Diode Heatsink

[dmk]

Hi all,

I am building an Aikido Pre-Amp and am going to use solid state rectification. I am planning on attatching diodes to a heatsink which will then be mounted on top plate of chassis along with TX's, Caps, Choke etc. Will mounting the heatsink on top plate be ok? Likely to cause any problems?

Cheers
Dave

[janneman]

Originally posted by dmk
Hi all,

I am building an Aikido Pre-Amp and am going to use solid state rectification. I am planning on attatching diodes to a heatsink which will then be mounted on top plate of chassis along with TX's, Caps, Choke etc. Will mounting the heatsink on top plate be ok? Likely to cause any problems?

Cheers
Dave

You probably want to make sure the diode anode as well as the cathode are insulated from the chassis. What's the diode physical appearance?

Jan Didden

[dmk]

Hi Janneman,

I was looking to use TO-220 - On Semi MUR860 type.

Cheers
Dave

[leadbelly]

Originally posted by dmk
Hi Janneman,

I was looking to use TO-220 - On Semi MUR860 type.

Cheers
Dave

IMHO, that a bad choice. A 600V PIV is low for what I am assuming is a 240V secondary, and it's a non-isolated package, so you'll have to use insulators to mount it to your top plate. A messy solution, fraught with maintenance hazards.

[janneman]

Yes, 240VAC gives a peak of square-root of 2 * 240 = about 340V. So, if the AC goes max negative (-340) and the cap is at +340, the diode gets almost 700V. I would take at least 800, preferably 1000V diode.

Jan Didden

[dsavitsk]

Originally posted by dmk
I am building an Aikido Pre-Amp and am going to use solid state rectification. I am planning on attatching diodes to a heatsink

Why? Isn't the heat dissipated essentially the current multiplied by the voltage dropped? Both of those are low here -- I'd skip the heatsink.

[dmk]

Hi

Thanks for the replies, I will use another type of Diode and do
away with the Heatsink. Which Diode would you recommend?
I am aiming for 300VDC.

Cheers
Dave

[Renron]

I am building an Aikido Preamp with ecc802s tubes (12au7)

I found this diode for rectification. Ultra fast soft recovery type.
read this thread for more info. 1000v 4A
DIYAUDIO thread

Mouser has them for $0.66 ea. Gotta love that price!

Good luck with your project.
Ron

[Renron]

Sorry, not too much info on that link.. shoulda read it completely first. My bad.........

Maybe try a Fairchild Stealth diode, some people are reporting good success with them and they can be had in 1200V 8A To-220 package from Mouser for $1.95

I may just go that route instead of the Mur4100e as the FS do not need snubbers to keep them ultra quiet. (as reported, but not by me) (I have no practical experience with either of them)

FS stealth diode


Ron