Device for signaling the presence of liquid

 

(57) Abstract:

The device relates to signaling the presence of water in an irrigation machines, sprayers, vehicles, fertilizer and can also be used in other means of monitoring the presence of liquid. The device includes a pulse generator connected through the RS filter with one electrode contact sensor, a second electrode which is grounded, and shaper of the normalized signal, the output of which is connected to the selector, made in the form of an amplifying cells with inverting and reinvestiruet outputs between which the switched capacitor. The buffer amplifier is connected to the visual display, and shaper signal audible indication associated with the output of the pulse generator. Its output is connected to the sound detector. The device is equipped with inverter level onselectionchange signal low input resistance and the output logic levels of the signal, whose input is connected to the not inverting the output amplifier cell selector, and the output connected to the input of the buffer amplifier and the other input of the shaper signal audible indication. The presence of the inverter allows to stabilize the input Hao design. 3 C.p. f-crystals, 4 Il.

The device relates to the agricultural industry, and in particular to means of signaling the presence of fluid in sprinklers, sprayers, vehicles, fertilizer, and can also be used in other means of monitoring the presence of liquid.

The known device for signaling the presence of liquid, comprising a pulse generator associated with the sensor for placement in a liquid medium, a key element in the block comparison and indication unit [1, 2]. In all these cases, the terminals of the sensor fluid is triggering a key element and block comparison, after which the signal is displayed by the display unit.

However, in these cases, the signal from the sensor does not have a certain voltage drop due to the significance of the temporary front signal processing leads to significant error and therefore unreliable results display. The hysteresis in the signal processing system, which is due to the presence of inhomogeneity of the liquid droplets and vapor in the area of location of the sensor significantly reduces the accuracy of registration. And these factors for such devices are often nepreodolimymi close to the claimed is a device for signaling the presence of liquid, including a pulse generator connected through an RC filter with a single electrode contact sensor, a second electrode which is grounded, and shaper of the normalized signal, the output of which is connected to the selector, made in the form of an amplifying cells with inverting and reinvestiruet outputs between which a switched capacitor, a buffer amplifier connected to the visual display, and shaper signal audible indication, one input of which is connected with the output of the pulse generator, and the output connected to the sound detector [3].

When working with this device the signal from the pulse generator through the filter goes to the contact sensor and the driver of the normalized signal, then selectively and in the absence of the probe makes contact with a liquid selected signal triggers the audible signal and visual display. However, despite the better performance of this device still has a fairly significant hysteresis of the electronic unit of the device, caused by the above reasons, the resulting device has insufficient accuracy, and therefore informative.

any design of contact sensors.

The specified technical task is solved in that it is provided with the inverter level onselectionchange signal low input resistance and the output logic levels of the signal, whose input is connected to the not inverting the output amplifier cell selector, and the output connected to the input of the buffer amplifier and the other input of the shaper signal audible indication.

And the fact that the inverter level onselectionchange signal is made in the form of a transistor connected in the common-emitter, the base of which is the input of the inverter onselectionchange signal, as well as the corresponding Schmitt trigger, and the collector of the above-mentioned transistor is connected to the combined inputs of this trigger whose output is the output of the inverter level onselectionchange signal.

And, in addition, the fact that is supplied by the feedback circuit, made in the form of series-connected first electronic key corresponding to the Schmitt trigger with the combined inputs and the second electronic key, and the input of the first electronic switch is connected to the not inverting the output of the buffer amplifier, and a second output connected to the input of the buffer amplifier.

PR is soprotivlenie.

Searches conducted by the patent and other technical literature, showed that the claimed combination is unknown, i.e. claimed is the invention of "novelty."

Because the device contains known elements and nodes, and tested in the work, then it corresponds to a condition for the invention of "industrial applicability".

And as a result decides the goal of the project, and the operation device has a higher effect made obvious to the specialist way, that claimed meets the condition of "inventive step".

