JPH02290183A - Controller for fan for combustion equipment - Google Patents

Abstract

PURPOSE:To facilitate system deployment in the pulse width control of DC voltage supply by a method wherein the title controller is provided with a voltage comparing circuit, comparing the hold voltage of a hold circuit with the reference voltage of a triangular wave reference voltage generating circuit, a chopper circuit, controlled by the output of the comparing circuit and the output thereof is supplied to a fan, and the like. CONSTITUTION:The title controller is provided with a F/V circuit 17, converting the rotating number of a fan 27 into a voltage, a voltage comparing circuit 12, comparing the hold voltage of a hold circuit 7 with the reference voltage of a triangular reference voltage generating circuit 11, a chopper circuit 15, controlled by the output of the voltage comparing circuit 12 and whose output is supplied to the fan 27, and the like. The potential of the chopper circuit 15 is proportional to the rotating number of the fan 27 and is amplified by an amplifier 13 through the F/V circuit 17 utilizing the input voltage of a control signal input terminal 2a as a reference, then, is inputted into an inversion amplifying circuit 2. According to this method, a necessary rotating number may be obtained easily by inputting only a power source voltage and a control signal, whereby the deployment of the title controller for microcomputer applying equipments may be effected easily.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device for a blower for combustion equipment used in gas field boilers and the like. Conventional technology In conventional blowers for combustion equipment, the power supplied to the electric motor was supplied from another electrical equipment, and the motor simply rotated and sent the rotation signal generated by the rotation to the aforementioned electrical equipment. It was not possible to control the rotation speed of a single blower or to develop it systemically. A conventional example will be explained below with reference to Figure 2. As shown in the figure, 3l is an AC power supply, 32 is a blower 33 consisting of an electric motor 32a and a fan 32b, 35 is a snubber circuit, 34
is a filter for noise suppression, 36 is a semiconductor for phase control,
37 is a capacitor for stabilizing the operation of the semiconductor 3G; 38.
41 is a diode; 39 is an isolation transformer for supplying a trigger signal to the semiconductor 36; 40. 42 is a current limiting resistor, 43 is a phase control signal generation circuit, 44 is a signal input terminal, and 45 is a DC power supply. When a signal is input to the signal input terminal 44, a phase control signal corresponding to the signal is output from the phase control signal generating circuit 43 and applied to the primary winding of the isolation transformer 39 through the current limiting resistor 42. Then, a voltage is induced in the secondary winding of the isolation transformer, triggering the semiconductor 36, current flows through the diode 38, a phase control signal is generated in accordance with the signal input to the signal input terminal 44, and the motor 32a of the blower 32 is activated. is applied to. By adjusting this voltage, the rotation speed of the blower 32 was adjusted. Problems to be Solved by the Invention However, since this configuration uses an AC power supply, it is necessary to separate the control signal using an isolation transformer, etc., and there are also problems in that abnormal noise is generated from the motor due to phase control. ．． Furthermore, there was also the problem that it was difficult to develop system products for applications such as microcomputers. Therefore, the present invention has developed a blower for combustion equipment that can control the control signal without separating it with an isolation transformer or the like, and that facilitates system development by controlling the pulse width of the DC voltage supply instead of using a phase control method. It provides a control device. Means for Solving the Problems Therefore, in order to solve the above-mentioned problems, the control device for a blower for combustion equipment of the present invention includes a power supply terminal, a blower having an electric motor and a fan, and an F converting the rotation speed of the blower into voltage.
/ν circuit, an amplifier circuit that amplifies the output of the F/V circuit, an inverting amplifier circuit that amplifies the output of the amplifier circuit using the input signal from the control signal input terminal as a reference, and an output of the inverting amplifier circuit. a hold circuit that holds while having a time constant, a triangular wave reference voltage generation circuit, a voltage comparison circuit that compares the hold voltage of the hold circuit with a reference voltage of the triangular wave reference voltage generation circuit, and an output of the voltage comparison circuit. It consists of a chopper circuit whose output is controlled by the blower and whose output is supplied to the blower, and a case. Effects According to the blower for combustion equipment having the above