JP2552332Y2 - 2 times overvoltage excitation circuit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a DC-excited electromagnetic actuator such as an electromagnetic clutch, an electromagnetic brake, and a rotary solenoid (hereinafter referred to as "actuator or load").
The present invention relates to a double overvoltage excitation circuit capable of reliably performing the above operation.

[0002]

2. Description of the Related Art An actuator requires a larger starting current when starting from off to on than a holding current for maintaining an on state. For this reason, at the time of start-up, a drive circuit having the following configuration is used because it is necessary to apply a larger voltage to the actuator than in the steady state. This type of actuator is, for example, an apparatus for measuring and detecting a sheet-like object with upper and lower detection heads as disclosed in Japanese Utility Model Laid-Open Publication No. 2-14008, "Sheet-like object measuring apparatus". Used for maintenance of the detector by separating the detection head using an actuator. For example, after turning on an electromagnetic clutch (switch), which is an actuator, the detection head is separated and the power May be turned off.

FIG. 6 is a diagram for explaining a conventional overvoltage excitation circuit (FIG. 1A is an overvoltage excitation circuit diagram of voltage switching by a resistor R, and FIG. 1B is a time chart thereof). FIG. 7 is a diagram for explaining a conventional overvoltage excitation circuit.

In FIG. 6, an overvoltage E1 higher than a rated voltage can be applied to the actuator RL1 by turning on only the switch element Q1 for a predetermined time δ required for starting from off to on. Thereafter, in holding, only the switch element Q2 is turned on, so that the overvoltage E1 is divided by the resistor R1 and applied to the actuator RL1.

In FIG. 7, at the moment when the switch SW1 is turned on, the voltage E2 charged in the capacitor C1 can be applied to the actuator RL2. Normally, the voltage {RL2 / (R2 + RL2)}. E2 (1) is applied to the actuator RL2.

[0006]

However, such a conventional technique has the following problems.

In the technique shown in FIG. 6A, the resistor R1 is selected so as to be a holding voltage of the actuator RL1 (the holding period is represented by .tau. In FIG. 6B).
There is a problem with heat loss in 1.

In the technique shown in FIG. 7, the heat loss at the resistor R2 and the time of overexcitation depend on the capacitance of the capacitor C.
Therefore, a large-capacity capacitor is required.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object the purpose of using a simple configuration while taking into account over-excitation driving during actuator driving. It is an object of the present invention to provide a double overvoltage excitation circuit which realizes low cost.

[0010]

In order to achieve the above object, the present invention provides a start switch (SW ₂ ) and a start signal based on the operation of the start switch. The start signal is set by a timer at the rise of the start signal. A trigger circuit (11) that operates for a given period of time, a first switch element (Q ₂ ) that operates according to the output of the trigger circuit, a second switch element (SSR ₂ ) that is switched by the first switch element, a third switch element which S w production kitchen <br/> grayed AC power (E ₃₎ based on an operation of the start switch (SSR _1), all based on the input of the first switching element and the third switching element A rectifier circuit (21) for performing wave rectification and performing half-wave rectification when the second switch is turned off after a predetermined time has elapsed.

[0011]

[Action] The trigger circuit is triggered by a signal from the start switch.
Operates for a fixed time set by the immer and activates the first switch element.
Turn on. This first switch element forms a bridge circuit.
Second switch for turning on / off one element to be formed
Is turned on. The signal from the start switch is simultaneously
Operate switch element to rectify AC voltage from AC power supply
Apply to the circuit. The rectifier circuit includes a first switch and a third switch.
When the switch element is on, full-wave rectification is performed and a certain time elapses.
Thereafter, when the first switch element is turned off, half-wave rectification is performed.

[0012]

An embodiment will be described with reference to the drawings.

FIG. 1 is a circuit diagram showing a specific embodiment of the double overvoltage excitation circuit of the present invention. FIG. 2 is a time chart for explaining FIG.

In FIG. 1, Z denotes a DC-excited actuator serving as a load (in this case, for example, an electromagnetic clutch coil. In the description of this part, in order to show a difference from the prior art, in particular, (Expressed as "load")
It is.

