MXPA01001145A - Apparatus and system for controlling the operating frequency of an electromagnetic vibratory feeder at a submultiple of the power line frequency - Google Patents

Abstract

An apparatus and system are provided for controlling the operating frequency of an electromagnetic vibratory feeder (150) at a submultiple of the power line frequency. The apparatus is couplable to a terminal of an electromagnetic coil (155) of the electromagnetic vibratory feeder (150), to control the current through the electromagnetic coil (155) and thereby control power delivered to the electromagnetic vibratory feeder. The apparatus includes a quadrac (115) coupled to the alternating current source;a capacitor (125) coupled to the AC current power source and coupled through a first diode (120) to a gate electrode of the quadrac (115);and a resistive network (160) coupled through a second diode (130) to the capacitor (125) and to the first diode (120). The capacitance value of the capacitor (125) and the resistive value of the resistive network (160) form an RC time constant, which predetermined to provide a selected operating frequency for triggering the quadrac (115) and thereby providing power to the electromagnetic vibratory feeder (150) at a submultiple of the power line frequency.

Description

APPARATUS AND SYSTEM TO CONTROL THE OPERATING FREQUENCY DJ5 A VIBRATORY GLOBAL ELECTRO POWER SUPPLIER IN A SUBMULTILE OF THE FREQUENCY OF THE ENERGY LINE FIELD OF THE INVENTION The present invention relates, in general, to apparatuses and systems for controlling the operating frequencies, and more particularly, to an apparatus and system for controlling the operating frequency of a vibratory electromagnetic feeder in a submultiple of the frequency of the power line.

BACKGROUND OF THE INVENTION In the prior art, vibratory electromagnetic feeders are normally operated at frequencies obtained directly from the frequencies of the power line, such as at 60 Hz in the United States and generally in North America, and at 50 Hz in Europe, Asia, and other parts of the world. A particular advantage of operating these vibratory electromagnetic feeders at the frequency of the applicable power line is that the corresponding frequency controls are cooperatively simple and convenient for cost, especially for relatively small feeders, where the cost of > The control mechanism can be a significant portion of the cost of the global feeder. There are several "** - benefits of the operation of electromagnetic vibratory feeders, however, at frequencies lower than the frequency of the power line, because the acceleration is a function of the square of the operating frequency, the feeders that operate The frequencies of the power line are subject to high accelerations, which place great demands on the integrity of the mechanical structures, adding significantly to the equipment costs, and reducing the expected life time of the equipment. springs used in these electromagnetic vibratory feeders are also determined, among other things, by the frequency of operation, and therefore, the operation at the frequencies of the power line requires a large number of expensive springs which are subject to high voltages and that are difficult to maintain in a stable way. This is determined by different combinations of feeder amplitude, frequency and feed angle, so that better or more optimal combinations for operation can be obtained at lower operating frequencies. The prior art solutions for providing low frequency controls typically involve complicated electronic circuits, such as energy inverters or other complex control elements. Although these complicated controls may be economically feasible for large feeders, these controls are prohibitively expensive to use in smaller feeders. As a result, there remains a need for an apparatus and system to provide a means to control, at a low cost, the operating frequency of a vibrating electromagnetic feeder in a submultiple (or fraction) of the frequency of the power line, without sacrificing the power. exit control.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided an apparatus and system that controls the operating frequency of a vibratory electromagnetic feeder in a submultiple of the frequency of the power line. For example, when the frequency of the available power line is 60 H? , the apparatus and system of the present invention can be tuned, through the selection of the appropriate RC time constants, to provide an operating frequency, for example, at 40 Hz, 30 Hz, 24 Hz, 20 Hz, and so on. The apparatus and system of the present invention can be implemented at a low cost, and is especially useful for providing frequency control for smaller vibratory feeders, without sacrificing output control. "The present invention uses the firing of a% quadrac device, or other switching devices, for supplying power to a vibratory feeder at the desired operating frequency 4 or selected. The firing frequency of the quadrac, in turn, is controlled by the tuning of a RC time constant of a capacitor in conjunction with a resistive network. The capacitor is used to store charge, so that, when the capacitor reaches a trigger voltage or threshold, it will trigger or activate the quadrac. An RC time constant is selected, so that the capacitor reaches this threshold voltage or triggers at a frequency lower than the frequency of the power line. The quadrac is triggered in this manner at a frequency that is a submultiple of the frequency of the power line, and thus provides power to the vibrating feeder at an operating frequency that is also a submultiple of the frequency of the power line. The different embodiments of the present invention can be used to control the operating frequency of a vibrating electromagnetic feeder, both in regular submultiples as well as loose ones in the frequency of the power line. The different modalities can also be tuned to have an operating frequency at or near the resonant frequency of the vibrating feeder, thus resulting in a maximum vibration with a comparatively minimal applied energy. Numerous other advantages and features of the present invention will become clearer from the following detailed description of the invention, and from its embodiments, from the claims, and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a circuit and block diagram of a first preferred apparatus and system embodiment of the present invention. Figure 2 is a circuit and block diagram (ie a second preferred embodiment of the apparatus and system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Although the present invention is < susceptible to being incorporated in many different forms, the drawings are shown, and their specific embodiments will be described in detail herein, with the understanding that J. to this disclosure should be considered as an exemplification of the principles of the invention, and not it is intended to limit the invention to the specific embodiments illustrated.

