Digital scale converter
AssigneeThe United States of America as represented by the United States Department of Energy
InventorRichard G. Upton
Life of this patent
Estimating the term…
Abstract
A digital scale converter is provided for binary coded decimal (BCD) conversion. The converter may be programmed to convert a BCD value of a first scale to the equivalent value of a second scale according to a known ratio. The value to be converted is loaded into a first BCD counter and counted down to zero while a second BCD counter registers counts from zero or an offset value depending upon the conversion. Programmable rate multipliers are used to generate pulses at selected rates to the counters for the proper conversion ratio. The value present in the second counter at the time the first counter is counted to the zero count is the equivalent value of the second scale. This value may be read out and displayed on a conventional seven-segment digital display.
Claims3
A digital scale converter for converting a binary coded decimal (BCD) value of a first scale to the equivalent value of a second scale according to a known ratio X/Y, comprising:
- a readout means for registering the first scale value prior to conversion, said readout means having a plus/minus indicator output;
- a first BCD counter having inputs for accepting said first scale value from said readout means in response to a reset pulse applied to a preset input thereof, said first counter having a count pulse input and a zero count output;
- a second BCD counter having a count pulse input, a preset input and BCD count outputs;
- means for generating and applying said reset pulse to said preset inputs of said first and second counters at the beginning of each conversion;
- means for selecting an offset BCD value to be loaded into said second counter when said preset pulse is applied to said preset input thereof;
- a first programmable pulse rate multiplier having a clock pulse input and programmed to produce count pulses at a rate B according to a selected binary code applied to binary coded inputs thereof and applying the count pulses to said count inputs of said first BCD counter to count said first counter in the down direction at said rate B;
- a second programmable pulse rate multiplier having a clock pulse input and programmed to produce count pulses at a rate A according to a selected binary code applied to binary code inputs thereof and applying the count pulses to said count input of said second counter at said rate A during the count interval of said first counter, wherein the ratio of rate A to rate B is equal to said ratio X/Y;
- a clock pulse source connected to said clock pulse input of said first and second rate multipliers;
- switching means for selecting and applying said binary code to said binary coded inputs of said first and second rate multipliers according to the desired pulse rate ratio A/B;
- a bistable switching means having a reset output connected to a count direction control input of said second counter;
- gating means responsive to said plus/minus indicator output of said readout means for operating said bistable switching means in response to said reset pulse to switch said second counter to count in the up direction when said offset value is to be added to the converted value and to count in a downward direction when said offset value is to be subtracted from the converted value, said bistable switching means having a direct reset input connected to zero count output of said second counter so that said second counter is switched to count in the up direction when said offset value is counted down to zero during the conversion;
- and
- means responsive to the zero count output of said first counter for reading the count pulses registered by said second counter and displaying said second counter registered value as said second scale value when said first counter is counted to zero.
Dependencies are inferred from the claim text.