In Fig. 1 shows a General diagram of the device of Fig.2 and 3, respectively, of the contact type sensor, side and top, and Fig.4 is a connection diagram of the contact sensor and the visual indicator.

The device includes a pulse generator 1, which may be performed, for example, the Schmitt trigger DD1.1 with timing R1C1 chain, T-shaped RC filter capacitor C2 and resistors R2 and R3, shaper normalized signal 3, which is made on the transistor VT2 connected in the circuit of the generator current and the resistors R5 and R4, the selector 4, which is made on the basis of amplification acaitrim outputs of the transistor VT1, the inverter level onselectionchange signal 5, performed on the transistor VT3, the Schmitt trigger DD1.2 and the resistors R7, R5, and in this case the inverter is cascade with a low input impedance due to the inclusion of transistor VT3 for the common emitter. Shaper signal audible indication 6 is made on the Schmitt trigger DD1.3 and associated with a beeper BA1. The buffer amplifier 7, is performed on the transistor VT8 covered by the feedback circuit, which is made by serially connected transistor VT5 connected in the circuit with common emitter, the Schmitt trigger with the combined inputs of and included in the common-emitter transistor VT4, the collector of which is connected to the base of transistor VT8, while the emitter of the latter is connected to the base of transistor VT5. The collector of transistor VT8 is connected with the output terminal block K2. The device also has a unit voltage regulation 9, which is made on the transistor VT6, VT7, the diode VD1 and the Zener diode VD2, and the resistors R11, R14, R15 (Fig.1). When the input unit 9 is connected to the terminal K3 which is connected directly to one pole of the power source 11, the other pole of which is connected to terminal K1 and the terminal K2 is connected to the power source 10 through the visual is on one of the electrodes of the contact sensor 12, the other terminal of which is grounded. The output of the shaper 3 is the collector of the transistor VT2, which is connected to the input of the selector 4, i.e., the base of the transistor VT1, the emitter of the latter is reinvestiruet output of the selector 4 and through a resistor R7 is connected to the input of the inverter 5, i.e. to the base of transistor VT3. The output of Schmitt trigger DD1.1 is connected through a resistor R9 to the input of the buffer amplifier 7 and one of the inputs of the driver 6 on the trigger DD1.3, to the second input of which is connected to the output of the generator 1. Unit voltage regulation 9 feeds via the output transistor VT7 and capacitor C5 other blocks. It should be noted that the Schmitt trigger can be replaced by items 2 AND or similar nodes that perform the logic function of the comparison of the input signals, the results of which selects zero or one followed by invertatsii.

The device operates as follows.

