RC India

Good morning Friends..when i was started to make RC crafts in all means,the speed controller was my ever nightmare.at begining i was using a simple on and go type controls like any cheaper RC cars.but as i progress i started to use my knowledge in electronics to my applications. as a result i made several types of speed controllers still working nicely after years of gruelling service.i am posting this article here because i know many of my friends are need it..when i asked for a speed controller here at Chennai Town,they gave me a price list.and was
shocking while looking in to it.for a single channel speed controller, the price was Rs 4500/00-!!!!  with that money,i can buy a good quality DVD player, or a 20 inch CTV, or a Dual Core Mother board, or a good digital camera.!!!!...

   and if you ask for a two channeled one its 6000/00-almost...and for a motor differential one..9000/00..ohhhh...and can only work as the home made one..so i decided to make my controllers even better than before.now all it works nicely and flawlessly...
   
   to make a good quality solid state speed controller, you need heavy and expensive equipents and ample of money and ultimately a good knowledge in electronics..?  sure..? rethink..NOOOO....you need nothing, but some patience and mechanical mind with some time to spend.

here we are...you need only some handy things from around you...and sure a soldering iron in to 25 watt, a three pinned one to avoid leakage.soldering flux and good solder wire.you need not even a multi meter  !!!!!!!...   
   first of all find a sliding or rotating type volume controller can found at scrapyards or can buy at any electronics shop within

alf a dollar.if you are taking it from an old source the value of the potentio meter is not an issue...any value will work.so if you are buying one try to get it within 50 Kilo Ohms, and Linear type one.if you are using a conventional servo, the sliding one wll be the best bet.
and if you are using a toy RC a rotating type will be best.but you can use either for either use.

   i took this old tape recorder main board to take needed parts to me.here you can see some good sliding controller looking at me..
"hey Rachu we are waiting for you"...hi..hi..

desolder it from base carefully...now its free...
now we got the main part of the controller..the variable resistor, or a potentio meter...its value here is 50 Kilo Ohms.

now we need a power transistor to drive our motors, lights, or anything you need...here some inexpesive but ever classic silicon, and Germanium transistors, from, MJE 3055 up to 2 Amps..TIP 3055 up to 5 Amps..and 2N 3055 for 30 Amps or more as you can bridge it.
the TIP 3055 also can be used instead of 2N 3055 to save space. you can place these or this transistor anywere you like so you can save space and weight.and a heatsink is a must for higher amps.no fan is needed to cool it as most of these PTs can withstand temperature up to 180 degree of heat..

and here you have a second alternate for PT, is Darlington pairs..means two transistors in one..with this you can achieve a good soft start and stop..good for light crafts..

now its fixed and wired..you can see how simple it is..here i have wired it in a rough way..but you can simply place and wire neatly as you can...so everything will be tidy..a 470 ohms resistor is used with controller to protect the transistors from stalling current,when a stalling of motor occurs.as the TIP 3055 is employs a thermal protection inside you need not worry about burning it out while a short circuit happens...no worry...reverse polarity is not a matter here as we use a diode in series with this circuits.there is nothing to go wrong  with it so you need not worry about splashes of water..if this goes to water nothing happen..wait untill dry..and then works again..no money loss...

now i glued a piece of aluminium sheet on to the arm of servo, with many holes on it to adjust the stroke length of the actuating arm,as we need...

Make a hole at the tip of the controller..carefully..dont tear it....

ow yo can simply fix it as shown,all with foam boards,because it can absorb excess throw and shock,made out of servo if you switched of the transmitter first...no steel or plastic structure is needed...i used a brass rod here..its only for a guidance..you can simply do on
 your way with your own ideas...

now our controller is ready for the ordeal..but still lack one thing..a reverse switch..here i used a DPDT switch, can foud any land phones, or can buy at any electronics shops..much cheaper..here it costs only a 5 Rupees...

now wire a second line in reverse with wires from transitor out..and place the switch at the neutral position of the arm, after checking the play of servo arm..place the main throttle stick at this position as neutral...mark it or keep it in mind..

Now its ready...with a motor..this motor was actualy a toy motor, for 3 volts..and i reworked on it for 9 volts and 700 ma..and in to 6000 Rpm..for my KAAKKA..means the Raven,from strw board and bamboo sticks..a flying model of my own..have to compleate it..

And here i am adding some useful proven circuits , all tested and with me now,is first one is simple but effective inexpensive but works almost same as professional one.its much simpler , and using the ever basic principle of transistor biasing.here the base voltage is controlled via a variable resistor, our volume controler in this case,so the out put will remain as constant untill we alters the base voltage.

Second one is based on MOSFET( Metal oxide semiconductor field effect transistor),for greater amperage handling.you can simply fix a RS 500 or more powerfull motor to it.if feel bad can bridge same one with exsisting one so it will handle your load nicely.here you can see
that the circuit is more complicated, because this unit is based on PWM, or pulse width modulation. so it may generate some SAW, (Surface Accoustic waves)means some radio disturbances, so we must use good quality wires, and must use a shielded wire to connect
the variable resistor.

