I just came upon this page: ƒjƒtƒeƒB�[”Œ¾�W
As you can see the Tj is 120 C.
I assume but cant measure, only put my hand on the heatsink, that my SITs are running at 50-60 C whit 50W disipation at
ambient temperatures around 30 C...
I assume thats still in green zone.
As you can see the Tj is 120 C.
I assume but cant measure, only put my hand on the heatsink, that my SITs are running at 50-60 C whit 50W disipation at
ambient temperatures around 30 C...
I assume thats still in green zone.
Can I send you $10 via paypal so I don't have to wait?
Seriously.
Send me your email so I can keep you posted.
I just came upon this page: ƒjƒtƒeƒB�[”*Œ¾�W
As you can see the Tj is 120 C.
I assume but cant measure, only put my hand on the heatsink, that my SITs are running at 50-60 C whit 50W disipation at
ambient temperatures around 30 C...
I assume thats still in green zone.
Do you have a temperature probe?
Do you have a temperature probe?
No. Need to get one.
Did you measure yours?
For TO-3, I measured the case temperature and used .8C/W for the case to junction thermal resistance.
I got the probe and measured the temperature of the transistor case (drain),
it is 60-61 C and the heatsink has around 53 C...
I got the probe and measured the temperature of the transistor case (drain),
it is 60-61 C and the heatsink has around 53 C...
Need to make correction.
The Case temperature of the transistor after 2 hours of operation by
ambient temeprature 29 C is 75-80 C. The disipation is 52.7W.
I assume the Tj is even more!
I think I will have to lower the disipation to 40-45W.
52.7W? Which version did you build? What's your Vds/Id?
Also, using the thermal resistance from case to junction may result in a higher than expected estimate, so there's a little bit of room in there.
The Vds is 74V and the Id is 0.85A, the gate has -12V.
I build my own version whit parafeed topology and output transformer.
For insulation I use aluminum oxid, I bought here: Link
1 amp output transfo !!! schema pleaaaase
I am still working on the circuit, its an hybrid...Will post the schema
as I am finished.
This is a parafeed, so there is no current i primary.
I read something about an SIT SET in Linear Audio vol.4,
they used PASS SIT-1 and had an special made output transformer that
could take the current but didnt have enough inductance for low end.
can't wait , sounds good to replace the 10OOOuf output electrolyte with a parafeed film one
One thing Nelson has started doing is to just parallel the electrolytic with a 1 uF, say MKP or similar. Much cheaper than buying a large expensive non electrolytic cap =)
One thing Nelson has started doing is to just parallel the electrolytic with a 1 uF, say MKP or similar. Much cheaper than buying a large expensive non electrolytic cap =)
that's what i'm doing with a 10UF ones and it's really better ( say faster) than with the electrolyte alone .. i must deal with a full range speaker
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The Vds is 74V and the Id is 0.85A
I forgot you're doing that. Just lower that dissipation (as you mentioned) and I'm sure you'll be just fine.
For TO-3, I measured the case temperature and used .8C/W for the case to junction thermal resistance.
If those are the 4mm chips, then the figure is more like 2+
This just in: I'm informed the 2SK60 is 1.5 Max. Is it fair to assume the 2SK82 is a little bigger?
I don't assume that. I have seen a 4mm spec on the chip, and all the mfr
numbers point toward 2.5 deg/w - 150 deg C junction max, and a 63 watt
rating at 25 deg case temp.
I have seen photos of dual chips in a TO-3 case, but from the curves I get I
don't think that's what Acronman is selling. I guess I'll cut one open if I get
bored.
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