"Thermodynamics Of Power Amplifier Operation," David Engstrom, Sound and Video Contractor, April 20, 1973.
https://proaudiodesignforum.com/images/ ... 0_1973.pdf (18.6 MB)
"Thermodynamics of Power Amplifier Operation," Engstrom
- mediatechnology
- Posts: 5458
- Joined: Sat Aug 11, 2007 2:34 pm
- Location: Oak Cliff, Texas
- Contact:
Re: "Thermodynamics of Power Amplifier Operation," Engstrom
Unlike the phono preamp paper, it's clear these guys are NOT familiar with my heatsink work ( US patent 6,515,859 Roberts , et al. February 4, 2003) but since that article was published in 1993 a decade before my patent issued I guess I should give them a pass.
For the record their figure B where they talk about varying the spacing between devices on a forced air heat sink to allocate more heat sink surface area to accommodate the delta in cooling air temperature, to equalize device temperatures is drawn backwards.. The devices further away from the fan should be the ones spaced further apart to get more cooling from the warmer air, not the ones closer to the fan (like in their drawing). Perhaps if the fan was sucking rather than blowing air, their way would work, but with forced air cooling you get much better air flow control when blowing air, so cooling fans don't suck.
My patent describes an approach where a pair of vertical heat sinks are toe'd in closer together at the hot end as they get further away from the fan to equalize the cooling effectiveness.
JR
PS: One of the guys so wrote a side-bar for that article (Bob Lee) used to work for me back in the early '80s.
For the record their figure B where they talk about varying the spacing between devices on a forced air heat sink to allocate more heat sink surface area to accommodate the delta in cooling air temperature, to equalize device temperatures is drawn backwards.. The devices further away from the fan should be the ones spaced further apart to get more cooling from the warmer air, not the ones closer to the fan (like in their drawing). Perhaps if the fan was sucking rather than blowing air, their way would work, but with forced air cooling you get much better air flow control when blowing air, so cooling fans don't suck.
My patent describes an approach where a pair of vertical heat sinks are toe'd in closer together at the hot end as they get further away from the fan to equalize the cooling effectiveness.
JR
PS: One of the guys so wrote a side-bar for that article (Bob Lee) used to work for me back in the early '80s.
Cancel the "cancel culture", do not support mob hatred.