Rectifier

Any one has an experience in full-wave rectifiers with NTE5312? I purchased a bridge rectifier NTE5312. I hooked it up and tested it by inputting a 70 Hz sine wave from an online tone generator. It is supposed to be a full-wave rectifier, but looking at the oscilloscope, I got half-wave from the ± output. Can you explain? Thank you.

What voltage was the 70Hz signal?

That bridge is high power rectifier (8A) meant for power supplies, it has a 1.1V forward drop, and many other characteristics, that make it inappropriate for low level signal rectification. More typically 4 discrete signal diodes (e.g. 1N4148) wired as a bridge are used for that application.

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Thank you, PaulHutch.
Yes, I think you are right. My signal is around 1 V. I will try 1N4148.

Hi PaulHutch,

Is 1N4148 ok for signals around 1 V and 10 KHz? Thank you.

yes that is low enough hertz it would not be any issue.

As @Robert_1552 said the frequency is no problem, it’s a fast switching diode.

The forward voltage drop will be a problem if you try to draw too much current.
At 100uA it’s ~0.5V, 1mA ~0.7V, 10mA ~0.8V and when you get to 300mA it’s 1.2V (values from the Vishay 1N4148 datasheet Vf vs. If chart.

Thank you for your help. Would you suggest other diodes that have lower forward voltage?

Many thanks!

Max

would
SB1H100-E3/54 be ok for you ?

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How much current do you need to draw?

Hi mshao,

Getting half-wave rectification suggests that your signal source is not floating (i.e. the source probably share common ground with the oscilloscope via AC input chassis ground etc.).

Schottky diodes have lower forward drop than PIN-diodes. Try e.g. BAT54.

Note that if you are going to use the bridge for energy harvesting, the reverse leakage current spec is also important. That BAT54 works quite well there too.

Cheers,
heke, AsanaLab

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Hi Heke,
That makes sense. I’ll check the ground. Thank you very much.

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