i tested it five times today.. with no reward in this crap... oh well

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 01:38:20 am
content: Try to figure out why by probing circuit points, you could have made a mistake. I recently had wacky behaviour in a circuit I built because I'd put a voltage regulator in backwards and didn't realise; DON'T LAUGH, I *know* you've all put a three pin device in backwards before ;p

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 01:47:08 am
content: Couple questions (the schematic ison this threadfor anyone else who wants to look).1) The gates of the MOSFETs are supposed to connect to the collectors of the transistors. The muppet that drew this schematic left out the dots and it looks like they're supposed to cross without connecting. Did you connect them? That is absolutely critical.2) What kind of transformer did you use?3) Remove the MOSFETs (or the transformer) and run the circuit (it's harmless without the transformer attached, go ahead and mess around with it). Does it oscillate? If you have any way to measure the frequency, what it it? (Hint: It will oscillate at audio frequency. If you lack an oscilloscope or a multimeter with a frequency measurement, you can listen to it. It's your job to figure out how.)Edit:I see you have an oscilloscope. Sorry for not reading...

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 02:00:59 am
content: This might also help if you didn't already know what it was:http://en.wikipedia.org/wiki/MultivibratorP.S. do you have any opamps lying around?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 02:02:46 am
content: Quote from: c4757p on April 02, 2013, 01:47:08 am

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:05:33 am
content: Without the MOSFETs and transformer, it's just a classic astable multivibrator. There's nothing wrong with it at all, it should have no problem oscillating. There must be something wrong either with the way you've connected it, or with the transistors.

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 02:10:10 am
content: Quick questions:1) (repeat of the edit from my last post) have any opamps lying around?2) model of MOSFET you're using?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 02:11:56 am
content: ok... what i've done was disconnected the transformer off the circuit.. and took off the mosfets too... and hooked em up to the speaker to hear any humming from it... but nothin came out... hold on and i will show a picture of it

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:21:45 am
content: Connect the speaker in series with one of the 680 Ohm resistors. Any other configuration will load the multivibrator and make it stop oscillating.

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 02:24:36 am
content: Quote from: c4757p on April 02, 2013, 02:21:45 amHe's got a scope eh? Less painful..

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:27:50 am
content: I thought so, but I went back and looked, and realized I have absolutely no clue what this means.Quote from: Nickk2057 on March 30, 2013, 03:04:40 pmSo... do you have a scope, Nick?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 02:43:50 am
content: yes... its a software that uses the analog audio input of a computer to use it on... plus using a resistor too on it.. but stll nothin.. when i hook it up it does jump but still no vibrations on the screen

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:46:26 am
content: You've swapped collector and base...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 02:48:32 am
content: nope.. i did not... hold on and i will show you another picture of what the guy did

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 02:50:13 am
content: here is the picture of it

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:52:12 am
content: Not all transistors have the same pinout. 2222 is E-B-C, and with it connected the way you did, it will not oscillate. Swap C and B. The pinout should be on the back of the package, unless RadioShack have gone full-out muppet since the last time I bought stuff there (a long, long time ago...)The full datasheet for that transistor ishere.

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 02:54:34 am
content: Yep you did dude, can see it clearly in picture 271 from your first set of pictures. Easy thing to do, no worries.

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 02:57:46 am
content: To back myself up more, the only longer-body transistors I've seen like the ones in that video were Japanese 2SC ones, which are E-C-B.The good news for you is that unlike many ways you can hook things up wrong in a circuit (especiallyan inverter), those transistors are most likely not damaged and will work fine when you switch them around

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 03:02:32 am
content: Pretty much all bjts in that package have base in the middle, which can confuse you because the large mosfets you've been dealing with are ordered differently.Are those electrolytic caps? If so, one of them is backwards too. The +ve end should be connected to the 680Ohm resistors. Edit: never mind, they are clearly polyester film, my illiteracy.

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 03:04:31 am
content: Quote from: madshaman on April 02, 2013, 03:02:32 amLook at the video screenshot he posted - they really are connected that way. 2SCxxxx and a few other oddballs are E-C-B.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 03:10:09 am
content: Quote from: madshaman on April 02, 2013, 03:02:32 amby the way.. those are bi - poler caps

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 03:13:15 am
content: Quote from: Nickk2057 on April 02, 2013, 03:10:09 amMy bad, I should have seen the "PET" clearly written in subsequent pictures (I'm used to those being big and square)

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 03:40:45 am
content: totally alright... anyways.. i tried the PN2222 chips on it.. but this time it just stays on... no ocilation

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 03:46:23 am
content: Quote from: Nickk2057 on April 02, 2013, 03:40:45 am:-(, I'm heading to bed soon and busy tomorrow. c4757p's got much more experience than I, but if you're still having trouble by wed, I'll board one up and link a video here. It really should just work.If you're interested, you can also make a square wave generator out of a single opamp, might give you inspiration for further inverter design/experiments.Cheers

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 03:50:19 am
content: Can you take another picture? I can pretty much guarantee you that the circuit (at least, the oscillator part) will work fine, so either you have it hooked up wrong or the transistors are faulty.Quote from: madshaman on April 02, 2013, 03:46:23 amThe beauty of using a transistor multivibrator is that you get both a 0° and 180° output for free, making it easy to get true AC instead of just pulsed DC. Hard to beat a circuit that gives you exactly what you need at the cost of two transistors.

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 03:55:39 am
content: Quote from: c4757p on April 02, 2013, 03:50:19 amAgree, but figured it was a nice start to linking in more opamp circuits to make different waveforms etc., get used to buffering outputs so you don't destabilise the input circuit etc.@Nickk2057 you're in good hands with c4757, my advice though: save your pennies, beg borrow or steal (well don't do that) a scope, any scope (okay maybe not usb scope, you don't want that for your first scope), for the stuff you're interested in it's utterly vital and you'll never look back. Nice work keeping at it!!!Edit: if someone even offers you a USB scope for free, throw it at them and say: "I don't want that for my first scope!"

