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Old 21st Feb 2021, 3:51 pm   #11
Electronpusher0
Nonode
 
Join Date: Jun 2016
Location: Bognor Regis, West Sussex, UK.
Posts: 2,294
Default Re: Weller EC2000D repair

I have now plotted the curve.
I used a bit of aluminium foil wrapped round the element to fill the gap between the element and the bit. I used a modified bit with a hole drilled in it into which I fitted a type K thermocouple connected to a commercial temperature meter.

Allowing for the thermal gradient between the element and the bit the measured values are in reasonable agreement with the data I found on the net.

It would be very difficult to tailor the Hakko to mimic the weller exactly but if a 78 ohm resistor (68 ohm plus 10 ohm in series) is connected across the Hakko thermistor then the error vs the Weller is 6% low at 400 deg, 0% at 350 deg plus 4% at 300 deg and plus 14% at 200 deg.

Probably good enough to be useable.

I attach the Excel spread sheet with the calculations and a picture of the graph.

Peter
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File Type: xlsx Corrected Hakko 2.xlsx (14.3 KB, 60 views)
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