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PROGRAM ROZWOJOWY

^1 POLITECHNIKI WARSZAWSKIEJ

Fig. 1.17. a) One key switch. b) Unipolar current bridge.

Unipolar current bridge offers 3 independent conduction modes. This Circuit provides maximum control flexibility and efficiency with minimum active components. If transistor KI is “on” and K2 is “on” the output load terminal is short-circuited to supply and voltage across the load is +Uz (Fig. 1.18a). If K2 was formerly conducted and switches “off, the current commutates to diodę Dl, and the inductance load keeps the current flowing (Fig. 1.18b). This is equivalent to one key switch operation. If KI and K2 are both “off’ the voltage across the load reverses polarity from +Uz to -Uz (equivalent of applying reverse voltage as it is shown in Fig. 1.11), and remains at this value until the current decays to zero (Fig. 1.18c).

Fig. 1.18. Three independent conduction modes of unipolar current bridge.

UNIA EUROPEJSKA

EUROPEJSKI FUNDUSZ SPOŁECZNY

a

Materiały dydaktyczne dystrybuowane bezpłatnie.

Projekt współfinansowany ze środków Unii Europejskiej w ramach Europejskiego Funduszu Społecznego

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