So you are saying that the internet is wrong as are all of the people here who use the Darlington Transistor circuit for switching? It's the most popular method and searching the internet, here and any other forums which deal with switching from microprocessors all cover it and no other methods (or other methods are hidden very well).

Please provide clear descriptions with accurate part names, numbers and suppliers where possible. Also diagrams, schematics and photos. Using a spell checker and checking grammar in a tutorial wouldn't be a bad idea either. We know you dislike writing and are not in school but believe it or not, school isn't the only place you should use correct grammar and check your spelling. It makes it increasingly difficult to understand posts which are written poorly.

For an example of a well written and presented, easy to follow tutorial please refer to either the LiPo Balance Port Monitor or TIP Darlington Transistor Switching Circuit Tutorials.

Bear in mind people will be searching for this and they will not have the knowledge you have. They may not know what RDS is, what a MOSFET is, what n-channel means...

Having read that, I come out of it gaining very little other than the point that you are saying transistors are "old school" and shouldn't be used. Expand on it, give as much information as possible, include schematics, diagrams, part numbers etc.

DIDNT say the internet is wrong is old way of doing it,IT STILLS WORKS

Just not as good as a mosfet,a mostfet is improved design over a darlington transistor

this is just a start on it will explain what RDS is and more ,and there are way too many part # on mosfets

Mosfets are better because of low wattage something like using a 25watt darlington and 75 watt mosfet,no HEATSINK is needed on the mosfet at full power,switching is much faster

MOSFET is made up of 2 darlingtons

LOOK at the new designs on H-BRIDGES they use mosfets instead of darlingtons

Like i said soon as i get a chance will put up a schematic,hook up is still the same

A common TIP120 has a very large voltage drop across the collector to emitter witch you get higher heat dissipation

On a mosfet since its ultra low ohms NO large voltage drop and no heat

RICH ASK any electronic engineer witch is better and he will say the same

there are alot of internet info on transistors using as a switch,but look at the date it was done

HERE is a link on mosfets

all about mosfets

here is more info on schematics and how to use a mosfet

mosfet circuits

MOSFET is BETTER UPGRADE for darlington transistors

P-channel mosfet is for npn darlington and P-CHANNEL mosfet is for a PNP darlington

I just put the RDS info out there because some do know what it meens

But only important stuff is mostly heat dissipation,buy using a mosfet instead of a darlington you have less heat and low current drive and none is wasted like in a darlington

I design all my circuits to use very low current ,so a bigger battery is not needed or recharge alot or short robot run time

SAME on using LDO no power is wasted,look at the EZB,DJ changed from using regulator to LDO for same reason low drop out voltage

So it same with mosfets verses darlingtons low drop out voltage ,less heat and longer run time

RICH mostly your tutorials are only how to make the circuit and code to go with it

Doesnt saw much about the parts used and why,where in mine i put alot more info ,i am use to doing it since i am super good at designing circuits instead of just making them

i do a lot of reading on it,plus look at data sheets alot

will put a schematic up very soon,but first i wanted to put info up on a better switching design first

You must have missed the part numbers and links then... They are all on there where required. As are any relevant technical details that may be required and where and why any optional/additional components needed (see the additional diode section on the TIP tutorial).

My tutorials do not need to explain how something works. Details on all circuits can be found searching further on these forums and Google. My tutorials are detailed instructions on how to build the circuits and make a nice neat circuit which can be removed and reused should it be necessary. Should it be necessary for anyone to need to know the technical information they will ask and be answered.

I guess I was wrong to offer pointers on how to write a tutorial that's easy to read, you may use the advise given or disregard it. If you have a question on my tutorials please post in the correct topic.

I have nothing further to add to this therefore I shall not engage in conversation again other than to correct or amend any inaccuracies or to answer someone else should they have a question.

WHEN I PUT schematic it will have the part #'s ,it doesnt make sense to have part # without a circuit to go with it

YOUR are not wrong on pointers given,just its not same as mine tutorial yours mostly just circuit ,code and parts and photo on how it was put together

On mine i put the reasons why its better and more info about it,some info might be hard for most guys here and some is.

