My name is Berca Iulian, i`m from Romania, i have electrical engineering studies i work develop new 3Phase inverters for Brushless motors and PMSM.

I`m designing in Eagle-cad : brushless controller circuits, dc motor controller circuits,protection circuits,etc.
I`m constantly improving my design for a robust brushless controller, with all protection needed (overcurrent, over-temperature,fault output, torque control) also ramp acceleration and deceleration and adapting timing angle.
Now i also work on a new design of a large 48 pole 60kW direct drive brushless motor.

I am interested in a possible collaboration for electric car projects. How to build  and efficient brushless controller based on Motorola  MC33035  step by step. I ordered from On semiconductor as free sample 5pcs.maximum. You only pay for transport and handling.

  1. Features:
  • - Work only with sensored brushless motors.
  • - Speed adjustable via a potentiometer
  • - Adjustable acceleration deceleration
  • - Loop Control
  • - Fackword / Forward
  • - Dynamic breaking
  • - Over-current sense from external  shunt resistor 100mV threshold level.
  • - Overheat protection.
  • - Undervoltage protection.
  • - Fully Accessible Error Amplifier for Closed Loop Servo Applications
  • - Adjustable PWM frequency
  • - 6.25 V Reference Capable of Supplying Hall Sensor Power

I used Eagle Cad to make the schematic and the board.

I used only N-channel mosfets in junction with  IR2110 half bridge mosfet driver.

You also need a inversor gate for the Top Drives (4049)

This is the newest version with 4 mosfet in parallel per switch  IR4110 but doesn`t matter what mosfet you use as the volgate and current is good for you.

top driver_cr

The pin 3 JP8  goes  to the Board 2 (Comand module) at JP20 pin 1

The pin 1 JP8 goes to Board 2 JP20 pin 2

The Pin 3 JP9 goes to the Board 2 at JP20 pin 3

The pin1  JP9 goes to the Board 2 JP20 at pin 4

The pin 3 JP10 goes to the Board 2 JP20 pin 5

The pin 1 JP10 goes to the Board 2 jp20 pin 6

The pin 1 gnd of the JP5, JP6. JP7  can pe left in the air. becouse gnd is common.



Brushless controller schematic mc33025

In the upper part you can se the current sensor Allegro ACS758 200A.

You can also see in the left the bottom module next to it the driver+ top module.

In the right upper corner command module and in lower corner a dc-dc convertor module from ebay.

to power the cmomand module and the driver board.

You can put any mosfets channel N you need. Best are with internal resistance as low as possible and higher current.

Board 3 mc33035 Brushless controller







This diagram was draw by a website visitor by name “Bill Catalena” from my specification.

Brushless controller schematic mc33035

This is the 3-rd Board with bottom mosfets.

The U,V,W need to be connected to the U,V,W to the top part of the mosfets.

The Pin 1 of the JP1 goes to the pin 2 JP5 from the Board 1

The pin 2 of the JP1 goes to the pin 2 JP6 from the Board 1

The pin 3 of the JP1 goes to the pin 2 JP7 from the Board 1

Ground pin is connected from the power supply of 48v




bottom mosfets mc33035 driver



Toyota Prius IGBT module

This toyota prius igbt module inverter was from a scrap and i took apart the driver board. now i-m building my own diver board.igbt module toyota prius

In order to be able so start the motor  you need to put a floating dc power supply to the IR2110

I have tested some of 1200V 600A FZ600R12KE3 IGBT module and the input capacitance was ~ 55nF. The time rinse obtained with avago IC ACPL-P343 was 1,2uS at 12Khz, not so good  if you want the switching losses low. the datasheet:

In this video i used 12 Mosfets irf3205z and IR2110 driverInfineon IGBT



Now the big thing : Testing the Electric Go Kart to measure the results

After building a brushless controller i have decided to build my own brushless motor also. To  design the motor i used Autocad Inventor 3D cad software. Before start to design something you need to know the RPM needed and torque needed. This formula is for calculating the torque if you have the power and the speed motor Torque foruma  After reading the gear ratio on  Opel Agila it resulted that i need a speed of 4000RPM to reach 73.4Km/h in 3-rd gear ( i do not need more than that in a city) I decided to make a reverse outrunner motor because is more easy to cool the stator if is outside. If the sator is inside is more difficult to cool down. The draw-back is that you loose torque because you have a smaller diameter of the rotor. I opted for a 48 slots (teeth) and 40 magnets design and i will have 142.5Nm peak torque. You can check on if your design is good or not with this electric motor winding calculator. electric motor winding calculator

How to choose the magnets ?

After you choose the slots and poles you need to choose the magnets. This is not very easy task because you need hi temperature magnets and are not so cheap and easy to find for your needed size.

  •  The temperature rating for Neodymium is only a guide value. The actual temperature where magnet start to loose strength is size, shape and magnetic circuit dependent. If you have a magnet connected to a piece of steel  i will demagnetize at higher temperature than in a free space.  On the other hand temperature will be  lower if you subject the magnet to a strong opposite magnetic field such in a motor.
  • If the thickness of the magnet is bigger and  you will need a bigger magnetic field to start demagnetize at a certain temperature.