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 03:57:25 am
content: ok.... i checked the transistors hooked up to an LED to see if it will power it on and it did.. so the transistors are fine for the most part...... if one of you all have an insite on it let me know.. so i can try to fix it to see if i cna get it up and running.... also i am having the mosfets hooked up to an arduino with a code to set the frequency.. and it works just fine.. tho there is a hum when its on no load.. but it works good on it

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 03:59:26 am
content: here is the video of it...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 04:05:19 am
content: and excuse my speech on there too XD

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 04:08:54 am
content: Quote from: Nickk2057 on April 02, 2013, 04:05:19 amCool :-). With three opamps you can also do PWM, I'll stop pushing opamps now ;-). Get a scope! Throw USB scopes back at people or sell for beer money (or coca cola, sometimes it's much better). Off to bed am I. Keep at it!

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 04:10:41 am
content: thank you madshaman.. you were very helpful... and if you can... would you try it too to see if it works for you?... it be better if there are two heads then one... with that it will help me out greatly... or even three for that matter...

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 04:36:12 am
content: Give me a minute, I'll throw the circuit together here and see if I have any issues with it.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 04:45:54 am
content: okay... thank you

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 04:56:54 am
content: Works fine for me.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 05:13:12 am
content: now what kind of caps are those.. cause i was using the ones that is used for to use on a tweeter of a speaker on that circuit... the 2.2uf typeand plus 76 Hz is kinda high tho

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 05:16:05 am
content: They are Wun Hung Lo-brand electrolytics, 2.2uF. 76 Hz is reasonable for the tolerances given (those resistors are 1%, but the capacitors are something on the order of holy-shit%). If you need 60 Hz accurately, add a trimmer, or even use a crystal.Edit: The caps clock in at 2.1uF and 2.2uF, so pretty much perfect. However, those values actually give a frequency of about 70 Hz, so 76 is close. It's the circuit design that's off, not the build.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 05:18:32 am
content: trimmer? meaning like a pot?

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 05:29:07 am
content: Yup. You can replace part of the 4.7k with a pot. (Of course, since you're probably only building one of these, it would make more sense to just sub in a different resistor or capacitor value.) Or just settle for the 76 Hz.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 05:45:57 am
content: UGH!! it still won't work... even had it hooked up in a analog port on my computer with Zeloscope to read it but it just jumps and falls back to zero when i hook up the battery to it.

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 05:51:16 am
content: I really have no idea what's going on with it! Try using different transistors. I was going to suggest that a connection was loose (I actually was having problems with that myself, those 680 ohm resistors have thin-as-hell leads...), but I see you've soldered it all (probably overkill).Also - how exactly are you hooking this up to your computer? If there's no attenuator somebody is going to be unhappy with that 12V waveform. A single resistor isnotan attenuator. Use a real voltage divider with relatively high-value resistors (at least 100k total).AndgoddammitGoogle Chrome spell check, "attenuator"is tooa word!

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 05:58:18 am
content: hold on and i will hook up my arduino to it and it will show it...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:14:08 am
content: ok... here it is

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:16:41 am
content: Plus Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer. It uses your computer's sound card as analog-to-digital converter, presenting a real-time waveform or spectrum of the signal - which can be music, speech, or output from an electronic circuit. Zelscope features the interface of a traditional oscilloscope, with conventional gain, offset, timebase, and trigger controls. As a real-time spectrum analyzer, Zelscope can display the amplitude and phase components of the spectrum.

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 06:17:15 am
content: Wait, what? That's oscillating fine!

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:19:21 am
content: yea but that is with the Arduino.. not the other circuit

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:20:06 am
content: but not bad hmm?

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 06:21:25 am
content: Quote from: Nickk2057 on April 02, 2013, 06:19:21 amWell of course the Arduino one works! What exactly does the other circuit do? Can you show that? Maybe capture the behavior of both base and collector of one of the transistors at startup.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:22:26 am
content: the only way for me to do that is with a live show and stuff... or something else to use to show it...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:25:34 am
content: cant upload a vid cause it will take forever to load up to youtube and such.... so i figure it to do live and such.. but don't have a thing on here to do it with.. and with the size restrictions it does not do well

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 06:26:33 am
content: If you can't capture something then they're talking out of their asses about "storage oscilloscope". An oscilloscope that can only "store" a capture of a repetitive waveform is as much a "storage oscilloscope" as me waving a goddamn camera in front of my analog scope.

author: c4757p
author_rank: Super Contributor
timestamp: April 02, 2013, 06:27:14 am
content: Sorry, I'm going to bed now, it's 2:30 AM here. Good luck with this.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 06:29:27 am
content: as the same with me... I'll talk to you tomorrow... and also i will PM you the link to my live stream... when i get a chance when i get off work

author: madshaman
author_rank: Frequent Contributor
timestamp: April 02, 2013, 12:18:58 pm
content: For what it's worth, most audio stuff isn't going to like much more than 2vpp, but you should still a waveform. I have no idea the impedance of your soundcard based scope solution, but you could simply be loading the circuit too much and killing the oscillation.If things are still grim tomorrow I'll also board it up including a version you can switch from state to state maunally using push-buttons (turning it into a flipflop). I might even have time later tonight, we'll see.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 12:39:22 pm
content: ok... and hopefully we can do a live show together so we can share idea's maybe.. it be great to talk to another tinkerer like me

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 12:41:16 pm
content: and plus the soundcard i have goes up to 48000khz... at 16 bit sound sampling

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 02, 2013, 12:42:40 pm
content: anyways... i will talk to you all later... going to work now... laterz

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 01:41:18 am
content: ok... i am home now...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 02:52:36 am
content: and what a day today too... had to help make invoices. -_-

