Converting ac to dc has been accomplished by several different types of rectifiers through the years. Here are a few of the more common types of rectifiers used in the past 100 years. Mercury arc ...

Even if you aren’t a tube aficionado, you can’t help but be mesmerized by the blue glow inside a mercury vapor rectifier when it operates. It looks less like early 20th century tech and more like ...

A 4-pin plastic base with brass pins, two cylindrical electrodes mounted side-by-side below a metal cube. S-shaped envelope. Cold-cathode rectifier in original box with data sheet. Stamped on base: ...