Temperature classification for neodymium magnets, N stays from Neo from Neodymium

  • N42           ≤80℃                                      magnet
  • N42M      ≤100℃
  • N42H       ≤120℃
  • N42SH     ≤150℃
  • N42UH    ≤180℃
  • N42EH     ≤200℃
  • N42VH    ≤230℃

After choosing magnets you can start to designe the rotor and the stator. I`m currently working in Autodesk Inventor 3D CAD.

Mathematical magnetic flux density analysis.

Next step is to run mathematical analysis in magnetic field to see if i have some areas wit too much field that iron lamination can not carry. We want to avoid core saturation. For this i used Finite Element Method Magnetics Tool A Windows finite element solver for 2D and axisymmetric magnetic, electrostatic, heat flow, and current flow problems with graphical pre- and post-processors brushless simulation FEMM motor simulation   We can observe that i have areas with to much magnetic flux so i need to increase the thickness of the tooth.






Stator motor design



I encounter circular pattern problem,              extrude function is not possible because the  loops are not closed. Also the trim function is  not working after circular pattern function.
Another approach is needed in order to  succeed .



  • Can be : delta or Star ( WYE)
  • Can be: concentrated or fractional slot type.
  • If there are concentrated can be: LRK, distributed LRK etc.

Brushless motor60Kw

The final motor without the caps.

The motor with the caps and without the    bearings

PMSM 60kw

I did not have time to build a ball bearing.


In the last 6 months i`m working at my electric car conversion. The car was in good shape and was a good candidate for the conversion. 
After i found a place where to work to the car (a garage) i took out the ICE and i begun to measure all the interior spaces to see if the motor will fit.
Today (27.07.2013) i did the first test on the electric motor to see if the motor fits ok inside and join well the gear box. 




After i removed the engine i start taking measurements for creating  the mounting plates.




The car with the engine removed. Now i have space to work.



This motor is a Permanent Magnet Dc motor with 100Nm and 1900RPM total power will be limited to ~ 20Kw depending on how i will manage to remove the heat from the  motor.

  I also received the Batteries:
  Model : A123 Systems.
  Capacity : 20Ah
  Nominal voltage 3.3v
  Continuos Discarge 600A
  Puls discharge 1200A
  Total number of cells in series : 72

 As the DC motor Controllers are to expensive for my budget, and i have  experience in electronics i designed my own pwm controller using Eagle  Cad program.

Specs: Max voltage: 400V
            Max current: 200A
Adjustable current limitation feature,
Undervoltage lockout, thermal shut down, curent sense.




New 30 A123 Systems cells arrived.

The mounting plate for 24 cells in series

1234_cr4The schematic and PCB where designed in Eagle cad.

electric car PWM controller




This is the power module formed by 10 mosfets 500V 32A in parralel.

Now new Toyota Prius first generation IGBT module arrived from ebay.

Toyota Prius invertor igbt module


The internal schematic, Each igbt inside has 27nF gate capacitance.

toyota prius  invertor

Opel agila electric

electric car conversion




















Homemade Qadrocopter

Posted: 13th November 2012 by iulian207 in Homemade stuff
Tags: ,

Motors: 12v Dc Brushless 1000Kv, 20Amp
ESC Mystery 30A Blue series
Batt: 3 cell 2300mAh Li-Fe A123 Systems.
Home Made Contoller Board Atmega48, 3xMurata Gyroscops.

First you need to buy the materials:

  1.   Tow cubic meter of extruded polystyrene from insulation materials.
  2.   6 pcs  wooden planks
  3.   6 pcs threaded screw
  4.   3 meters of fiberglass mash.
  5.    Polyurethane foam
  6.    Some hot wire machine to make a trench in polystyrene



Now the actual construction.

How to make a pontoon boat step by step

How to make a pontoon boat step by step

pontoon boat build




How to make a pontoon boat step by step


First mount of the Boat to see if everything is ok,

And it was ok :D

Going to the lake site to test the boat.







Electrical motor 32lbs of trust.








NASA launched the twin Voyager 1 and Voyager 2 spacecraft to explore the outer planets in our solar system. Researchers had thought the probes, which are still occasionally beaming back data, might be exiting the solar systemby now  –  but the direction of the solar wind is telling them otherwise.

One way to think about the edge of the solar system is to measure it in terms of the solar wind, the stream of energetic particles pouring from the sun. The area dominated by the solar wind is known as the heliosphere.

The distant region where the solar wind slows as it begins to run into interstellar gas and dust is known as the heliosheath. The mysterious boundary where the solar wind finally ends and the interstellar medium begins is called the heliopause.

Past research suggested the Voyager probes were entering an unknown part of the heliosheath (dubbed the “transition zone” or the “stagnation region”) where the flow of solar wind had apparently calmed down. Scientists thought that by now Voyager 1 would start to see the solar wind deflected from its straight outward path into a more northward or southward manner as it curved to form the heliopause. [Photos from NASA's Far-Flung Voyager Probes]

NASA’s Voyager 1 spacecraft has entered a new region between our solar system and interstellar space, which scientists are calling the stagnation region. This image shows that the inner edge of the stagnation region is located about 10.5 billion miles (16.9 billion kilometers) from the sun. The distance to the outer edge is unknown.