As mentioned above, there remains a need for an apparatus and system, which can be manufactured and implemented at a low cost, to provide control over the operating frequency of a vibratory electromagnetic feeder, preferably in a submultiple of the frequency of the line. Energy. In accordance with the present invention, this apparatus and system is provided, which allows the operation of a vibratory electromagnetic feeder at a low frequency, without sacrificing the output control. Figure 1 is a circuit and block diagram illustrating an apparatus 105 and system 100 in accordance with the present invention. As illustrated in Figure 1, a terminal of the power line 110 is connected to a conductor of a quadrac 115, and to a negative conductor of a capacitor 125. A second terminal of the power line 112 is coupled to one of the terminals of an electromagnetic coil 155, which is part of the electromagnetic vibrating feeder 150. In use, the terminals of the power line 110 and 112 are connected through suitable switches or contacts of an electromagnetic energy relay, which is fused with the available AC power source ("AC"), and may take various forms in different embodiments of the present invention. In the preferred embodiment, the power source is a standard AC power line of 120V, 60 Hz.

Continuing with the reference to Figure 1, the positive conductor of the capacitor 125 is connected to the anode of the diode 120 and to the cathode of the diode 130. The cathode of the diode 120 is connected to the gate conductor (or trigger) of the quadrac 115 The anode of the diode 130 is connected to a resistive circuit 160, which consists of the resistor 135 connected in series with the parallel configuration of the resistor 114 and the potentiometer 145. Then the apparatus 105 is coupled to the other terminal of the electromagnetic coil 155. The electromagnetic feeder 150 is illustrated in Figure 1 as a two-mass system, and consists of the trough side mass members 151 connected to a base mass 152 by means of the spring banks 153. The members of the lateral mass of tundish 151 consists of a tundish 154, an electromagnetic armature 156, and a mounting bracket 157 (which connects one side of the springs 156 with the tundish 154, and also attaches to the armature ele ctromagnetic 156). The base mass 152 contains the electromagnetic coil (and the core) 155, together with the connections for the remaining ends of the spring banks 153, with the mounting elements for the isolating springs 158 (which isolate the dynamic vibration forces produced by the feeder from its mounting bracket). Next, the operation of the apparatus 105 and system 100 of the present invention is explained. When the system 100 is connected through the power conductors 110 and 112 with an alternating current power source, such as a 60 Hz or 50 Hz alternating current power source, the capacitor 125 is allowed to charge to through the resistive circuit 160 and the diode 130. When the load of the capacitor 125 reaches a tripping voltage or gate threshold of the quadrac 115, the capacitor 125 provides power to activate the quadrac 115, and discharge through the gate of the quadrac 115. Once energized, the quadrac 115 allows the current to flow through the electromagnetic coil 155 of the electromagnetic feeder 150 by half cycle. the waveform of alternating current energy. More specifically, as the current through the electromagnetic coil 155 decreases, when the applied AC power decreases, the current falls below the containment current of the quadrac 115, and the quadrac 115 self-switches. to off. Then the capacitor 125 is allowed to charge one more time, as explained above, as the alternating current cycle is repeated. When the quadrac 115 is activated, the flow of current through the electromagnetic coil 155 of the electromagnetic feeder 150 creates a magnetic flux that attracts the armature of the feeder, and bypasses the springs 153, pulling the trough 154 in a first direction (backward and downward), due to the mounting angle 159 of the springs 153. Conversely, when the flow of current through the electromagnetic coil 155 of the electromagnetic feeder 150 is reduced, the energy stored in the springs 153 is released. , moving the trough 154 to a second opposite direction (forward and upward). When the cycle is repeated, the created angular vibration will cause the material contained in the tundish 154, such as small packages, to be fed to a discharge end of the tundish 154. The frequency of the vibration of the electromagnetic feeder 150 will be the frequency of the dsl quadrac time 115, which is controlled by the load of the capacitor 125 when it reaches the threshold or trigger voltage of the quadrac 115. The natural frequency of the electromagnetic feeder 150 (ie, the frequency at which the feeder mass and the system spring vibrate freely when a momentary external force is applied) can be adjusted, for example, by changing the number or thickness of the springs 153. When the natural frequency of the electromagnetic feeder 150 is in the vicinity or otherwise close to the frequency of the applied energy, by adjusting the natural frequency or the operating frequency, a condition known as resonance can be created. where the maximum displacement of the tundish 154 can be obtained with a comparatively minimal applied energy. In accordance with the present invention, the frequency (time or delay) of the quadrac 115 trip is adjusted by corresponding adjustment of a time constant of the RC network consisting of the capacitor 125 and the resistive network 160. By varying the time to reach the threshold voltage, the frequency of the quadrac 115 that is activated or driving will be varied, from the frequency of the power line, such as the quadrac 115 that is activated and driving every third cycle (or more). The diode 130 is used to prevent a discharge path of the capacitor 125 when the voltage changes polarity between the terminals 110 and 112, thereby enabling the capacitor 125 to retain its load for any number of cycles of the power line that can be presented for the correspondingly selected RC time constant. For example, for a selected output frequency of 30 Hz, and using a TECCOR Q4010LT (such as quadrac 115), which has a threshold voltage of approximately 33 volts, the capacitor 125 is loaded just below its