Ripple voltage

Ripple voltage (switching power supplies) This is measured in peak-to-peak volts, and its frequency and level should be acceptable to the load circuits. 

The advantages of forward-mode eonverters are they exhibit lower output peak-to-peak ripple voltages than do boost-mode eonverters, and they ean provide mueh higher levels of output power. Forward-mode eonverters ean provide up to kilowatts of power. 

Within multiple-output forward converters, it is possible to easily combine the filter chokes of complementary outputs (i.e., +/- 5V, etc.) together on the same core (see Figure 3-2f). This offers several advantages it saves space, vastly improves cross-regulation of those outputs, and exliibits superior ripple voltage levels on both outputs. 

The DC filter choke is used for ripple voltage and current reduction on the output of the switching power supply immediately following the existing filters. It is also used as an EMI filter on switching power supplies that have a single power line on the input, such as battery and distributed power systems. 

Ultimately, the designer must try-out the final design and check the output ripple voltage and the temperature rise of each capacitor. 

The typical design goals for the ripple voltage are about five to eight percent of the peak rectified input ac voltage for ac off-line converters and about 0.1 to 0.5 volts peak-to-peak in dc-dc converters. The value of the bulk input capacitor can be found by... 

Maximum output current Output ripple voltage Output regulation ... 

Once again, high and low frequency limiting must be introduced on the control IC in order to minimize output ripple voltage and zero switching loss conditions. 

Suppression of the ripple voltage fed back to the fuel cells... 

It appears that the circuit still functions properly since the output of the regulator is constant at 15 V. When you look at the input to the regulator, the ripple voltage across the capacitor is about twice the magnitude of the ripple voltage of the full-wave rectifier. This is the expected result. ... 

The results of the breadboard waveforms and the IsSpice waveforms are compared side by side in Figs. 4.15 and 4.16. Figure 4.15 shows the output ripple voltage at the top, with the inductor voltage at the bottom. Figure 4.16 shows the oscillator frequency at the top, with the... 

The transient domain model shown in Fig. 4.33 was used to measure output ripple voltage, transient response, gate voltage, and inductor current. This model properly predicts the cycle-by-cycle switching effects of the regulator. 

Figure 4.40 shows the simulated output ripple voltage, while Fig. 4.41 shows the simulated output voltage ripple. The measured transient response is shown in Fig. 4.42, while the simulated transient response is shown in Fig. 4.43. 

An improvement to the conventional and cascade doublers shown above is the bridge rectifying doubler. Instead of half wave rectification, a bridge doubler provides full wave rectification. The advantages of full wave rectification include less input impedance and a ripple voltage at twice the input frequency, which improves ripple-filtering capability. The schematic for the bridge doubler is shown in Fig. 10.10. The IsSpice equivalent schematic is shown in Fig. 10.11. 

Ripple voltage Vrip describes the maximum AC voltage that can be applied to a DC capacitor. 

Where n is the ripple number, in the above case n = 3 and Vdo is the average ripple voltage at no-load. 

The six-pulse rectifier bridges can be connected in such a manner as to produce a 12-pulse DC output voltage. The average value of DC ripple voltage is thereby reduced. From the AC power system point of view the magnitude of the harmonic components is reduced and some harmonics are eliminated. Figure 15.6 shows a typical circuit of a 12-pulse bridge. 

For full-wave rectifiers, the discharge period is half that of a half-wave rectifier. Therefore, the ripple voltage is given by... 

A full wave rectifier with a choke input L type RC filter (as shown in Fig. 10.22(a)) improves the ripple factor and DC regulation. The ripple voltage across R and C for the first harmonic is given by... 

The ripple voltage is inversely proportional to inductance L and capacitance C. This discussion is valid when continuous current flows through the inductor. The current through the inductor is continuous if the inductance is greater than the critical inductance Lc, where Lc is greater than or equal to R/ 3co). 

Ripple voltage The AC voltage associated with the DC in a rectifier circuit. 

C1 is chosen to provide a maximum ripple voltage at the output node at the maximum load current. This ripple voltage is calculated from the average current per cycle that enters and leaves the capacitor. From... 

The main role of the LPF for this study is to extract DC component only, thus the cut off frequency of the LPF is decided based on this. The amplitude ratio of AC component to DC component is 1/1000 (-60 dB) when PI is 0.1 %, thus the LPF should satisfy the following conditions the maximum ripple voltage in pass band is less than 0.001 (0.00868 dB) and the attenuation in stop band should be greater than 60 dB. Since the phase response of an HR filter has non-linear characteristic, only finite impulse response (FIR) was examined by using Filter Design and Analysis tool of MATLAB [3] [4]. 

The low-pass filter shown in Fig. 3.117 does, however, increase the output resistance, which encourages the voltage to fall as the load current increases. This can be reduced if the resistor is replaced by a choke, which has a high impedance to the ripple voltage but a low resistance, which reduces the output ripple without increasing the output resistance. 

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