NASA’s Voyager 1 spacecraft, which launched 35 years ago today (Sept. 5), surprisingly may have far more to travel before it leaves the solar system, researchers say.

How much more is up for debate. The scientists say their new finding suggests much about the outer reaches of the solar system remains unknown.

Voyager 1, which left Earth on Sept. 5, 1977, is about 11.3 billion miles (18.2 billion kilometers) from the sun. Meanwhile, Voyager 2, which launched 16 days earlier on a longer trajectory, is approximately 9.3 billion miles (14.9 billion km) from the sun.




I just finished a new controller for my electric scooter project.

The current is limited to 50Amp but it can sustain at least 80Amp.

It is also based on Mc33035 IC and it is capable to decode signal from the hall sensors.



Now i`m also building a new Go kart controller.I will use the same logic board as the scooter.

The board was designed in Eagle Cad:

The Brushless motor Controller Schematic: (command module)


I used photo resist PCB to make the circuit :




After that i used  Ferric Chloride etchant to remove all the unnecessary cooper.

And the result was :

Here is a picture of my Homemade Electric Go Kart:





Today i received the charger and i put it to the test.
I am very satisfied about the capability of the charger.


ICharger 1010B+ insite board




After i discharged all the cells with 8 Amp load  (using a watt-meter and 6 pcs 12v light bulbs)  until 2,4v i started to charge one by one.

At 2,7v the voltage started to drop fast so 2,6-2,7v is the point where you need to stop the discharge to protect the life of the battery.

At the first cell i obtained 19.901 Ah. I used a Turnigy Accucell 150W charger



Now i need to find away to join the battery tabs to make a 12S 1p pack.

First in mind was to solder the tabs. I tried to solder on aluminum with a flame underneath like in the link




I put the cells on a smart charger so see the Capacity.

Also i tested the battery with a discharge current via a long and thick cable measuring 350Amps with a DC  clampmeter.


Is better to put more wires or thicker to have lower voltage drop on the cables.

In this way you avoid the charger reading   3,6v sooner than normal and the charger will reduce the current sooner.You will loose about 2hours depending on initial charging current.


  1. First cell had 19.9 Ah
  2. Second cell 19,3Ah
  3. Third cell 20,1Ah

Today 29.06.2012 i received the second bach of cells made in korea in not very good shape.

The tabs were bended. And one cell was little bended.




I alo received the BMS for Li-po4 cells 12S the in the description they give the maximum discharge current at 20Amp.

The price was 26,6 USD



This is the best cheapest DC motor speed controller circuit that you can find on internet.

In the past i tried wit NE555 and other circuits but the results were every time in shorted mosfet`s :D and not stoppable GO KART (not very good thing when you do not have a big red kill switch).

In in the following i will  present my DC Motor speed controller capable of adjusting speed (PWM)  form 0 – 100% and the frequency form  ~ 400Hz to 3kHz, based on LM339 comparator.

The power supply is from 14-30volts,  expandable to practical any value with little modification.

From R15 VR 10k you can adjust the speed from 0 -100%

From R14 VR 100k you can adjust the frequency.

If the jumper JP1 is shorted you can adjust the PWM frequency from 400Hz  to 3kHz. If jumper is open Freq is fixed at 100Hz.

The circuit is designed in Eagle cad 6.2



You can use almost any Channel N mosfet`s you want. The fets will be mounted on a radiator if the current is  higher than 2-5 amp.

It is possible to increase the voltage supply to any value if you separate the power to the logic circuit from power to the load and mosfet`s

This is my second prototype of dc motor controller


Depending on Rds ON value of the mosfet`s you will need a smaller or bigger radiator.

The wires will be at least 12 AWG for a 30 -35  amp load.

For any questions you can  ask me any time via my e-mail found on about menu.

Success with the circuit.

This is the real life testing of the circuit.




High quality improved PWM controller based on MC33035 IC.

Schematic :





Eagle 6.1 design.



I used as mosfet driver the TC4452 IC with is capable of 12Amp output.

I used this schematic in conjunction with power stage formed by 10 mosfets in parralel with all gate connected via 10pcs  20 ohm resistor to the output of the IC driver.

For current sense circuit i used allegro sensor ACS758

50-200A current sensor IC

The Allegro CA and CB package current sensor ICs are fully integrated current sensor solutions. They contain the primary conductor, concentrating ferromagnetic core and the analog output Hall-effect linear in a single IC package. The conductor resistance is a typical of 100 µΩ for ultra low power loss when sensing current up to 200 A. These sensors are automotive grade devices that can take the heat and deliver highly accurate open loop current sensing in the most harsh applications environments.

The Allegro medium current devices are much smaller than bulky current transformers and have the added advantage of sensing both AC and DC currents. The package design also provides galvanic isolation to 3000 VRMS and can be used in many line side applications.