Simple gretz bridge rectifier questions

[JordanElektronika]

Good day! I have 2 options, I saw that when we use a bridge rectifier, we get on the output an impulse DC signal with double the frequency than the AC signal? On the second place I saw that the frequency remains the same? Logically the frequency should be doubled, if not, why is that? If we use a 2 diode rectifier with a transformer with 2 secondary coils and a middle point we should get double frequency again? Every diode rectifies the positive wave of every coil? On a single secondary coil transformer with a bridge rectifier, the frequency should be doubled, if we use 2 diodes on this transformer, the frequency should remain the same?

As far as I know a bridge rectifier is a full wave rectifier, because it takes both the positive and negative AC signal 180 degree wave, and outputs them only as positive signals, meaning it rectifies the whole 360 degree wave, or the whole period of the AC signal?

I saw that in the forum that they give a 2 diode rectifier, with a transformer with 2 coils and a middle point, as full wave? They even say this one is used for power electronics and higher power, but that makes no sense, because the 1 diode will only rectify 1 positive impulse from every coil, instead getting 2 impulses of every coil if we connect a bridge rectifier (gretz with 4 diodes)? This will give double efficiency and we can even go with a transformer with 1 secondary coil and not middle point?

 

[CataM]

The Graetz bridge uses 4 diodes but only 2 of them are ON every half cycle.

The center tapped transformer only needs 2 diodes and only 1 of them is ON every half cycle, so less power lost in the diodes with respect to the Graetz one.

An advantage of the Graetz however is that the PIV is the supply voltage whereas in the center tapped it is doubled. Likewise, the 1 secondary coil transformer is less expensive than the center tapped.