I am working on project called "Polarization Modulator". Idea is the having sinusoidal current on the inductor.(100uH) Frequency ( 500Hz - 2500Hz ) and current (peak current) (0A - 10A) on the inductor should be adjustable. I have 28V power supply only. I tried to use H - Bridge with NMOS but it has some problems. Hardest point for this project is @2500 Hz. @2500Hz ZL = 1.57Ohm. In order to get 10A peak, i need at least 17VAC. So, frequency changes mean VAC changes. Lower frequency >> @Constant VAC >> Higher Peak Current

In summary; 28VDC to adjustable frequency and AC Voltage Converter that can give at least 10A peak current.

Is that resolvable ? Worth to start on this project ? Any different ideas are welcome

( I newly graduated from university )

I have Adjustable sine wave generator (0V - 1V) (1Hz - 5Mhz )

Thank you

  • \$\begingroup\$ Sounds like a fairly large audio amplifier (perhaps Class D) will do most of what you want. \$\endgroup\$ – Brian Drummond Feb 10 '17 at 14:18
  • \$\begingroup\$ So, what were the problems with your H bridge - it seems to me that if you want help, the easiest answer is to improve on what you have done to fix the "problems". Also, it might be a good idea to explain what you are trying to build in case the "wheel" already exists. \$\endgroup\$ – Andy aka Feb 10 '17 at 16:10
  • \$\begingroup\$ @BrianDrummond sounds ok. I have 2500W class D amplifier. I will try that. \$\endgroup\$ – Firat Dagkiran Feb 11 '17 at 12:38
  • \$\begingroup\$ @Andyaka Problems occurs after 1.2kHz. First, top 2 NMOSs are gettin too hot. To get pure sinusoidal waveform on the inductor, i have to use Capacitors parallel with inductor and it cause the capacitors too hot. And the company only uses 28V and i couldn't find DC-DC Buck converter that i can play with it's output voltage. I was using XL4015 with DAC ( MCP4921 ) to play it's output voltage but it is only 75W which is not enoug for this projec \$\endgroup\$ – Firat Dagkiran Feb 11 '17 at 12:44

If I understood correctly, you need a 280W power amplifier, which can be a little costly. And if you want precise sinusoidal waveform in the output, you will need a Class A one. They waste heat a lot, so the actual wattage & current will be higher. Not all environments may be suitable for this experiment, because most fuses in single phase powered areas will open in 16 Amps. If none of these are problem for you, go ahead.

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