Third one is even more complicated because here we are using a CMOS Ic for making pulse.(Complimentary Metal Oxide semiconductor).
the Ic is easily available, and cheap.
   The next circuit is based on Darlington Pair transistor means two PTs in one.here is the circuit. its too easy to make and an ameter is connected in series to output, so you can simply determine the load current in output.this circuit is meant for only under 2 Amps.
you can also use this circuit as a battery charger and voltage eliminator for electronics service...its based on BD679, a cheap PT to buy.
   so..now its on the way..woooommmmm....try it...and you can save ample of money...and you can do many other things with those saved money...

and sure..if there is an idea..there must be a video...see here...http://www.youtube.com/watch?v=SS3gkDgQSz4

now you all may think that it will only work with less powered motor...no...here is...i am adding the same circuit with a powerful RS motor...from a drill...

and wedded to a prop..

and se here...

now friends..time to wake up...do some thing for yourselves for you...save a lots of money...sharpen your creativity...and with saved money you can make more models for you...and se the video here...http://www.youtube.com/watch?v=9-HSQ1Ubeek

Do note that these designs will only work with brushed motors. Also, except for the PWM design, the dissipation in the power transistor would be high at low voltage and high current.

OK for small motors.

Sushil..you are absolutely WRONG....i will post a detailed brushless cofiguration,. here as i got time, and not for small motors...i think you commented this without looking in to ful postings...the last postings shows a big RS motor, and droping more than 6 amps...and you can bridge the transistors so you can go with up to 50 amps...but i am advicing you that you need not any power ful motor to drive a craft in to high speed as i can show you here one of my craft, is working on 3.6 volts and a reworked toy motor...http://www.youtube.com/watch?v=kKh6NGzlXJg

so all you must change your concepts at first...it drops only 700 ma at full throttle..so ample of playing time..it will fly off the water if i used a 6 volt battery pack...still it runs for a long time without any trouble..still running...on..and on...

and a brushless motor is not a miracle...dont get afraid of it...you can see a simple PWM oscilator in my circuits, and then you need only a circuit with IC CD 4020, and some power transistors according the number of coils...i will post all here...so one thing that i am telling you that its not a need to use a brushless or high power motor in to our crafts...none of my models are based on any brishless or high powered motors...stil it flies over water...all with reworked toy motors...and toy Rcs...see some more here...http://www.youtube.com/watch?v=EV4RnsjOzvA

http://www.youtube.com/watch?v=fImQzDac3WQ

http://www.youtube.com/watch?v=AxVYv5m-2jA so rethink...dont waste hard earned money..

Wow!! some serious electro-mechanics here.!! Glad to see some home brew electronics coming back to the forum. I believe many boat enthusiast would benefit abundantly from Rathi mam.

Mam all our prayers and wishes are with Mr Roopesh, for his speedy recovery and getting back to normal active life.

My comment was based on the circuits posted so far. I am sure you have successfully developed designs for brushless motors also.

But they have not yet been posted, as far as I can see. Maybe I have missed out something, somewhere. Apologies. in advance, if that is the case.

And an added bit of, perhaps, useless information. Germanium transistors are virtually "jurassic age", again to the best of my, albeit limited, knowledge.

Sushil...when we see a mother board of a computer..we amazes...because of its layout..still we do not know what are the materials udes in...germanium, has its cussioning effect, in a circuit, that because i cant explain here simply..must go for a detailed study...still you are not redaing all of my postings well...     [PDF] TIP3055 NPN SILICON POWER TRANSISTORFile Format: PDF/Adobe Acrobat - Quick ViewTIP3055. NPN SILICON POWER TRANSISTOR. PRODUCT. INFORMATION. 1. DECEMBER 1970 - REVISED SEPTEMBER 2002. Specifications are subject to change without notice. ...
www.bourns.com/pdfs/tip3055.pdf - Similar   so try and study well about transistors...its not a germanium transistors...and shortly, i was using all of my circuits to me with all of my crafts, and i won gold medals from Naval, and eng: modelling, all among from crafts with brushless and with cutting edge equipments...so i hope all of my efforts may help you all...none of my postings are intended for rich members who can buy some expensive stuffs from...but to friends ith ample of creativity and ideas...and dedication for a self scratch model...so all of my postings are only a key..and you all can go for your own i deas...i realized that a brushless is not a needed thing to make a craft...so have anice crafts...

