Projector for displaying electronic circuits - uses circuits formed on transparent circuit boards, and meter with transparent scale, and liq. crystal digital displays

摘要

The teaching and demonstration circuits are mounted on transparent plastic plates whose size is suitable for daylight projection. Holes are drilled in the plate at junction points of the circuit, and provided with fastenings for actual components and meters. A measurement result display unit (2) has in its transparent projection surface (12) several light transmitting liquid crystal elements (8-10) for digital display of numbers, letters and symbols, and a scale (14, 16) allocated to a pointer (7) whose ranges can be selected and displayed by a control unit.