Rapid electronic weighing balance - uses circuit to determine equilibrium value during oscillation by comparing its frequency with empirically derived values

摘要

When objects are placed on an electronic weighing machine, it is normally necessary to wait for oscillations to cease before obtaining an accurate result. The present circuit measures several of the early swings of the damped sinusoidal oscillation to determine the eventual weight at which the balance will settle. The time necessary depends on the oscillation frequency but, for example, an oscillation of 30 to 40 Hz can be resolved in about 100 ms. The weighing machine (4) output (1) is amplified (6), integrated (7), band pass filtered (8) and fed to a voltage-to-freqeuncy connecter (9). The connecter output is counted (10) to produce an output figure, under the control of a sequence controller (11).