Long description

This is a photograph of a breadboard on which the circuit shown in Figure 17 has been constructed. The op-amp is a black rectangle with eight pins. The resistors are small beige components with stripes to show their value (as described in Table 3), and the light-dependent resistor is a circular component with a red photosensitive stripe on the top surface. The LED is a small red cylinder.

Two photos of the breadboard are shown, one in light conditions (where the LED is not illuminated) and one in dark conditions (where it is).