Conversion of digital pulses into analogue DC - uses period range related to level and surface content equivalent to imaginary pulse

摘要

Circuit for converting pulses in direct voltages, is used where it is necessary to convert digital signals into analogue signals. The pulses are fed to an integrating circuit which produced direct voltage outputs used for tuning television or radio receivers. The different pulses fed to the integrator all have a period which lies within a given range. The period range involved is related to the desired level of the direct voltage. The sum of the surface contents of the generated pulses over a given period and a given direct voltage is equal to the surface content of an imaginary pulse in the same period with a pulse duration which is related to the direct voltage and the maximum voltage. The number of pulses spread over a given period remains constant and the pulse width is chosen to respond to the value of the direct voltage.