Calculator indicating instantaneous revolutions - uses analogue current varying between zero and 20 milliamps. depending on position of decimal point of result stored in 4 digit memory

摘要

A calculator indicates the instantaneous revolutions using a load-independent analogue current output. The strength of the current varies from 020 mA. This analogue current is completely linear and a controlling tachogenerator is no longer necessary. The result from the calculator is stored in a four digit memory and converted by means of a d-a converter into a corresponding current. Circuit connections decide on the validity of the conversion. If, for instance, a speed of 10 to 99.99 r.p.m. is necessary for the control the connections are formed so that the decimal point signal after the second place of the result releases the control. If the decimal point signal appears after the first place, the analogue current increases to 20 mA. If it appears after the third place, the current sinks to OmA.