JPS63111472A - Power source frequency detector - Google Patents

Abstract

PURPOSE:To accurately detect the frequency of a power source by rotating an AC motor which constitutes a damper device by >=1 cycle when the power source is turned on and rotating a cam by this AC motor. CONSTITUTION:When the AC power source 52 is turned on, a contact Ra is made by the initial setting of a microcomputer 50 and the AC motor 24 is driven. A 1st cam 27 rotates by said driving. At this time, when the projection 40 of a swing arm 31 contacts the small arc surface 34 of the 1st cam 27, a read switch 32 is off and a position detection part 56 is therefore at low level. A timer part 58 begins to count up when the detection part 5 falls to the low level after being at high level. A decision part 58 decides the level of the detection part 56 at a specific point of time after the start of the counting operation to detect the power source frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention provides an accurate power source for devices that have operating equipment that is affected by the power frequency and that is controlled by a microcomputer without the need for a special detection circuit. This allows for easy frequency detection.

(B) Conventional Technology A necessary device for detecting the power supply frequency is, for example, a motor damper (using an AC motor) device used in a microcomputer-controlled refrigerator as shown in Japanese Patent Application No. 165209/1982. This device energizes the moke for a certain period of time to open and close the damper, but if there are multiple power supply frequencies, the energization times will differ for each, so it is necessary to detect the frequency.

(c) Problems to be solved by the invention In the above-mentioned conventional technology, the voltage is stepped down by a transformer and the AC power source is waveform-shaped and then input to a control device (microcomputer) to detect the frequency. Not only does it require a circuit, but it also picks up noise mixed in with the power supply, which can lead to false detections. In order to avoid malfunctions caused by this, it is sufficient to install position detection sensors in multiple positions, but since the damper device is not originally very large, it may require a structure to mount multiple sensors. was becoming more complicated.

The present invention provides a method for easily and accurately detecting the power supply frequency that eliminates such inconveniences by measuring the time required for a motor damper device that operates in synchronization with the power supply frequency to change from one state to another using a clock within a microcomputer. However, the frequency of the power supply is determined based on that time.

(d) Means for Solving the Problems In order to solve the above problems, the present invention provides an AC motor (
24), the AC motor (24) is driven when the power is turned on to perform at least one predetermined periodic operation, and the power supply frequency is detected by measuring the time of this one cycle. I will provide a.

(E) According to the working example, when the AC power supply (52) is turned on (the same applies after a power outage), the fill (Re) of the relay (Ry) is energized by the initial setting of the microcomputer (50), and its contact (
Ra) is closed and the AC motor (24) is driven. With this drive, the first cam (27) rotates, and at this time, the protrusion (40) of the swing arm (31) rotates, for example, as shown in FIG. , the reed switch (32) is off, the position detector (56) is at low level (L), and the protrusion (4)
0) is the large arc surface (
33), the reed switch (32)
is on, so the position detection section (56) is at high level (H
) However, in any case, the timer section (58) starts counting when the position detection section (56) shifts from high level (H) to low level (L). That is, when the reference value is the count end time, for example, 16.5 seconds as shown in FIG. 4, at a frequency of 50)1z, the first cam (27)
For a period of 18 seconds and a frequency of 60Hz, the first cam (27〉
Since it takes 15 seconds for one cycle of , when the reference value is reached, the determination unit (58) should determine whether the position detection unit (56) is at a high level (H) or a low level (L). This enables accurate detection of power supply frequency.

(F) Embodiment An embodiment will be explained with reference to the drawings. FIG. 5 shows a refrigerator-freezer (1) as an example. (2> is a heat insulating box body, and the interior of the refrigerator is divided into upper and lower parts by a heat insulating partition wall (3), with a freezer compartment (F) serving as the first compartment at the top and a refrigerating compartment (R) serving as the second compartment at the bottom. ) are formed into sections.(6
) and (7) are heat insulating doors that separately open and close the front openings of the freezer compartment (F) and the refrigerator compartment (R).

A cooling chamber (8) is formed within the partition wall (3), and a cooler (10) included in the refrigeration cycle is housed inside the cooling chamber (8). A duct (11) communicating with the cooling chamber (8) and both chambers (F) and (R) is formed behind the cooler (10), and a blower (
At step 12), air cooled by the cooler (10), that is, cold air, is sucked in and forcibly blown out into the duct (11). (
12M) is a motor that drives the blower (12). The cold air blown into the duct (11) is blown into the freezing compartment (F) through the discharge port (14) and into the refrigerator compartment (R) through the discharge port (15). (17) is the discharge port (1
5) A damper device installed in the refrigerator compartment (R) to open and close the discharge port (15) using a baffle plate (18) that can freely rotate forward and backward based on the temperature in the refrigerator compartment (R). Then, the temperature of the refrigerator compartment (R) is controlled to be, for example, between +7°C and +3°C to an average of +5°C. (19) is a damper device (
17) is the heat insulating cover. Also, (20) is a refrigerator-freezer (
1) A condenser (22), which is also included in the refrigeration cycle, is installed in the lower machine room (21) and is an electric compressor included in the refrigeration cycle. (22) and a blower (23) for cooling the aforementioned electric compressor 20).

Note that (5) is an operation panel attached to the front surface of the door (6).