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 03:28:47 am
content: ok... so my next question is this... where can i find a decent Oscilloscope but wont break the wallet... my limit is $100

author: RPBCACUEAIIBH
author_rank: Contributor
timestamp: April 03, 2013, 07:08:40 am
content: Quote from: Nickk2057 on March 30, 2013, 03:41:10 pmmy transformer was winded by my father 12v input, 220V out and 50 Hz and it's huge, I barely can lift it. It could probably give about 1-2KW or so(My father had access to truck accumulators)... It worked well with light bulbs in the whole house at that time, but because of the square wave input AC motors didn't liked it...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 12:12:08 pm
content: Quote from: RPBCACUEAIIBH on April 03, 2013, 07:08:40 amWOW...... that must be one heck of a whopper that is.... and how many power mosfets was it using on it?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 12:32:49 pm
content: well... i went back on that circuit to find out whats wrong and it was in the wrong side with the base and the collector... and not it is working... tho the wave is kinda high on it... going to try different resistors on it to find the sweet spot to see if i can get it to be the 60Hz frequency (or close to it)

author: c4757p
author_rank: Super Contributor
timestamp: April 03, 2013, 01:33:44 pm
content: Quote from: Nickk2057 on April 03, 2013, 12:32:49 pmDude. That is what I told you was wrong with it.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 03, 2013, 11:42:30 pm
content: lol... i am sorry bout that... but i still having issues with it being at 74Hz on it

author: c4757p
author_rank: Super Contributor
timestamp: April 03, 2013, 11:57:56 pm
content: Quote from: Nickk2057 on April 03, 2013, 11:42:30 pmSureyou are...It's OK.Increase the 4k7 resistors to 5k6 and it should run just under 60 Hz. For "exactly" 60 Hz the ideal resistor is 5455 Ohm, but a two-transistor multivibrator is nowhere near accurate enough to bother with that. Of course, we have no idea what your "2.2uF" capacitors really are, so it's kind of pointless to go calculating it anyway.If you didn't know, when the circuit is symmetric (same resistor and capacitor values on both sides), the frequency is ideally0.72/(RC).

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 12:11:37 am
content: they are radioshake brand... i will have to be sure tho

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 12:13:16 am
content: and on whick part of the diagram to put that resistor parts?

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 12:14:41 am
content: Quote from: Nickk2057 on April 04, 2013, 12:11:37 amI'm not saying they're unreliable or counterfeit or anything - even good capacitors often have awful tolerance. -20% +80% is not uncommon for electrolytics.Quote from: Nickk2057 on April 04, 2013, 12:13:16 amHuh? Replace the 4.7k ones.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 12:40:14 am
content: and i will try that in a bit...will see what happens

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 01:48:58 am
content: the caps are nichicon 2.2uf 50v B P.... 85*C 1115 PET

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 02:08:21 am
content: If you're wondering,hereis the datasheet for those caps. Tolerance is 20%, so that allows your nominal 70Hz frequency to be anywhere from 56Hz to 83Hz. Aren't capacitors wonderful?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 02:12:36 am
content: so if i use higher resistors it will get lower in frequency.. so if i use the pots on them instead of the resistors i can adjust them to the level i want... and also find the sweet spot to use too.... plus when i find that sweet spot i will check the resistance on the pot to find the resistor i need

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 02:14:19 am
content: and yes... caps are VERY wonderful XD

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 02:19:17 am
content: Quote from: Nickk2057 on April 04, 2013, 02:12:36 amSure, but remember that the ideal resistor in this circuit is 5.4k. The only standard (E12) values in that neighborhood are 4.7k, 5.6k and 6.8k, which give nominal frequencies of 70Hz, 58Hz and 48Hz respectively. No matter what that pot ends up at, the closest fixed resistor is always going to be 5.6k, unless those capacitors are way the hell out. You can combine resistors to get different values, but come on - the frequency isn't that critical.

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 02:23:34 am
content: Quote from: c4757p on April 04, 2013, 02:08:21 amActually, I'm not so sure that's the datasheet any more - it says they have a PVC sleeve, but the sleeve on yours is clearly stamped PET. (There are also actual PET capacitors, but those are not, they're bipolar aluminum electrolytics - Nichicon never made film caps that look like that.) I can't find any other Nichicon caps that meet those specs, though, so I can't find the real datasheet. Whatever they are, they seem to be a discontinued part, so it's hard to find information on them. Anyway, I can make out a (M) on one of them, and that's the tolerance specifier - 20% - so at least that part was right.I really wish they'd just stamp the full, proper part number on the things. There's obviously room for it.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 02:39:28 am
content: haha... yea i know... you know it be great to talk with you in person... you sound like a great person to talk to as well.... of how smart you are on those things.. it be great to talk with you so we can help share information if you like that is

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 02:41:02 am
content: I'm surprisingly boring in person.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 02:47:42 am
content: now who would of said that? >_> the way you talk on here you sound like a smart person.... anyways.. i will try that out with the 5.6k resistors... just hope it works.. but now i ran out of those IRF chips

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 03:07:55 am
content: now i got to get some more ordered... hope they are cheap.... and i HOPE i don't have to order them from china... takes forever to get here

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 03:09:56 am
content: i probably have to make a reinforcment thing to keep the IRF chips steady on the board thats also on the heatsink

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 03:17:34 am
content: Quote from: Nickk2057 on April 04, 2013, 03:07:55 amOrder from Mouser. IRF3205 is $1.70 each. There are a ton of similar parts - for an exact equivalent, they are all about the same price, but if you're willing to go a bit lower on some of the specs (IRF3205's 110A maximum current is probably a bit excessive, for instance), you can get them cheaper. IPP093N06N3 e.g. is $0.78, but only 50A.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 03:30:49 am
content: does this sound right?http://www.ebay.com/itm/IRF3205-BY-IR-LOT-OF-20-/160605834301?pt=LH_DefaultDomain_0&hash=item2564da8c3d

author: c4757p
author_rank: Super Contributor
timestamp: April 04, 2013, 03:33:18 am
content: It's definitely the right part. It's a suspiciously low price, but then, they do have excellent feedback. I'm not sure - I'd probably take the chance if I were in a good mood.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 03:36:35 am
content: well until i get my next paycheck i will defenantly get it... i am out at the moment till i get the MOSFETs... but that will give me time to work on the oscillator

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 07:57:10 pm
content: hmm... i found an old inverter thats broken and i can salvage the mosfets from thatAWESOME... now to work on that project.... and maybe i might use a resistor between the gates and the oscillator... it might be a good idea i guess

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 04, 2013, 11:54:40 pm
content: ok... i wonder if there is the datasheets for the IRF1404 and the IRF640... and what the amps are going to be

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 12:01:05 am
content: Quote from: Nickk2057 on April 04, 2013, 07:57:10 pmYep. I pretty much dive upon old shit that I can salvage from like that.QuoteSometimes this is a good idea, but it's not good to just sprinkle resistors about because you've heard of it. Why do you want it? You already have a resistor between the gate and Vcc.

