|
This shows why a voltage doubler might want 4 diodes, not 2. The two circuits on the left show the circuit with 2 diodes and with 4 diodes. There is no difference seen because of the light load. The two circuits on the right are identical to the two circuits on the left except for the heavy load. The version with two diodes is limited by the capacitors causing it to produce a very low voltage since the capacitors are just 10uF, and the version with 4 diodes acts as a full wave rectifier when the voltage produced is less than the voltage produced by a full wave rectifier thus setting a minimum voltage it can get to. Therefore, for very heavy loads, it will act as a full wave rectifier since it’s unable to produce enough current to make even unity gain, let alone a gain of 2, when acting as a voltage doubler. If your dealing with light loads or it is designed for heavy loads, then two diodes will be fine. However, if it’s designed for an application that mostly acts as a light load, but can act as a heavy load briefly, such as during startup to charge some capacitors, then 4 diodes will be preferred since it can supply the extra current during the short period of heavy load.
|
