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Rectification of line voltage? Answered

I need to get 230V DC for controlling the brightness of the bulb using a mosfet transistor. The problem is that the rectified line voltage'll get 230 * sqrt (2) = 325 V .. it is too much. I didn't find a transformer AC / AC 230/160 V or step-down IO DC / DC 320/230 V on a market. How can it be solved? Sorry for my english. Thank you for answer.

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AntonínO1

3 years ago

I think I figured it out. I simply rectified voltage but not filter it with capacitor. And use high PWM frequency to avoid interference with the ripple voltage. So it ll be OK for lamp.

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AntonínO1

3 years ago

I have a good reason, this is why I ask!!! I have to use controller SIMATIC S7-1200 por PID regulation of temperature, source of heat is IR bulb. I created a circuit with a triac, but the PWM signal must be synchronized with the phase voltages. I also created a circuit with detection of zero crossing. However, the controller is too slow to make it usable. When i dont want to use another microcontroller, there is a simple solution with a rectified source. Can someone please just answer my question?

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-max-AntonínO1

Answer 3 years ago

If you need a transistor to switch in phase with power, you could always capacitively couple a wire to live wire and have that go into a analog input of a microcontroller. It is a getto solution but it might be an option.

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steveastrouk

3 years ago

To run a triac ZVC, use a MOC3021 optoisolator. The ZVC is built in

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AntonínO1AntonínO1

Answer 3 years ago

But it's still not exactly the happiest solution.

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Downunder35m

3 years ago

Why is it that people with obviously no clue have the need to risk their life playing with mains voltage?....