CN2129933Y

CN2129933Y - Digital frequency instrument with infrared photo electric sensor

Info

Publication number: CN2129933Y
Application number: CN 92230663
Authority: CN
Inventors: 龚兆岗
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-08-19
Filing date: 1992-08-19
Publication date: 1993-04-14
Anticipated expiration: 2002-08-19

Abstract

The utility model relates to a digital frequency instrument with an infrared photo electric sensor, comprising an electrical signal input channel part, an infrared photoelectric sensor part, a time-base circuit, a digital display part and a control part. The two front parts are all provided with two input and detection channels; various measurement, such as frequency, shift time of an object, etc. can be conducted conveniently.

Description

Digital frequency instrument with infrared photo electric sensor

The utility model relates to the numerical frequency instrument, particularly a kind of numerical frequency instrument with infrared photoelectric sensor.

The numerical frequency instrument is a kind of frequency measurement instrument that shows with numeral, it can measure the electric signal frequency of various waveforms, and after being converted to electric signal with mechanical vibration number of times, object velocity of rotation, through the physical quantitys such as product quantity of travelling belt by sensor it is carried out frequency measurement or count measurement.

The existing digital frequency recorder does not generally have the sensor change-over circuit, just must use sensor in addition in order to carry out above-mentioned second type measurement, very inconvenient, in addition, most of numerical frequency instrument is because have only one to measure passage, can only carry out simple frequency measurement and generally can not carry out for example measurement of two signal frequency ratios.

The purpose of this utility model is exactly to provide a kind of numerical frequency instrument with infrared photoelectric sensor for the deficiency that overcomes existing frequency recorder, the part of directly electric signal being measured all is respectively equipped with two identical passages with the part of non-electrical signal being measured through sensor, with convenient to two signal frequencies for example than and the measurement of ohject displacement time.That frequency recorder of the present utility model has is multi-functional, reading directly perceived, measure advantages such as accurate and easy to use fast.

Below referring to accompanying drawing the utility model is described in detail, wherein

Fig. 1 is a circuit block diagram of the present utility model,

Fig. 2 is the circuit theory diagrams of the time base circuit part in the above-mentioned block scheme,

Fig. 3 is decay, amplification, the shaping in the above-mentioned block scheme, the circuit theory diagrams of amplitude indicating section,

Fig. 4 is the circuit theory diagrams of the infrared photoelectric sensor part in the above-mentioned block scheme,

Fig. 5 is the circuit theory diagrams of the control section in the above-mentioned block scheme.

At first referring to Fig. 1, the electric signal input channel partly is provided with two passages of A, B, and each passage is made up of decay, amplification, shaping and amplitude indicating circuit, two channel signals warp or door output, and A channel is f with frequency _AConverting electrical signal be the pulse signal that counting pulse signal that counter can be accepted maybe can trigger the master control door, the B passage is f with frequency _BConverting electrical signal for can trigger the pulse signal of master control door, so that carry out the measurement of frequency, frequency ratio etc.

Infrared photoelectric sensor partly is provided with two sense channels of C, D, each passage is made up of circuit such as vibration, modulated luminescence, reception, pulse amplification, widened pulse, gating and demodulation, two passages also are respectively equipped with photoelectric probe position alignment indication, and two channel signals are also through one or door output.

The time base section comprise that crystal oscillation, frequency division and Shi Ji select circuit, crystal oscillating circuit produces the standard signal of 1MHz, becomes the signal of a series of different frequencies behind frequency division.

The counting display part comprises counting, deposits, deciphers, driving and display circuit.

Circuit such as control section comprises function selecting, gate bistable, block bistable, master control door, send that rapid pulse dashes, quenching pulse and remote manual control.Control section produces the co-ordination of various command signal control instrument each several parts, makes instrument finish measuring task by certain working routine.

Fig. 2 is the circuit theory diagrams of time base circuit part in the above-mentioned block diagram, the oscillator of crystal JT and two not gate D5 formation 1MHz, output to by six integrated package MC14518(D6 through the 3rd not gate D5, D7, D8) carry out six grades very frequently, again by integrated package C186(D9) carry out one-level six frequency divisions, at last by another piece MC14518(D10) carry out one-level very frequently, the cycle that obtains respectively is 1us, 10us, 100us, 1ms, 10ms, 100ms, 1s, the square-wave signal of 6s and 60s, select the required cycle through selector switch SA4, signal also can be made standard signal source by socket XS4 output simultaneously as gate time and timing signal To.

Fig. 3 is decay, amplification, the shaping in the circuit block diagram, the circuit theory diagrams of amplitude indicating section, and A channel is identical with B channel circuit structure, is the principle of work that example is set forth circuit below with the A channel.

From the input electrical signal of socket XS1 after the attenuator circuit decay that resistance R 1～R5 and selector switch SA1 constitute, deliver to the amplifier that constitutes by integrated operational amplifier N1 and resistance R 20～R22, adjustable resistance R23 through capacitor C 1 and amplify, be shaped as output signal f behind the square wave by Schmidt trigger D1 then _A

To drive diode VD1 through another Schmidt trigger D1 when spike potential is greater than 6V over the ground luminous when the signal of amplifier output, and to drive diode VD2 through another Schmidt trigger D1 during greater than 9.2V luminous when peak value.Selector switch SA1 is placed suitable gear, make VD1 luminous and VD2 does not work, then attenuated input signal is suitable, satisfies measurement requirement.

