Device for converting a frequency, proportional to a measurement variable, of an electric measurement pulse into a quantity which can be represented as a quasi-analog quantity.

摘要

This device is particularly suitable for displaying a pulse frequency of a distance pulse transmitter which is proportional to the speed of a motor vehicle. The device has two resettable measurement value counters which are constructed as period counters and successively form counts which are produced by counting out the period of the measuring pulse by means of clock pulses which can be switched step by step. For this purpose, the period counters are controlled by control means so that during the counting, in a measuring period using one period counter, the measurement value formed in the preceding measuring period is read out from the second period counter and conversely. In accordance with these period values counted out, step display values reciprocal to these period values, which are converted into addresses, are taken from a read-only memory and fed into a display memory. From there, they determine a rotation of the stepping motor corresponding to the step display value, to which sign-weighted motor control pulses are applied. The clock pulse frequency is halved step by step with increasing period of the measuring pulse in order to keep the memory content of the read-only memory low inspite of a fine resolution of the step display values. <IMAGE>