JUST mosfets are just a better design then darlingtons,both work

ON USING A DIODE look at the link mosfets circuits i have up

diode on the darlington it can be used in bost places just like on a mosfets

but it DOESNT STOP INDUCTIVE KICKBACK only protects the darlington

Thanks Rich for the nice write-up, switching transistors are well known, simple and very useful for hobby robot enthusiasts. Still we need very clear examples like yours so we can collaborate and continue building. Please keep up the technical writes, they are very valuable and they are what make this site fun and useful.

yes ,but they are the old design now,all new designs use mosfets ,easy way to check it look at H-BRIDGES that did use switching transistors before and now the use mosfets,same with dc-dc converters and everything else

mosfets are a better upgrade then switching transistors,too bad not many or none ELECTRONIC ENGINEERS with a degree are on this robot forum but me

Because they would agree with me

There are so many many links on using mosfets to switch loads on and off just like there are so many links for darlington switching circuits use for switching on loads on the internet

Fred, re-read your tutorial posts before sending. When teaching, clarity is key.

See post #4. "P-channel mosfet is a npn darlington and P-CHANNEL mosfet is a PNP darlington"

I would have taken a different approach and explained in the beginning the differences in MOSFET and TIP120 switching. Then explain the virtue of MOSFETs. That way other people will start using them because they are better and not because Fred the "ENGINEER" says it's "old school" and I shouldn't use them.

As another tip, see post #1: "I design alot of circuils been electronic engineer". If you write as a professional then you will be believed as a professional. As I've said last year, you have experience to offer the forum. Please keep trying to improve your writing skills so that we may learn from you as another of many available resources.

i only do it fast and dont recheck it,doesnt meen i am not professional I know i am not a writera i am designer thats why i have a secretary to fix my mostakes at home i dont have one ,

but i guess i need to double check and re-edit some,but still my points are the same when i use the term old school it only meens that there is a better design that works better will fix the posts ,but i do see others spell ords wrong and nobody complains about them only me AND mostly RICH

TROY ok i missed one word on this See post #4. "P-channel mosfet is a npn darlington and P-CHANNEL mosfet is a PNP darlington

should be" P-channel mosfet is for npn darlington and P-CHANNEL mosfet is for a PNP darlington " missed the word FOR OR could used "used for "

Problem is that this is only forum i ever write for,even work didnt need it that much,only data,schematic and my circuit and mostly they never need that only i design and make the circuit and let them re-test it and if ok it passed but mostly it a full tester

SO In over 20 years this is my first post i did any writing for . so thats another main reason my posts are bad grammar or spelling ,been well over 20 years ,last time was in college

mosfets are made using darlington to have faster switching and lover heat dissipation without the need of a heatsink ,plus no wasted power

BUT guess in robots nobody cares about power loss and want to use to bigger battery

In my designs i look at every circuit to use less current as i can,so i dont have short run times or problems with a bigger battery

I use low current sensors ,LDO like DJ uses now ,before he used regular regulator LDO is another great example of mosfet design it uses them in the circuit for low RDS on for low drop out voltage,

SAME when i design my own servo's it uses a lot less current then ones you buy

also using lot of protection in my designs ,like DAVE said it cost more and takes up more space and said that is never fails,thats not a great idea saying it never fails

old saying goes "better to be save then sorry latter".most circuits that dont use protection ,wont go bad right away or few months ,but it may go bad latter

Thats why big companies add them in thier designs battery or ac testers

I hope soon a engineer with a degree on this forum will say the same thing about using mosfets over darlington ,thats mostly what this post it about,

The top heading word tutorial is spelled wrong ,but i could not re-edit after i saw it

So you don't see the problem with P-channel vs P-channel you posted? As it's written, NPN is the same as PNP because you listed them as having the same type channel.

I'm going to take an educated guess and say that none of us have a secretary writing our posts and we manage.

Let me say it again in a different way. If you write as the average person can, your credibility as an engineer gets better. People will wonder how you earned a college degree without writing term papers, etc. Let me get away from that title. It's not necessary to be an engineer to post on the forum.

