Charles S Potter

US Patent:

43061931, Dec 15, 1981

Filed:

May 8, 1979

Appl. No.:

6/037129

Inventors:

Charles W. Potter - Cypress TX

Assignee:

Lasertron Company - Houston TX

International Classification:

H03K 524

US Classification:

328146

Abstract:

A comparison circuit for use in an apparatus including a source of a coherent light beam of low divergence for quickly and simultaneously establishing a plurality of reference lines or planes for use in leveling, squaring, plumbing, and other alignment functions and for controlling the operation of construction equipment is disclosed. The present invention is a circuit that finds particular utility in automatically adjusting the orientation of the tool. More particularly the present invention is a circuit for comparing the amplitude of a first alternating current signal to the amplitude of a second alternating current signal, such signals being in phase with one another and having the same frequency.