Respected Modellers..now we are going to make a simple but 100% effective speed controller for small motors that drops current up to 4 Amps max.. means the stall current ( stall current means, the maximum current flows through the total motor circuit when a running motor stopped by an external force, for example, imagine, that the propeller of your boat strnding suddenly with a fishing net, and stops instantly, because of the net, but the power to the motor still ON..) must be 4 Amps for safety.. with this we can control all motors like EP 60 to EP 120, Pr 40 to Pr 80, SS 40 to SS 80 and loats of toy motors , tape recorder motors ( speed controller removed), VCR motors and a lots.. you can also convert your toy car or boat with this novel stuff, by using a hobby radio.. along with reversing.. we can also add FWD and REV lights that goes on automatically..all without any complicated or tough Lelectronic circuits.. "CAN ANYONE MAKE THIS ONE..?"   yes sure, i told you once earlier, if you are a modeller, who can connect a receiver to your craft for RCying, or you are one, that can light up a torch bulb with a dry cell with two pieces of wire.. then "YOU CAN MAKE AND RCYIT..." its sure.. here, we are not using any formulas ,fundas, theories etc.. all easy.. and handy..

         Now, we are taking a look on using components once.. here you can see a power transistor,named as MJE 3055, and can use any related substitute like MJE 13005 and similar.. this transistor costs about 5 to 10 Rs/- and is very reliable one.. while looking in to the photographs, some experts may laugh, and feel funny, but i rquest to keep an eye on beginners and Modellers who are excellent in making models, but not advanced in Electronics..
         Here you can see the actual transistor, that we are going to use, in my palm, with three leads just under the black body.. you can also see a tab, with a hole, just top of the device, is used to fix the transistor on heat sink..
in second photograph, i placed it on my thumb nail, to show you the actual size of the device..!!

       Its must we must understand the specifications of any used devices and materials in our model making.. usage without a proper understanding of the specifications, lead us in to failure and dangers.. so some specifications and safe limits..

This transistor is simple and proven power transitor, goes in to N P N catagory.. this one can hold a 4 to 5 Amps continues current when used with a proper heat sink.. the idea of heat sink explained later..

This transistor has three leads as Emitter, Base, Collector.. if you hold or place the transistor like shown in photograph, the leads are will be like this.. in this position you can simply read the number of the transistor.. if so, the lead confguration will be like this..

      You do not worry about leads are what and why.. instead can follow easy steps once and will work.. i will explain in such an easy way to follow by taking lots of time and effort.. dont worry..

      Here is the second transistor, that we use in this same simple set up.. this one is a general purpose transistor, used in lots of proven circuits like voltage controllers, relay drivers, audio amplifiers etc.. this also goes in to N P N catagory.. see actual size, and the physical structure and can see the actual size over my nail..

Beautiful! This is what will help ALL of us who are using brushed motors. Thanks Roopesh.

Carry on........

       Here how to identify the leads..?  its all easy.. here you can see a simple toung, protuding from the main body.. this toung denotes the lead EMITTER..  and if you carefully watch the lead settings you can see the LEADS EMITTER and BASE are isolated from the body, but the COLLECTOR lead is directly fixed to the body..!! why..? yes the maximum heat dissipation will take place while the transistor conducts ( in working).. so the heavy heat will be disspated to atmosphere of the device.. so the COLLECTOR junction is directly joined to the metal casing of the transistor.. so, we can easily add the heat sink on the same junction to absorb any heat..  
     Here we can see the pin configuration of the transistor..

         VC Sir.. thanks for the grace.. and i am happy to know my humble efforts helps you.. and hope many Modellers will benify this by keeping the cost within and utilizing this.. so happy..
         Another major electronics components are we using a power diode and L E Ds.. all are simple and do not worry about the leads and connections.. without that i will guide you to make this ESC by close up photographs in detail..

