More New Toys!

From: Steve Thatcher <>
Date: Sun Feb 27 08:55:18 2005

first, you can't consider an under the covers part a feature... there are
plenty of small companies out there doing transformer winding so cost
wasn't that much more than a standard transformer. Keep in mind that this
product was developed back in the late 70s/early 80s. It was before small
switching supplies and you couldn't find a standard transformer with three
secondary taps anyway. There was room for one transformer and adding a fan
would have made noise. In the long run, you would have had to dissipate
more power, require larger parts for the power supply section along with
heatsinks, require a larger cabinet, and added a fan that made noise. The
box retailed for around $4K and these were sold in the hundreds. If it was
a higher quantity product, then cost reduction would have been more important.

secondly, all the EM series used the same transformer for 110V 60Hz.

best regards, Steve

At 08:22 AM 02/27/2005, Joe R. wrote:
>At 10:35 PM 2/25/05 -0500, you wrote:
> >basically to get the constant voltage output even when the AC supply goes
> >from 90 to 120. A normal transformer will "follow" the line voltage. The
> >power supply board uses schottky diodes and the transformer puts out just
> >enough voltage to be regulated to five volts with minimal power loss (there
> >are a couple of other secondary windings for + and - 12 for RS232). With a
> >normal transformer, the power supply design would have to been different to
> >deal with the higher wattage that it would have had to dissipate.
> I understand all that but AC power is cheap and so is a fan to dissapate
>the excess heat. It's surprising to see a company spent money for features
>like this unless there is a very real requirement for them. Even HP doesn't
>go to this length with their power supplies.
> >transformer was custom wound for AMC.
> And expensive I'll bet!
> >
> >By the way, the EM189 was a 6809 emulator...
> Oops. I guess it was late and I was tired. I had it setting right in
>front of me and I still got it wrong. I should have said EM-180B. I'd sure
>like to find a pod for it but it doesn't look likely. BTW I'm assuming
>that the transformers for the various models all put out the same voltage.
>Is that true?
> Joe
Received on Sun Feb 27 2005 - 08:55:18 GMT

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