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Heat sinks from Conrad Heatsinks

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J

jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
Re: Might be to big, but......

Flodstroem said:
Hi SCD and jleaman

Those Conrads (# MF-35-151) has a dissipation factor of 0.21°K/W and it means if the dissipating power is 72 W as a maximum, one of those sinks will rise in temperature by 0.21 x 72 = 15.1° K (C) above ambient. If ambient is 25°C heat sink temp. will be ca 40-41°C.

This is a rather moderate temp. rise and indicate the sink would be a little bit "overkill". If building a stereo amp. using two of those sinks will yield a class-A amp running very cold compared to traditional ones.

But, if you later come to the conclusion that this output power was to low for you and would like to rise output power to say, 25-30W, then those (GB-) Conrads would fit perfectly.

Its finally up to you to decide if this is what you want or you could buy a smaller type heat sink making total costs for the amp lower.

Regards :cool:
Click to expand...

If they are over kill that is great. That means we can up the bias and get a little more power :)
 
F

Flodstroem

Member
Joined 2004
Ordering Monday next week

Hello
all members who join this GB for the Conrads heat sinks.

Status so far:
84 pcs payed for
14 members payed for sinks (its all that should), only 2 members did pass this opportunity.

I shall try to order sinks in Monday next week (04.24.06).

All of you will receive a tracking number for to check package in the route (but I havnt confirmed that with Conrads but I expect there is a tracking number to receive).

Thank you all for joining this GB, I really appreciate all your support in this GB.

BTW,
there is a new thread started at "Solid Stale" by Mark G.: Krell clone KSA 100 mk-2 if there is someone who dont know what to use those Conrads for.

Best Regards :cool:
 
J

jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
Re: Ordering Monday next week

Flodstroem said:
Hello
all members who join this GB for the Conrads heat sinks.

Status so far:
84 pcs payed for
14 members payed for sinks (its all that should), only 2 members did pass this opportunity.

I shall try to order sinks in Monday next week (04.24.06).

All of you will receive a tracking number for to check package in the route (but I havnt confirmed that with Conrads but I expect there is a tracking number to receive).

Thank you all for joining this GB, I really appreciate all your support in this GB.

BTW,
there is a new thread started at "Solid Stale" by Mark G.: Krell clone KSA 100 mk-2 if there is someone who dont know what to use those Conrads for.

Best Regards :cool:
Click to expand...



I'll email scd about this to see if he has paid or not. I don't want him to miss out on this.

I hope all goes well and even tho im not apart of this buy. I would like to say Good job and hope all goes well.

Jase
 
mpmarino

mpmarino

Member
Joined 2004
Re: Re: Hello SCD

jleaman said:



I got this.. HIs amps are going to be. >


Voltage after the rectifier 12.0 V
Voltage at the Fets 24.0 V
Bias 1.5 A
Ac current gain 55%
Number of fets 4
Peak current 1.67 A




An externally hosted image should be here but it was not working when we last tested it.
Click to expand...

Sorry but is there an error? Voltage at the fets is entered at full swing. Should it not be entered as 'plus' to ground? I'm not nit-picking here, just want to make sure I'm using the spreadsheet right and the info is right:confused:
 
mpmarino

mpmarino

Member
Joined 2004
jleaman said:
The spread sheet just helps you determin your bias and rail voltages you wish to achieve. Do you need help ?
Click to expand...

I don't think so. I am just noticing that you doubled the rail voltage for the "voltage at the fets" field. Shouldn't this field be populated at a number somewhere around 2 volts less than the "actual rail voltage between positive and ground at the fets"?

Should it be as below?..much less dissipation as estimated above. Not to mention, aren't the voltages discussed a bit low for good linearity? I'm not trying to be a jerk here. I'm in the midst of designing an A-X myself right now and want to be sure I have my facts straight.

This is all OT anyway so my apologies for the thread clutter, I seem to be pretty good at that
:rolleyes:
 

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TonyTecson

TonyTecson

Member
Joined 2003
AKSA said:
I am a good friend of Julian Wales, the owner of Conrad Heatsinks. We often do coffee on Sunday mornings and discuss Jaguars (he likes them much more than I do, owned a V12 for years, and now drives a lowly 318i BMW with lamentably poor torque!!)

I use his heatsinks in all my kit amplifiers. They are magnificent, inexpensive by comparison with extruded sinks, and come with a ledge cast on which makes it very easy to mount amplifier modules without thermal penalty.

Flodstroem, the MF18 you are using is unique. When you have it in your hands, you will see why. The tips of the fins are only 1.5mm thick and exquisitely fine; this is an incredible achievement for an Al casting. With a 120mm x 120mm fan at half voltage, turning around 1500 rpm, I once dissipated 175W of heat from five mosfets with only 27C rise above ambient using just one MF18-200; this is an exceptional heatsink, as suited to cooling oil from an internal combustion engine as it is to electronics!

Cheers,

Hugh
Click to expand...

hello Hugh,

how's your hybrid amp going?

any chance you can convince him to make bigger castings, say 700mm x 200mm.?
 
F

Flodstroem

Member
Joined 2004
All sinks payed.

Hi all the members at this GB for Conrads Heat Sinks.

jimbo1968:
So,
Were they ordered?
Do we get a tracking number?
Click to expand...

Yes I can understand you are interested to receive information regarding the shipment etc...

Payment done for a totals of 86 pcs in the end. Waiting for the info. from the Conrads.

You will hear from me soon.

Regards :cool:
 
F

Flodstroem

Member
Joined 2004
Updates for shipment, + inform.

Hello

This information was received from the Conrads by Julian Wales:

Thank you for your reply and payment has been received - also with thanks.
All the consignments should be despatched by Tuesday 16th May (Wednesday at the latest) except those that are drilled and tapped - allow an extra week for those. I will confirm despatch and advise consignment numbers when they are sent.

Concerning loss/damage in transit, we will cover loss or damage in transit with replacement at no extra expense.
I don't envisage any difficulties - we have found Aus. Post very reliable and none of our consignments have ever been lost to date and only once was there any slight damage.
Click to expand...

Any further information, please e-mail me.

Regards :cool:
 
T

tommak

Member
Joined 2003
Re: Shipping status

Flodstroem said:
Information from Conrads says heat sinks been shipped, finally. To some of you mambers that this is relevant: tracking number will be sent to you as soon as I receive them from the Conrads.

Regards :cool:
Click to expand...


Flodstroem,

I received your email with the tracking number, but I'm not sure where to check the status. Is there a web site I should be looking at, such as FedEx, UPS, etc.?

Thank you,

Tom
 
F

Flodstroem

Member
Joined 2004
Tracking inquiry

Hello!

Tracking inquiry should be made at your local (national) Postal Services, for example like the USPS in the USA, or what ever the name would be of your local postal services (here in Norway it is "Posten Norge")

There you will find the date of package-arrival and other relevant information.

If you dont find any information of your package, please let me know by a PM or an e-mail directly to my address: ramon.flodstrom@knett.no.

I would also take the opportunity to thank you all for joining and making this GB possible, -Thanks a lot all of you!

Best Regards :cool:
 
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