PROJECTS DETAILS, thanks R.ASHOK KUMAR MAASTECH 89. RANGARAJAPURAM MAIN ROAD(NEAR SBI BANK) KODAMBAKKAM CHENNAI-600024 PH:044-24844676 ASHOK KUMAR-098402 34766 PL VISIT http://www.maastechindia.com

1. RF based Wireless Speed Control of DC
Motor Drive using MOSFET
In this project, We have a wireless control of speed of
DC Motor. i.e., when a speed is set at a sending end it is
transferred to a remote reveiver section through RF Media
and then it is converted into a command and sent to an
Embedded PIC Microcontroller for controlling the speed of
the DC Motor. The Drive uses the MOSFET to change
the firing angle, so that we can vary the speed of the DC
Motor. It has field and armature control.
The RF Channel used is 433.92 MHZ. The speed
can be set by using a Keypad.
The Block Diagram for the Project is given below.
89 RANGARAJAPURAM MAIN ROAD,KODAMBAKKAM,CHENNAI-24
PL VISIT www.maastechindia.com,mobile:098402 34766

2. Block Diagram (Transmitter section)
Power PIC Microcontroller RF
Supply Transmitter
Rectifier
and Filters KEYPAD LCD
Display
Line
Voltage
(230 VAC)
89 RANGARAJAPURAM MAIN ROAD,KODAMBAKKAM,CHENNAI-24
PL VISIT www.maastechindia.com,mobile:098402 34766

3. Block Diagram (Receiver Section)
Line
Voltgage Zero
Bridge Crossing Ramp
Rectifier Detector Generator
DAC Err Comparator Buffer
Ramp
Volatage Feedback Comparator
PIC Microcontroller
Pulse Multiplier
RF
Recceiver
Current Amlifier
Line Volt
230 VAC Pulse Transformer
MOSFE MOSFE
T1 T2
Rectifier Using Diode
Rectifier Using MOSFET
Field DC Motor Armature
89 RANGARAJAPURAM MAIN ROAD,KODAMBAKKAM,CHENNAI-24
PL VISIT www.maastechindia.com,mobile:098402 34766

4. Drive Operation:
The input Voltage is rectified and fed as a input to a
ZCD for Ramp generator. Speed of the motor can be set
through a remote RF Transmitter, which is acquired by a
RF Receiver and then processed by the PIC
Microcontroller, which further sends an output voltage
using a DAC to the feedback comparator section.
Both this ramp and the feedback voltage are
compared and a pulse is generated for firing the
MOSFET. Sometimes MOSFETs cannot be triggered by a
single pulse. So we have a multiple pulse generator
section using 555 timer IC.
The output of the IC is fed for current amplification
and given to a pulse transformer to isolate and produce
simultaneous signals for firing two MOSFETS at a time.
By controlling the firing angle of the MOSFET we can
control the speed of the DC Motor.
89 RANGARAJAPURAM MAIN ROAD,KODAMBAKKAM,CHENNAI-24
PL VISIT www.maastechindia.com,mobile:098402 34766