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Flat Top A.C.

Flat Top A.C., Clipped A.C.

The flat top A.C. power sine wave illustrated becomes more and more common.

This is because the widespread use of devices with a rectifier and capacitor input.

In those devices, the internal capacitor charges up when the actual voltage of the AC power (at a short period of time) is greater than that of the capacitor which is already charged.

This results in a relatively large current being drawn only at the voltage peaks of the sine wave and there is no current for the rest of the cycle.

Loads with rectifier/capacitor input include switched mode power supplies, electronic lighting ballasts and inverter drives for motors.

The waveform illustrated can also be caused by fluorescent or discharge lamps on copper / iron ballasts, and by large battery chargers.

If a discharge lamp is connected to the A.C. supply via a traditional ballast, then it will only draw current from the supply during that part of the cycle when the actual voltage exceeds the lamp voltage, i.e. at the peaks.

Likewise when charging a battery, current will only flow from the line into the battery when the line voltage exceeds the battery voltage, i.e. at the peaks.

For the HIFI fans, the clipped A.C. peaks are not acceptable; however, there is no cheap way to solve it ... ... At this moment, there is only one way ... ... A.C. regeneration .

A.C. Regeneration -
A.C. -> D.C. -> A.C.

For better / High End A.C. regenerator, there is one more part and give you at least 2 more benefit -
A.C. -> D.C. -> Battery -> A.C.

  • The Battery can make the D.C. output much more linear and stable than only using D.C. Voltage Regulator.

  • The battery can provide you a function of UPS ( uninterruptible power supply ), it can give you time to switch off your equipment as usual when power down accidentally and save your investment.

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