C Section Purlongs used as heat sinks

John Biles · 26th July 2005, 12:16 PM

as i had some 52mm x 150mm "C" Sections laying around i decided to see if i could used them to make heat sinks for my amplifier project.

i decided to build a john Hood 10W class A amplifier and found that if i used a piece of "C" Section 800mm long with 6 2N3055 transistors evenly space the transistor case temp only got to 45 degrees C in a room with a temp of 25 degrees C

this was with a supply voltage of 28volts and the current set to 1.4amps

from this i plan to build a amplifier using "C" Section stanging up back to back to form a towel giving the amp a different look

John Biles · 27th July 2005, 03:38 AM

to save money, what else have you been using for heat sinks on your projects.

Also "C" Section allow you to build cheap strong amplifier cases, as all you have to do is join 4 pieces of "C" Section to the size you want cut at 45 degrees with right angle brackets, screw a flat piece of metal on the top and bottom and you have you case.
you can get 50mm x 75mm "C" section.
you can get 52mm x 150mm section or bigger.

i only paid $3 a metre second hand for my 52mm x 150mm, so i can build my Amplifier case for around $20 and it's alot stronger than the cases you buy from suppliers.
Paint it black and add a Aluminum front and your done, easy!

John Biles · 29th July 2005, 08:15 AM

here's some pics using a "C" Section as a heatsink.
3 transistors in parallel for each power transistor of the JLH 10watt Class A amplifier. Works Well at 25 degree room temp.
transistors only get to 45 degrees case temp

John Biles · 29th July 2005, 08:17 AM

pics

John Biles · 29th July 2005, 08:20 AM

more pics

destroyer X · 29th July 2005, 09:51 AM

That the heat conduction speed.... heat transference speed, is not so good, as this kind of aluminium, called duraluminiun, hard aluminium, is a result of metal mixing to improove mechanical resistance.

You will perceive that you will have hot point around transistor, and cold points distant of it.

Resulting a not so good heatsink.

Despite of that, i had used it many times...this is diy, the spirit!, and i think was interesting you publish that.

regards,

Carlos

John Biles · 29th July 2005, 09:57 AM

Hello Distroyer X,
even worst, the stuff is made from steel not aluminum.
I have run my JLH CLass A 10watt Amp for hours and the temp stayed the same?
One thing for why it might have worked was that i was powering the amp with 28volt rails and not 40volts as is the norm.
same ampage levels 1.3amps.

26th July 2005, 12:16 PM	#1
John Biles diyAudio Member Join Date: May 2005 Location: Victoria Australia	C Section Purlongs used as heat sinks as i had some 52mm x 150mm "C" Sections laying around i decided to see if i could used them to make heat sinks for my amplifier project. i decided to build a john Hood 10W class A amplifier and found that if i used a piece of "C" Section 800mm long with 6 2N3055 transistors evenly space the transistor case temp only got to 45 degrees C in a room with a temp of 25 degrees C this was with a supply voltage of 28volts and the current set to 1.4amps from this i plan to build a amplifier using "C" Section stanging up back to back to form a towel giving the amp a different look

29th July 2005, 09:51 AM	#6
destroyer X diyAudio Member Join Date: Feb 2004 Location: Recife - Brasil Northeast	This is really interesting John...but...i am sorry to say, that i am afraid That the heat conduction speed.... heat transference speed, is not so good, as this kind of aluminium, called duraluminiun, hard aluminium, is a result of metal mixing to improove mechanical resistance. You will perceive that you will have hot point around transistor, and cold points distant of it. Resulting a not so good heatsink. Despite of that, i had used it many times...this is diy, the spirit!, and i think was interesting you publish that. regards, Carlos __________________ Audiophoolery; http://www.youtube.com/watch?v=m7ERMu825m4; Dx Super Etching; http://www.youtube.com/watch?v=WED3Bvmxepk

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27th July 2005, 03:38 AM	#2
John Biles diyAudio Member Join Date: May 2005 Location: Victoria Australia	to save money, what else have you been using for heat sinks on your projects. Also "C" Section allow you to build cheap strong amplifier cases, as all you have to do is join 4 pieces of "C" Section to the size you want cut at 45 degrees with right angle brackets, screw a flat piece of metal on the top and bottom and you have you case. you can get 50mm x 75mm "C" section. you can get 52mm x 150mm section or bigger. i only paid $3 a metre second hand for my 52mm x 150mm, so i can build my Amplifier case for around $20 and it's alot stronger than the cases you buy from suppliers. Paint it black and add a Aluminum front and your done, easy!

29th July 2005, 08:15 AM	#3
John Biles diyAudio Member Join Date: May 2005 Location: Victoria Australia	here's some pics using a "C" Section as a heatsink. 3 transistors in parallel for each power transistor of the JLH 10watt Class A amplifier. Works Well at 25 degree room temp. transistors only get to 45 degrees case temp

29th July 2005, 09:57 AM	#7
John Biles diyAudio Member Join Date: May 2005 Location: Victoria Australia	Hello Distroyer X, even worst, the stuff is made from steel not aluminum. I have run my JLH CLass A 10watt Amp for hours and the temp stayed the same? One thing for why it might have worked was that i was powering the amp with 28volt rails and not 40volts as is the norm. same ampage levels 1.3amps.