Fred – a light-seeking robot by Peter Holland.
from Radio Control Models & Electronics, December 1964.
Fred is a light seeking elictrically propelled tricycle with a light sensitive automatic homing device. The basic principles of light sensitive circuits have been combined with a simple scanning device to give proportional automatic steering to a single driving wheel.
see full pdf here 
.
See David Buckley's version here.
A design by Peter Holland, Radio Control Models & Electronics, December 1964.
Probably the first published design for a phototropic vehicle which didn't follow Grey Walters design of a scanning turret coupled to the front wheel. Instead Fred's turret independently rotates and a sensor integrates the light level over the Port and Starboard sectors and directs the steering to head to the brightest sector.
Photos show David's version, May 1990.