Low Cost High Linearity Solid State Digital Double Boxcar

Abstract

In this article, we describe a digital solid state double boxcar of infinite holding time and very high linearity. It uses a Hewlett-Packard (HP2212 A-M3) voltage-to-frequency converter (VFC) whose output is accumulated on a running counter, thereby providing signal averaging with an infinite holding time. The combination of FET signal gates with zero offset and the highly linear VFC results in a linearity of better than ±0.01% over an input range of ±1.0 V, which is a considerable improvement over that available with other digital boxcars. Integrated circuit pulse generators of high stability provide gating times from a fraction of a microsecond to many seconds. A unique monitoring system allows ease of adjustment with a simultaneous ``master'' display of all gating and signal functions. Other features of this boxcar are extreme compactness, low cost, and very high stability.

A low-cost gated integrator boxcar averager

“…The development of boxcar circuits has continued since the first circuit in 1954 [6], with the utilization of ceramic diodes [7], digital technology [8], discrete transistors [2], voltage to frequency conversion [9], frequency lock-in [10], solid state memory [11], multiple channels [12], fast sampling [13] and microprocessor based circuitry [14].…”

Health Status of Family Members on Family Investment

“…To this end, Sharpe (1963) [3] proposed a simplified model to associated the yield of a certain securities with the volatility of the whole market. Later, the CAPM model was developed on this basis, the core of which was to explain the rate of return investors should demand to compensate for a certain degree of risk.In terms of expanding the time dimension, Samuelson (1969) [4] uses a dynamic stochastic process to develop the single-phase asset-selection model into a discrete cross-phase model.…”

A simple and inexpensive two channel boxcar integrator

“…Boxcar integrators are widely used in pulsed NMR measurements to improve the signal-to-noise ratio. Most of the circuits described in the literature (Allen et al 1970;Blume 1961;Clark and Kerlin 1967;Hodby 1970;Niemela 1972;Packer and Strike 1970;Reichert and Townsend 1964;Samuelson and Ailion 1969;Sandhu 1974;Stejskal 1963;Ware and Mansfield 1966;Woessner et al 1969) do not incorporate a digital display and the few that contain systems for digital conversion are based on commercial units and are therefore generally expensive. In this paper we describe a simple and inexpensive two channel boxcar integrator with digital output, built from readily available components.…”