Power Conversion Circuits

The schematic diagram shown here is for a “boost” converter circuit, a type of DC-DC “switching” power conversion circuit:

In this circuit, the transistor is either fully on or fully off; that is, driven between the extremes of saturation or cutoff. By avoiding the transistor’s “active” mode (where it would drop substantial voltage while conducting current), very low transistor power dissipations can be achieved. With little power wasted in the form of heat, “switching” power conversion circuits are typically very efficient.

Trace all current directions during both states of the transistor. Also, mark the inductor’s voltage polarity during both states of the transistor.

The schematic diagram shown here is for an “inverting” converter circuit, a type of DC-DC “switching” power conversion circuit:

In this circuit, the transistor is either fully on or fully off; that is, driven between the extremes of saturation or cutoff. By avoiding the transistor’s “active” mode (where it would drop substantial voltage while conducting current), very low transistor power dissipations can be achieved. With little power wasted in the form of heat, switching” power conversion circuits are typically very efficient.

Trace all current directions during both states of the transistor. Also, mark the inductor’s voltage polarity during both states of the transistor.

The schematic diagram shown here is for a “Cuk” converter circuit, a type of DC-DC “switching” power conversion circuit:

In this circuit, the transistor is either fully on or fully off; that is, driven between the extremes of saturation or cutoff. By avoiding the transistor’s “active” mode (where it would drop substantial voltage while conducting current), very low transistor power dissipations can be achieved. With little power wasted in the form of heat, “switching” power conversion circuits are typically very efficient.

Trace all current directions during both states of the transistor. Also, mark the both inductors’ voltage polarities during both states of the transistor.