Ad Widget

Collapse

Announcement

Collapse
No announcement yet.

Rectifier Diodes

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
  • #1

    Rectifier Diodes

    I can't find any threads about this but is the reverse leakage what I need to be concerned with when checking the rating of a diode?

    I have some SR305 diodes I want to use but they are only rated for 50 Volts

    I had 2 1N5408's but one was bad and not rectifying....
    Tags: None
  • #2
    (Assuming you want them for a B+ supply) just use the common garden variety 1N4007 (1,000V 1A). 2 or more in series on each side of the High Tension winding for a FW rectification will cover most PIV issues in most amps. (3 or more in series should cover all PIV issues in just about any tube guitar amp) they are cheap and plentiful.

    http://www.freewebs.com/valvewizard/fullwave.html
    Building a better world (one tube amp at a time)

    "I have never had to invoke a formula to fight oscillation in a guitar amp."- Enzo

    Comment

    • #3
      Yep, 1N4007 gets you through most needs.

      1N5408 is a 3 amp diode, while the 1N4007 is a 1 amp diode though.

      The point of a rectifier is to let current through one way and block it the other. SO it is reverse voltage to look at, yes. I don;t call that leakage. Leakage would be the actual reverse current that gets through even though the diode tries to prevent it. Reverse voltage is how migh a voltage you can apply to it in reverse before it breaks down.

      If your power supply is making for example +400v, that still means that every half cycle, the rectifiers have to block -400v from coming through. SO a 50v diode wouldn;t be near enough.

      Of course if your power supply is only making 35v in the first pplace, then a 50v diode is enough, barely, but enough. I'd use 100v or more for that, myself.
      Education is what you're left with after you have forgotten what you have learned.

      Comment

      • #4
        You can get 1N4007's almost anywhere that sells components. Radio shack, Fry's, etc. Cheap because they're so common. Even though they're rated at 1A and 1000V PIV they are often seen in circuits like preamp tube cathodes where their 1V foreward voltage drop is used as bias voltage, anywhere ordinary diode function is needed and a host of creative applications. Perhaps the only silicon component whose specs are known by most tube amp builders. Not hard to find.
        "Take two placebos, works twice as well." Enzo

        "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

        "If you're not interested in opinions and the experience of others, why even start a thread?
        You can't just expect consent." Helmholtz

        Comment

        • #5
          Yeah I found a data sheet now so I know they won't be of much use on the b+ but I may keep them for other applications as they can handle high current at lower voltages. I just happened to find them in my stash of components and almost mistook them for 1N5408's because they are similar shape.

          I needed some for a 320-0-320 B+ supply, I'm just gonna use a pair of 1N5408 diodes.

          Comment

          Previous template Next
          Working...
          X