JP2771796B2 - Power supply circuit in dynamic braking circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply circuit in a power generation braking circuit for performing power generation braking by using a generator receiving rotational torque as a load, short-circuiting its output, and performing power generation braking.

[0002]

2. Description of the Related Art Recently, it has become essential to provide an evacuation passage in a tunnel for evacuation in the event of an accident such as a fire. In the event of an accident, the access doors must be closed after evacuation to prevent the ingress of smoke and gas. As such a door, an automatic door using a photoelectric switch or the like may be used. However, in the event of an accident, a power failure may be considered, so that the entrance door cannot be used as the above-mentioned automatic door.

There is an automatic closing door which stores a spring when opened and closes with the stored spring force. However, since the spring force when opening is large, a force is required and the released hand must be released. If the door closes suddenly, it must be held down by hand or opened by hand one after another in order for people to pass continuously, making it difficult for people to pass. There is a problem that stagnation occurs in front and confusion increases.

In order to provide a large braking force for a certain period of time for closing the door and to delay the closing time of the substantially opened door, a generator is connected to a rotating shaft interlocked with the door, and the output is connected. By short-circuiting with a load, a mechanical load can be applied to the rotating shaft to brake the rotational force. This is so-called dynamic braking. In short, it is sufficient to simply short-circuit the generator output with a resistance load.However, each door has a short-circuit with a resistor with a certain resistance value because of differences in characteristics such as spring force, friction force, and inertia. Therefore, an appropriate braking characteristic cannot be provided. It is sufficient to adjust the load resistance according to each characteristic, but not only fine adjustment work on site is required, but also a problem occurs in the variable resistor receiving short-circuit current, aging is a problem, Was not a suitable braking means.

If the short circuit of the generator output is controlled by using a control circuit, the above-mentioned problem can be solved, but in this case, a power supply for the control circuit must be separately prepared. . Therefore, power generation braking using the control circuit cannot be performed in a place where there is no power supply, a place where it is difficult to obtain power supply, or a place where there is a possibility of a power failure.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a power supply in a power generation braking circuit capable of controlling power generation braking without using an external power supply or a built-in power supply such as a battery. The present invention has been made in order to provide a circuit, and is particularly used for power generation braking of an automatic closing door or the like, and realizes suitable braking characteristics.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a braking DC generator connected to a rotating system via a one-way clutch, and a control circuit for interrupting connection between the braking DC generator and a load. In the power supply circuit in the dynamic braking circuit, the braking DC generator is a DC generator that does not have a power supply for rotating the braking DC generator as a DC motor and does not operate as a DC motor, and the braking DC generator The output of the smoothing circuit for smoothing the output of the power supply of the control circuit,
The control circuit has no other power supply.

[0008]

FIG. 2 is a schematic diagram showing the whole of an embodiment of an automatic closing door to which the dynamic braking circuit of the present invention is applied. In the figure, 1 is a door at a closed position, 2 is a door moved to an open position, 3 is a roller chain, 4 is a driving sprocket, 5 is a braking sprocket, 30 is a suspension rail, and 31 is a suspension roller. The door is
The roller chain 3 is suspended on the suspension rail 30 by the suspension roller 31 and moves while being guided by the suspension rail.
Attached to. By opening the door 1 by hand, the door 1
The roller chain 3 is driven with the movement of. As a result, the driving sprocket is rotated, and the rotational force is stored in a spring (not shown). On the braking side sprocket 5,
A generator (not shown) is connected via a one-way clutch. Since the one-way clutch uses the one that rotates the generator when the door is closed, the generator does not become a rotating load when the door is opened. The door 1 moves from the closed position to the open position, and becomes the position of the door 2. When you release your hand at this position, door 2
The drive side sprocket 4 is rotationally driven by the force of the stored spring, and moves in the closing direction by the roller chain 3. At this time, the braking-side sprocket 5 is also rotated. At this time, since the one-way clutch is engaged, the generator is connected to perform power generation braking, and the door is driven very slowly in the closing direction by the braking action.

