Power Conditioning Circuits

Power conditioning aims to convert power at one V, I, or f to another as efficiently possible.

Efficiency

Efficiency is defined as:

$$\eta =\frac{P_{\text{system}}}{P_{\text{source}}}=\frac{P_{\text{out}}}{P_{\text{in}}}=\frac{V_{\text{system}}{I}_{\text{system}}}{V_{\text{source}}{I}_{\text{source}}}$$

I/O Classification

Power conditioning circuits are broadly classified by stating input/output as AC/DC. So, we have:

• AC/AC: Transformers (AC)
• AC/DC: Rectifier Circuits
• DC/DC: Linear Regulators, Switching Regulators
• DC/AC: Power Inverter

Example

How efficient is this DC/DC board-mount module:

• $V_{\text{source}}=72{\text{ V}}_{\text{DC}}$, $I_{\text{source}}=0.93\text{ A}$
• $V_{\text{source}}=3.3{\text{ V}}_{\text{DC}}$, $I_{\text{source}}=20\text{ A}$

We have:

$$\begin{array}{r}\eta =\frac{P_{\text{out}}}{P_{\text{in}}}=\frac{3.3\times 20}{72\times 0.93}=98.6\%\\ P_{\text{out}}=3.3\times 20=66\text{ W}\end{array}$$