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 12:01:58 am
content: Quote from: Nickk2057 on April 04, 2013, 11:54:40 pmSo what kind of Internet connection gives you EEVblog but not Google?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 12:22:41 am
content: LMAO!!! haha.. yea.. i got it now.... the 1404 has up to 75 amps and the 640's has up to 18....which one will i pick? well... you will have to figure that out

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 12:26:41 am
content: Besides that - 1404 has a lower resistance. 640 has a higher voltage rating (significantly). 640 also has half the gate charge, which means you'll be able to switch it faster (not really a concern unless you're doing high frequency stuff). 1404 is rated for higher power, but you're not getting anywhere near the maximum of either one without one hell of a heatsink anyway.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:01:30 am
content: well.. i got it.... and with the 1404 MOSFET's.. and working like a charm too

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:08:41 am
content: and remember the video on page three on here? those are the heatsinks i am using too

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:13:14 am
content: They're big, but they're not 100W heatsinks, by a long shot. 100W is in the range of "large CPU heatsink with fan", and even then only if you're very careful about mounting.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:16:54 am
content: tho this one is at a good rating... the heatsinks and chips do not evr get hot... which is good on this setup.... and with 200W load on it it handled it beautifully

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:21:41 am
content: Remember that the heat comes from the power lost in the MOSFETs, not the power successfully transferred to the other side of the transformer. If you have a 200W load on the transformer, you're probably not losing anywhere near 200W in the FETs. You're losing I2R, where I is the current flowing through the FET and R is its RDS(on)- a minuscule 4 milliohm in this case.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:24:46 am
content: but i tell you one thing... the load on the battery is HUGE on the input.... with no load it takes 6 amps... and with load it will take 15 to 18 amps

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:25:55 am
content: but even with that load the heatsinks are still cool

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:28:24 am
content: Quote from: Nickk2057 on April 05, 2013, 01:24:46 amHoly shit.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:32:43 am
content: yea... i have a amp meter that came from a battery charger and it did read that.. the max amps on the meter is 15 amps

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:39:28 am
content: How hot is the transformer?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:40:39 am
content: not even hot... still cool to the touch... now when the load is hooked up it will get warm but not hot

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:42:17 am
content: With 6A flowing from a 12V battery you've got 72 watts going somewhere. I suggest you figure out where before the mystery heat sink starts to complain loudly.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:43:42 am
content: but thats with no load while the inverter is running...

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:44:33 am
content: Quote from: Nickk2057 on April 05, 2013, 01:43:42 amYep. No load. So where is the 72W going? 72W is a lot.It's almost definitely being dissipated in the transformer winding resistance. The transformer is not going to be pleased.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:49:34 am
content: well... the transformer is a type from a UPS unit.. which has pretty big windings in it... i will show it off when i am ready... it will be soon tho...

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:51:45 am
content: A UPS transformer might be a bit more equipped to handle that than what I suspected, but still,find the 72W. Let it run for a little while and start feeling stuff. 72W doesn't disappear into thin air, and there a lot of places it could be going. Most of those are things that are going to bepissedto have to dissipate 72W.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:52:28 am
content: btw.. here is the stuff (or numbers.. i think) on the transformer...430-2002.11class 130(B)(not sure if its an "I" or an "L")eI-4 9843its a transformer that is in a APC Back-UPS 500 unit

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:53:15 am
content: ok... i will do a test with it with a 100W load on it.... and see if it will heat at those spots... but first i will try it with no load on it...

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 01:54:11 am
content: Are you sure it's a mains transformer and not a flyback (SMPS) transformer? They are meant for much higher frequencies.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 01:55:00 am
content: plus it was mostly on a Arduino chip when it was at 6 amps... maybe with this circuit it will be less... i will see tho

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 02:02:38 am
content: ok.... with no load it uses 2 amps... and with a 100W load it uses 12 amps... which sounds about right

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 02:06:03 am
content: 2A is acceptable for an inverter that's not even designed around its own transformer. 12A/12V in for 100W out is actually surprisingly efficient.

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 02:15:22 am
content: (God, this is weird. With the kind of stuff I usually do, I start worrying if it takes 100mA...)

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 02:22:06 am
content: haha.. well i did a load test.... 100W on it for 15 minutes and it dimmed at 15 minutes around 10%

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 02:25:27 am
content: maybe i will do a load test on a CFL next... a 22W CFL... to see how many amps it will take then on a incedesant... maybe less

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 02:26:06 am
content: That's pretty good. 144W -> 100W is 70% efficiency. A 60 Hz square wave shoved up the backside of a mains transformer is rarely expected to perform very well.Edit: I now suspect your "100W" is based on the rating of an incandescent lamp, not a measurement, so disregard numbers. Still, seems like decent performance.A CFL may not care for the waveform. Definitely try it, though, if you've got a cheap one you don't mind blowing.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 02:32:01 am
content: now you know that will not stop me from trying

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 02:39:47 am
content: Quote from: Nickk2057 on April 05, 2013, 02:32:01 amI'm all for blowing shit up if you can afford to do it, especially if you learn from it. Hell, I blew up a cap yesterday just because it was a new kind I hadn't played around with before and I wanted to know whatit smelled liketo expect if something went wrong with it

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 02:42:49 am
content: Remember that anything with a transformer may be less than grateful for that square wave, especially if it's a cheap transformer.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:12:59 am
content: SHIT!!! the gates hit the ground area of the case and blew one side out... hope it did not harm the other side

