Switched-mode power-conversion

Figure 3.1 Hertzian oscillator (circa 1900) demonstrating basic switch-mode power-conversion technology. Note n, = rip and rij =...

Figure 3.2 Switch-mode power-conversion circuit topologies and their associated maximum voltage and current stress. Note n, = n and Oj = n. ...

Figure 3.3 Operating regimes of the basic switched-mode power-conversion topologies.

Switch Mode Power Conversion Basic Theory and Design, K. 1 Sum... 

R.D. Middlebrook and S. Cuk, Advances in switched-mode power conversion, vols. I and II, TESLACO, 1983. 

A particular application requiring soft ferrites that has rapidly grown in importance in the last few years is power supplies for computers, peripherals and small instruments. A compact and efficient power unit can be obtained by using a technique known as switched-mode power supply (SMPS). It may seem peculiar that in this technique, involving a dc to dc conversion, one of the key elements is a high-frequency transformer. 

This AAA-alkaline battery will last approximately 4.65 years [3]. This duration indicates 16% higher efficiency, which will result in a 7% increase in battery service life with a 60% decrease in battery cost. This particular battery clearly offers impressive improvements in efficiency, cost, and service life by using more modern dynamic concepts of energy conversion. These gains or improvements are strictly dependent on the duty cycle of the functions that derive the maximum advantage from the high-efficiency power supply. As the duty cycle increases, so too do the benefits of using an alkaline battery source with a switched-mode power supply. 

A similar laser, with diode end-pumping, could produce pulses of 128 ns at a repetition rate of 230 kHz, with a slope efficiency of 9 % [151, 152]. One of the examples was a LD-end-pumped passively g-switched Nd YAG ceramic laser, operated at 1319 nm with a V YAG saturable absorber [151]. An average output power of 1.8 W was achieved at the pump power of 23.7 W, which corresponded to an optical conversion efficiency of 7.8 % and a slope efficiency of 9 %. The minimum pulse width of 128 ns at a pulse repetition rate of 230 kHz was obtained with a T = 2.8 % OC at the pump power of 23.7 W. Another example was a side-pumped Nd-doped Gd(0.6)Y(0.4)VO(4) bounce laser, which was combined with a V YAG saturable absorber crystal [152]. It offered a passively g-switched output of 6.5 W at 1.3 pm. Output powers of 6.5 and 6 W were observed at a maximum pump level for the multi- and TEM(00)-mode operations, demonstrating optical-to-optical efficiencies of 17.5 and 16.2 %, respectively. 

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