[Coco] Re: 512k CoCo 3 with 6309 on ebay (Mike Pepe)
theother_bob at yahoo.com
Thu Jun 16 11:38:23 EDT 2005
> > Dave wrote:
> >> Nice machine Mike!
> >> Where did you pickup the 5V off the board for the fan and any current
> >> limitation?
> > Right off the main power transistor. The power consumption is really
> > quite low, though I usually like to run 12v fans off the unregulated DC.
> > Only annoying thing about that is the busier the computer is, the more
> > that unregulated supply sags, and the fan's speed drops. I guess its
> > like an audio cpu load meter.
> Ok, so I was not hearing things :-)
> I hooked up a small 12 vdc fan also to the unregulated side of the power
> supply to try and avoid as much as possible overloading the already taxed
> regulated side of the CoCo 3 ps.<snip>
> Depending on what I was doing while using the CoCo the pitch noise of the
> fan would definetively change, and I figured the pitch change was a result
> of a speed change due to a fluctuaing unreg 12Vdc as the load from the CoCo
> electronics shifted.
> While my current internal fan does cool off pretty well the CoCo, it is very
> noisy and currently I am in the process of setting up a new fan in there,
On my portable CoCo3 I hooked a 12v PIII CPU fan up to the regulated 8v power.
This dropped it from a bit noisy to a faint whisper, and it still cools quite
well. At 8v it's drawing only about 40mA, and a finger on the 8v regulator
feels barely warm.
I have a floppy drive running off the CoCo's 5v regulator, as well as a small
amp/speaker, Turbo LED circuit and an inverter chip (which lets me swap sides
of the 3.5" disk). I plan to replace the 5v reg. heat sink with a finned one,
and the fins are angled to "duct" the air towards the fan, which is already
pulling it out the top of the case.
Find restaurants, movies, travel and more fun for the weekend. Check it out!
More information about the Coco