trigger level during the first half positive cycle of the AC power source (after the quadrac 115 has stopped driving). The capacitor 125 retains its charge during the next half negative cycle, and then completes its charge to the level of 33 volts to trigger the quadrac 115 in the next half positive cycle, skipping in this way every third cycle, to produce the 30 Hz output from a 60 Hz power source. In the preferred embodiment, a satisfactory time constant has been obtained for the RC delay network when the resistors 135 and 140 and the potentiometer 145 were each one of 1 megaohm, rated at half a watt, with capacitor 125 of 0.033 microfarads, rated at 250 volts of alternating current. The time constant can also be varied through the potentiometer 145, which can be in parallel with the resistor 140, or it can cut the resistor 140, to create the minimum and maximum time constants. The delay of the trigger point between these minimum and maximum levels, provides control over the power supplied to the vibrating feeder 150, because it can reduce the time quadrac 115 by a subsequent shot to form positive halfwave. The diode 120 is used in the preferred embodiment to ensure that the quadrac 115 only triggers on the positive half-cycles, and can otherwise be omitted. The diodes 120 and 130 used in the preferred embodiment are both 1N4007, evaluated at 1,000 volts and 1 amper. In addition, as alternatives to the quadrac 115, other devices can also be used. switching without departing from the spirit and scope of the present invention, such as TRIAC or SCR. According to the present invention, the operating frequency of the electromagnetic feeder 150 is controlled and determined by the firing of the quadrac 115. The firing of the quadrac 115 once every cycle and a half of a 60 Hz power source, would result in a operating frequency of 40 Hz (2,400 vibrations per minute (VPM)); triggered once every third cycle, would result in an operating frequency of 30 Hz (1,800 VPM), triggered once every 2 and a half cycles, would result in an operating frequency of 24 Hz (1,440 VPM), and so on. In the embodiment illustrated in Figure 1, because the capacitor 125 does not charge when the quadrac 115 is activated, and the diode 130 allows the capacitor 125 to charge only when its anode is positive with respect to its cathode, the operating frequencies obtained of this apparatus 105 are even submultiples of the frequency of the power line, i.e. 60 Hz, 30 Hz, 20 Hz, and so on. To obtain frequencies of loose submultiples, such as 40 Hz, 24 Hz, etc., both the positive and negative half waves of the energy source are used, as illustrated in Figure 2. Figure 2 is a circuit diagram illustrating a second apparatus 105 'and system 100' used for ... &JÍ_.J_S; providing control of the operating frequency of the electromagnetic feeder 150 during both positive and negative half cycles of the power source. The quadrac 115 is implemented in a first configuration to control the application of energy during the half cycles going to positive, and the quadrac 115 'is implemented in a second configuration to control the application of energy during the half cycles going to negative. As described above, the diode 130 allows the capacitor 125 to charge in the half cycles going to positive for the required period of time, without being discharged before reaching the firing voltage of the quadrac 115. In a similar manner, the diode 120 'allows capacitor 125' to be charged in half cycles that go to negative for the required period of time, without being discharged before reaching the tripping voltage of quadrac 115 '. The diode 120 is used to ensure that the quadrac 115 only triggers on the positive half-cycles, and the diode 120 'is used to ensure that the quadrac 115' only triggers on the negative half cycles. In operation, the apparatus 105 'of Figure 2 can operate at the 40 Hz self-generating frequency, for example, where the capacitor 125 is charged for a period of time comprising two half positive cycles for charging, interleaved with three negative half cycles where no load occurs, followed by the firing of quadrac 115 at the beginning of the next half cycle that goes to positive. In a similar manner, capacitor 125 'would be charged during a period comprising two negative half cycles to charge, interspersed with three positive half cycles, where no charge occurs, followed by the trigger of quadrac 115 at the beginning of the next half cycle that goes to negative. Then, the operating frequency of the vibratory feeder 150 is the sum of the activated frequencies (trigger) of each of the quadracs 115 and 115 '. In this example, the total time between the trigger points for any quadrac 115 or 115 'would be 50 milliseconds, resulting in an operating frequency of 40 Hz. Apparatus 105 'of Figure 2 can also be used to control the applied energy even in submultiples of the frequency of the power line, usually by disabling half the circuit. In addition, this control for regular submultiples can be implemented by adjusting the time constants of the trigger circuits, such that the quadracs 115 and 115 'shoot approximately immediately one after the other, resulting in a longer duration of the applied energy, but at an effective frequency equal to the individual firing frequency (not added) of the quadracs 115 and 115 '. As can be seen from the above description, there are numerous advantages of the present invention. First, the apparatus and system of the present invention provide control over the operating frequency of a vibratory electromagnetic feeder, preferably in a submultiple of the frequency of the power line. Also, in accordance with the present invention, an apparatus and system are provided that allow the operation of a vibratory electromagnetic feeder at a low frequency, without sacrificing output control, which can be manufactured and implemented at a low cost. From the foregoing, it will be appreciated that numerous variations and modifications may be made without departing from the spirit and scope of the novel concept of the invention. It should be understood that no limitation is intended or inferred with respect to the specific methods and apparatus illustrated herein. Of course, it is intended to cover, by the appended claims, all modifications that fall within the scope of the claims.

