fan cooled gainclone

[steven344]

Here is a stereo bridged clone using computer cpu heatsinks and fan to cool it,advantage of small size.Fan are controled with chip that changes fan speed dependant upon heat

 

[metal]

Hello steven344

Nice work in deeeeed, I use a FAN, but not controlled, seems interesting to add one now, what chip did you use, and what sensor.

 

[n00beR]

I dont know if this is what steven344 has done, but you could use a voltage regulator, in conjunction with a thermistor to regulate the voltage going to the fan.

Just an idea.

here is a link to get you started.

n00b

 

[metal]

Hello n00beR

Brain cooling ideas in deed, thats very good one.... thanks alot man

 

[I_Forgot]

I'm not sure why anyone would need a fan to cool these amp chips, but if it is getting hot, and it isn't oscillating, then you may want to consider this:

The fan will cool the chip after it gets hot, but the package and heatsink have pretty long thermal time constants. By the time your temperature sensor heats up enough to kick on/up the fan, the die inside the package may already be frying. You can sense the current drawn by the amplifier and use that to trigger the fan turn-on/speed up. Here is an article that gives the details:

http://www.elecdesign.com/Articles/ArticleID/5695/5695.html

I_F

 

[youyoung21147]

Is the fan really necessary on such big heatsinks ??

Cooling is always welcome on this kind of thing, but if you take the main trafo's supply, it may pollute the PSU because brushless fans switch the motor phases.

Hope it isn't too noisy

 

[Upupa Epops]

Little bit " nonaerodynamical " tunnel, isn't it thruth ?

 

[karma]

ya but it a fan, makes the amp APPEAR more Powerful and it looks cool

 

[carlosfm]

I'm not sure why anyone would need a fan to cool these amp chips, but if it is getting hot, and it isn't oscillating, then you may want to consider this:

Those are CPU (P4?) heatsinks, not big enough for a bridge amp.
The fans are recommended here, if you use small heatsinks, well done.

Is the fan really necessary on such big heatsinks ??

They are not big, the pic is misleading, I know those, I have some of those CPU heatsinks.
They are fine for two chips, but not in bridge mode

Cooling is always welcome on this kind of thing, but if you take the main trafo's supply, it may pollute the PSU because brushless fans switch the motor phases.

Hope it isn't too noisy

Oui, vous être correcte, a small trafo and independent PSU should be used for the fans.

 

[youyoung21147]

I'w even wondering if this phase switching is not causing some EMI/RFI that could travel in the air to the amplifier, despite the metal heatsink between the chip and the fan.

 

[carlosfm]

I'w even wondering if this phase switching is not causing some EMI/RFI that could travel in the air to the amplifier, despite the metal heatsink between the chip and the fan.

The chips are isolated.
The chassis is grounded (I hope), so if the heatsinks are in direct contact with the chassis, they are grounded too.
Should be no problem.