DIY High Precision Digital Inductance Meter Capacitance Meter Frequency Meter Kit

Description: The circuit consists of comparator U1B, discharge transistor Q1, Q2, etc. Set the forward input of the comparator to Uc, (Uc = 0.632E, The Rref is adjusted, and the measured capacitor CEx is connected to the reverse input terminal. When the pin of P15 is low level, the capacitor discharges. Note that the pull current of 51 single chip pin is very small, and Q1 can not be directly driven, otherwise the discharge time will be very long. When P15 pin of MCU is high level, capacitor charges, when charged to Uc, comparator flips and triggers outside MCU. The capacitance can be calculated by measuring the charging time and the charging resistance. Name Parameter PCB Mark Quantity Resistor 1K R4 R8 R9 R11 R12 5 10K R2 R17 R18 3 100K R5-R7 3 2K R1 R13 2 100ohm R14 1 47K R3 1 5.6K R15 1 Adjustable potentiometer 502(5k) RP1 1 IC 89C51 U1 1 lm393 U2 1 Inductor 100uh L1 1 DIP 16 hole 1 Self-locking switch 5 Electrolytic capacitor 470UF C4 1 10UF C7 1 1UF C5 1 Monolithic capacitor 105 C14 1 Crystal 12MHz Y1 1 Diode IN4007 D1 1 Resistor packs 10K J1 1 Adjustable resistor 10K RP 1 LED 3MM red D5 1 IC socket 40P U1 1 8P U2 1 Ceramic capacitor 102 C12 C13 2 22P C1 C2 2 Regulator 7805 V1 1 LCD screen LCD1602 1 Transistor 9015 Q1 1 9014 Q2 1 Self-locking switch cap 6 Power socket DC5.5V 1 Female pin header 16p JP1 1 Pin 4P 1 Package Included: 1 x DIY High Precision Digital Inductance Meter Kit