FIG. 1 is a circuit diagram of an embodiment of a power generation braking circuit according to the present invention which can be applied to the above-mentioned automatic closing door and the like. In the figure, G is a DC generator connected to the braking shaft, AVR is a constant voltage circuit, Z1 is a constant voltage diode, VR is a variable resistor,
R1 to R13 are resistors, C1 to C4 are capacitors, D
2, D3 is a diode, CP1, CP2 are comparators, FE
T is a field-effect transistor.

The output of the DC generator G is a constant voltage circuit AVR
Is applied and a capacitor C is connected through a resistor R6.
It is smoothed by charging 1. The constant voltage diode Z1 is a protection circuit. Resistor R6 and capacitor C1
Is connected to the output of the smoothing circuit, the DC generator G is short-circuited by the resistor R6 when the transistor FET is in a conductive state, and the power generation is in a braking state. Comparator CP1
Is applied with the divided voltage of the output of the constant voltage circuit AVR.
That is, a divided voltage of R3 and R8 is applied to the + input side, and a divided voltage of R1, VR and R2 is applied to the-input side. Further, the drain voltage of the transistor FET is fed back to the + input side by the resistors R4 and R5, and the voltage drop due to the short-circuit current of the DC generator G is superimposed by the resistor R6 to the-input side. The output voltage of the DC generator G is divided by the resistors R10 and R11 and applied to the + input side of the comparator CP2. The output voltage of the constant voltage circuit AVR is applied to the input side, but when the output of the comparator CP2 is-, the resistor R1
Since the right side of 3 is grounded, the voltage is divided by the resistors R12 and R13, and when +, the voltage is applied without being divided because the grounding of the resistor R13 disappears.

The operation of the above circuit according to the magnitude of the output voltage of the DC generator G, that is, the rotation speed, will be described.

First, when the rotation speed of the DC generator G at the time of rising is low, the output voltage of the DC generator G is low (for example, up to 0.8 V or less). At this time, the gate voltage of the transistor FET is lower than the operating voltage, and F
ET does not work. The power supply voltage is too low for the comparator to operate. Therefore, in this state, the DC generator G is rotated in a no-load state if the dark current of the circuit is ignored.

The rotation speed of the DC generator G slightly increases. For example, when the voltage is near 1.1 V, the voltage of the constant voltage circuit AVR is lower than the set voltage. Is applied, and the generator output voltage is divided and applied to the + input by the resistors R11 and R10. Therefore, the output of the comparator CP2 becomes-(0 V), and the gate of the transistor FET is grounded via the diode D3. Therefore, the generator output voltage (in this case,
It is a voltage close to 1.1V. ) Is applied by the resistor R9, the transistor FET remains OFF.

The rotation speed of the DC generator G further increases,
For example, when the voltage becomes slightly higher than 1.1 V, the comparator C
The positive input and the negative input of P2 are almost the same (the values of the respective elements are set to be the same). If the generator output voltage rises even slightly, the-input of the comparator CP2 does not change because it is the output of the constant voltage circuit AVR, and the + input increases. Therefore, the output of the comparator CP2 becomes + (constant voltage). Circuit AVR). When the output of the comparator CP2 becomes +, the-input is applied without being divided, and the-input side becomes larger than the + input side, and the comparator CP2 becomes larger.
Is-. When the output of the comparator CP2 becomes-,
The minus input is divided, and the plus input increases, and the above-described state is repeated. Thus, when both inputs of the comparator CP2 are substantially equal, the comparator CP2 is in an oscillating state. The voltage range in which this oscillation occurs is determined by the voltage division ratio of the resistors R11 and R10, and the repetition time range is determined by the voltage division ratio of the resistors R12 and R13. In this oscillation state, the diode D3
Is turned off when the output of the comparator CP2 is + and turned on when the output is-, so that the comparator CP2 turns on and off the diode D3 alternately. On the other hand, since a positive input is given to the gate of the transistor FET via the diode D2 and the resistor R9, except when the diode D3 is turned on and the gate voltage is bypassed,
The transistor FET is turned on. That is, the transistor FET repeats ON and OFF. When the transistor FET is turned off, the capacitor C1 is charged via the diode D2 with a transient spike voltage due to the inductance of the generator winding. Therefore, a high-capacity and large-capacity capacitor C1 higher than the generation voltage
Can be charged and an operating voltage can be supplied to the circuit.

