Ratio_V_F_converter

Published:2009/7/24 1:14:00 Author:Jessie | From:SeekIC

Fig. 12-25 This circuit converts the ratio of two voltages to an equivalent frequency (essentially the same function as performed by the circuit of Fig. 12-16). In this circuit, the two op amps convert the inputs to proportional currents. The 1-kΩ scale-factor trim is adjusted so that the frequency output equals the ratio of V1/V2 x 10 kHz. Full-scale output is 15 kHz. The circuit can accept positive inputs when the op-amps are rearranged, as shown in Figs. 12-25B or 12-25C. Trimming out the offset in the Op amp gives the ratio converter better linearity and accuracy, e trim circuit Fig. 12-25B needs stable positive and negative supplies for the offset trimmer, but the trim In Fig, -25C needs only an astable positive supply. Unmarked components in Fig. 12-25C are the same as those in Fig. -25B.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Power_Supply_Circuit/Ratio_V_F_converter.html

Print this Page | Comments | Reading(3)