Hi there folks,
I am repairing a friends Yamaha active subwoofer. It uses a Sanyo STK power module. This 60W module has a Tc max of 125 deg. Celsius.
The original power module is a direct short across V+ and V- . The Sub. design has no 'finned heat sinking' and only uses the sheet metal
control panel as cooling. I am assuming that the power module 'blew' due to being pushed very hard at a high temperature.
There is room very close to the module to mount a 240V thermal switch. My local electronic parts shop has a 100 deg. (trip) thermal switch.
My question is >
Is 100 deg. too low, too high or just right in such an application ???
I am repairing a friends Yamaha active subwoofer. It uses a Sanyo STK power module. This 60W module has a Tc max of 125 deg. Celsius.
The original power module is a direct short across V+ and V- . The Sub. design has no 'finned heat sinking' and only uses the sheet metal
control panel as cooling. I am assuming that the power module 'blew' due to being pushed very hard at a high temperature.
There is room very close to the module to mount a 240V thermal switch. My local electronic parts shop has a 100 deg. (trip) thermal switch.
My question is >
Is 100 deg. too low, too high or just right in such an application ???
Agree with 70C being safe, specially in a poorly cooled amp such as that one.
Show a back panel picture, maybe you can add a small finned heatsink on the outside surface, over the Chipamp location.
Probably using some kind of clamp, or bolted to sheet metal if space is available.
Add heat sink grease between new heat sink and original panel surface.
Show a back panel picture, maybe you can add a small finned heatsink on the outside surface, over the Chipamp location.
Probably using some kind of clamp, or bolted to sheet metal if space is available.
Add heat sink grease between new heat sink and original panel surface.
Thank you for your post.
For an extra $20 I will be recommending to my friend the addition of a 'proper finned heatsink' added to the
outside of the 'sheet metal control panel'. I think this will require stripping the black paint back to metal + transfer compound.
I also have the choice of both 70 & 90 degree thermal switches locally.
Cheers
For an extra $20 I will be recommending to my friend the addition of a 'proper finned heatsink' added to the
outside of the 'sheet metal control panel'. I think this will require stripping the black paint back to metal + transfer compound.
I also have the choice of both 70 & 90 degree thermal switches locally.
Cheers
If I'm not mistaken, the STK series of power-modules don't have a very good reputation for quality (?)
Other types of Chip Amps have thermal/current limiting built into design. Some are even output short circuit protected.
Why would a company as large as Yamaha choose such a device ???
( at least there is a DC protection relay circuit incorporated )
Other types of Chip Amps have thermal/current limiting built into design. Some are even output short circuit protected.
Why would a company as large as Yamaha choose such a device ???
( at least there is a DC protection relay circuit incorporated )
With TWO of these heatsinks fitted, I am going to 'push my luck' and go with a 90 degree switch.
https://www.jaycar.com.au/high-efficiency-fan-type-heatsink-55mm-long/p/HH8570
https://www.jaycar.com.au/high-efficiency-fan-type-heatsink-55mm-long/p/HH8570