Seed drill sensor with two complementary housing sections - has seed duct between transparent plastic and incorporates light source with sensor and impulse transmitter

摘要

The seed sensor consists of two housing halves (50, 51) each of which has a cavity (56, 57). The first cavity (56) has a circuit section consisting of a lighting diode and resistor. The second cavity (57) contains the other electronic circuit-section. The housing halves have ducts for leads joining the resistor and diode. On the inner sides of the housing halves (50, 51) are several lengthwise ridges (60, 61) running outside the end surfaces of the diode (23a) and light sensitive transistors (27a). The ridges diode (23) and transistors (27a) are coated with transparent epoxy material (62, 63). A printed circuit board (70) is mounted on a pin (71) inside the first cavity (56). Inserted through the board (70) are leads (74) fixed by soldered connections (72, 73). A circuit section (22a) on a printed circuit board (84) is carried by two supports (86, 87) and has inserted through it leads (81) of the transistors (27a) attached by soldered connection (80). One lead (100) leads to the outside.