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 03:14:55 am
content: Quote from: Nickk2057 on April 05, 2013, 03:12:59 amIt happens, dude. You don't get to work above half an amp or so without the occasional fried silicon.Mmm... fried chips.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:16:52 am
content: damnit man... now your making me hungry XD

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:17:18 am
content: at least i have more lying around XD

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 03:18:47 am
content: Two words: electrical tape. Insulate that shit.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:21:00 am
content: oh i will... but its for test purposes.... but i will make a sturdy case for it to for the setup i have... maybe i will make a case for it to go in too..... tho it has to be plastic since the heatsinks do not get hot on this...

author: c4757p
author_rank: Super Contributor
timestamp: April 05, 2013, 03:23:15 am
content: Even more important for test purposes because you're bumping it around.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:29:32 am
content: true.... lucky me i got extras now anyways XD

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 03:37:09 am
content: but i am not going to work on it tonight... to tired right now anyways

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 02:35:22 pm
content: hmm.... i found something that might proove useful..... i found a neon transformer (electronic type and not magnetic) with a 7555 timer chip setup in it on its own board... only had six pins on the board leading to the main board (which has the transformer leading to the neon sign) hope this works out... but i might need to tweak it to get it to lower frequencies

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 05, 2013, 04:03:46 pm
content: well... the circuit i found is too high in frequency.... its at 120Hz... tho i know of how to lower it but can't find the location right now

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 08, 2013, 12:25:56 pm
content: well... i am back to the arduino circuit and made some modifications to it..... i added two more osscilator pins on there and made some higher output on itwhich was great too... it lit the 200W lights with no problem and still held at 130V AC... without load it held at 180V AC... but with 200W it held at 130V.. but in the input from the battery it went to 30 AMPS.... which i know is overkill for a 7Ah battery.... but it still works good..... maybe i should make a cutout circuit next when the voltage gets too low ....

author: c4757p
author_rank: Super Contributor
timestamp: April 08, 2013, 01:24:31 pm
content: 200W from a 12V battery is 16A. 30A is definitely high, but you aren't going to get it any lower than 16A. And you might be putting out more than 200W, anyway.Like I said before, the extra power has to go somewhere, and 168W will make something hot. You should be able to find where the lost power is going, and start working on it from there.One point - wires. How heavy are they? If I remember correctly from the picture, I probably wouldn't put more than 8A-10A through them. Are they hot?I highly recommend you find yourself a true RMS multimeter for this stuff so you can take usable measurements. That 130V is going to be really far out from an average-responding meter. Your output waveform is nowhere near a sinusoid.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 09, 2013, 04:31:00 am
content: right now i was am using a cheapy on from radio shack... which is rated up to 500V... i am using a 12G house stranded house wire to do the circuit from the transistors to the transformer..... but for the inputs to the transistors i am using some cheap wire (which i keep close eye on) to see how much amps it uses.... (kinda like a fuse) but still... 30 AMPS IS kinda high for the circuit

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 14, 2013, 02:54:43 pm
content: well now... insead of going to big transistors.. i went to a bigger transformer... preferably a big transformer from an old car charger... it is a toroid transformer that was a 200A model from that unit...which was a score for this type of unit.... and trust me.. a picture is worth a thousand words... and also that can is a 12oz can as well... so that you all will understand the size of this beast

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 14, 2013, 02:58:36 pm
content: and also it was the type of transformer i was using that was not working right....but this one i am using works ALOT better than the square ones...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 14, 2013, 03:17:47 pm
content: and also was able to light up a 500W halagen light and also a couple of 100W (with two of them) while the 500W light was still plugged in too... and it only took close to 38 amps.... which was better than with the other transformer....tho i try to do a load test andone of my transistors.oh well... more will come

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 14, 2013, 11:56:04 pm
content: *wonders if anyone has seen this*

author: c4757p
author_rank: Super Contributor
timestamp: April 15, 2013, 12:05:00 am
content: I tend to miss things if they scroll off the "new posts" list.Quote from: Nickk2057 on April 14, 2013, 03:17:47 pmSounds good. The increased performance with a high power transformer makes me suspect I was right that the lost power was in the transformer. You really should try to find a way to measure the true output power. Anyone you can borrow a true RMS multimeter from?QuoteDoing power electronics,especiallywithout "proper" equipment, you're going to break a lot of transistors. Get used to the smell...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 15, 2013, 12:28:33 am
content: you seen the transformer i got from a charger? that one was a 200Amp model... which should do very well.... then i will order the transistors and line them up so i could get more power to the transformer then it being lost in the transistors... and also to use heavy guage wire of course

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 15, 2013, 12:42:58 am
content: Quote from: c4757p on April 15, 2013, 12:05:00 amcurrently i do not know of any friends at the moment that has an RMS meter.... and if i do they will have it at work... and they will not let me in there work environment... oh well.... more braking things i guess XD

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 15, 2013, 12:49:44 am
content: and also i will get a RMS meter soon too... i might have to pick one up at Home Depot i guess

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 15, 2013, 01:59:06 am
content: anyways.... i will be getting some high amp transistors soon... just hope they arrive soon... i am running out here

author: c4757p
author_rank: Super Contributor
timestamp: April 15, 2013, 02:02:21 am
content: Are you breaking them by making mistakes, or does this circuit eat them when it's operating "properly"?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 15, 2013, 02:24:11 am
content: oh it operates correctly... just with the load it goes out... maybe i should put them in line to make it go higher in power to the transformer.. and also a more heavy guage wires to help it

