JPH1141802A - Encoder power supply voltage regulation circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate a power supply output voltage in accordance with the fluctuation of a load regardless of a distance between a power supply and an encoder of a load, by a method wherein the state of the encoder is detected and the opening/closing of a switching means is controlled in accordance with the detection result to change a voltage dividing ratio proportional to the value in the resistor. SOLUTION: In an encoder power supply voltage regulation circuit, a voltage supplied to an encoder 110 of a load, i.e., a load terminal voltage VL, is detected through an A/D converter 111 which is a load state detecting means. Then, the ON's/OFF's of analog switches 1041-1045 are controlled by a microcomputer (CPU) 112 which is a control means in accordance with the detection result to change a voltage dividing ratio in the resistance-type voltage division. With this constitution, an output voltage VO can be controlled in accordance with the fluctuation of the load. Further, as the state of the load, i.e., the load terminal voltage VL, is directly detected by remote sensing, the accurate state of the load can be detected and the output voltage VO can be regulated securely regardless of a distance between the power supply and the load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoder power supply voltage adjusting circuit for adjusting a DC voltage by a regulator and a resistive voltage divider and supplying the adjusted DC voltage to an encoder as a load.
The present invention relates to an encoder power supply voltage adjustment circuit capable of adjusting an output voltage according to a change in load irrespective of a distance from an encoder, and preventing a power supply circuit from being damaged due to an abnormality by detecting a load state.

[0002]

2. Description of the Related Art As a conventional encoder power supply voltage adjusting circuit, for example, there is one as shown in FIG. The encoder power supply voltage adjustment circuit shown in FIG. 3 adjusts the DC power supply voltage VI with the regulator 301 and the resistive voltage dividers 302 and 303 to supply the output voltage Vo to the encoder which is a load. While observing at 307,
This is to adjust by changing the voltage division ratio of the resistance partial pressures 302 and 303. That is, in this conventional example, the DC power supply voltage VI
Through a regulator 301 to a parallel connection of a capacitor 305 and a resistor 302 (resistance value R1) to a variable sliding resistor 303.
The output voltage Vo is taken out from a voltage dividing circuit in which (resistance value R2) is connected in series via a smoothing (ripple removing) capacitor 306, and when the output voltage Vo is changed, or when the load in the load (encoder) 310 is changed. In the case of fluctuation, the output voltage Vo is monitored by the measuring device 307, and the variable voltage dividing ratio is changed by sliding the variable sliding resistor 303 to adjust the output voltage.

[0003]

However, in the above-mentioned conventional encoder power supply voltage adjusting circuit, a measuring instrument 307 is required for adjusting the output voltage Vo, and the variable sliding resistance 303 is manually adjusted. There was a problem that it was necessary to do. Further, the load (encoder) 310
There is also a problem that the distance from the camera and the load change need to be readjusted. The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of a load (encoder).
It is an object of the present invention to provide an encoder power supply voltage adjustment circuit that can adjust an output voltage according to a change in load irrespective of a distance from the power supply circuit, and can prevent damage to a power supply circuit due to an abnormality by detecting a load state.

[0004]