Reference numeral SW2 denotes a start switch SW2 for starting the load Z.

Reference numeral 10 denotes a full-wave / half-wave rectification switching unit which starts operation by a start signal for starting the load and generates a signal having a sufficient time width required for starting the load (referred to as a start time width signal). And a timer signal generation circuit (a drive circuit for driving a load). The timer signal generating circuit 10 receives, for example, a start signal P based on the operation of a start switch SW2 and starts operation by the start signal, that is, a monostable multivibrator triggered by the rise of the start signal.
(The output pulse width adjusting capacitor CT and the resistor R
T is connected) 11 and this monostable multivibrator
And has a sufficient time width (a time width T as shown in FIG. 2 (b) to be described later) for the load Z to start when there is a start signal P. And outputs the start time width signal (hereinafter, referred to as a timer signal) F.

Reference numeral 20 denotes a start signal and a timer signal, which are supplied with an AC voltage from an AC power supply E3. The AC voltage is subjected to full-wave rectification / half-wave rectification (timer-timer).
This signal is output to the electromagnetic actuator as a full-wave rectified voltage as long as the signal is present, and as a half-wave rectified voltage during the start signal after the timer signal is turned off). This is a load voltage supply circuit for supplying Z. The load voltage supply circuit 20 includes an AC power supply E that is turned on by a start signal P based on the on operation of the start switch SW2.
3 and a zero-cross solid-state relay (hereinafter, referred to as "SSR2") provided on one of the lines, and a zero-cross solid-state relay (hereinafter, referred to as "SSR2") which is turned on by a timer signal F. ) May be incorporated into one side of a bridge (diode bridge) to constitute a rectifier circuit 21 that outputs a voltage subjected to full-wave / half-wave rectification.

Hereinafter, it is possible to supply and apply a full-wave rectified voltage to the load Z while the start signal P and the timer signal F are present, and a half-wave rectified voltage while only the start signal P is present. Will be described.

(A) A start signal P based on the ON operation of the start switch SW2 as shown in FIG.
R1 is turned on, and the AC voltage is guided to the rectifier circuit 21.

(B) On the other hand, at the same time, the monostable multivibrator 11 is operated by the start signal P, and the timer output F for a fixed time T is supplied to the SSR2 from the switch element Q2.

(C) As a result, SSR2 is equal to time T
During this period, the rectifier circuit 21 supplies a full-wave rectified voltage waveform as shown in FIG. 2 (d) to the load terminal.

(D) As described above, the full-wave rectified voltage can be supplied to the load for a certain period of time at startup (while there is a timer-output F for a certain period of time T).

(E) When a predetermined time T has elapsed, a timer
Since the signal F is turned off, SSR2 is also turned off.

(F) Thereafter, based on the start signal P, the rectifier circuit 21 supplies a half-wave rectified voltage waveform as shown in FIG. 2 (d) to the load terminal. That is, after the elapse of the fixed time T from the start, the output of the rectifier circuit 21 is switched to the half-wave rectification, and the half-wave rectified voltage is applied to the load to maintain the ON operation.

More specifically, for example, when the load is one using a rated 90 VDC, a certain period of time T from when the start switch SW2 is turned on from off.
During this time, both SSR1 and SSR2 are on.
A full-wave rectified voltage with an average value of 180 VDC is then applied to SSR2
Is turned off, a half-wave rectified voltage having an average value of 90 VDC is applied to the load Z.

Therefore, at the start-up time when the full-wave rectified voltage is applied, the load is excited twice as much as the voltage applied after the start-up time. Therefore, actuator operation based on load can be ensured. Then, after the start, the rated voltage based on the half-wave rectified voltage is applied to the load, so that the heat generation of the load can be suppressed. In addition, it is necessary to allow a sufficient time, for example, 0.1 to 0.5 seconds, for the fixed period T for the actuator such as the electromagnetic clutch which has become a load to be turned on.

[0027]

Other Embodiments The present invention is not limited to those described above. For example, you may comprise as follows.

(1) SSR1 and SSR2 may be of a non-zero cross type instead of the zero cross type.