What kind of degree is needed to satisfy your request? Is it necessary that we say the school it was from or can we just look online and find credible sources about MOSFETs?

For the record, I agree that in some applications that MOSFETs are the way to go.

LIKE I SAID COLLEGE I DID A LOT OF WRITING AND TERM PAPERS AND WAS NO PROBLEM and about 25 years ago and after 25 years you forget grammar because at least with me i never needed after college i didnt need grammar until this forum

I guess you didnt understand the posting i did on P-CHANNEL with pnp darlington

THE P-CHANNEL mosfet iin place of the pnp darlington and same with n-channel ,

and i dont have a secretary doing my posts too

people love to find mistakes in others ,witch i dont mind that much and i dont mind beening corrected also i did it the same on ther posts i see missed spelled words that person didnt use spell check also

I guess it better to show proof from the internet then write about it and others say i am wrong about it,when most dont have a degree to prove me wrong

so next posts i will put up links and do less writing

TROY why do you think that darlingtons are better MY POINTS EASY CAN BE PROVEN

Take a mosfet and turn it on and put a load on it and see if it gets hot and do the same with a darlington ,,you will see more heat on the darlington,both have to be the same wattage also try a power loss test to see about the wasted voltage.

SUPER EASY TEST under $5 to prove a person wrong also on the link on the mostfet thats close to darlington TIP120 you dont need a diode.check the data sheet same spot RICH has his diode across so you same money and space with a mosfet and its same price as TIP120 $.88

TROY if you find mistake i dont mind you point them out to me,or RICH ,i can easy re-edit my posts

i will do the same for others ,seen many posts with bad spelling.not much or any in grammar

USING bad grammar doesnt make a person less smart or doesnt know what he is talking about

J ust might make it had to read,dont really to capital letters or add periods we are beening graded for it in school or college

TROY you are lucky i like you and DAVE do give fair good advice,dont know how much you know about electronic design

And RICH you are still ok too

but from now on will find links to same stuff i talk about and post the words from it

so no more bad GRAMMAR problems will get put up,pretty easy to find my proof on the internet ,may not use the same words ,but still have the same point come across

Last one is a circuit like RICH is using with correct place to put the diode.

Doesnt meen that where RICH has the diode wont work it will protect only the transistor.

But like all links say is called a flyback diode fior inductive kickbacks ,with diode across the coil no kickbacks,but on the transistor still will have it,it doesnt block the inductive kickback.

Pretty easy to see why.

TROY see any bad grammar on this post.

Don't tempt people to pull you up on your bad grammar by a question that doesn't end with a question mark...

Removed sarcastic correction - I do not wish to rock the boat further.

As Troy said, when posting a tutorial ensure it is clear, easy to read and as free from spelling mistakes as possible. Spelling tutorial incorrectly in the title isn't a good sign of what's to follow... And writing fast, or not liking to write is not an excuse, if that is the case then don't do it. If you had flagged up this method in my switching transistor tutorial I would have looked in to it and given the option for using Darlington transistors or Mosfets, the circuit is practically the same anyway.

It is not an attack on you so please refrain from getting defensive or taking offence. You must understand that a lot of people who read these posts may not have the same knowledge as you and they may not be able to understand what you are posting. Minor spelling mistakes and punctuation errors are neither here nor there, they can be overlooked but if it just doesn't make sense or isn't clear enough then people will struggle.

I'm sorry you missed the point about perception. You aren't being graded. That isn't the case. People are trying to understand you. It's pretty important when writing about technical things to a varying audience of technical experience. True or false? We do want to be helpful to the entire EZB community don't we? It's not about misspelling "meens" or using "witch" instead of which. Those thing are easily overlooked. Most times it's the missing word or part of a sentence that is confusing even before getting to a technical part. For the record, English was my worst subject in high school. I also haven't trained formally in component level electronics in 23 years but I do a bit of signal flow troubleshooting for all of that time. I will leave it at that. I'm trying to be helpful to you Fred. It's clear that you are taking offense even when you say you aren't so I will stop helping. Hopefully someone else will explain it better as I seem to have clearly failed.

TROY i understand what you are trying to do,but this post is not about bad grammar ,same with RICH trying to help me .

