Utility model content
Technical problem to be solved in the utility model is to provide a kind of contactless electrostatic potential tester, and it is little that described tester has volume, and testee current potential is affected to little feature.
For solving the problems of the technologies described above, technical solution adopted in the utility model is: a kind of contactless electrostatic potential tester, it is characterized in that: comprise the parallel plate capacitor for induction charging surface current potential, processes the data processing circuit of the digital signal that generation single-chip microcomputer can process for electric potential signal that parallel plate capacitor is collected, for the microprocessor of the electric potential signal after computational data processing circuit processes, and for showing the display unit of the electric potential signal numerical value after microprocessor processes.
Preferably, described data processing circuit comprises resistance R 1-R3, operational amplifier U1-U2, controllable switch S 1 and analog-to-digital conversion module U3, ground connection after one end of controllable switch S 1 is electrically connected with one end of capacity plate antenna C1, after being electrically connected with the other end of controllable switch S 1, the other end of capacity plate antenna C1 is electrically connected with the in-phase input end of operational amplifier U1, the inverting input of operational amplifier U1 is electrically connected with the output terminal of operational amplifier U1, the output terminal of operational amplifier U1 is successively through resistance R 1, resistance R 3 is electrically connected with the output terminal of operational amplifier U2, one termination power of resistance R 2, the other end of resistance R 2 is divided into two-way, the node of first via connecting resistance R1 and resistance R 3, the second tunnel connects the inverting input of operational amplifier U2, the in-phase input end ground connection of described operational amplifier U2, the input end of the output termination analog-to-digital conversion module U3 of described operational amplifier U2, the control end of described controllable switch S 1 is electrically connected with the output control terminal of microprocessor, the output terminal of analog-to-digital conversion module U3 is the output terminal of described data processing circuit.
Preferably, described microprocessor is single-chip microcomputer or RAM processor.
Preferably, described display unit is LED display or LCD display.
The beneficial effect that adopts technique scheme to produce is: described potential test instrument is measured the current potential of testee in real time by parallel plate capacitor, do not use mechanical hook-up, reduce the volume of potential test instrument, and parallel plate capacitor does not contact with testee, less on the current potential impact of testee; In addition, described tester is used in conjunction with by gate-controlled switch and single-chip microcomputer, can make capacity plate antenna make zero, and efficiently solves the drift problem of tester, has realized the real-time measurement of testee current potential.
Embodiment
Described in background technology, the utility model provides following technical scheme to solve problems of the prior art:
As shown in Figure 1, a kind of contactless electrostatic potential tester, comprise the parallel plate capacitor for induction charging surface current potential, processes the data processing circuit of the digital signal that generation single-chip microcomputer can process for electric potential signal that parallel plate capacitor is collected, for the microprocessor of the electric potential signal after computational data processing circuit processes, and for showing the display unit of the electric potential signal numerical value after microprocessor processes.
It is more than the application's core concept, below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, obviously, described embodiment is only a part of embodiment of the present utility model, instead of whole embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the utility model protection.
A lot of details are set forth in the following description so that fully understand the utility model, but the utility model can also adopt other to be different from alternate manner described here and implement, those skilled in the art can do similar popularization without prejudice to the utility model intension in the situation that, and therefore the utility model is not subject to the restriction of following public specific embodiment.
Embodiment mono-
As shown in Figure 1, a kind of contactless electrostatic potential tester, comprise the parallel plate capacitor for induction charging surface current potential, processes the data processing circuit of the digital signal that generation single-chip microcomputer can process for electric potential signal that parallel plate capacitor is collected, for the microprocessor of the electric potential signal after computational data processing circuit processes, described microprocessor is single-chip microcomputer or RAM processor; And for showing the display unit of the electric potential signal numerical value after microprocessor processes, described display unit is LED display or LCD display.
Data processing circuit has a lot of forms, and in the present embodiment, described data processing circuit comprises resistance R 1-R3, operational amplifier U1-U2, controllable switch S 1 and analog-to-digital conversion module U3.Ground connection after one end of controllable switch S 1 is electrically connected with one end of capacity plate antenna C1, after being electrically connected with the other end of controllable switch S 1, the other end of capacity plate antenna C1 is electrically connected with the in-phase input end of operational amplifier U1, the inverting input of operational amplifier U1 is electrically connected with the output terminal of operational amplifier U1, the output terminal of operational amplifier U1 is successively through resistance R 1, resistance R 3 is electrically connected with the output terminal of operational amplifier U2, one termination power of resistance R 2, the other end of resistance R 2 is divided into two-way, the node of first via connecting resistance R1 and resistance R 3, the second tunnel connects the inverting input of operational amplifier U2, the in-phase input end ground connection of described operational amplifier U2, the input end of the output termination analog-to-digital conversion module U3 of described operational amplifier U2, the control end of described controllable switch S 1 is electrically connected with the output control terminal of microprocessor, the output terminal of analog-to-digital conversion module U3 is the output terminal of described data processing circuit.
Principle of work: before (1) test, gate-controlled switch is in off-state, parallel plate capacitor during near electrified body due to electric field induction, parallel plate capacitor front surface will be responded to certain voltage, owing to responding to, electric weight is less can not realize direct measurement, first through a voltage follower being formed from steady zero formula operational amplifier U1 by copped wave, it is low that the voltage signal of being exported by operational amplifier U1 has height to have, there is positive voltage also to have negative voltage, can not meet the acquisition process of data processing circuit below, then the anti-phase adder calculator through being formed by operational amplifier U2, make induced voltage signal Numerical Control between 0-3.3V, to meet signals collecting voltage request.The signal of being exported by operational amplifier U2 is converted to digital signal through A/D module by simulating signal, then obtains testee magnitude of voltage through single-chip microcomputer collection, reverse computing, and preserves measurement result, through display unit, test result is shown.
(2) single-chip microcomputer sends instruction by gate-controlled switch closure subsequently, and in this process, single-chip microcomputer stops data acquisition, and after closed a period of time of gate-controlled switch, single-chip microcomputer sends instruction disconnection gate-controlled switch.
(3) after gate-controlled switch disconnects, repeat the measuring process of (1), the test number obtaining and the numerical value of last test storage are added, and obtain the final magnitude of voltage of testee, and preserve test result, through display unit, test result are shown.
(4) repeat (2), so just realized the real-time measurement to electrified body surface potential size.
Can draw by above principle: described potential test instrument is measured the current potential of testee in real time by parallel plate capacitor, do not use mechanical hook-up, reduced the volume of potential test instrument, and parallel plate capacitor do not contact with testee, less on the current potential impact of testee; In addition, described tester is used in conjunction with by gate-controlled switch and single-chip microcomputer, can make capacity plate antenna make zero, and efficiently solves the drift problem of tester, has realized the real-time measurement of testee current potential.