JPH0652968B2 - Drive circuit controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive circuit control device for a power system, such as a magnet, a stepper motor, and a head pin, which is used in a terminal device having a mechanical mechanism.

2. Description of the Related Art Generally, a drive circuit control device for a power system such as a magnet, a stepper motor, and a head pin has an input power source of the drive circuit + V.
₁ and the output power supply + V ₂ for power drive are configured to be supplied to the drive circuit. In the power supply device that generates these power supply voltages + V ₁ and + V ₂ , when power is turned on and off, The power drive output power supply + V ₂ is provided with a sequence control of delayed throw and early cut to prevent malfunction of the magnet, stepper motor, head pin, etc. and the generation of abnormal sound when the power is turned on and off.

FIG. 4 shows a conventional controller for a drive circuit. In FIG. 4, reference numeral 1 is a control unit for generating a drive signal,
Reference numeral 3 indicates a drive circuit. The drive circuit 3 includes a transistor 5 that drives the load 7, a clamp diode 6 that absorbs a counter electromotive voltage when the transistor 5 is turned off, and an input resistor 4 that determines the base current of the transistor 5. Each has one circuit, and usually consists of 20 or more. Reference numeral 2 is an open collector type inverter, which controls the drive circuit 3 to be turned on or off. Reference numeral 8 denotes a power supply device having a sequence of high-voltage output delayed throw-off and early cut-off.
₁ for obtaining a low voltage regulator 11, a high voltage regulator 12 for obtaining a power driving output voltage + V ₂ for driving a load, a low voltage delay circuit 13, and a high voltage delay quick disconnect circuit 14 and a control circuit 15 for monitoring the voltage on the secondary side of the transformer 10 and notifying that it has completely started up.

Next, the operation of the conventional example will be described. In FIG.
When the AC switch 9 is turned on, first, the low-voltage regulator 11 that constitutes the power supply device 8 outputs the + V ₁ power supply.
When this voltage + V ₁ rises by 90% or more, this is detected by the high-voltage delayed throw / early disconnection circuit 14, and the output + V ₂ of the high-voltage regulator 12 rises after a predetermined time. Then, the control circuit 15 monitors these voltages + V ₁ and + V ₂ , confirms that they have completely risen, and then raises the voltage valid signal PCL after a fixed time T ₃ .

The control unit 1 having a microcomputer inside is activated by the voltage valid signal PCL from the power supply unit, and the control unit 1
The drive signal output inside is initialized. The initialized drive signal output is input to each drive circuit 3 via the open collector type inverter 2, and the load 7 connected to the output side of the drive circuit 3 is de-energized.

And thereby to the supply voltage + V ₁ of the control unit 1 rises in the output voltage + V ₂ for power driven to the OFF state, even after the voltage + V ₁ is up standing, a drive signal output, voltage Initialized by valid signal PCL, output voltage + V ₂ for power drive
The load 7 is pressed down so that it will not be energized even if it rises.

As described above, have a sequence after power on,
This prevents malfunction of the drive circuit and generation of abnormal sound a.

Next, even when the power is turned off, first, the AC switch is turned off, and the power supply device 8 detects an off state, that is, a power failure as shown in FIG. 5, and outputs the voltage valid signal PCL from the control circuit 15. Turn it off and output it to controller 1.
Then, when a few ms or more elapses, the high voltage delayed throw-off circuit 14 rapidly discharges the power drive voltage + V ₂ to forcibly reduce the voltage.

On the other hand, the low voltage delay circuit 13 detects the power driving voltage + V ₂ and delays the low voltage + V ₁ to the control system by delaying for several ms when it reaches 10% or less.

This enables the voltage valid signal PC from the control circuit 15.
The control unit 1 performs the power failure process by L, sets the drive signal output to the same as in the initial state, and disconnects the power drive high voltage + V ₂ . Finally, the uncontrollable voltage band in the falling process of the voltage + V ₁ applied to the control unit 1 is reached. At that time,
Since no voltage is applied to the load 7, the drive circuit 3
It is possible to prevent abnormal noise from being generated due to the malfunction and the load operation.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional drive circuit control device, the power supply device is provided with a high-voltage delayed throw-off circuit and a low-voltage delayed circuit. It is designed to control the disconnection sequence. Therefore, the power supply becomes large,
In addition, the weight is heavy, and the discharge noise at the time of shutting off the power supply device is large, so that there is a problem that economical efficiency is remarkably lacked when viewed as a whole terminal having a mechanical mechanism.

