chinuhark
Member level 5
I want to make a Push Pull type DC-DC converter with multiple outputs for driving the gates of an inverter and also some control circuits. While bootstrap method is popular, it has it's limitations. All the people at our college use a large no of isolated power supplies to do this and I want to make the Power supply part compact and cheap.
I am thinking of using an off the shelf 12V,1A SMPS supply for the input primary voltage. There will be about 10 isolated secondaries with atleast 600V insulation level between them.
I will be using an ETD39 core at 40kHz switching frequency and 3Volts per turn. Thus the no of turns are as follows:
Primary: 4+4 turns centre tapped (1Amp)
Secondary: 1) 6 isolated secondary windings of 7 turns each (350mA)
2) 4 isolated secondary windings of 4 turns each (350mA)
I was thinking of using IC78xx Linear regulator ICs at each output to get the desired regulated voltage level. The input will be a constant 50% duty cycle 12V p-p square wave at 40kHz and since I am using Linear regulators, there is no need to work on a closed loop regulation system (which I cannot imagine to be easy or even possible due to the presence of multiple secondaries with varying load levels on each).
1) Does everything seem OK and would it work?
2) Is this the best way of doing it?
3) I am thinking of using a simple atmega 8 to get the pulses for the MOSFETs which will have constant duty cycle and dead time. Should it be OK?
I am thinking of using an off the shelf 12V,1A SMPS supply for the input primary voltage. There will be about 10 isolated secondaries with atleast 600V insulation level between them.
I will be using an ETD39 core at 40kHz switching frequency and 3Volts per turn. Thus the no of turns are as follows:
Primary: 4+4 turns centre tapped (1Amp)
Secondary: 1) 6 isolated secondary windings of 7 turns each (350mA)
2) 4 isolated secondary windings of 4 turns each (350mA)
I was thinking of using IC78xx Linear regulator ICs at each output to get the desired regulated voltage level. The input will be a constant 50% duty cycle 12V p-p square wave at 40kHz and since I am using Linear regulators, there is no need to work on a closed loop regulation system (which I cannot imagine to be easy or even possible due to the presence of multiple secondaries with varying load levels on each).
1) Does everything seem OK and would it work?
2) Is this the best way of doing it?
3) I am thinking of using a simple atmega 8 to get the pulses for the MOSFETs which will have constant duty cycle and dead time. Should it be OK?