It’s a power electronics project. It is able to give output voltage(DC) more and less than input voltage as per requirement.
We can generate variable DC voltage which is less than input, but, the special things about this converter is, it has capability to produce variable DC voltage as high as twice the input voltage.
We have specially designed and manufactured inductor for this project.
OPERATION OF CONTROL CIRCUIT
To drive the mosfet op-amp based circuit is
Op-amp(A) is used as an integrator
Op-amp(B) and op-amp(c) is used as a comparator
Transistor 2N5294 is used as a switch to provide
Frequency and duty ratio of output signal can be
controlled by using potentiometer in this circuit
Output waveform of Op-amp(A)
Output waveform of Op-amp(B)
Output waveform of control circuit
OPERATION OF POWER CIRCUIT
Step 1: when mosfet is ON
Voltage across inductor L is equal to V (source voltage)
Step 2: when mosfet is OFF
Voltage across inductor L is equal to Vo (in reverse
Here output voltage developed across load is Vo
Step 3: When mosfet is ON in next cycle
Load is isolated from voltage source
In this case charged capacitor across load will maitain
voltage across load
Duty ratio(D) is defined as Ton/T
here, Ton=ON time
T=time period of gate signal
VOLTAGE ACROSS INDUCTOR
When mosfet is ON, voltage across inductor is equal to
When mosfet is OFF, voltage across inductor is equal to
As average voltage across inductor
This equation shows that output voltage depends
on duty ratio(D)
For buck operation
D=0 to 0.5
For boost operation
D=0.5 to 1
Used in many industrial applications such as
subway cars, trolley buses, battery operated
vehicles, battery charging etc.
To provide smooth control on output, high
efficiency, fast response and regeneration.
To provide efficient control on dc motor operation
To provide long life and less maintenance due to
absence of moving parts.