(2) If the contact life is not particularly problematic, a mechanical relay or the like may be used. This may be determined within the range of use in designing.

(3) In the case of the configuration as shown in FIG. 1, the usual use, that is, the AC power supply E3 and the DC power supply (+ V
s), the start switch S is turned on first.
There is no particular problem when operating W2. However, if the start switch SW2 and the DC power supply are turned on first, and then the AC power supply E3 is turned on, there is a relationship between the timer and the time. Sometimes, a situation in which a voltage twice as high as the rated voltage cannot be applied to the load is also conceivable.

In consideration of this, the following may be performed.

That is, at the time of starting, the AC power supply is full-wave rectified and a voltage twice as high as the rated voltage is applied to the load to reliably start the power supply. Based on the configuration shown in FIG. 1 that suppresses the heat generation of the power supply, the start-up timing of the timer signal generation circuit can be triggered by a start-up signal of the load, and is also triggered by the rise of the AC power supply voltage (or by the load). When the load is activated, over-excitation is performed twice, and when the operation of the load is completed, the fact that the load has operated is fed back to switch to the normal excitation.
Thereby, the timer signal generation circuit, SSR1 / SSR
2. Regardless of the order in which the AC power is turned on, at the time of startup, overload excitation can always be performed twice the load.

FIG. 3 is a diagram showing another embodiment of FIG. 1 for realizing such a thing. FIG. 4 is a diagram provided for explanation of FIG.

In FIG. 3, reference numeral 30 denotes an AC power supply monitoring section connected to both ends of the AC power supply E3 and having, for example, a photocoupler PC1 for monitoring the ON / OFF state of the AC power supply E3. Reference numeral 40 denotes a main switch for outputting a start signal Pa for the load Z. Reference numeral 100 denotes a start time width signal generation circuit which starts operation by a start signal for starting the load and generates a signal (start time width signal) having a sufficient time width required for starting the load. Is called a timer signal generation circuit. Therefore, the start time width signal is also referred to as a timer signal here.

Here, the timer signal generating circuit 100 outputs a start signal Pa (meaning that the ON / OFF of the AC power supply E3 is transmitted to the timer signal generating circuit) based on the operation of the start switch SW2 to "-Trig". Terminal (triggered by the falling edge of the start signal Pa), and furthermore, the output signal PE from the photocoupler PC1 of the monitoring unit 30 is input to the "+ Trig" terminal to output a signal PE based on the rising edge of the AC power supply E3.
Monostable multivibrator 11 triggered by rising edge
a and a switch element Q2 operated by the output of the monostable multivibrator, and a time width T sufficient for the load Z to start based on the respective input signals.
A timer signal Fa having W is output.

The operation will be described below with reference to FIG.

In the time chart of FIG. 4, a section "A" shows the operation relationship of each part when the starting switch SW2 is turned on and the load Z is turned on when both the AC / DC power supply is on, Section "B" is a start switch S
AC power supply E when both W2 and DC power supply are on
The operation of each part when 3 is turned on is shown.

In the section "A", for example, when the start switch SW2 is turned on at time t1, the start signal Pa is output from the main switch section 40. At this time, it is assumed that both the AC / DC power supply are in the ON state (however, the state diagram of the DC power supply is omitted on this time chart).
Accordingly, at time t1, the timer signal Fa having a sufficient time width TW for starting the load Z is output from the timer signal generation circuit 100. Therefore, at time t2 when the AC power supply crosses zero, SSR1 is turned on by the start signal Pa and SSR2 is turned on by the timer signal Fa, so that the full-wave rectification is performed while the start signal Pa and the timer signal Fa are present. The half-wave rectified voltage can be supplied and applied to the load Z while only the start signal Pa is present (this is substantially the same as FIG. 1 and FIG. 2).