author: c4757p
author_rank: Super Contributor
timestamp: April 15, 2013, 02:49:06 am
content: You can safely parallel them, though if they have a large gate capacitance you may find that the oscillator has to be redesigned a bit to be able to drive all those gates.What I'm concerned about is that if that transformer isn't "perfect", you could be getting some nasty high voltage spikes that are blowing up your transistors. If you have access to the parts, try adding something like this. (If that resistor gets hot - not warm,hot, then you have a problem that a little snubber isn't going to solve. And don't touch it to find out, at least while the circuit is running.) It will eat some of those spikes. The parts are important, though - the resistor can't be too low in power rating, the capacitor has to be able to handle a good bit of voltage, and the diode must be a fast rectifier (no 1N400x or anything).Edit: Er, yeah, I'm aware that the center tap goes to +12, not ground...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 16, 2013, 02:42:38 am
content: its really not the high voltage spikes that was killing them... it was the load itself... meaning i was trying it out on a bench grinder to see if it will start up and blew it out... lucky i had a resistor between the arduino and the gates of the mosfets

author: c4757p
author_rank: Super Contributor
timestamp: April 16, 2013, 02:47:16 am
content: Quote from: Nickk2057 on April 16, 2013, 02:42:38 amQuote from: c4757p on April 15, 2013, 02:02:21 amYeah, I'm pretty sure sticking a bench grinder on a homemade inverter made with a couple FETs and a backwards mains transformer counts as amistake...

author: c4757p
author_rank: Super Contributor
timestamp: April 16, 2013, 02:50:47 am
content: Quote from: Nickk2057 on April 16, 2013, 02:42:38 amThismaybe part of the problem. The resistor will limit the rise time of the gate, and the poor little FET burns a ton of heat in the stage between fully off and fully on. Try putting capacitors (preferably the biggest ceramic or film capacitors you have) in parallel with the resistors, so that the resistor "disappears" while the voltage is transitioning.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 16, 2013, 11:26:26 am
content: well the thing is that i don't want to blow my arduino out... and i am using 680Ohm 1/2W resistors too

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 16, 2013, 11:35:59 am
content: and also i know that each of the PWMs on the arduino is only about 50ma each... and also here is the programming i got too and also added two more poles on there to use two more mosfets..Quote

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 16, 2013, 11:40:01 am
content: Plus there is a guy by the name of Kerry Wong that made this inverter as the same way i did..... and here is his site that made it toohttp://www.kerrywong.com/2010/03/12/a-power-inverter-with-arduino-pulse-source/

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 01:06:15 am
content: i just hope it works out with that..... plus here is another one but with a modified signal too... but now my program has expired to use the oscilloscope on my input on my computer.... will update in a few....Quotend those icons of the sunglasses smilies is the 8 area in there.... Not an emotioncon

author: c4757p
author_rank: Super Contributor
timestamp: April 17, 2013, 01:55:01 am
content: Quote from: hello007 on April 17, 2013, 01:47:40 amModerator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 02:11:12 am
content: thats EXACTLY what i was about to say...Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 02:24:00 am
content: Quote from: c4757p on April 17, 2013, 02:16:53 amexactly... i think we should tell Dave this... if he is around that is since he is always so busy with shitModerator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

author: c4757p
author_rank: Super Contributor
timestamp: April 17, 2013, 02:29:46 am
content: Quote from: Nickk2057 on April 17, 2013, 02:24:00 amYou mean the spamming? "Report to moderator". Already done.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 02:42:12 am
content: Quote from: c4757p on April 17, 2013, 02:29:46 amcheater

author: c4757p
author_rank: Super Contributor
timestamp: April 17, 2013, 02:44:09 am
content: Quote from: Nickk2057 on April 17, 2013, 02:42:12 amI fuckinghateforum spammers. I pounce on that link when I see them. Stupid fuckers.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 02:57:33 am
content: if i was you i would go over there and spam them back XD... THAT will get there attention

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 17, 2013, 12:06:09 pm
content: well.... i think i will order the FET's today... i hope lol

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 18, 2013, 03:58:49 am
content: well.. i will be ordering the MOSFETS soon... tho i have to wait till i get paid first... lol... but will get some soon

author: c4757p
author_rank: Super Contributor
timestamp: April 20, 2013, 08:21:28 pm
content: Quote from: c4757p on April 17, 2013, 01:55:01 amI did...Anyway, just thought I'd mention - I came very close to using something like this circuit as an unregulated, high power stepdownconverter. Speed it up to 30 kHz, slap on a couple snubbers in case I suck at winding transformers, custom wound transformer (two center-tapped windings, 2 x 2 mH and 2 x 125 µH, on a toroid), full wave rectified by an MBR2045CT dual Schottky that I salvaged from a power supply gives 30VDC -> 6-8VDC at 5A. Works fine, but I think I'm going to skip it and do a regulated one instead...

author: andrealmer
author_rank: Newbie
timestamp: April 20, 2013, 10:21:05 pm
content: can someone helP me build a 15kilowatt inverter

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 20, 2013, 11:03:32 pm
content: Quote from: andrealmer on April 20, 2013, 10:21:05 pmdepends on what it is... does it have to be a square wave or a sine wave type?and what circuit you looking for?and be sure to have alot of transistors handy and alot of other stuff too...or else you will have alot ofcrap there

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 20, 2013, 11:04:54 pm
content: Quote from: c4757p on April 20, 2013, 08:21:28 pmhow so you mean as in to be regulated?

author: c4757p
author_rank: Super Contributor
timestamp: April 20, 2013, 11:57:20 pm
content: Quote from: andrealmer on April 20, 2013, 10:21:05 pm15kW?? No. No amount of tinkering will get you 15kW, though it might get you dead. It's going to take a ton of experience, knowledge, and probably dangerous failures before anyone has a successful 15kW inverter. Buy one.Quote from: Nickk2057 on April 20, 2013, 11:04:54 pmWith a controller circuit to drive it so that it gives precisely a certain voltage output, instead of the voltage depending on the input voltage and load conditions. Currently I'm using my old standbyMC34063controller with anunnecessarily big output transistor(all I had).

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 02:06:31 am
content: Quote from: c4757p on April 20, 2013, 11:57:20 pmhmm..... but how do i make it in true sine wave on my inverter instead of being square wave?

