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Assembly and Operating Instructions for Kits


Parts for the Light Sensor Kit (LT2)


Assembly instructions for other kits


Parts Guide (LT2)


Below is a list of the parts supplied with the LT2 Light Sensor Kit. Click on the photos for larger images.

PCB-mount parts


Project box parts

Connectors, cable, and wire


We may occasionally make changes to the parts list without notice in order to improve the product.


Name/Description part no.


Quantity Notes
PCB-mount parts
PC board PCB PC board 1  
14-pin socket 14PS 8-pin socket 1


100-Ω fixed 100R

100-ohm resistor


1-kΩ fixed 1kR

100-ohm resistor


0.01 μf 0.01C 0.01-uf capacitor 1  
555 timer 555 555 timer 1

555 timer pins

Note the location of pin 1 relative to the notch on the IC.

Optocoupler PS2501 PS2501 optoisolator 1  


Click here for replacement parts.


Phototransistor or Phototransistor

v1       or        v2


For the piece with two legs, the longer leg is positive. For the piece with 3 legs, see the diagram below.


Project box parts

Click here for replacement parts.

Name product code Photo Quantity Function Polarity and Connections

Small project box

3.125" long x 2.0" wide x 0.875" deep

(7.9x5.1x2.2 cm)

PB-S project box 1    
Project box labels     1 strip Stick on labels are provided in strips to identify the components on the project box.  
Template for box lid   LT2 box lid template 1 A paper template sized for the lid of the project box is provided in order to obtain the correct placement of holes for the components.  
9-V battery holder with hook and loop strips 9BH laydown battery holder 1 9-V battery clips in to this laydown container. The supplied hook and loop strips are used to stick the holder down to the inside of the project box. red wire is positive; black is negative
Toggle switch SW2 SPDT switch (red) 2 On-off switch for power and focus no polarity
Linear-taper potentiometer, 1M


linear taper pot


Sensitivity adjustment


Pointer knob

PK knob 1 Pointer for potentiometer setting  
3.5mm mono panel jack 35MJ 3.5mm mono panel jack 1 Receptacle for phototransistor cord Pin 1 is for ground; pin 3 is for positive
3.5mm stereo panel jack 35SJ 3.5mm stereo panel jack 1 Output jack for the shutter cable

Terminals 1-3 connect to the sleeve, ring, and tip respectively of the corresponding stereo plug.

Connectors, Cables, and Wire

Name product code Photo Quantity Function Polarity and Connections

3.5mm mono connector (male)


3.5mm mono plug

1 For the phototransistor cable  
2-conductor cable 2CA-3 3-conducor cable 3 ft For the phototransistor cable  
Hook up wire







4 in





3/32" heat-shrink tubing HST332 heat-shrink tubing 2 in For the phototransistor cable  
3/16" heat-shrink tubing HST316 3 in  






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