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Registered Member #1321
Joined: Sat Feb 16 2008, 03:22AM
Location:
Posts: 843
Take a look at this diode:
It's avalanche rated and they call it a "[f]ast 'soft recovery' rectification diode".
Newark has them in stock $0.0155 each (qty. 100 - 249).
It's a 2 amp diode with Ifsm = 50 Amps. It also has a relatively low Vf (1V typical @ 1A).
(Apparently the price you pay for a lower Vf is a longer recovery time, which in this case is 300 nS, but I think that should be fast enough for what most us are doing).
This diode seems like the ideal part to string together for a robust high power multiplier. I think I'm going to get some of these myself.
Patrick wrote ...
Proud Mary wrote ...
You can calculate XL @ 100 kHz once you have made decisions over d and the length of each diode element i.e. including its wire and termination i.e. to arrive at the total number of turns N.
In the meantime, I will try and fish out some old papers where the helical diode units are described in more detail than I can now remember. ('Ere long we shall have regressed to the Voltaic Pile and the Electrophorus! )
Im more worried about the " snapy-ness " of the switching action with so many diodes in series. Instead of just the simple impedance.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
jpsmith123 wrote ...
Take a look at this diode:
It's avalanche rated and they call it a "[f]ast 'soft recovery' rectification diode".
Newark has them in stock $0.0155 each (qty. 100 - 249).
It's a 2 amp diode with Ifsm = 50 Amps. It also has a relatively low Vf (1V typical @ 1A).
(Apparently the price you pay for a lower Vf is a longer recovery time, which in this case is 300 nS, but I think that should be fast enough for what most us are doing).
This diode seems like the ideal part to string together for a robust high power multiplier. I think I'm going to get some of these myself.
I may buy some ofthese just to see, but i need them to operate at 100kHz square wave too, so i dont know 300ns is 4 times slower than the HER108's or SF4007's.
Registered Member #1321
Joined: Sat Feb 16 2008, 03:22AM
Location:
Posts: 843
You're referring to Fig 1?
They're showing how the junction-to-ambient thermal resistance varies as a function of lead length, with "Tl = constant" meaning that the temperature at the ends of the leads (however long they are) is held at a constant value.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
jpsmith123 wrote ...
You're referring to Fig 1?
They're showing how the junction-to-ambient thermal resistance varies as a function of lead length, with "Tl = constant" meaning that the temperature at the ends of the leads (however long they are) is held at a constant value.
Thats what I think, so I like these, when I get the money.
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
Not fully proud of my 25KV fullwave 1A rectifier, because its large, since i stuffed my series diode inside 1/2" PVC pipe, 10" long, and painted it to LOOK like diodes. I put 25 1N4007's in series as close as possible. Then I put hotglue below and above, so the diodes where incased in hotglue, which then was shoved in PVC pipe for looks. Works great.
Now obviously this take up more room because its a long strand, but it would work good for a large CW or something i guess, making PVC shape diodes. Plus you could oil fill them too.
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Putting many diodes in series for a HV diode.
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