Speed Controller
Shop Engineering RoboGeddon Speed Controller


SC Manual






DogZ BolloX - SPEED CONTROLLERS from RobotsRus . . . CyberRaptor Custom speed controllers

160Amp Continuous (Approx 400 Amp Surge)  with integral variable current limit and heat sink

bulletSmall (fit nicely into Razer)
bulletEffective - they don't waste power (longer battery use)
bulletNo fans needed - heat sink is the mount plate
bulletSurface mount technology
bullet4 Full Proportional FET Channels Plus 1 relay channel (2 drive & 2 weapon)
bulletFeedback end-stop (Fwd & Rev) for weapon channel
bulletOn board failsafe
bullet15v - 48v Working
bulletPerfect for Robot Wars
bulletThey really are the MutZ NutZ

These boards are now available  . . . . .

The RobotsRus speed controller has been specifically engineered for use in robotic applications. The speed controller performs speed, steering and weapon functions for robots powered by DC motors.  The speed controller consists of one Control board and up to four high-power H-Bridge FET boards. The control board utilizes two high performance low power RISC microcontrollers running at 12MHz that gives a throughput of up to 24 MIPS (12MIPS per controller).  The H-Bridge FET boards use the latest Automotive power MOSFETs that have ultra low on-resistance and fast switching times. The FET board also incorporates a variable current limit circuit to protect the MOSFETs in a fault or stalled motor condition. Each H-bridge FET board consists of 16 automotive power MOSFETS (8 for forward operation and 8 for reverse operation). The combinations of these two boards provide a system that delivers reliable high switching speeds that ensure ultra smooth speed control.




Controller Board:

bulletFive R/C Input Channels

Four PWM output Channels (selectable as independent or mixed)

One Auxiliary Output (open collector 200mA suitable for driving relays etc.)

bulletTwo logic inputs for limit switches etc.
bulletBrake Mode (Jumper selectable for Brake/Coast)
bulletDead band (jumper selectable for 40uS or 80uS)
bulletBattery Eliminator Circuit (BEC) for R/C receiver 5.0V output
bulletSize 70mm*171mm
bulletCurrent Limiting circuit (fully variable) so you don't blow the FETs!


The control board has up to five standard R/C input channels; four are converted into PWM outputs to interface to the H-bridge FET boards with the remaining one used as an auxiliary output. For the PWM channels each pair of R/C inputs may be individually selected for mixed (single stick) or normal (tank driving) operation.  The dead band and brake mode may also be individually selected for each pair.



bulletBattery Eliminator Circuit if this jumper is installed the +5V from the controller is used to power the R/C receiver. If the jumper is not installed the R/C receiver must be powered by other means.  This jumper is common to both channel 1 and channel 2.


Channel Definitions . . . . .


 Channel A - Receiver Input: This signal is used to control the right motor controller or steering, in mixing mode, and is output to the H-bridge FET board for the right motor via JP1


Channel B - Receiver Input: This signal is used to control the left motor controller or the power, in mixing mode, and is output to the H-Bridge FET board for the left motor via JP2.


Channel C - AUX Receiver Input: This signal controls the aux high and low outputs on J1 screw type header.


Channel D – Receiver Input: This channel is used for our weapon system control and is output to the FET board via JP6. Feedback control for this channel is via J2. We use two micro switches to control the forward and reverse limit of this channel via J2 .


Channel E – Receiver Input: This channel is a spare FET control, fully proportional channel and is output to a FET board via JP11.


Channel F – Weapon control feedback. Channel F connector is no longer used and should be ignored. The channel has been used solely for weapon control feedback.




bulletDB: This jumper selects the amount of ‘dead band’ around the stick centre position.  With the jumper ‘OFF’ approx 60-70uS of dead band is applied. With the jumper ‘ON’ approx. 20-30uS of dead band is applied.


bulletMIX: This jumper selects if the left and right R/C inputs are used to drive the left and right independently or mixed for ‘tank’ style steering and power.


bulletBRK: This jumper selects the break mode operation. With the jumper ‘OFF’ the robot with “coast” when zero drive is applied.  With the jumper ‘ON’ the robot will break to a stop when zero power is applied.


H-Bridge FET Board:  

Note: The FET's are cooled by the aluminium panel that attaches them to your robot - they need NO OTHER cooling.

bulletVoltage Range 15-48V
bulletContinuous Current 160A

Surge Current >400A

bulletVariable Current Limiter   
bullet16 Automotive MOSFETS

8 for forward operation and 8 for reverse operation

bulletUltra Low On-Resistance
bulletFast Switching
bulletSize 92mm*192mm (excluding heat sink)
bulletHeat sinks are shipped with the FET boards and act as a shield for the rear of the PCB -  (In tests we have had no problems at all with overheat even after prolonged use).



The H-Bridge FET boards use the latest Automotive power MOSFETs.  The MOSFETs have been specifically developed for the demanding automotive industry. The MOSFETs have a junction operating temperature of 175deg.C, ultra low on-resistance and fast switching times. These features ensure extremely efficient and reliable operation. Each H-bridge FET board consists of 16 automotive power MOSFETS (8 for forward operation and 8 for reverse operation). The current limiter monitors the current input from the battery and disables the power MOSFETs in the event of an over current condition. The current limit is variable and may to set by the user to limit the current for particular motors / applications. Limiting the current, for example in a stalled motor, significantly extends the battery life and prevents over heating of the motor.



Pricing: See on line shop for detail

Controller card is now £95.00 

FET Board is £120.00 and each board now includes current limiting (which you can adjust by means of a pot on board).

Please note: You need a FET board for every motor you wish to control. Each controller card is capable of controlling four FET boards.

Anderson Power connectors (required for all power connections to boards) - are included in the price of the boards - all you need to do is solder the cables onto the connectors then fit the plug.

Please call or email us for more information - We are happy to ship product overseas but shipping charges would apply.  Speed Controllers on line shop



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Last modified: April 28, 2003