In the section "B", it is assumed that both the DC power supply and the start switch SW2 are in the ON state (the state diagram of the DC power supply is omitted). For example, the AC power is turned on at time t3. In the monitoring unit 30, since an input current having a rising curve with a certain response as shown in FIG. 4C is applied to the photocoupler PC1, the photocoupler PC1 receives the input current at the time t5. The rising output signal PE is "+ Trig" of the monostable multivibrator 11a.
Triggered by this signal PE, a timer signal Fa having a time width TW is output from the timer signal generation circuit 100 in the same manner as described above. Therefore, at time t6, SSR1 and SSR1 are output. Since SSR2 is turned on, the full-wave rectified voltage while the start signal Pa and the timer signal Fa are present, the half-wave rectified voltage while only the start signal Pa is present, and the load Z Can be supplied and applied.

(4) When considering the order of turning on the DC power supply, the AC power supply, and the start switch, the structure is not limited to FIG. 3 and is further illustrated in FIG. 5 for explaining the embodiment. It is possible.

In FIG. 5, reference numeral 50 denotes a starting time width signal generating circuit which starts operation by a starting signal for starting a load and generates a signal having a time width sufficient for starting the load. For example, the operation state of the transistor Q3 is turned on / off by a signal of the operation state detector 60 using a photo-interrupter so that the output is turned on when the excitation operation of the load is completed, for example. By doing so, a start time width signal Fb for operating / deactivating SSR2 is output. The activation time width signal generation circuit 50 is represented here as a load operation / state confirmation circuit.

Therefore, in the case of this configuration, the start switch S
When the start signal Pa is output by turning on W2, SSR1 is turned on in the same manner as described above by the start signal Pa, and SSR2 is turned on by the start time width signal Fb from the load operation / state check circuit 50. The load Z
, Excitation can be doubled. When the exciting operation of the load is completed, the transistor Q3 of the load operation / state confirmation circuit 50 is forcibly turned off by the signal of the operation state detector 60, and the SSR2 is turned off by the start time width signal Fb. That is,
In this case, a sufficient time width required for starting the load is determined by the presence or absence of a signal from the operation state detector 60, whereby a half-wave rectified voltage is supplied and applied to the load Z.

In other words, with this configuration, over-excitation is performed twice before the load operates and the operation state detector 60 is turned on. The order of the inputs is not limited at all.

[0044]

As described above, according to the present invention,
The trigger circuit and the AC power supply are
Operation, and adjust by trigger signal side switching.
A full-wave / half-wave output in the flow circuit is performed. So
Output pulse from the trigger circuit
Signal and turn on for a certain period of time determined by the timer circuit.
It is turned off if it passes, and the first signal
The switch element was turned off. As a result,
The timer is set even if the start switch is turned off / on
The rectifier circuit is kept on for a certain period of time.
Must output a full-wave rectified signal and perform a reliable excitation operation.
Can be.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a specific example of a double overvoltage excitation circuit according to the present invention.

FIG. 2 is a time chart for explaining FIG. 1;

FIG. 3 is a diagram showing another embodiment of FIG. 1;

FIG. 4 is a diagram provided for explanation of FIG. 3;

FIG. 5 is a diagram provided for explanation of still another embodiment.

FIG. 6 is a diagram for explaining a conventional overvoltage excitation circuit.

FIG. 7 is a diagram for explaining a conventional overvoltage excitation circuit.

[Explanation of symbols]

Z Load (electromagnetic actuator for DC excitation) 10, 100 Start-up time width signal generation circuit (timer-signal generation circuit) 50 Start-up time width signal generation circuit (load operation / state check circuit) 20 Load voltage supply circuit E3 AC power supply

Claims (1)

(57) [Scope of request for utility model registration] An activation switch (SW ₂ ), a trigger circuit (11) that receives an activation signal based on the operation of the activation switch, and operates for a predetermined time determined by a timer at the rise of the activation signal; The first which operates by the output of
A switching element (Q _2), a second switch element which is switched by the first switch element (SSR _2), the third switch element of S w etching AC power source (E ₃₎ based on an operation of the start switch (SSR ₁ ) and a rectifier circuit (21) for performing full-wave rectification based on the inputs of the first switch element and the third switch element and performing half-wave rectification when the second switch is turned off after a lapse of a predetermined time. twice overvoltage excitation magnetic circuit, characterized by comprising a.