In order to solve the above problems, an encoder power supply voltage adjusting circuit according to a first aspect of the present invention adjusts a DC voltage by a regulator and a resistive voltage divider and supplies the DC voltage to an encoder as a load. In the encoder power supply voltage adjusting circuit, a load state detecting means for detecting a state of the encoder as the load, a switching means for changing a voltage dividing ratio in the resistance voltage dividing, and a load state detecting means according to a detection result of the load state detecting means. Control means for controlling the opening and closing of the switching means. An encoder power supply voltage adjustment circuit according to a second aspect is the encoder power supply voltage adjustment circuit according to the first aspect, wherein the load state detection means detects a load state by detecting a supply voltage to the encoder. It is. In the encoder power supply voltage adjusting circuit according to the present invention, by the load state detecting means,
When the state of the encoder, which is a load, is detected by detecting, for example, a supply voltage to the encoder, the control unit controls the opening and closing of the switching unit according to the detection result of the load state detection unit, and determines the voltage division ratio in the resistance voltage division. I am trying to change it. As a result, the output voltage can be adjusted according to the load (encoder) fluctuation without requiring a measuring device or the like for voltage adjustment as in the related art, and an abnormal state such as a load short circuit can be detected by detecting the load state. Therefore, it is possible to prevent the power supply circuit from being damaged. Furthermore, since the load state detecting means directly detects the load state (load supply voltage or load terminal voltage), accurate load state detection becomes possible, and reliable voltage adjustment can be performed regardless of the distance to the load. it can.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an encoder power supply voltage adjusting circuit according to the present invention. FIG. 1 is a configuration diagram of an encoder power supply voltage adjustment circuit according to an embodiment of the present invention. The encoder power supply voltage adjusting circuit of the present embodiment adjusts the DC power supply voltage VI by the regulator 101 and the resistance voltage division, and supplies the output voltage Vo to the encoder 110 as a load.
A / D converter for load supply voltage VL (load state detection means)
The output voltage Vo is adjusted by changing the voltage division ratio of the resistance voltage division while detecting the voltage via the resistor. In FIG. 1, an encoder power supply voltage adjusting circuit according to the present embodiment includes a regulator 1
01, resistor 102 (resistance value R1), resistors 1031 to 10
35 (resistance values R21 to R25), analog switches (switching means) 1041 to 1045, capacitor 10
5, a ripple removing capacitor 106, an A / D converter (load state detecting means) 111, and a microcomputer (control means) 112. A /
The D converter 111 converts the supply voltage (load terminal voltage) VL to the encoder (load) 110 from analog to digital and supplies it to the microcomputer (CPU) 112.
The microcomputer (CPU) 112 controls the analog switches 1041 to 1045 according to the load terminal voltage VL.
Open / close control. The resistors 1031 to 1035 have one end connected to one end of the resistor 102 and the other end connected in series to the analog switches 1041 to 1045, respectively. That is, the microcomputer (CPU) 1
12 controls the analog switches 1041 to 1045
Is controlled to open and close, and any one of the resistors 1031 to 1035 is inserted into the circuit, so that the parallel resistance can be variably adjusted.
The resistances R21 to R25 of the resistors 1031 to 1035 may have the same or different values, and the resistance 102 and the resistance 1
The output voltage Vo by changing the voltage dividing ratio by
Can be adjusted. Next, in the encoder power supply voltage adjusting circuit of the present embodiment configured as described above,
The operation will be described with reference to the flowchart shown in FIG. First, in step S201, the microcomputer (CPU) 112 inputs the load terminal voltage VL via the A / D converter 111 and observes the load state. next,
In step S202, it is determined whether or not the load terminal voltage VL is within a specified value range. If it is within the specified value range, the process proceeds to step S205 and ends normally. Proceed to step S203. Step S20
In 3, it is determined whether the load terminal voltage VL is an abnormal value.
For example, if the load terminal voltage VL is almost zero [V], an abnormal state such as a load short circuit can be predicted. If the load terminal voltage VL is higher than normal, an abnormal state such as no load or disconnection of the voltage supply line can be predicted. If such an abnormality occurs, the process proceeds to step S206, where it is determined that the load is abnormal, and all the analog switches 1041 to 1045 are turned off to lower the output voltage Vo. Step S
If the load terminal voltage VL is not an abnormal value in 203, a load fluctuation or the like is expected, and the process proceeds to step S204 to adjust the output voltage Vo. That is, when the load terminal voltage VL falls below the standard value, the resistances 1031 to 1031
The analog switches 1041 to 1045 are controlled to open and close so that the parallel resistance value (R2) increases by 35, and the output voltage Vo is boosted. When the load terminal voltage VL exceeds the standard value, the parallel resistance of the resistors 1031 to 1035 increases. Value (R
2) analog switches 1041 to 1
045 is controlled to open / close to lower the output voltage Vo. Here, the output voltage VRout of the regulator 101 and the output voltage V
The relationship of o is represented by the following equation (1). Vo = (R1 + R2) / R1 · VRout (1) Also, the resistance values R21 to R25 of the resistors 1031 to 1035
For example, R21 = R, R22 = 2R, R23 = 4
By setting R, R24 = 8R, and R25 = 16R, the parallel resistance value (R2) of the resistors 1031 to 1035 becomes 0 by opening and closing the analog switches 1041 to 1045.
The setting of the range from to 31R can be changed in R increments. As described above, in the encoder power supply voltage adjustment circuit of the present embodiment,
The supply voltage (load terminal voltage) VL to the encoder (load) 110 is detected via the A / D converter 111, and the microcomputer (CPU) 112 controls the opening and closing of the analog switches 1041 to 1045 according to the detection result. And
Since the voltage division ratio in the resistance voltage division is changed, the output voltage Vo can be adjusted according to the load fluctuation, and the abnormal state such as no load, overload, or load short circuit can be detected by detecting the load state. The power supply circuit can be prevented from being damaged in the event of a load abnormality, and the load state (load terminal voltage VL) can be directly detected by remote sensing.
, It is possible to accurately detect the load state,
Reliable adjustment of the output voltage Vo can be performed irrespective of the distance to the load.

[0006]

As described above, according to the encoder power supply voltage adjusting circuit of the present invention, when the load state detecting means detects the state of the encoder which is a load by detecting, for example, the supply voltage to the encoder, the control is performed. In the means, the switching of the switching means is controlled in accordance with the detection result of the load state detecting means, and the voltage division ratio in the resistance voltage division is changed. Therefore, the output voltage can be adjusted according to the fluctuation of the load (encoder). Further, by detecting the load state, for example, an abnormal state such as a load short circuit can be detected, so that the power supply circuit can be prevented from being damaged, and the load state detecting means can directly detect the load state (load supply voltage or load supply voltage). Load terminal voltage), which enables accurate detection of the load state, and encoder power supply voltage adjustment that enables reliable voltage adjustment regardless of the distance to the load. It is possible to provide a circuit.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an encoder power supply voltage adjustment circuit according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of an encoder power supply voltage adjustment circuit according to the embodiment.

FIG. 3 is a configuration diagram of a conventional encoder power supply voltage adjustment circuit.

[Explanation of symbols]

101, 301 Regulator 102, 302 Resistance (resistance R1) 1031 to 1035 Resistance (resistance R21 to R25) 1041 to 1045 Analog switch (switching means) 105, 305 Capacitor 106, 306 Ripple removing capacitor 110 Encoder (load) 111 A / D converter (load state detecting means) 112 Microcomputer (CPU) (control means) VI DC power supply voltage Vo Output voltage VL Load terminal voltage 303 Variable sliding resistance (resistance value R2)

Claims (2)

[Claims] 1. An encoder power supply voltage adjusting circuit for adjusting a DC voltage by a regulator and a resistive voltage divider to supply the load to an encoder as a load, wherein: a load state detecting means for detecting a state of the encoder as the load; An encoder power supply voltage adjusting circuit, comprising: switching means for changing a voltage dividing ratio in pressure; and control means for controlling opening and closing of the switching means according to a detection result of the load state detecting means. 2. The encoder power supply voltage adjustment circuit according to claim 1, wherein in the encoder power supply voltage adjustment circuit, the load state detection unit detects a supply voltage to the encoder.