COMDYNA GP-6

From: Dwight K. Elvey <dwightk.elvey_at_amd.com>
Date: Mon Nov 4 16:11:00 2002

Hi
 My understanding of the multiply is that you
connect the gray to the input of one of the amps
that show a feedback resistor. The amp inputs are also
gray. You leave all the green leads open. If you
apply a small level to the x and y, the output of
that amp should be the multiply of the x and y.
You can use the pots in the center to create the
small levels used. Remember that there is also
a scale factor involved. K*X*Y= output. I don't
know what the K would be for this setup.
Dwight


>From: "Patrick Finnegan" <pat_at_purdueriots.com>
>
>On Mon, 4 Nov 2002, Doug Coward wrote:
>
>> You wrote:
>> > One last thing - does anyone have an idea of what the "SW" and "OP" jacks
>> > at the bottom of the front panel are,
>>
>> Here is a quotes from a GP-10 brochure:
>> "The OP termination is the system's mode control bus.
>> For centralized integrator mode operation, the SW
>> switch control is patched to the OP bus."
>>
>> My take on this is that if you are not controlling
>> the operation mode from a digital computer or other
>> external device, then you need to jumper OP to SW
>> for each integrator in order to control the mode
>> from the front panel buttons.
>> IC = Initial Condition mode
>> HD = Hold mode
>> OP = Operate mode
>> RO = Repetitive Operation mode
>
>Ummm, I seem to have an older GP-6 that has no such front-panel switches.
>It just has the 'Y/POT Select', 'X Select' and 'Compute time' knobs on the
>front (along with the 8 coefficient pots). There's also four small
>potentiometers, with a slotted shaft (for using a tweaker screwdriver for
>adjustment) along the bottom of the front (on the banana jack half)
>which are unlabelled.... any ideas what they are for? They seem to be
>missing from the model pictured on COMDYNA's web site.
>
>> > and how to use the multipliers? I
>> > can't quite seem to get them to 'multiply'...
>
>I guess you can attribute my lack of understanding this part to my lack of
>usage of analog computers... sometimes engineers need to be a little more
>reasonable in their descriptions IMHO.
>
>> Here is a quotes from a MICROPATCH brochure:
>> "Two multiplier networks may be arranged as
>> multipliers, dividers, squarers, or square root
>> extractors of input variables. Two attenuator-switch
>> networks are needed to electronically program a
>> multiplier or divider. One output is patched to the
>> "X" terminal; the other is patched to the "Y" terminal.
>
>Ok, got that
>
>> When the network is patched as an input to an
>> operational amplifier that has a resistor as the
>> feedback, the amplifier's output is the product
>> of the input variables. When the network is
>
>Does 'the network' refer to the output of the multiplier ( the terminal
>not labeled 'x' or 'y')? If so, that's what I've been doing...
>
>> patched as the amplifier's feedback, the amplifier
>> output is the quotient of the two input variables."
>
>But I just used up the X and Y inputs, how am I supposed to use the
>multiplier as feedback for the op-amp?
>
>It'd be helpful if someone had an example schematic or block diagram of
>some sort...
>
>Pat
>--
>Purdue Universtiy ITAP/RCS
>Information Technology at Purdue
>Research Computing and Storage
>http://www-rcd.cc.purdue.edu
>
>http://dilbert.com/comics/dilbert/archive/images/dilbert2040637020924.gif
>
>
>
>
Received on Mon Nov 04 2002 - 16:11:00 GMT

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