Page 20 - PEN eBook NOVEMBER 2022
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POWER SUPPLY                                                                                                                                                                                                    POWER SUPPLIES




























                                                                                                                                 *The enable pin is designed to connect to the remote on/off pin of the DC/DC converter as a power-good signal.
                                                                                                                                  Power-factor correction is a method to adjust the   100˚C (–40˚F to 212˚F). On top of that, this module has
                                                                                                                                                                                     a more extended lifetime than usual because there is
                                                                                                                                 harmonic distortion and reduce reactive power by
          The Application                                                                                                        overlapping the voltage and current waveforms.      no existing electrolytic cap inside.

                                                                                                                                  There are “passive” and “active” modes to maximize
                                                                                                                                                                                      The most common way of applying the PFC750
          and Features of                                                                                                        the effectiveness of PFC. The active mode employs a   module is to partner with DC/DC converters: to take
                                                                                                                                                                                     the AC/DC module as the front end and the DC/DC
                                                                                                                                 boost converter to enhance the switching frequency
          Cincon’s PFC750 AC/DC                                                                                                  and control the shape of the waveform of the input   converter as the back end.
                                                                                                                                 current. The passive mode utilizes an inductor and
                                                                                                                                 capacitor to decrease the effect of the peak current.
          Power Supply                                                                                                           Both methods are applicable; however, the operation
                                                                                                                                 of active PFC adjusts the PF value more efficiently and
                                                                                                                                 directly. That’s why active mode is more popular than
                                                                                                                                 passive mode.
          By Cincon Electronics
                                                                                                                                 CINCON’S PFC750 MODULE
           While the concept of energy saving is popular      an AC system. It is normally defined by the ratio of real           As mentioned, Cincon’s PFC750 module successfully
          among industries today, almost all the power supply   power and apparent power (see Figure 1).                         achieves the criterion of a 0.99 PF with a 750-W power
          manufacturers are expecting a breakthrough in the                                                                      supply. Its specification is a standard half-brick, low-
          feature of lower power consumption with high efficiency.  Practically, the harmonic phenomenon occurs when             profile AC/DC power converter with the universal input
                                                              the current and voltage are distorted and away from                range of 90–264 VAC and a high 390-VDC output.
           According to the “Energy Star” guideline, consumer   normal waveforms. To be more specific, the harmonic
          products over 100 W are suggested to reach at least   currents exist at the point that the line voltage goes            Accordingly, the PFC750 is designed by a boost
          a 0.9 power factor (PF) to promote energy efficiency.   beyond the cross-voltage, which causes current from            converter; thus, its efficiency performs up to 96.5%.
          PF is also crucial to reduce energy consumption: The   the bulk capacitor and results in the waveform being            The working case temperature ranges from –40˚C to   Figure 2: PFC750 mechanical drawing
          higher it is, the less power wasted on running the   discontinued. These harmonic currents contribute to
          devices.                                            reactive power, which lowers the value of the apparent
                                                              power.
           Cincon’s new PFC750 module not only reaches
          a PF of 0.99 but comes with appealing features
          when combining DC/DC converters. In the following
          paragraphs, we will discover more about PF and
          power-factor correction (PFC), as well as PFC750’s
          applications.

          WHAT ARE PF AND PFC?
           Power factor is a digit between –1 and 1 that
          represents the efficiency of incoming power usage in   Figure 1: PF and harmonic current distortion                    Figure 3: Application circuitry

  22      NOVEMBER 2022 | www.powerelectronicsnews.com                                                                                                                                       NOVEMBER 2022 | www.powerelectronicsnews.com   23
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