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Old 26-11-2016, 12:26 PM
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rcheshire (Rowland)
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rcheshire is offline
 
Join Date: Apr 2010
Location: Geelong
Posts: 2,617
Wish I had the time. Great project and I have D70 CCD. Project burn out.

Is this of any help for your TEC calculations.

TEC hot side (TH) formula; where

TA = air temperature
Q = heatload - active + passive

Calculate Heatsink RQ

TH = TA + (V*I + Q)RQ

Transposing;

Heatsink Rating C/W

RQ = (TH - TA)/(V*I +Q)

or, substituting W for V*I

RQ = (TH – TA)/(W + Q)

Calculate copper plate passive heat load

Passive heat load formula Qp = kAD/L where;

k = the conductivity value of the material
A = the area of the conduction source
D = the differential between air temperature and component temperature.
L = the length of the conductive medium
k (kappa) of copper = 348 - steel k = 56 - fibreglass or plastic attributed k = 0.04.

Sensor active heat load
~250mW / MP - just an estimate.

I've attached an RQ calculator which is interesting to play with. Based on the TH formula above.
Attached Thumbnails
Click for full-size image (RQCalcUsage.jpg)
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Attached Files
File Type: zip RQCalculator.xls.zip (4.0 KB, 26 views)

Last edited by rcheshire; 26-11-2016 at 04:39 PM.
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