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Shottky diode bridge for 6o Hz any guess why?

I've been asked to reverse engineer a product that has a very unusual DC power supply I'm trying to understand It has a power transformer for the line with two secondary windings with a shottky diode tying one end of each together The outer ends of these windings are then connected to a 4 diode full wave bridge made of more shottky diodes then to a conventional voltage regulator . I'm trying to understand why one would not simply tie the two outputs in series and then feed a conventional full wave bridge The output of this power supply is 12 Volts the diodes are rated 8 amps but the transformer in my opinion is not capable of that current as it is only 2"X2"X2" Any opinions are appreciated Thanks in advance Bob

Reply to
Bob T
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Dug thru my old books and found this little note. Why they used them, the price was right!

Shottky barrier diode

Diodes are used to rectify alternating current into direct current. However, rectification will not occur when the frequency of the alternating current is too high. This is due to what is known as the "reverse recovery characteristic." The reverse recovery characteristic can be explained as follows: IF the opposite voltage is suddenly applied to a forward-biased diode, current will continue to flow in the forward direction for a brief moment. This time until the current stops flowing is called the Reverse Recovery Time. The current is considered to be stopped when it falls to about 10% of the value of the peak reverse current. The Shottky barrier diode has a short reverse recovery time, which makes it ideally suited to use in high frequency rectification.

The shottky barrier diode has the following characteristics.

The voltage drop in the forward direction is low. The reverse recovery time is short.

However, it has the following disadvantages.

The diode can have relatively high leakage current. The surge resistance is low.

Because the reverse recovery time is short, this diode is often used for the switching regulator in a high frequency circuit.

Gary S. Bahret, EE, PhD

Reply to
n5ahm

Could you post a schematic? I'm not visualizing what you're describing.

Cheers,

Phil Hobbs

Reply to
Phil Hobbs

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