configuration, the required rotational speed can be easily obtained without abnormal noise from the motor by simply inputting the power supply voltage and control signal, and there is no need for an isolation transformer, etc., which is often associated with AC power supplies. First, it can be easily extended to microcomputer-applied equipment. EXAMPLE Below, a control device for a blower for combustion equipment according to an example of the present invention will be explained with reference to the drawings. As shown in FIG. 1, the power supply terminal 1, the electric motor 27a, and the fan 2? an inverting amplifier circuit 2 having an air blower 27 having a rotation speed b, an F/V circuit 17 that converts the rotation speed of the air blower 27 into voltage, an amplifier circuit l3 that amplifies the output of the F/V circuit l7, and a control signal input terminal 2a. , a hold circuit 7 that holds the output of the inverting amplifier circuit 2 with a time constant, a triangular wave reference voltage generation circuit 11, a hold voltage of the hold circuit 7, and a reference voltage of the triangular wave reference voltage generation circuit 11. It consists of a voltage comparator circuit 12 that compares the voltage with the voltage comparator circuit 12, a chopper circuit 18 that is controlled by the output of the voltage comparator circuit 12 and whose output is supplied to the blower 27, and a case. In the above configuration, the power supply terminal 1 from the microcomputer application system, etc.
Assume that power is supplied to the computer and a signal is input to the control signal input terminal 2a. Initially, the blower 27 is not rotating, so the output of the amplifier circuit l3 is zero, and the control signal input terminal 2
When a certain potential is input to a, the inverting amplifier circuit 2 operates with that voltage as a reference, and the capacitor 9 constituting the hold circuit 7 is charged with voltage, and that potential and the reference of the triangular wave reference voltage generation national route 11 are used. The output of the voltage comparator circuit 12 that compares the voltage becomes a high potential and can drive the chipper circuit 18. This potential is proportional to the rotation speed of the blower 27, and is based on the input voltage of the control signal input terminal 2a.
is amplified by the amplifier circuit 13 via the /V circuit 17,
The signal is input to the inverting amplifier circuit 2. As a result, assuming that the reference voltage of the triangular wave reference voltage generation circuit l1 is high potential HA% and low potential LA, the output of the inverting amplifier circuit 2 is determined by the resistor 6, resistor 7, and capacitor 9 that constitute the hold circuit 7. The hold circuit 7 is charged with a constant, which is higher than the reference voltage L& of the triangular wave reference voltage circuit l1<H. The pulse width of the transistor 22 that constitutes the chopper circuit 18 is controlled. This also controls the power transistor 20, resistor 19.21, coil 24
A voltage is applied to the blower by a chopper circuit 18 consisting of a diode 23 and a capacitor 25. This causes the blower 27 to rotate at a rotation speed proportional to the voltage input to the control signal input terminal 2a. Effects of the Invention As described above, since the present invention does not use an AC power supply, there is no need to separate the control signal with an isolation transformer, etc., and since the voltage applied to the motor is lowered by pulse width control, no abnormal noise is generated from the motor. do not have. In addition, the blower can be rotated simply by connecting a circuit to the n signal input terminal via the power supply terminal, making it easy to deploy to microcomputer-applied equipment.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a control device for a blower for combustion equipment according to an embodiment of the present invention, and FIG. 2 is a circuit diagram for controlling a conventional blower for combustion equipment.

Claims (1)

[Claims] A power supply terminal, a blower having an electric motor and a fan, an F/V circuit that converts the rotation speed of the blower into voltage, and the F/V circuit that converts the rotation speed of the blower into voltage.
an amplifier circuit that amplifies the output of the V circuit; an inverting amplifier circuit that amplifies the output of the amplifier circuit with reference to the input signal from the control signal input terminal; and an inverting amplifier circuit that holds the output of the inverting amplifier circuit with a time constant. a hold circuit, a triangular wave reference voltage generation circuit, a voltage comparison circuit that compares the hold voltage of the hold circuit and a reference voltage of the triangular wave reference voltage generation national route, and a voltage comparison circuit that is controlled by the output of the voltage comparison circuit and whose output is applied to the blower. A control device for a blower for combustion equipment, consisting of a chopper circuit that is supplied to the combustion equipment, and a case.