         Here you can see the power diode.. see the actual size.. and you can buy any general purpose high ampere Diodes like this one.. this one is IN 5407.. and can buy anyone that holds 6 Amps.. this one is used as a protector, of the transistors, while motor shuts off instantly.. the back E M F ( a motor is a Generator also.. so when it rotates freely, this makes a current to backwards.. this current can damage any electronics devices used.. )  will be absorbed by this high Ampere Diode..

         Another one device is the L E D s.. ( L E D is the short form of Light Emitting Diode, is a type of electronic Diode, who emits visible light when conducts means , while current passes through it..)  you can see the actual L E D here, and can see two leads, is one is longer than the next.. there s a theory and science behind it.. leave it all.. here we are using it for indication of the Power on, and gain of the ESC.. leave all theories.. when connected.. it must light..thats all.. so, here we can see the two leads as one is to connect to battery + and the short lead is to battery -  please DO NOT CONNECT THE L E D DIRECTLY TO BATTERY.. INSTEAD MUST USE A 1 KILO OHMS RESISTOR IN POSITIVE LINE, OR ON THE LONG LEAD OF THE L E D.. IF NOT IT WILL BURN INSTANTLY..
so, at 12 volts we can use a 1Kilo Ohms 1/4 watt resistor to it and at 6 volts a 470 Ohms ( ONLY OHMS..not KILO OHMS), for a better working..

      As i mentioned earlier, that we are not going to use any complicated electronic circuits here, including a Micro Controller, how can we adjust the speed..? yes, its a must we have to keep all as easy, at this stage, thats why, we are going to use a micro servo to alter the speed variations.. so, we must need a device, the device must be driven by the servo.. its the potentio meters.. or known as the variable Resistors.. here you can see two types of variable resistors, as one is Sliding and the next is Rotary type.. both are good, but i prefer the Sliding because of the easy of installation.. this kind of variable resistors came in to two froms, are single,(MONO), and Compound (STEREO).. in single type you can see three leads and in compound are six.. for easy under standing i noted the leads as 1, 2, 3.. so both are same in function.. here we need tha variable resistor in 47 or 50 Kilo Ohms value..

      And as we are not using any complicated Electronic circuits, how can reverse the motor..? at this easy stage, we are going to use two simple types of switches.. one is i introduced you earlier on the first set up.. and the second one is the simple toggle switch.. this switch are small, but capable of carriyibg a decent 10 Amps at 24 Volt DC.. this switch is a DP DT, means Double Pole and Double throw.. more clearly, the switch contains two individual switches, and can goes ON and OFF in either directions.. or can switch on different loads on each end when switch handle moved from one side to other..

                 Here is the detailed description of the switch that we are going to use in this motor control set up, for reverse.. you can see a red line that i drawn.. this line seperates each switches in imagination.. then you can see two identical switches, and the similar poles that contains.. a C point can see on both sides.. this denotes the COMMON point.. and can also see two poles as 1 and two as 2.. these are poles when switch contact goes from to other.. i expalied hereonly for explanations .. dont worry about the connections..
Friends..MOM is too angry.. time to lunch and medicine.. will be back..

   

Yes, he is off for "lunch". Before you guys start sniggering about 'lunch at 11:30pm', check this out:

lunch
   [luhnch]
noun
1.
a light midday meal between breakfast and dinner; luncheon.
2.
any light meal or snack.

source: http://dictionary.reference.com/browse/lunch

VC Sir.. thanks for the correction.. but when my MOM starts to shout.. nothing will come to brain.. so, i corrected it as "dinner" hope is correct.. 

  Luckily, my Mom stays with me, I know what you mean. God bless them!

yes sure VC Sir.. thanks for the graceful words.. God may bless them 

        We saw and examined all needed parts to make a simple but effective ESC for brushed motors.. here to retain the simplicity, we are using some electromechanical method, to achieve the reverse function.. so, we can do it in two ways.. will understand as we progress, thus can avoid lots of confusion once..  this simple ESC can made on a vero board, card board, plastic card, and anything that apropriate.. and can make without any PCB, makes it even more simple and compact.. so, we can simply add this device within a very little place, all around our crafts, like airplanes, boats,ships, hover crafts and lots more.. here we are starting the assembly procedures once..
        What you need as essential..?  yes, a good soldering iron, with three pin top, and make sure that the thirdth pin is surely Earthed..  some good quality soldering paste,(flux), good quality, solder wire.. a simple round head nose plier, a twizer, and a scrap or art knife.. thats all.. and yes if you have a multimeter will help you extensively, but not a must here as i will show you how can we check the connections without a multimeter.. this procedure also helps us to understand the load testing..