The present invention solves such a conventional problem, and does not perform the sequence control of the delayed throw-in / turn-off of the power system high voltage in the power supply device, but controls the input power supply voltage + V ₁ of the drive circuit. It is an object of the present invention to provide a control circuit for a voltage / current and a control circuit for a drive circuit having a drive system enable signal indicating that initialization of a drive signal has been completed by program control.

Means for Solving the Problems In order to achieve the above object, the present invention provides a control circuit of low voltage and small current for controlling the input power supply voltage + V ₁ of the drive circuit, and further, initialization of the drive signal is performed. With the drive system permission signal indicating that the program control is completed, the control circuit is turned on and off, and the input power supply voltage of the drive circuit is controlled.

Therefore, according to the present invention, after the power is turned on, all the drive signals are set to the power-on reset state until the low voltage for controlling the drive circuit rises and the CPU that executes the program is activated. Then, the CPU sequentially supplies the drive circuit input voltage + V ₁ ′ from the low voltage small current control circuit by enabling the drive system enable signal after completing the drive signal to the initialization state. This has the effect of preventing malfunction and abnormality of the magnet or the like after power is turned on.
Similarly, even when the power is cut off, the drive system permission is enabled before the control voltage + V ₁ and drive voltage + V ₂ fall when the CPU receives the OFF state of the power failure detection signal PCL detected in the power supply device. The signal is disabled and the low voltage small current control circuit drives the drive circuit input voltage.
Stopping + V ₁ ′ has the effect of invalidating the drive circuit regardless of the logic of the drive signal and similarly preventing malfunction and abnormality.

Embodiment FIG. 1 shows the structure of an embodiment of the present invention.
In FIG. 1, reference numeral 21 is a control unit having a CPU that also executes a program procedure for generating a drive signal, and 23 is an example of a drive circuit. The drive circuit 23 includes a transistor 25 that drives the load 27 and a clamp diode 26 that absorbs a counter electromotive voltage when the transistor 25 is turned off.
And an input resistor 24 that determines the base current of transistor 25
The load 7 has one circuit each, and normally has 20 to 100 circuits. 22 is the control unit 2
The open collector type inverter provided in 1 controls ON / OFF of the drive circuit 23 by the program control of the CPU. Reference numeral 26 is a low-voltage small-current control circuit, which is connected to the input voltage terminal of the drive circuit 23. 29 is a switch for turning on / off the AC power, and 30
Is an ordinary power supply device that does not have a sequence of delayed throw-off of high voltage output. That is, the power supply device 29 includes a transformer 33 for separating the primary side and the secondary side of the AC power source, a low voltage regulator 31 for supplying a control system voltage, a high voltage regulator 32 for supplying a voltage for driving a load, and a power failure. And a control circuit 34 for detecting

Next, the operation of the above embodiment will be described.

In FIG. 1, when the AC power switch 29 is turned on, AC power is applied to the power supply device 30, and the power supply device 30 is
In the low voltage regulator 31 via 33, the control voltage + V ₁
And the high voltage regulator 32 generates a drive system voltage + V ₂ for driving the load. In this power-on state, as shown in FIG. 2, there is no regulation of the order of the rise time of + V ₁ and + V ₂ , and there is no sequence.

Next, the control 21 includes the control low voltage + V ₁ from the power supply device 30.
However, at the same time when this voltage + V ₁ is applied, the control unit 2
Output signal 1 is set to power-on initial (reset) mode. When the control unit 21 is powered on initially, the low-voltage small-current control circuit 28 and each drive circuit 23 are all turned off, and the drive circuit input voltage + V ₁ ′ is not applied,
The drive circuit 23 maintains the non-energized state.

Next, the power supply device 30 is a control circuit for detecting a power failure.
At 33, after the power is turned on, the output voltage of the secondary side + V ₁ and + V ₂
Is detected to rise completely, and as shown in FIG. 2, the CPU start permission signal PCL is raised after a few ms, and this is supplied to the control unit 21. The control unit 21 receives the CPU activation permission signal PCL, activates the CPU, executes the program according to a built-in program procedure, and sets the drive output signal from the inverter 22 to the initial state. Then, when the initialization of the drive output signal is completed and it is confirmed that the drive system is valid, the drive system valid signal a is output to the low voltage small current control circuit 28. As a result, the low-voltage small-current control circuit 28 receives the control system voltage + V ₁ and turns on the drive circuit input voltage + V ₁ ′ at almost the same level. Here, the drive circuit input voltage + V ₁ ′ is determined as follows.

