Changes must be reviewed before being displayed on this page. The wide silver band on the diodes indicates the cathode side of the diode. The essential feature of a diode bridge is that the polarity of the output is full wave rectification pdf same regardless of the polarity at the input.
Therefore, in the discussion below the conventional model is retained. The fundamental characteristic of a diode is that current can flow only one way through it, which is defined as the forward direction. A diode bridge uses diodes as series components to allow current to pass in the forward direction during the positive part of the AC cycle and as shunt components to redirect current flowing in the reverse direction during the negative part of the AC cycle to the opposite rails. In each case, the upper right output remains positive, and lower right output negative. Since this is true whether the input is AC or DC, this circuit not only produces a DC output from an AC input, it can also provide what is sometimes called “reverse-polarity protection”. DC power source have been reversed, and protects the equipment from potential damage caused by reverse polarity. This kind of electric power is not very usable, because ripple is dissipated as waste heat in DC circuit components and may cause noise or distortion during circuit operation.
For example, for a three-phase AC input, a half-wave rectifier consists of three diodes, but a full-wave bridge rectifier consists of six diodes. Power-supply transformers have leakage inductance and parasitic capacitance. When the diodes in a bridge rectifier switch off, these “non-ideal” elements form a resonant circuit, which can oscillate at high frequency. This high-frequency oscillation can then couple into the rest of the circuitry. Snubber circuits are used in an attempt to mitigate this problem. A snubber circuit consists of either a very small capacitor or series capacitor and resistor across a diode.