Claims (15)

1. An apparatus for controlling an operating frequency of a vibratory electromagnetic feeder in m submultiple of a frequency of the power line, the apparatus being able to be coupled with a first terminal of an electromagnetic coil of the vibrating electromagnetic feeder, and a second terminal of the Z coil can be coupled electromagnetic with an AC power source having the frequency of the power line, the apparatus comprising: a quadrac that can be coupled with the AC power source; a capacitor that can be coupled with the alternating current power source, the capacitor also being coupled through a first diode with a gate electrode d quadrac, the capacitor having a capacitance value; a resistive network coupled through a second diode with the capacitor and the first diode, the resistive network having a resistive value, forming the resistive value in conjunction with the capacitance value a time constant RC, wherein the capacitance value, the resistive value, and the RC time constant are previously determined to provide a selected operating frequency for firing the quadrac, and thus providing current through the electromagnetic coil, and energy to the electromagnetic vibratory feeder, in a submultiple of the frequency of the power line.

2. The apparatus of claim 1, wherein the RC time constant is previously determined, such that a voltage reached during charging of the capacitor for a half cycle of the alternating current source following a first trip of the capacitor. quadrac, is less than a threshold voltage for a second shot of the quadrac.

3. The apparatus of claim 1, wherein the RC time constant is previously determined so that the quadrac is triggered on a submultiple of the frequency of the power line in the vicinity of a resonant frequency of the vibrating electromagnetic feeder.

The apparatus of claim 1, wherein the resistive network further comprises: a first resistor; a second resistor connected in series with the first resistor; and a potentiometer coupled in parallel with the second resistor.

The apparatus of claim 1, wherein the capacitor can be charged during a first half positive cycle of the frequency of the power line, wherein the second diode prevents a capacitor discharge during a first negative half cycle of the frequency of the power line, and where the capacitor can be charged up to a threshold voltage of the quadrac for a second half positive cycle of the frequency of the power line, thereby firing the quadrac in a submultiple of the frequency of the line of energy.

