Question

Could someone please write worked solutions for part 2-5 of this question? Thank you

Q3 (35 marks) An accelerometer with a charge sensitivity of 83 pC/g and a capacitance of 1000pF is connected to a voltage follower with an input connector capacitance of 15pF (in parallel with the cable capacitance), a 10,000pF blocking capacitor and a 100M2 resistance. A 3m long cable with a capacitance of 312PF connects the accelerometer and the voltage follower. Determine 1) The schematic of the instrument; (5 marks) 2) The instrument's voltage sensitivity in mV/g; (10 marks) 3) The time constant of the instrument; (5 marks) 4) The minimum sampling frequency required to sample the data; (5 marks 5) The gain required in order that the instrument can measure the acceleration from 0.01g to 1g using a 12-bit +5V A/D converter. (10 marks) Ampiifier input Cable Transducer Voltage follower Съ С, С. 2 83 =62.55MV/g 1327 . S= C 3) f =2.72Hz 4) G=3.90313 5)

Answer 1

Sat with a acceleronmeley Charge Sen Silivily of 23 and a Capa citanu Cc of looo Pf i's Conneted +o a followe wrth am Popu Conneclov Capacilanu (Cin) of 15 Pi, ReSistanu (do00 Pf blocking Capacitoy -A 3m Lable Orth a Capacilanu C) of 32 Pf Connedts Th accelevometey and The Votage follower. houn Given data the schemaic of The Pnstrument is Cg occ (COMO 5PE (2) nThe Circoit he Ca pacitors C, Cin, m ona i'n Parlla J be Capacitanu s eICalnlent C Cm+C coo P t5 PF t312 PE - 32-1 PF The Voage sensitivity is, Sa Sy 83X161- 13T 62.55 m V/g

(3) he ime Ccnslant of -1be Inslhument 5 P tOX (05 (H.5x (o 0ll115 Second =O-ol15 secm 71Sms (4) The minimum Sampling De0ency Peqoired -to Samele the data 7URC Capacitanu i -1he Sevies Combination of Capacitors Hoe The and CB Ca CB Ce tSB 12 (1337 10) (100co x16 )+Ct occo X16) C1321 KO O I 54 PF Now 2TIRC CtooxiCtr.sy xiö - 3585 2

Conside The folowing elation) 5) CtCint -B) CA -1) 831 A 2 (o00 x ö + 15 x 10 +312 X 10 "-0000X 10 (-tl 22 (83)A (-T613) 5C-A-1) 39.2A 5 A-5 44 2-A =5 A o.l3 thus, The Reoied gain is, -A 0-3