We need to stick to what this post it about adding the the comments even if you are trying to help makes me look bad

Comments like that should be off line or in a email ,then it doesnt make a person look bad

WHAT happen is you are in my place ,and you was the engineer and had bad grammar and you havent dint any writing in a long time and i said the comments to you

SOME say that the mosfet is not better then darlington how do the know that.

DATASHEETS and links can always show the proof,on using darlingtons they are used alot and have about the same info on the internet at mosfets and well known.

BUT doesnt make them better

IN about 2weeks when i get back can make some tests to show how its a better device but really is not needed,all you need is basic math and resistance of the dievices under test

Almost if not everyone never really use mosfets that much,i been using them for a very long time and used darlington transistors too

great example is H-BRIDGE before they used darlington transistors to turn on and off a motor load and now every design now uses a mosfet ,why ?

BACK to the tutorial what this is mainly about

I ordered 25 mosfets at less then $1 each and with 1 (1k)resistor whole circuit can be made for about $1

MOSFET has a built-in diode ,and alot smaller with higher wattage rating then TIP120 darlington.

So you save space,higher current (wattage ) and lower cost

And when i get back in 9 days will make a few boards and post them.

Hooking it up is the same as using a TIP120 DARLINGTON TRANSISTOR

As already explained and covered in the updated information (from a couple of days ago) on the TIP120/122 tutorial under additional information in post #1 of page 1.

This not about USING TIP120 its about using a MOSFET JUST another idea thats a little cheaper and handles a bigger load

Second i see you took credit for the mosfet by adding to your tutorial.

Again, perhaps a little clearer so you don't miss it this time. Using a Mosfet is included in the TIP120/TIP122 Tutorial

Information about the mosfet and where it fits in to the circuit has been added to the original post under additional information.

YES i saw that it was my idea to use a mosfet ,when you made your it was first using TIP120 and now you took credit for my idea.

I'll pay you 90% royalties then... Idiot...

I've taken no credit from anyone. I have not claimed the TIP circuit is mine nor have I claimed using mosfets are my idea. I offer the information in a clear and easy format for anyone regardless of experience and knowledge to use.

This is a community which relies on clear information relayed by other community members. It is not a competition, a rivalry or a case of who has the best ideas, it is about providing the community with clear and easy to understand information, please try to understand that.

Not important to pay me and dont need it Just making a point THAT your tutorial is about TIP120/TIP122 TUTORIAL not about using a mosfet

my idea are not to compete with anyone its to HELP OTHERS ONLY

Just like your idea's are to help others too.

Re-edit it for a missed spelled word

Again, the tutorial I wrote now covers using a MOSFET. This "tutorial" is pretty redundant.

I've nothing more to say on this.

P.s. you are aware 90% of nothing is nothing right?

You should make a new one then tip120 and mosfet tutorial. I see you made to change of using a mosfet after you saw my tutorial. ,witch is not a problem

BACK to my design using a mosfet witch this POST IS ABOUT ,its not about using TIP120 THERE IS A LINK FOR THAT

tip120/tip122 tutorial MY idea i have uses a smaller mosfet package at less then $1 each ,handles higher wattage then TIP120 with T-220 CASE ,mine has 17 amps at 45 watts I-PAk size

Also RICH may be i should add info about the TIP120 in my post and make the circuit. IT not good idea since it will take away of what my post is mainly about ,

But here is a photo of a TO-220-3 TIP120 photo looks like to compare to the mosfet one,also doesnt give the size ,but i think it much wilder the TO-220-3 ,but the height is much lower as you can see.

EDIT 3-20-2013

TO-220-3 is .415 by .600 inches and I-PAK is .255 by .250 so its about half the size

IF you think i am wrong check the datasheets.

Fred, you are correct it should be offline. Give me your email and I will assist you in private.

Rich, chill. It's ok to have more than one avenue to information. He has a point that his is about switching in general. That doesn't mean you both can't include more than what your title is about.

Both, this is a simple circuit in which no one has claim to it being their idea. That is unless someone can produce a patent# he was awarded. There's no prize to be had....no title to be credited. With that being said, it's polite to mention where your idea came from or who was your inspiration but improper to insist on it.

