Hi. I've received a project for a design course whereby we have to build a variable frequency drive that will run a shaded pole motor for as little as possible. The frequency of the drive should be set using a voltage of 0V-5V DC. I have come up with the attached design. This is my first design project and i need to know if this is okay or will make the motor burn up.
As far as the design is concerned i have a 555 timer generating a 50Hz square wave on top. This is fed to a pair of IGBT's and an inverted signal is fed to another pair of IGBT's. The voltage at the bottom left is the reference voltage. The bottom 555 timer produces a 120Hz wave that is 180 degrees out of phase with the other. This basically fakes deadtime of a pwm signal. Any suggestions? The output from the load is attached.
As far as the design is concerned i have a 555 timer generating a 50Hz square wave on top. This is fed to a pair of IGBT's and an inverted signal is fed to another pair of IGBT's. The voltage at the bottom left is the reference voltage. The bottom 555 timer produces a 120Hz wave that is 180 degrees out of phase with the other. This basically fakes deadtime of a pwm signal. Any suggestions? The output from the load is attached.
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