Using the Temperature Sensor/Heater circuit for the PICNIC camera.

For now, please contact Marc Lacasse before using this equipment.

The Circuit and cables are on the bottom shelf of the left black cabinet .  
There is also a PICNIC  readout cable there which is not needed.

There are 3 parts
Bendix 10  to  DB9M & dual inline connector with 6 positions but 4 wires.
DB9 M&F ribbon cable  to  Single inline connector with 3 positions & wires.
NICMOS3 T-Sensor Board
Circuit. .Schematic. .Photo of board. .Photo of three parts 

The Bendix 10 pin  connects to the bottom of the Dewar.
The Dual inline  connects to the center header on the NICMOS3 T-Sensor board.

(I have not changed the labels yet - 
the labels are appropriate for the NICMOS3 and not the PICNIC.
The cable can be used to sense temperature with either 
   but an adapter will be needed to heat the NICMOS3.)

The DB9 Male on the ribbon cable connects to the PICNIC Power supply 
(not the  small card cage).
If detector is used, the DB9 Female connector powers the small card cage.
The inline connector is to the 3 pin header on the T-Sensor board.

Hook up a voltmeter to the GND point and to the Temp Test Point.
A reading of 1.0 volt indicates a temperature of 77K, 
a reading of 0.5 volt indicates room temperature.

Heating feature

There is a 10 ohm resistor in the chip carrier 
which acts as a current limiting resistor.  
There is a net 250 ohm resistor network  between 
+15V and  one end to the resistor.
The other end of the resistor is connected to the 130 ohm 
heating resistor near the PICNIC chip in the Dewar.

If you remove this resistor there will be no heating.

You can put a larger resistor in to get a smaller 
amount of heat introduced.

Carrier R   Current      Chip Power
10            0.038        0.192  
100           0.031        0.127
220           0.026        0.081 
330           0.021        0.058 
560           0.016        0.033 
1000          0.011        0.015
2200          0.006        0.004

Here is the cable pinout in case it is needed

Bendix   DB9   dualinline
A         2  
B         1
C       5 & 9
D                 gray
E                 black
F                 brown
G                 white
H         3
J         6
K         7

gray   x   black
white  x   brown

Marc Lacasse
1/14/2005   rev 2/1/2005