full wave rectifiers?

Question

we know the conventional FWR wit centre tapped transformer and etc......
let us try another thing.this is relatively less famous...
using two diodes in parallel...but one is connected in P-N while the other N-P...
basic logic is that total voltage will appear across both,but only one will conduct during a half cycle.....
obviously this is more economical...
why dont we use this.......
there must be some major disadvantage...
point that out to me...
thanks.............

Answer 1

You are halfway to a rectifier. As previous answerers said, your scheme conducts in both directions. Now if you put another set of diodes parallel on the other supply line and take the power out at the two points where the diodes meet from each pair, you have built a full-wave bridge rectifier, which is famous and economical.

Answer 2

2 diodes back-to-back in series with the current is not a rectifier. 'It' will pass current in both directions (AC). The only thing it will do to the AC is drop the voltage by the forward bias voltage of the diode (approximately 0.5 to 1.0 volts).

2 diodes back-to-back in a shunt configuration is not a rectifier, either, as one of the diodes will be turned on on 1/2 the cycle, while the other one will be turned on the other 1/2 of the cycle. This is an AC limiter, and the output will be an AC wave of +/- 1 volt (approx.) probably looking close to a square wave.


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Answer 3

If you have two diodes that are connected in parallel with cathodes to anodes, the diode pair will conduct on both the positive and negative cycle and will act as if they're not even there. You won't have a rectifier.

Answer 4

FWR 2 wires for ac input, 2 for rectified output
Your arrangement has 2 wires only - for the input
Where does the output connect to ??