# Accession Number:

## ADA595934

# Title:

## Principles of the REAC

# Descriptive Note:

## Research memo

# Corporate Author:

## RAND PROJECT AIR FORCE SANTA MONICA CA

# Personal Author(s):

# Report Date:

## 1949-01-19

# Pagination or Media Count:

## 12.0

# Abstract:

The purpose of this report is to acquaint potential customers with the capabilities of the Reeves Electronic Analogue Computer REAC now in operation at RAND. The REAC does with electric circuits what the mechanical differential analyzer does with gears, shafts, and discs, but operates roughly at ten times the speed and one-tenth the accuracy. A problem of average complexity requires a few hours of REAC preparation and testing, after which individual runs can be made in a few minutes. The components of the machine have been adjusted to make the error of a single operation addition, integration, multiplication, etc. less than .1 percent of full scale. The machine will be particularly useful in the solution of nonlinear or implicit equations, or systems of equations which are extremely difficult to handle analytically or numerically. In an electronic differential analyzer, quantities are represented by voltages. The constant of proportionality between the voltage at a point in the circuit and the quantity it represents is referred to as the scale factor. It is the number of volts representing one unit of the quantity. In the REAC, variables must lie between -100 volts, since greater values produce erroneous results. Lights and bells indicate any variable exceeding these limits. The next section will present the components which permit summation, integration, multiplication, etc., of these variables the principles of the components are given in the appendix.

# Descriptors:

# Subject Categories:

- Computer Hardware