When the number of revolutions of the generator further increases and its output reaches a sufficient voltage, for example, 1.3 V, the + input of the comparator CP2 is 1.3 V, and the-input is a constant voltage circuit. The output voltage of the AVR is applied, and the output of the comparator CP2 becomes +. However, the increase of the −input due to the fact that the voltage is not divided by the resistors R12 and R13 cannot be larger than the + input, and the comparator CP2 becomes Keeps the + output, and the diode D3 keeps the OFF state. On the other hand, the comparator CP1
Is a voltage obtained by dividing the voltage between the resistors R3 and R8 at the + input, and-
A voltage divided by the resistors R1, VR1, R2, and R6 is applied to the input. If the value of each resistor and VR1 are adjusted so that the + input becomes higher, the comparator CP1 generates a + output, The transistor FET is turned on, the output of the generator G is short-circuited by the resistor R6, and power generation braking is applied. When the rotation speed decreases due to braking, the voltage on the + input side decreases due to the resistors R4 and R5, and when the rotation speed drops below the voltage on the-input side, the output of the comparator CP1 becomes-and the transistor F
Turn off ET. Thereby, the dynamic braking is released,
The DC generator G has no load and the rotation speed increases. Eventually, the DC generator G is controlled to be ON and OFF, and is maintained at a constant braking speed. The variable resistor VR is for adjusting the set voltage of the braking speed.

If the generator output is short-circuited, the terminal voltage of the generator drops below the internal voltage. Therefore, in the short-circuit state, it is necessary to adapt the set voltage to the dropped value. The resistor R6 applies a voltage drop due to the short-circuit current of the generator so as to lower the negative input of the comparator CP1, thereby turning off the transistor FET earlier with respect to the feedback voltage by the resistors R4 and R5 at the time of short-circuit. Speed fluctuations during braking can be reduced.

Although the output voltage of the DC generator G decreases due to the power generation braking, the above-described state can be maintained for a certain period of time due to the high-voltage and large-capacity charge of the capacitor C1, and sufficient braking can be performed.

[0018]

As described above, according to the present invention,
Appropriate dynamic braking is applied to the braking DC generator using a braking DC generator connected to the rotating system via a one-way clutch, and a control circuit for interrupting connection between the braking DC generator and the load. be able to. And the power supply of the control circuit is
By using a power supply that smoothes the output of the braking DC generator, the control circuit can be operated without requiring an external power supply for operating the control circuit or a built-in power supply such as a battery. Therefore, it is possible to perform power generation braking on an automatic closing door or the like installed in a place where there is no power supply, and since there is no use of a built-in power supply such as a battery, there is no need to pay attention to the life of the battery and the like. There is.

[Brief description of the drawings]

FIG. 1 is a circuit diagram for explaining an embodiment of the present invention.

FIG. 2 is a schematic view showing the entirety of an automatic closing door for explaining an example to which the dynamic braking circuit of the present invention is applied.

[Explanation of symbols]

G: DC generator, AVR: constant voltage circuit, VR: variable resistor, R1 to R13: resistor, C1 to C4: capacitor,
D2, D3: diode, CP1, CP2: comparator, F
ET: Field effect transistor.

Claims (1)

(57) [Claims] 1. A power supply circuit in a dynamic braking circuit having a braking DC generator connected to a rotating system via a one-way clutch, and a control circuit for interrupting connection between the braking DC generator and a load. The braking DC generator is a DC generator that does not have a power supply for rotating it as a DC motor, does not operate as a DC motor, and
A power supply circuit in a power generation braking circuit, wherein an output of a smoothing circuit for smoothing an output of the braking DC generator is used as a power supply of the control circuit, and the control circuit has no other power supply.