A channel and B channel signal are through sending t with the negative logic OR circuit of door D3 and not gate D5 formation _A-BGate-control signal.

Fig. 4 is the circuit theory diagrams of the infrared photoelectric sensor part in the circuit block diagram, describes C-channel for the same.

Time base circuit N2 and resistance R 29, R30, capacitor C 5, C6 formation dutycycle are 51 multivibrator, make infrarede emitting diode VD5 obtain modulating current through resistance R 31, and VD5 sends modulated infrared light.

Phototriode VT4 receives the infrared pulse modulation signal, inductance L 1 is the load of VT4, L1 presents Low ESR to stable direct current, modulating pulse is presented high impedance, through capacitor C 7 couplings, every removing direct current, can select required modulating pulse letter, the amplifier of forming through resistance R 33, R34, R35 and triode VT1 amplifies, and send the input end with door D3 after Schmidt trigger D2 shaping, and another input end receives the signal of multivibrator through not gate D2.

With door D3 be storbing gate, when the pulse signal that receives when the pulsed current signal of modulator glow tube and light-receiving tube is " 1 ", send level"1" from storbing gate, like this, have only with modulating pulse same frequency and synchronous undesired signal and just might pass through storbing gate, obviously, anti-interference is better.

To realize demodulation to paid-in photosignal, therefrom take out the output signal that really needs, the time clock CP end that d type flip flop D4 is guided in pulse that device produces is swung in complex resonance, utilize the rising edge of pulse to trigger d type flip flop, and the pulse that storbing gate is sent is guided to the D end of d type flip flop D4, like this, when phototriode is received modulated infrared light, produce strobe pulse, the D end is " 1 ", d type flip flop Q end always presents high level " 1 " after receiving the CP pulse at every turn, and the Q end is low level " 0 " when not receiving modulated infrared light.

C-channel and D channel signal are through sending gate-control signal t with the negative logic OR circuit of door D3 and not gate D2 formation _C-D

The circuit theory diagrams of control section as shown in Figure 5 in the block scheme, function selector circuit is made up of switch S A3-1 and SA3-2, the gate bistable circuit is by constituting with door D11 and d type flip flop D12, the Q1 end of gate bistable is linked the CP end that blocks bistable, rising edge with Q1 goes to trigger the blockade bistable, and Q2 point current potential is risen, and the rising of Q2 point current potential is the decline of Q1 point current potential just, this is the end of a count measurement, and master control door D11 closes.The Q2 end is linked the input end of gate bistable and door, and Q1 point waveform promptly is blocked with door after descending, and the state of keeping two d type flip flops is till clear circuit produces reset signal.

The rising edge of Q1 point waveform is delivered to by what Schmidt trigger D13 and resistance R 51 and capacitor C 16, C17 formed and is sent several circuit, several signal LE are sent in generation, make display circuit show institute's count word, the rising edge of Q2 point waveform is delivered to the clear circuit of being made up of Schmidt trigger D13 and resistance R 53, R54 and capacitor C 18, C19, adjustable resistance RP1 and is produced reset signal CR, counter and two d type flip flops are all resetted, one-shot measurement finishes, and be to measure next time to get ready, regulate RP1 and can change delay time.

Switch S A5 selects to show cumulative total mode or counting servo-actuated display mode, and display digit was beated with the counter accumulative total when SA5 placed below ground connection.

Because of capacitor C 21 both end voltage can not transition produce high level reset signal CR, if press pushbutton switch SB2, then because of capacitor C 20 both end voltage can not transition obtain a high level reset signal, the electric charge of C20 charging accumulation can be released by resistance R 55 during start.

Resistance R 57 and R58 are bleeder circuit, satisfy the requirement of counting circuit to guarantee count signal CP amplitude.

Triode VT3, socket XS3, pushbutton switch SB1, resistance R 47 and D5 form manually and remote control circuit, press SB1 or introduced a closure signal or sent here a positive pulse by the B passage by XS3 all to make not gate D5 export a low level.Diode VD13, resistance R 48, capacitor C 13 and not gate D5 form the monostable circuit that negative edge triggers, and prevent the harmful effect that switch from fluttering brings.

Counting in the circuit block diagram, deposit, decipher, driving and display circuit for example can select for use six 2-10 systems of LCL601 count/deposit/decipher/drive/LED shows assembling device.

Claims

1, the numerical frequency instrument, comprise electric signal input channel part, time base circuit, counting display part and control section, it is characterized in that also comprising the infrared photoelectric sensor part that is used for the non-electrical signal measurement, above-said current signal input channel part partly is respectively equipped with two passages that circuit structure is identical with infrared photoelectric sensor, each electric signal input channel is by decay, amplify, shaping and amplitude indicating circuit are formed, each infrared photoelectric sensor passage is by vibration, modulated luminescence, receive, pulse is amplified, widened pulse, gating and demodulator circuit are formed, and the signal of two passages is via exporting with the negative logic or the door of door and Schmidt trigger composition.