The utility model relates to the technical field of weighing instruments, and provides a static weighing instrument, which comprises a weight detection circuit, and the weight detection circuit comprises an
operational amplifier U1, an
operational amplifier U2, a
triode Q2, a
triode Q3 and a
pressure sensor U4. The in-phase input end of the
operational amplifier U1 is connected with a Vref reference
voltage, the output end of the operational
amplifier U1 is connected with the base
electrode of the
triode Q2, the collector
electrode of the triode Q2 is connected with a + 12V power supply, and the emitter
electrode of the triode Q2 is connected with the first power supply end of the
pressure sensor U4; the inverting input end of the operational
amplifier U2 is connected with the in-phase input end of the operational
amplifier U1, the output end of the operational amplifier U2 is connected with the base electrode of the triode Q3, the collector electrode of the triode Q3 is connected with the second power supply end of the
pressure sensor U4, the emitter electrode of the triode Q3 is connected with the-12V power supply, and the output end of the pressure sensor U4 is connected with the main
control unit. According to the technical scheme, the problem that the weight information collected by a static weighing instrument in the related technology is inaccurate is solved.