Mini-a Heatsinks Help!!

[sandstorm33]

Need some help on heatsink dissipation. Have two sinks black anodized measuring 10"X 4" X1 1/4" with a 3/8" thick base ,drilled for two TO-3 cases. Plan to use these in my MINI-A with irf231 TO-204AA(TO-3) which are 100W devices with 800pf input capacitance and 9a rating. Have a bunch of these.

Will these sinks do it ?? I have no idea how to calculate the dissipation character of these sinks.Can someone help??

[bluemartini]

There is calculator here:

http://sound.westhost.com/download.htm#hsink

[sandstorm33]

Originally posted by bluemartini
There is calculator here:

http://sound.westhost.com/download.htm#hsink

Thanks very much!!

[sandstorm33]

Using the calculator and assuming 50-60c operating temp I arrive at.53-.58 C/w . Does this put me in the ballpark?? assume bias devices
to pull 1.5amp @+/-15volts.

[bluemartini]

The zen v9 has this quote:

"This amplifier idles at about 100 watts per channel, which means that each
channel needs a heat sink rated at .25 deg C. per watt."

I have not followed the Mini A thread, but if it is 100 watts per channels then you will need two of your heat sinks per channel

I use two 12x4.5x2 per channel for my zen v9 and it run just below what I would classify as hot. Meaning I can keep my hands on the sinks for a minute or two.

[Dennis Hui]

Originally posted by sandstorm33
Using the calculator and assuming 50-60c operating temp I arrive at.53-.58 C/w . Does this put me in the ballpark?? assume bias devices
to pull 1.5amp @+/-15volts.

Sounds like it should be ok. Assuming the calculated
themal rating is in the right ball par, each heatsink should be
able to handle the 45W or so of dissipation per channel.

Cheers,
Dennis

[sandstorm33]

Originally posted by bluemartini
The zen v9 has this quote:

"This amplifier idles at about 100 watts per channel, which means that each
channel needs a heat sink rated at .25 deg C. per watt."

I have not followed the Mini A thread, but if it is 100 watts per channels then you will need two of your heat sinks per channel

I use two 12x4.5x2 per channel for my zen v9 and it run just below what I would classify as hot. Meaning I can keep my hands on the sinks for a minute or two.

The Mini runs at between 30 and 50 watts depending on how you bias the circuit. Looks like I'm in the ballpark alright. From the many comments in various threads "HOT IS IN". These circuits sound better "HOT". What is Nelson's comment ...Finger on the sink for 5 seconds..

anyway thanks for your help All..

JT