Thank you both for digging up all the data and references. I'm sure people are more informed because of it. Free information...it's a good thing.

@Troy, I totally agree, don't get me wrong. I was pointing out that the circuit is already covered with clear to follow instructions. Any technical information that can be provided to aid someone in choosing the right thing for their specific situation is another matter but detailing building a circuit the same as one that's already detailed seems redundant to me, that was my point.

@Fred, I've not said you are wrong, please stop thinking that whatever I say is saying you are wrong. I don't dispute anything you have said in this subject and there is no need to become defensive. Yes the Mosfet was added after you flagged it up, there is a post from me explaining that if you flag something up I'll update the post (I can't remember which topic, you seem to cross over and spread over all topics), no intention of steeling your spotlight is intended as explained, it's all for clear and easy to follow instructions.

RICH where did i say you are wrong. So far what i see in every post i did on anything i am mostly wrong and never right on anything,and i went to school to learn and passed and got a degree.

I think i was right on only one post.yet like mosfets is my main field i work with and others

ALSO TROY if you noticed like on his project hearoid i only said good things about his project and gave him some real good ideas.

BUT not once has he said any of my project where good or any ideas.

TROY leave me your address,since i may get others email me when i dont want them too

Read slower, understand, post if you need to. You obviously haven't read it correctly.

And if by others you don't want to have your email address you mean me don't worry, I have your Jamericanfreddy email address...

As for mosfets, the IRLZ34 is a really good choice. It's logic level so it'll work with the EZ-B and other microcontrollers, it can drive 30A at 55V and it's nice and fast. I'm currently using it to PWM dim a 3W RGB LED.

I like Mosfets. Their tough little suckers. US pinball manufacturers started using them in some of their circuits back in the 1980's because they were more reliable.However the humble switching transistor never went out of style. The only drawback I know of with them is that there is no way to test them to see if one is shorted out or open.

Ferd, what institutions did you attend and where did you earn your degree? Hope not to offend with this personal question.

first who is FERD second is U OF M COLLEGE,was going to get my masters at FIU but at that time it was too hard with work and then going to school.

I know my grammar is bad only because i havent used it in so many many years or needed it,but as you can see its much much better.

Mosfets are made from darlington transistors and its a better upgrade,one main reason it was made.

Where on darlington transistors it has very high resistance and mosfets super low ohms ,but easy to use and some are logic level ,with meeds direct connection to cpu or logic

BEST example is H-BRIDGE is you look at the long time ago when they came out they use transistors to make them ,and now they use mosfets ,so ask your self the question why did they change to mosfets ?

NEIK yes IRLZ44 is a very good choice its called a logic fet,i have some of those.

One i am using is in a smaller package 17 amps high wattage and lower cost $.77 plus no diode is needed its has one built-in

Main reason i picked this one is small size and high current without a need for a heatsink,but mostly using mosfets or transistors a heatsink is not needed on some designs.

PLUS like most guys here everyone wants to save money ,so very low cost over a transistor.

Nothing wrong with using a Transistor as a switching device.

Here is a little background on when transistors and mosfets first came out

TRANSISTORS came out in 1948 and about 10 years latter mosfets came out in 1959 s a improved replacement.

Info is on the WIKI site on both of them.

Also DAVE can i ask the same question to you about what school or college you went to ? And RICH if he cares to answer it.

Woops, sorry. Didn't mean to misspell your name. should have been Fred and not ferd.

I was at Texas A&M for only a short while. No degree. I learned most of what I know in the school of hard knocks.

I know you didnt misspell my name,seems i am not the only one that doesnt use spell check

Some of my friends playing with me call me FERD,EVEN MY GIRLFRIEND TOO.

IT seems on this forum people without a degree knows more then ones with a degree,that not right.

IT like saying the student knows more then the teacher.

I am on many many electronic forums this is only one thats like that.

DAVE i did enjoy college alot,but i love my work alot better,free travel ,my own room with a pretty secretary and pay was more then i ever need.