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 02:10:31 am
content: With extreme difficulty, expensive equipment, and piles of expensive, custom magnetics.Well OK, maybe notpiles, that depends on the desired output power. Usually what is done is to first convert the voltage to the peak DC voltage with a DC-DC converter, make a PWM'd sine wave out of that, and run it through filters. Not easy to do and not safe to design without proper equipment.

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 02:12:34 am
content: Amodifiedsine wave inverter is much easier, and actually something that I would recommend using a microcontroller for - the timing will be very easy that way.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:08:09 am
content: Quote from: c4757p on April 21, 2013, 02:12:34 ambut with an Arduino.... will it be the same as well?... ok here is the coding for it to work... i think..Quotedarn site keeps making the smily faces on here... and its not toobut will this work? i hope

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:11:42 am
content: Quote from: Nickk2057 on April 21, 2013, 03:08:09 amYou know that chip on the Arduino is a microcontroller, right?QuoteUse [ code ].Code::) :o |OSee - it doesn't do it there.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:14:00 am
content: Code:void modifiedSineWave(float dutyCycle){if (dutyCycle > 0.5) dutyCycle = 0.5;else if (dutyCycle < 0) dutyCycle = 0;cli();TCCR1B = _BV(WGM13) | _BV(CS11) | _BV(CS10) | _BV(ICNC1);//f0 = fclk / (2 * N * Top)long topv = (long) (F_CPU /(60.0 * 2.0 * 64.0));ICR1 = topv;OCR1A = (int) ((float) topv * dutyCycle);OCR1B = (int) ((float) topv * (1 - dutyCycle));DDRB |= _BV(PORTB1) | _BV(PORTB2);TCCR1A = _BV(COM1A1) | _BV(COM1B1);sei();}int pin1 = 7;int pin2 = 8;int pin3 = 9;int pin4 = 10;void setup() {pinMode(pin1, OUTPUT);pinMode(pin2, OUTPUT);pinMode(pin3, OUTPUT);pinMode(pin4, OUTPUT);}void loop(){digitalWrite(pin1, HIGH);digitalWrite(pin2, LOW);digitalWrite(pin3, HIGH);digitalWrite(pin4, LOW);delay(8);digitalWrite(pin1, LOW);digitalWrite(pin2, HIGH);digitalWrite(pin3, LOW);digitalWrite(pin4, HIGH);delay(8);}

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:14:18 am
content: I don't know which pin is which, but that code looks a bit problematic.One easy point - ditchfloat. Do everything with integers and your code will be significantly faster and smaller. The ATmega (as well as every1other microcontroller) has no hardware for floating point arithmetic, so it has to be done in software.1I'm sure there's one bizarre example to prove me wrong.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:18:05 am
content: you mean like this?Code:int pin1 = 7;int pin2 = 8;int pin3 = 9;int pin4 = 10;void setup() {pinMode(pin1, OUTPUT);pinMode(pin2, OUTPUT);pinMode(pin3, OUTPUT);pinMode(pin4, OUTPUT);}void loop(){digitalWrite(pin1, HIGH);digitalWrite(pin2, LOW);digitalWrite(pin3, HIGH);digitalWrite(pin4, LOW);delay(8);digitalWrite(pin1, LOW);digitalWrite(pin2, HIGH);digitalWrite(pin3, LOW);digitalWrite(pin4, HIGH);delay(8);}

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:19:18 am
content: and also i am using the Arduino UNO on my circuit... which has the ATMEGA328 on it

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:20:20 am
content: tho i DO have two versions of it.... one i baught from TigerDirect... and one from radioshack

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:21:07 am
content: Again, I don't know what your pins are, but I'll take a stab at it. That does not look capable of a modified sine. Looks like a plain square to me. Modified sine is a square wave with dead time to more approximate the shape of a sine wave.Looks like this.. After you turn off one FET, pause before turning on the next. Make sure you properly calculate the delay time vs. the on time - do some Googling.And if you had a problem with high voltage spikes when turning off your FETs, it's going to be worse now. Protect the Arduino with gate resistors and prepare to lose FETs. I suggest you take a look at my snubber circuit I gave earlier.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:22:06 am
content: i am using 7, 8, 9, and 10 for the pins... with the high side coming on on 10 and 8 for a moment and then turn off and then turning on low side on it for a moment...... same with the 7 and 9 pins... but the are oppisite

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:25:48 am
content: Quote from: Nickk2057 on April 21, 2013, 03:22:06 amYeah, I see that.What are they connected to? If you're using the same circuit as before, I don't see why there are four. You've only got two gates.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:27:10 am
content: Quote from: c4757p on April 21, 2013, 03:25:48 amyea but i am now using four... but two on each on there

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:31:30 am
content: By the way - If you choose four pins that areon the same port(all PDx, PBx or PCx - yes, you can use the analog pins as digital pins as well, they leave that out a lot in the Arduino stuff, but the analog inputs are just peripheral functions attached to normal pins), you can set them simultaneously in a single line of code. Read throughthis AVR GPIO tutorial. Might help with timing. It's also much faster than a call to digitalWrite, so if you need to speed up your code a bit, try that.Quote from: Nickk2057 on April 21, 2013, 03:27:10 amYou are putting multiple FETs in parallel? You can just parallel the gates as well and share a pin.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:35:48 am
content: yea but its more easier to me for that... meaning that with those extra pins (as well as extra resistors on there) it works better... meaning that the voltage and ma on the pins will be the same.....and be seperated apart...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 01:59:08 pm
content: plus from what i remember is that each of the pins is 50ma....

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 02:08:05 pm
content: The gates should take no current except in the transitions. The transitions will exceed that, but only briefly, and at that frequency I wouldn't worry about it.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 02:48:32 pm
content: and from what i remember is that of a delay of 8 on there it gives close to 60Hz..... if not closer that is...... and when i had it at a delay of 7 it gave close to 70Hz...which did not help at all with the circuit i am using

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 02:55:10 pm
content: Try DelayMicroseconds for closer timing. You'll need it for modified sine.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 02:58:58 pm
content: Quote from: c4757p on April 21, 2013, 02:55:10 pmand how do i do that?... you can copy mine and make modifications to it if you like and post it back....