Generator 1 generates rectangular signals with a repetition frequency that is located in the audio range and is defined by a chain R1C1. From the output of the generator 1 pulse arrives at the filter 2 and then by the sensor 12 and the imaging unit 3. When non-immersed in the liquid electrodes dataintegration rectangular pulses of substantially smaller amplitude. These signals are converted by the imaging unit 3, which is made according to the scheme of the current generator, which allows due to the nonlinear characteristic of the p-n transitions of the transistor VT2 significant amplitude signal to limit at a given level, and the signal amplitude is small enhance within certain limits and thus to achieve a relatively stable level of the output signal of the circuit. Further, the signal comes to the selector 4, i.e. to the base of transistor VT1, and when immersed in the liquid electrodes of the sensor 12 when the signal is positive, the transistor VT1 is opened and at its inverting and reinvestiruet outputs appear the same of different signals due to the presence of capacitor C4 are subtracted (in this case, due to the selection of the capacitor and, thus, at the input of the inverter 5, the voltage did not differ from zero, which corresponds to its closed condition and sound signalling device BA1 and visual indicator 11. Thus, when the electrodes of the sensor 12 is immersed in a liquid, the device does not produce the initiating signals. If the electrode sensor 12 is located outside the liquid, the influence of the fluid on the shape of the signal and no signal is elem 3 and to the input of the selector 4. Since in this case the increase of positive edges of the signal fast enough, the capacitor C4 is quickly discharged through almost outdoor transistor VT1, and the scheme loses the ability to subtract the signals appearing on her inverting and reinvestiruet outputs, so at the last, i.e., the resistor R7, is allocated a positive signal. In those moments of time when the signal output from the imaging unit 3 takes a negative value, the transistor VT1 is locked and the capacitor C4 is slowly charged from unit 9 through a relatively large resistor R6, i.e., in this case, the capacitor C4 performs its integrating function. As a result, reinvestiruet the output of the emitter of the transistor VT1 is almost constant positive voltage, which opens the transistor VT3 inverter 5 with low input impedance, since it is included in the common-emitter. The saturation voltage of its transition when the base current of about 1 mA constant and is 0.8-0.9 C. Thus, the voltage divider resistor R6, the transition collector-emitter voltage VT1 and the resistor R7 forms a normalized voltage source to maintain the input characteristics of the cascades at VT1 and VT2 Prora in the prototype depended on the volume of the controlled fluid, the magnitude of the wetted area of the electrodes of the sensor, and so on, but In this case it was possible to lower the input impedance of this stage and the choice of the value of resistor R7 to adapt the device for any design of sensors with installation of the necessary threshold, allowing you to easily reach the repeatability of the device settings. The output signal from the conducting transistor VT3 opens the amplifier 7 and visual display 11 is switched on. In addition, the output signal of the oscillator 1 and the output of the trigger DD1.2 arrives at the shaper 6 trigger DD1.3, the output of which is converted into a sound signal by the detector BA1. In this case, the trigger DD1.2 allows due to the presence of threshold and threshold release to exclude weak light 11 that took place in the prototype, and to compensate for the deviation of the useful signal in the input stages. It is possible to eliminate the influence of dripping, splashing, dripping liquid on the electrodes, etc. For faster and more effective inclusion of the indicator 12 is entered, the circuit of transistor VT5, trigger DD1&4 and transistor VT4, to more clearly define the moments of the inclusion of the indicator 12 to exclude the impact of channel LEDs per channel sound, cattolico for availability control fluid, but to control the availability of certain liquids, such as level control section of two different liquids, and in this case can be controlled as low and signalextraction solutions, etc., the Efficiency of this device is very high at high operating parameters.

Sources of information

1. Prospects for the development of machines and equipment for protected ground /Sat. the scientific. Tr. Vishama, M., 1975.

2. Analysis of global trends in the development of agricultural machinery /Sat. the scientific. Tr. Vishama, M., 1986.

3. Patent Of The Russian Federation, 2010498. class A 01 G 25/16, 1994.

1. Device for signaling the presence of liquid, comprising a pulse generator connected through an RC filter with a single electrode contact sensor, a second electrode which is grounded, and shaper of the normalized signal, the output of which is connected to the selector, made in the form of an amplifying cells with inverting and reinvestiruet outputs between which a switched capacitor, a buffer amplifier connected to the visual display, and shaper signal audible indication, one input of which is connected with the generator output impulse the new signal with a low input impedance and the output logic levels of the signal, the inlet of which is connected to the not inverting the output amplifier cell selector, and the output connected to the input of the buffer amplifier and the other input of the shaper signal audible indication.

2. The device under item 1, characterized in that the inverter level onselectionchange signal is made in the form of a transistor connected in the common-emitter, the base of which is the input of the inverter onselectionchange signal, as well as the corresponding Schmitt trigger, and the collector of the above-mentioned transistor is connected to the combined inputs of this trigger whose output is the output of the inverter level onselectionchange signal.

3. The device under item 1, characterized in that it is provided with a feedback circuit, made in the form of series-connected first electronic key corresponding to the Schmitt trigger with the combined inputs, and the second electronic key, and the input of the first electronic switch is connected to the not inverting the output of the buffer amplifier.

4. The device under item 1, characterized in that the inverter level onselectionchange signal made with the possibility of changing its input impedance.

 

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