       time to make.. as keeping beginners and Modellers less advanced in electronics, we can make this one on a piece of foam board.. so will get a clear idea.. can also make on a vero board, (common PCB), but will be hard to trace and understand, while we progress.. so, here i am starting with a piece of foam board.. and you can see the simple diagram of the Darlington pair of the transistors.. this makes easy.. but it is not a need to stick to the circuits or theory, but will work all nicely, by keeping the assembly order once.. all simple..

      here the diagram..
and here you can see a little piece of foam board in my hand, in to 2X2 inch size.. this will consume a little extra space, but will be easy to understand the wiring.. and after that we will make this without any PCBs..

       i told you that the transistor will heat up when it starts to work..(conducts).. so it is essntial to cool it down in to a feasible level.. for this we have to use a heat sink on the transistor, that the heat sink must be within the criteria of loading.. means if you are going to add a big load to the ESC, you have to add a good big heat sink on it, or must cool the ESc with liquid or water or with air..heat sinks can be buy from electronics shops or can make from aluminum channels or can take from any old electronic devices like TV or tape recorder.. or from SMPS..here you can see the heat sink that purchased from an electronic shop for Rs 2/-..

       you can see the transistor seated in the heat sink nicely..

      because of the nature of the transistor, the collector is directly connect to the tab of the transistor.. that is why, the tab of the transistor will be the COLLECTOR, as to meat the need of heat transfer.. so, when we connect the transistor to battery, the taab of the transistor will be same of the battery positive .. B+..  so, if we connect the transistor directly to heat sink, the heat sink will be the B+... in such case, theres a chance of short circuit if any of the wire, or any of the part of the craft, may shorted.. to avoid this head ache, we must use an insulation kit, to our transistor heat sink combination at all the while.. so, for this we can simply can purchase the transistor insulation kit, or transistor isolation kit from any electronic shops.. this costs about Rs/5-... this will be either Mica sheet, or may be a new generation flexible asbestose insulator.. this also can scrap from many old electronics devices..

here you can see the transistor, it's insulator, and a special washer, that fits to the tab of the transistor, to avoid shorting the tab with heatsink..

      Place the insulator on heat sink, then fix the transistor to the heat sink, with specified screw set, as shown..

tight the screw nicely, while avoiding the over torque..

      Place the transistor, over the foam board, in a convenient place and mark the transistor leads..
make three holes with a point iron, or with a twist drill in small size..( .5mm almost..)

insert the transistor through the holes.. then can see the three leads protuding on other side..

     now, we have to add an other transistor to form the darlington pair.. for that, you can fix the second transistor like this.. please note the EMITTER lead..

make only two holes and insert the second transistor, while the BASE lead free from the holes as shown..

      its claer to see the BASE lead.. this lead is used to feed  or control the transistors while using as an ESC..
at back of the foam board, we can simply see all leads of two transistors.. note the specified leads as i mentioned..of the big first transistor..

       you can see the two leads from the little transistor is linked to the leads of the bigger transistor.. while keeping the lead configuration just solder it..  

               after soldering the transistors as shown in the above photograph, our main job is completed.. means the making of the Darlington pair is over.. this time we done it over a piece of foam board.. so, sure it will take a little space to accomodate.. this same can do wothout any PCBs.. if so it will be much weightless, and also will be much convenient to place on crafts.. its far easy than we think.. and i prefer this boardless making as it is much small and easy of installation.. so, we can check the second option once.. so all you will find how easy it..
               By following easy steps once again, you can make this ESC within minutes.. and it drives needed motors well..