H7140 PDP 11/24 Power Supply Advice

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Tue Nov 13 14:08:31 2001

At 11:09 AM 11/13/01, Tony wrote:
>I have never understood this arguement, never will. Suppose the
>difference (in the quantity they use the caps) is 10 cents per component.
>Suppose overall they sell the machine for $1 more as a result. Do they
>honestly think they'll sell significantly fewer machines?

The argument goes like this:
      - You sell 5 million units.
      - Your average selling price is $3500 (some are
         more some less, depending on channel, sales aggression
         etc.)
      - You save $0.10 on a each of 10 capacitors for
         a costs saving of $1.

That is $5 million dollars ($1/unit) that you add to your bottom line. If
you've got 5 million shares of stock outstanding that add 1 cent/share to
your earnings.

If that makes your product fail more often and you have to repair them
(warranty etc) then you subtract that cost, but the "argument" for "value
engineering" as it is euphemistically referred to, is simply numbers. Well
run businesses run exactly like your computers Tony with very similar
schematics, however money replaces current and credit replaces voltage.

The equivalent argument in electronics could be made with a resistor
     - You are pumping 5 amps of current
     - Your circuit has to drop 3.5 volts
       on average (some more some less depending
       on control settings)
     - You add three diodes rather than using a switching
       regulator. This causes you to dissipate 17.5 watts
       from the diodes.

That's 17.5 watts that goes into heat rather than doing useful work. If the
circuit can tolerate the heat then it is simpler than a switching
regulator. But it may shorten the life of the circuit.

Its a mechanical analytical thing, not a big profit conspiracy as some
would have you believe.

--Chuck
Received on Tue Nov 13 2001 - 14:08:31 GMT