Rathi - I want to clarify something, because we would love to have you active on the forum for the long term :)

This forum has a variety of members, ranging from absolute newbies, to people who are just getting their arms around stuff, people who are working designing next generation electronic gadgets for some of the worlds premier companies, people who have started with chuck gliders 40+ years ago etc.  They all will chip in with comments, questions and suggestions from time to time.  Some of the questions may seen unwarranted, some might seem illogical ! But to them, they are valid questions, and are NEVER meant to be in any way detrimental to your (or anyone else's) efforts :) 

Being an open forum, we promote active dialogue, so everyone here expects pretty much all sorts of questions and comments.  Just wanted to caution you, so that we all can be prepared for the future.  I can see that you have already handled the concerns pretty nicely !

All your ports have elevated the status of this forum, I hope that summarizes it for you ! :)

Sure Anwar...thanks for the guidance...

My input referred to this. And I have re-read your posts. I am sorry if this sounds as if I am raining on your parade but I see no circuit for a brushless design, so I still am in the dark as to where I was wrong.

BTW your projects are very well made and finished!

hmm...time to test the circuit on a brushed motor plane with some mods ! 8-)

nice one.

sahil

Looks like this thread brought Sahil out from hibernation :) 

Hello Rathi,

Welcome to the forum. Your builds are just amazing.. Nice to have such experienced people in the forum.

On the speed controller circuits, I am with Sushil. The circuits #1 and #4 will have higher power dissipation on the transistors. So, they would need a bulky heatsinks. Since you are into boats water cooling is the best option for these.

The other PWM based circuits are much better and should be fine for high current applications (See datasheet of the Fet/xsistor)..  For more higher currents you can always parallel the FETs/xsitors. Further, at max dutycycle of the PWM the FET/xistor will still get hot.

I am quite interested to see your brushless speed controller design. Most designs use the backemf from the motor... I would expect more that just a counter to do the job. Anyway, do share us your ideas.

-Ismail

hall sensor are best option for the positioning and cheap too :iagree:

very nice!
 :goodjob: :goodjob:

Good morning Friends..and thanks for the comments and so happy that my ideas are usefull for you...and i have one request to you all..my ideas are only a key..and you can go for your extreame for a nice creations...so, all we know the we can bridge the transistors,and mosfet s in parelell.. you can see in my second video, its a big motor, draining more than 5 amps..constant..still i am using the same setups that i used at first..so, i know its not a an emergency to use any complicated circuits with my crafts, because all it are proven..by last year i won the gold medal, for the competition of Naval model competition, and three of my crafts were based on same speed controllers used here, but wasnt driven by a servo, but a toy motor with atoy RC..and the running was along with crafts with brushless motors and Lipo battries..still i got first..so i know there is no need of a complicated equipments on our crafts...

and sure in my case, i will not make any aeromodel, from an electric motor..because i know that, as i am an expert RC pilot, and as real,its not feasible to make a airplane model from an electric motor...so to me , i always make aero models from fuel engines, ultimately with petrol engines from a chain saw...its too nice and flawless..but here my postings are based on water based crafts...i love them much than that of all models..because, i know , from my own experience, an aero model is messy, and only gives us a liitle time of joy..and ample of risk factors...i am an eyewitness of a serious injury, happened in 2003, in a flying meet at bangalore, as one craft ranover a person..as it losts its control by wind...and i always teach my cadets for safety, than sheer enjoyment from an aeromodel..the cost is the main burning thing with aeromodels..then when i consider the land based crafts, i feel it like playing with cheap chinese toys..still i can buy it for a mere 500 /- Rs..but when i turned to water based crafts..its amazing..gives me real life experiences...and all in scale...so, i hope all of my postings will help more for the boat and ship modellers, instead aero...and sure i will post all of my goodies here all are proven, and inexpensive..now i am in my work room to make a brushless motor from a CPU fan, driven by a LED chaser and some transistors..so all you can see how simple it is...but need some time to post it, because now i am held up in some official matters..too busy...will back..have a nice day and god may bless us...

and you can use any transistors, that available with you...but i suggest the TIP 3055, for a great work as it costs only 22 /- Rs here..and can also use 2N 3055, in germanium config:..and can use any darligton pair...all according to you..and instaed of wandering behind it, we can simply note it out all needed parameters from transistor data book..is germanium, or silicon, Ib, Ic, dissipation..etc..etc..and again..request..all of my ideas are only a key..and all you must do all in your way..and prove it..then share us all...why..? because we need ample of our own ideas...for more crafts..yummy crafts...and we all plays with it..wooosh....and wrooooommmm...hi..hi...all of my videos proves it..you can see in my destroyer, is a co axial, proped and driven by a simple reworked toy motor..and rated within 6 volts..then you can see how fast and powerful is is...so dont waste your money and material..while you can make all simply...so have some nice crafts again...i will post to make a nice craft from thermocol...wait..

RachuDIDI,

why not use a simple PWM controller whle you ate driving a variable resistance.
The output of the ckt with free wheeling diode will save lots more power not only but also less costly transistor will be used.

A Simple picture s given here.

Kalyan...its nice..and thanks....thus we are getting more ideas..post it all.....yummy...hi...hi....