But now working at home as a freelance engineer for the company ,is much better

PLUS i get to check all the parts and most of the test equipment when i retire early in under 2 weeks

Only thing bad is going to miss my pretty secretary,but my girlfriend will be there and soon getting MARRIED to her.

Fred, I've often known more than the teacher - that was my main problem in school, why I didn't like it, it wasn't challenging at all and very boring... I did poorly in school and had to bluff my way on to the courses I took afterwards. Some qualifications I hold have prerequisites that I don't actually have which shouldn't happen. When I took my AutoCAD course I knew more than the teacher and ended up teaching him a thing or two... Similar when I was an apprentice electrician. It doesn't really say much about the teachers!.. But then I do have a natural ability to pick things up almost instantly (proven by only using ARC for less than 3 months and being on these forums for 4 months).

My training has been at various places. Mainly at the technical college in my county, which no longer exists. Some has been online, some has been in the class room, some has been home study, some has been self taught by just doing.

YEP i thought that,student know more then the teacher,how come you dont have a degree.

teacher in college is professor and has the highest degree.

i also pass the course and i am licensed electrician

I GUESS you think teachers are not needed

ON teachers they get there degree from a college professor. So teachers dont know that much.

in high school i had a very high IQ most then most in my class,and was a sub teacher for a few hors on science ,where every year i has straight A'S

I don't have a degree for a few reasons;

1. Cost. There was no way I could have possibly been able to afford to go to a good university even if I had wanted to. It would leave £75,000 of debt for a 4 year course without living expenses. We did not have that kind of money but also couldn't get any grants or student loans due to both parents working and a household income above the threshold.
2. Lack of pre-requisites, I don't have good enough grades in all of the required subjects (English mainly, despite my proper use of the English language) due to not being interested at all through high school - no challenge, no interest. I did poorly in school despite having the highest IQ of anyone to have ever attended the school, as far as I know it still stands today, although irrelevant since it is not an accurate enough test to measure intelligence. From memory I believe it was 172 at 15, I'll have to dig out the results sometime, I know it was just in the top percentile which is 1/1000000.
3. A degree is worth as much as the piece of paper it's written on. I've not needed a degree to get where I have got today. My work and reputation speak louder than anything. I've not needed any qualifications to build the client base I currently have.

And for the record I don't think I got a single A in school, grades mean nothing.

so thats why you dont know very much,except for coding and software

Wow... Going down the route of attempting to insult and belittle now are you? Thought you said you were always nice and never nasty to anyone? That post says otherwise with a blatant insult like that which is not only untrue but also uncalled for especially considering I'm attempting to be civil with you. Or will that post get edited shortly when you realise I wont be dragged down it? (edited it is then)

P.S. It's spelled "wonder" and don't has an apostrophe in it.

RICH college doesnt cost much ,may be a better poaying job would help. for it was a easy cost and i really enjoy college

MY next answer to this post unless somebody has a good thing to say and not finding a faults with another person .like one missed spelled word.

With photos of my design and circuit in about 8 days from now .

YOU said you dindt get A'S i school in reading and writing i didnt too.mostly C+ or B once in while mostly because i didnt like to read ,but after college i really like reading stuff alot on electronics.

I have big library full of electronic books that i read alot

to much garbage on this post and keeps others from find good proven info on my design.

So after 8 days we re-post the info all over again.most likely copy and paste

ALSO very rare do you see others say anything wrong with my designs or make any comments and most are really good in electronics

Read this slowly... When have I said there is anything wrong with any of your designs? And it's your garbage, I tried making conversation and you turn around with an insult (that's been edited now but we both know what you wrote). I ignored you for a while so you didn't frustrate me, I tried being civil but still you continue to bang on with triple posts of useless crap. I refuse to fill the forums with this crap.

I didnt say the garbage came from you ,its all the info that has nothing to do with the post

yes i did re-edit it to be a little better like you told me to

NOTES D1 is only needed for inductive loads like relays and motors Also most any mosfet will do,only i pick this one because it matches TIP120 darlington and a smaller size LINKS and prices

IRFU110 MOSFET $.88 EACH

IN4004 DIODE $.029 EACH

Will make the board when i get back