Ad7750 ot
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Will,
Thank you for the info, I will check out your link.
It would be great to get kilowatt-seconds pretty accurately, its a hot
forming app, we need to
measure bends and meet dimensional requirements after heating,i.e. the
different heat input gives different dimensions. Right now, its all done by
seat of the pants, some senior personnel are incredibly good at it.
Also was considering a gaussmeter, any comments
on this method?
Thanks again,
Mark
Original Message
From: will koopman <kiddies@t...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Sunday, August 13, 2000 3:42 AM
Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750
>what you could do is use a standard radio watt meter
>microchip.com have got how to make one in there pic application section
>this would be the ideal thing for an induction heater coil type
>application
>
>
>
>
>
Thank you for the info, I will check out your link.
It would be great to get kilowatt-seconds pretty accurately, its a hot
forming app, we need to
measure bends and meet dimensional requirements after heating,i.e. the
different heat input gives different dimensions. Right now, its all done by
seat of the pants, some senior personnel are incredibly good at it.
Also was considering a gaussmeter, any comments
on this method?
Thanks again,
Mark
Original Message
From: will koopman <kiddies@t...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Sunday, August 13, 2000 3:42 AM
Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750
>what you could do is use a standard radio watt meter
>microchip.com have got how to make one in there pic application section
>this would be the ideal thing for an induction heater coil type
>application
>
>
>
>
>
Comments
The induction heater runs from 120 or 240 AC line, I assume. Have you
looked into watt-second measurement of the AC input? There should be pretty
good correlation between input and output power.
Just a suggestion,
Ray McArthur
> It would be great to get kilowatt-seconds pretty accurately, its a hot
> forming app, we need to
> measure bends and meet dimensional requirements after heating,i.e. the
> different heat input gives different dimensions. Right now, its all done
by
> seat of the pants, some senior personnel are incredibly good at it.
Build an adjustable counter/timer that controls how many cycles of AC line
are applied to the input of the heater. This is often done with SCRs
controlling spot welders, where a little trial and error is used to set weld
time and achieve optimum welds. The main disadvantage is inconsistency when
line voltage changes excessively, but it should be a big improvement over
"seat of the pants".
> Ray McArthur
>
> > It would be great to get kilowatt-seconds pretty accurately, its a hot
> > forming app, we need to
> > measure bends and meet dimensional requirements after heating,i.e. the
> > different heat input gives different dimensions. Right now, its all done
> by
> > seat of the pants, some senior personnel are incredibly good at it.
Thanks for the great suggestions.
Actually, they run on 440VAC, not that it makes any difference, (they do say
there's a huge rate savings on 440VAC (?)) I'm not an expert on this
subject, so humor me a little on the following, but I didn't think measuring
changes in the 440VAC input would give meaningful for a few of reasons.
-The wide 30°F daily ambient shop temperature swings, from early in the
morning to late afternoon.
-They're radiator cooled.
-All the senior personnel are fiercely protective of their "special
settings", i.e, taps, power setting, etc, don't even want to think about
interfering here.
So, I really though I should concentrate on somehow measuring power output
from coil, using a STAMP of course, hooked up to an LCD.
From technical standpoint I like these suggestions a lot, very interesting,
especially counting the cycles-now that's good, learned a lot.
Thanks,
Mark
Original Message
From: rjmca <rjmca@w...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Sunday, August 13, 2000 12:45 PM
Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750 OT
>Mark:
>The induction heater runs from 120 or 240 AC line, I assume. Have you
>looked into watt-second measurement of the AC input? There should be
pretty
>good correlation between input and output power.
>
>Just a suggestion,
>Ray McArthur
>
>> It would be great to get kilowatt-seconds pretty accurately, its a hot
>> forming app, we need to
>> measure bends and meet dimensional requirements after heating,i.e. the
>> different heat input gives different dimensions. Right now, its all done
>by
>> seat of the pants, some senior personnel are incredibly good at it.
>
>
>
>
>
>
That's a tough problem that I have no good ideas for.
Ray McArthur
Original Message
From: techno_masai <plunkettm@e...>
To: <basicstamps@egroups.com>
Sent: Monday, August 14, 2000 11:34 PM
Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750 OT
> So, I really though I should concentrate on somehow measuring power output
> from coil, using a STAMP of course, hooked up to an LCD.
> Mark:
> That's a tough problem that I have no good ideas for.
>
> Ray McArthur
>
>
Original Message
> From: techno_masai <plunkettm@e...>
> To: <basicstamps@egroups.com>
> Sent: Monday, August 14, 2000 11:34 PM
> Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750 OT
>
> > So, I really though I should concentrate on somehow measuring power output
> > from coil, using a STAMP of course, hooked up to an LCD.
Maybe you are " looking " at the wrong end of things ????
What I mean is this ,, how is the heater controlled now .
If it is a " pot " then you most likely have a DC. voltage level
And I bet you a cup of tea that there is circuitry that converts the
output power level to a DC voltage that is compared to the
control voltage level to set the phase angle for driving the SCR's
Also I would think that a " heater " of the size that you are describing
would have some type of output level indicator ... If there is no meter
on the control panel , there is still a chance that there is some kind of
circuitry for a output level meter on the driver board.
Also you might want to try this . Put a few turns of insulated wire
around the main output bus - bar connect this " coil " to a
bridge rectifier AC. put a cap and a meter on the DC. and
adjust the turns till you see a workable voltage level.
Good Luck Raven
current coils to make connections relatively easy, and all the metering
functions you'll need.
Paul
rjmca wrote:
> Mark:
> That's a tough problem that I have no good ideas for.
>
> Ray McArthur
>
>
Original Message
> From: techno_masai <plunkettm@e...>
> To: <basicstamps@egroups.com>
> Sent: Monday, August 14, 2000 11:34 PM
> Subject: Re: [noparse][[/noparse]basicstamps] RE:AD7750 OT
>
> > So, I really though I should concentrate on somehow measuring power output
> > from coil, using a STAMP of course, hooked up to an LCD.