+ V ₁ ′ ＝ + V ₁ −V _CE (V) V _CE is the saturation voltage when the transistor is on, 0.2 to
0.6V.

As described above, when the power is turned on, the drive circuit input voltage + V ₁ ′ is controlled to be valid or invalid with respect to the load of the drive system to prevent load malfunction and abnormal operation noise. still,
After that, the CPU executes normal operation under program control.

Next, a case where the AC power is turned off will be described. When the AC power switch 29 is turned off, the input of AC power is stopped, and the output voltage of the low-voltage regulator 31 and the high-voltage regulator 32 gradually decreases. In this case, in the power supply device 30, the output voltages + V ₁ and + V ₂ are not particularly forcibly controlled, and only the holding capacity and the load constant of the low-voltage regulator 31 and the high-voltage regulator 32 are used. Discharge decreases naturally. Among them, in the power failure detection control circuit 34, when the voltage drop of the AC power supply is detected and the power failure is detected, the PCL signal is turned off immediately to notify the power failure detection state. In response to this PCL signal (b), the CPU of the control unit 21
Performs power outage processing. As one of them, when the drive system permission signal (a) is turned off, the low voltage small current circuit 28 turns off the drive circuit input voltage + V ₁ ′. This operation should be completed by the time the output voltages + V ₁ and + V ₂ begin to drop.
Inside the power supply device 30, a minimum holding characteristic when turned off is provided.

Even when the AC power to the cross-sectional Thus, before the output voltage + V ₁ and + V ₂ starts to decrease, the drive circuit input voltage + V
₁ 'turned off, the driving system load and the non-conductive state, the occurrence of a malfunction and abnormal operating noise of the load can be prevented.

Incidentally, FIG. 5 shows a schematic flowchart of a control program in the control unit 21.

As is apparent from the above-described embodiment, the present invention changes the power supply ON / OFF control of the drive circuit from the high voltage large current type to the low voltage small current type, so that the input voltage of the drive circuit is activated by the power supply device. Upon receiving the signal PCL, the CPU of the control unit controls the low-voltage small-current control circuit to turn on and off. Therefore, the control power is reduced by the current amplification factor hFE of the drive circuit. Have. That is, since the current amplification factor hfE is usually 50 to 5000, the electric power of 1 / (50 to 5000) is enough.

In addition, this eliminates the need for the low-voltage delay circuit and high-voltage delay throw-off circuit required in the conventional power supply device.
This has the advantage that the power supply device can be greatly reduced in size and weight. Further, according to the present invention, charging / discharging noise at the time of turning on / off the power supply device can be significantly reduced, and the economical efficiency of the entire terminal having a mechanical mechanism can be significantly improved. Have.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an embodiment of a drive circuit control device of the present invention, FIG. 2 is a timing chart diagram of output signals of respective parts at power-on and power-off of the embodiment, and FIG. 3 is the same. FIG. 4 is a schematic flow chart of a control program of a control unit that constitutes an embodiment, FIG. 4 is a schematic block diagram of a conventional drive circuit control device, and FIG. 5 is a diagram showing output signals of each unit when the power is turned on and off in the device. It is a timing chart figure. 21 ... Control part, 22 ... Open collector type inverter, 23 ...
Driving circuit, 24 ... Input resistance, 25 ... Driving transistor, 26
… Clamp diode, 27… Load, 28… Low voltage small current control circuit, 29… AC power switch, 30… Power supply device, 31… Low voltage regulator circuit, 32… High voltage regulator circuit, 33
… AC transformer, 34… control circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Uno 4-3-1, Tsunashima-higashi, Kohoku-ku, Yokohama-shi, Kanagawa Matsushita Communication Industrial Co., Ltd. (72) Inventor Katsuji Miyata 1-7, Toranomon, Minato-ku, Tokyo No. 12 Oki Electric Industry Co., Ltd. (72) Inventor Hirofumi Kawauchi 4-3 Jonai, Hanamaki City, Iwate Prefecture Shinko Seisakusho Co., Ltd. (72) Inventor Toshiro Katsumata No. 78 Minamimachi, Mishima City, Shizuoka Prefecture Tokyo Electric Co., Ltd. Mishima Factory (56) References JP-A-50-8020 (JP, A)

Claims (1)

[Claims] 1. A drive circuit for driving a power element such as a magnet, a step motor, a head pin, etc., and a low-voltage small-current control circuit for controlling an input power source of the drive circuit to prevent malfunctions when the power source is turned on and off. , A drive circuit control device having a control unit for controlling on / off of a drive system permission signal by executing a CPU program after power is turned on.