6. An apparatus for controlling an operating frequency of a vibratory electromagnetic feeder in a submultiple of a frequency of the power line, the apparatus being able to be coupled with a first terminal of an electromagnetic coil of the vibrating electromagnetic feeder, a second terminal of the electromagnetic coil with an alternating current source having the frequency of the power line, the apparatus comprising: a first quadrac that can be coupled with the alternating current source in a first configuration; a first capacitor that can be coupled with the alternating current power source, the capacitor also coupling through a first diode with a gate electrode of the first quadrac, the first capacitor having a first capacitance value; a first resistive network coupled through a second diode with the first capacitor and with the first diode, the first resistive network having a first resistive value, forming the first resistive value in conjunction with the first capacitance value, a first time constant RC; a second quadrac that can be coupled with the alternating current power source in a second configuration; a second capacitor that can be coupled with the alternating current power source, the second capacitor also being coupled through a third diode with a gate electrode of the second quadrac, the second capacitor having a second capacitance value; a second resistive network coupled through a fourth diode with the second capacitor and with the third diode, the second resistive network having a second resistive value, the second resistive value forming in conjunction with the second capacitance value a second RC time constant; wherein the first capacitance value, the first resistive value, and the first RC time constant ee are previously determined to provide a first selected frequency to trigger the quadrac during a half positive cycle of the frequency of the power line, wherein the second capacitance value, the second resistive value, and the second RC time constant are determined s previously to provide a second selected frequency to trigger the quadrac during a negative half cycle of the frequency of the power line, and thereby providing current through the electromagnetic coil, and power to the vibrating electromagnetic feeder, at a frequency which is a submultiple of the frequency of the energy line.

The apparatus of claim 6, wherein the sub-multiple of frequency is the arithmetic sum of the first frequency selected and the second frequency selected.

8. The apparatus of claim 6, wherein the first selected frequency is equal to the second frequency selected, and is also equal to the submultiple of the frequency.

9. The apparatus of claim 6, wherein the first RC time constant is previously determined, such that a voltage reached during the charging of the first capacitor during a half cycle of the AC power source, followed by a The first shot of the first quadrac is less than a threshold voltage for a second shot of the first quadrac.

The apparatus of claim 6, wherein the first RC time constant and the second RC time constant are determined previously for the first respective quadrac and the second quadrac, to be fired at a combined frequency in the vicinity of a resonant frequency of the vibrating electromagnetic feeder.

11. A system for controlling an operating frequency of a vibrating electromagnetic feeder in a submultiple of a frequency of the power line, the system being coupled with an alternating current power source having the frequency of the power line, comprising the system: a vibrating electromagnetic feeder, the vibrating electromagnetic feeder having an electromagnetic coil that can be coupled with the alternating current power source; a quadrac that can be coupled with the AC power source; a capacitor that can be coupled with the AC power source, the capacitor also being coupled through a first diode with a gate electrode of the quadrac, the capacitor having a capacitance value, a resistive network coupled through a second diode with the capacitor and with the first diode, the resistive network having a resistive value, forming the resistive value together with the capacitance value an RC time constant, where the capacitance value, the resistive value, and the constant of RC time are previously determined to provide a selected operating frequency for firing the quadrac, and thereby providing current through the electromagnetic coil, and power to the vibrating electromagnetic feeder, in a submultiple of the frequency of the power line. The system of claim 11, wherein the RC time constant is previously determined, such that a voltage reached during capacitor charging, during a half cycle of the alternating current source, followed by a first The quadrac's trip is less than a threshold voltage for a second trip of the quadrac. The system of claim 11, wherein the RC time constant is previously determined for the quadrac, to trip on a submultiple of the frequency of the power line in the vicinity of a resonant frequency of the vibrating electromagnetic feeder. The system of claim 11, wherein the resistive network further comprises: a first resistor; a second resistor connected in series with the first resistor; and a potentiometer coupled in parallel with the second resistor. The system of claim 11, wherein the capacitor can be charged during a first half positive cycle of the frequency of the power line, wherein the second diode prevents a capacitor discharge during a first negative half cycle of the frequency of the power line, and where the capacitor can be charged up to a threshold voltage of the quadrac during a second half positive cycle of the frequency of the power line, thereby firing the quadrac in a submultiple of the frequency of the line of energy. _ -MtwA iflWfarti