Patent ID: 11891228
Assignee: CHANGZHOU BESTFULL MOULD & PLASTICS CO., LTD
Field: Handling (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 1:
2. The automatic air-extracting sealing box cover according to claim 1, wherein the collection circuit comprises a first operational amplifier (IC11) and a second operational amplifier (IC12); a first signal output end and a second signal output end of the pressure sensor are connected respectively to in-phase ends of the first operational amplifier and the second operational amplifier, out-phase ends of the first operational amplifier and the second operational amplifier are connected respectively to output ends of the first operational amplifier and the second operational amplifier; the output ends of the first operational amplifier and the second operational amplifier are connected in series respectively to a first voltage dropping resistor and a second voltage dropping resistor (R13 and R14) and then connected to an out-phase end and an in-phase end of a third operational amplifier, and an output end of the third operational amplifier is connected in series to a third voltage dropping resistor (R20) and then connected to the pressure signal input end of the controller; an RC parallel circuit is provided between the out-phase end and the output end of the third operational amplifier (IC13); an output end of a fourth operational amplifier (IC14) is connected in series to a fourth voltage dropping resistor (R12) and then connected to the in-phase end of the third operational amplifier, and the out-phase end and the output end of the fourth operational amplifier (IC14) are connected; a first voltage dividing resistor and a second voltage dividing resistor are connected in series between +2.5V direct current power source end and a grounding end, and an in-phase end of the fourth operational amplifier (IC14) is connected to the connecting ends of the first voltage dividing resistor and the second voltage dividing resistor.