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 03:28:06 pm
content: if you want you can PM me what you did if you like....

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 03:31:47 pm
content: What I did? You mean squinted at your posts groggily through the steam rising from my morning coffee? I don't have any code...

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 04:09:25 pm
content: are you familiar with magic sinewaves?http://www.tinaja.com/magsn01.shtmlIf I were to try and build an inverter I would use magic sinewaves then a IGBT driver and IGBT's

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 04:16:42 pm
content: WTF is a "magic sine wave"? Is that BS-speak for PWM, or am I missing something?

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 04:20:11 pm
content: pulse sequences that remove the harmonics associated with pwm switching

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 04:29:14 pm
content: So selective harmonic elimination?

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 04:38:43 pm
content: http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=54257&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel1%2F28%2F1948%2F00054257.pdf%3Farnumber%3D54257Selective harmonic elimination should be easy, I would imagine Don Lancaster has already covered most of it pretty well.

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 04:42:51 pm
content: It does look like he's covered the implementation fairly well. Unfortunately, he's also done a good job of making his web site look, at least at first glance, like a big old tome of woo-woo and bullshit. Might help if he'd drop the word "magic", stop acting like it's new stuff and just admit it's SHE...

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 04:53:45 pm
content: now why would you judge the engineer by his web site?http://en.wikipedia.org/wiki/Don_LancasterYou're welcome to contact him if you'd like and tell him about it,,,,,,,I'm sure you wouldn't be the first

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 09:23:01 pm
content: seriously... that site looks like a child has built it.... do us a favor.... esp. me.... GO AWAY!!! that is not what i was looking for... if i need something i would buy it myself.... and i ONLY would buy it off ebay..... have a nice day... consider yourself %-B out

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 09:23:53 pm
content: and sorry for to be rude and all... but i dont want stuff like that that is not what i want in my circuit....

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 09:42:08 pm
content: anyways..... i ordered the parts.... so now i have to play the waiting game... hehe... hope everything turns out goodwish me luck

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:01:36 pm
content: i ordered different types as well to see how good they withstand the load i put on it

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 10:24:18 pm
content: Quote from: Nickk2057 on April 21, 2013, 09:23:01 pmIt was just a suggestion, chill out. Not a bad suggestion either.

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 10:26:03 pm
content: Quote from: Nickk2057 on April 21, 2013, 10:01:36 pmIf you would take the time to read the more theoretical information you have been given you would know how to calculate this and save your money. You still haven't bothered with a snubber, have you?

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:30:11 pm
content: Quote from: c4757p on April 21, 2013, 10:24:18 pmunderstandable... i was an admin before on another site but that was years ago...... like 5 years ago... so i seden stuff like that all the time... tho i guess i got carried away... my apologies

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:34:08 pm
content: Quote from: c4757p on April 21, 2013, 10:26:03 pmand yes i know about the snubber... but i have no parts to make it at the moment.... unless i can use other types of parts thats equivilent

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:46:04 pm
content: Quote from: Nickk2057 on April 21, 2013, 09:23:01 pmI'm not selling you anything, and you aren't insulting me you're insulting one of the guys that wrote the book on this stuff.I think an apology is in order...... and read stuff before you spout off

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:55:34 pm
content: and i did as well...anyways... what about a buffer on it... you think that will work? in order to even out the square to a sine type

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:58:19 pm
content: There's several ways to do it, and you're not the first one.I already showed you the best way to do it, and you insulted me.GOOD LUCK......you're gonna need it.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 10:58:59 pm
content: Quote from: 4to20Milliamps on April 21, 2013, 04:09:25 pmand by the way.... i know i got carried away.... but how on earth does that work? O.oi rarely ever heard of such a thing

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 11:05:58 pm
content: Quote from: 4to20Milliamps on April 21, 2013, 10:58:19 pm-sighs- my apologies sir.... i am sorry for what i said.... but when i looked at that site i got confused on there... made me think its something else... again.. my apologies -as i bow-man... now i feel like a complete durp

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 11:08:48 pm
content: Quote from: Nickk2057 on April 21, 2013, 11:05:58 pmWell, I'll give you this much, you apologized. It's been a long time since I sawthaton the Internet...Quote from: Nickk2057 on April 21, 2013, 10:58:59 pmMath! The magic of math. Lots and lots of information on it - google "selective harmonic elimination". Not sure I can explain it without sounding like an idiot, so I won't.

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 11:09:47 pm
content: anyways... i will take a break for a bit... going to be off here for a week til i get the parts.... if anyone want to let me know in the meantime... just PM me... thank you... and i am terribly sorry for what i have said

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 11:11:25 pm
content: Quote from: c4757p on April 21, 2013, 11:08:48 pm

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 11:12:06 pm
content: darn it... i still need to practice on here for how to seperate stuff on here

author: c4757p
author_rank: Super Contributor
timestamp: April 21, 2013, 11:13:41 pm
content: Quote from: Nickk2057 on April 21, 2013, 11:12:06 pmHuh? If it's between  and  it's included!And try "Preview"...

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 21, 2013, 11:15:22 pm
content: i will next time.... anyways.. i got to get off for now... going to play the waiting game... for the parts to come that is.. lol

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 22, 2013, 11:50:09 pm
content: anyways... i also ordered 5 CD4047 chips.... i will try those out next as well with this

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 26, 2013, 07:19:50 am
content: well... i tried the circuit with the 4047 chip... tho it looked promising.. but it DOES have a flaw.... meaning that when it is running it would jump on the output... kinda like a spike on the setup... which is strange because everything is soldered down for it not to move... oh... and also i recieved the MOSFETS finnaly

author: Nickk2057
author_rank: Regular Contributor
timestamp: May 02, 2013, 01:07:32 am
content: well.... i think i will stick with the Arduino Circuit... it is more usful then the other circuits i was using.... everytime i use the CD4047 chips on them it has issues... like it keeps going out of filter... or it has hiccups and such... oh well... the Arduino seems like a total winner i guess