In addition to the baffle plate (18), the damper device (17) is equipped with an AC motor (24) serving as a driving source as shown in FIG.
A first gear (26) and a first cam (27) provided on the rotating shaft (25) of this AC motor, a second gear (2B) that meshes with this first gear, and a second gear provided on this second gear. a second cam (29), and a pin (29) that opens or closes the baffle plate (18) as the second cam rotates.
30), a swing arm (31) that reciprocates in the left-right direction as the first cam (27) rotates, and a reed switch (31) that opens or closes as the swing arm reciprocates. 32). The first cam (27) has a large arc surface (33) far from the center on its circumferential surface;
The second cam (29) has a small arc surface 34) near the center and two stepped surfaces (35) that are the boundaries between the large and small arc surfaces. The bottle (30) has a high part surface (36), a low part surface (37), and a slope (38) serving as a boundary between the two high and low parts on the surface where one end touches the low part surface. When in contact with the surface (37), the baffle plate (18) closes and the pin (
30) is in contact with the high part surface (36), the baffle plate (18) can maintain its opening action, and the pin (30) passes through the slope (38) and is in contact with the high part surface (37). When moving to the site plane (36) or vice versa, the baffle plate (18) moves from closed to open or from open to closed, respectively. The swing arm (31) has a hole (39) that receives a shaft K (not shown) and serves as a fulcrum, and a tip thereof that is connected to the first
It has a protrusion (40) in contact with the circumferential surface of the cam (27), and a magnet (42) embedded in the widened part (41) whose negative side is in contact with the reed switch (32), as shown in FIG. )(d), the small arc surface (3) of the first cam (27)
4>, when the protrusion (40) is in contact with the widened part (4)
1) is separated from the reed switch (32>), and the second
As shown in Figures (B) and (C), the large arc surface (
33) is in contact with the protrusion (40), the widened part (
41> is in contact with the reed switch (32). The reed switch (32) has a pair of contact pieces (43) and (44), and the swing arm (31) has a second UgJ (
(b) When in contact with the reed switch (32) as shown in (c), the two liquid pieces (43) (44>) come into contact with each other, that is, turn on, due to the magnetic force of the magnet (42).

The seal member (45) shown in FIG. 6 is a sealing member that also serves as a buffer member and is provided on the back side of the baffle plate (18), and is made of foamed polyethylene or the like, and is intended to improve airtightness when the baffle plate (18) is in the closed state. In addition, baffle plate (18)
Alleviates the impact when the door closes. (46) is a resin case that covers the heat insulating cover (19), and cold air outlets (47) (47) are formed on both left and right sides.

Figure 3 shows the control electric circuit, (50) is a microcomputer, and its input terminal is a full-wave rectifier (50).
1) is connected to the output terminal. The full wave rectifier (51
) is connected to an AC power source (52). or,
The AC motor (24) is connected to a relay contact (R) which will be described later.
a), and the reed switch (32) forms a series circuit with a resistor (R) and is connected to the output end of the full-wave rectifier (51). (
53) has one end connected to the reed switch (32) and the resistor (R
A signal line is connected to the middle point (a) of the AC motor (
When the reed switch (24) is closed as the reed switch (24) rotates, a high level signal is input to the position detection section. (
Ry) serves as a turn-off switch from the microcomputer (50). The microcomputer (50) has a freezing room temperature control unit (54) that receives the output of a sensor (FS) that detects the temperature of the freezing compartment (F), and a sensor (R5) that detects the temperature of the refrigerator compartment (R). A refrigeration room temperature control section (55) that receives the output as input, a position detection section (56) that detects whether the reed switch (32) is on or off, and a position detection section that detects whether the reed switch (32) is turned on or off (or vice versa). a timer section (57) that outputs a clock pulse for a certain period of time when switching;
A determining unit (5) determines whether the reed switch (32) is on or off when the clock pulse accumulation of this timer unit is completed.
8) and a storage unit (59) that receives the output of this discrimination unit as input.
It is equipped with. The freezing and refrigeration room temperature control section (54)
(55) each has an A/D conversion section, a comparison section, and a temperature setting section, and the measured values detected by the respective sensors (FS) (R5) are A/D converted and set to the respective upper and lower limits. When the measured temperature of the freezing compartment (F) reaches the upper limit setting temperature when the measured temperature of the freezing compartment (F) is compared with the constant temperature of both membranes, the compressor (20) is stopped by the microcomputer (50), while the measured temperature of the freezing compartment (F) is When the temperature reaches the lower limit set temperature, the microcomputer (50) operates the compressor (20) to control the temperature of the freezer compartment (F), and the measured temperature of the refrigerator compartment (R) reaches the upper limit set temperature. When it reaches the relay (R
The coil (Re) of y) is excited, its contact (Ra) closes, the AC motor (24) is driven for a predetermined period of time, and the baffle plate (18) opens, while the measured temperature of the refrigerator compartment (R) is When the lower limit set temperature is reached, the AC motor (2
4) is driven for the same length of time as the predetermined time and the baffle plate (
18), the temperature of the refrigerator compartment (R) is controlled. The AC motor 24) is also driven when the relay (R7) is energized by the program or initial setting of the microcomputer (50) when the AC i source (52) is input to the control electric circuit.

Next, power supply frequency detection will be explained with reference to FIGS. 1 to 4.

When the AC power supply (52) is turned on (the same applies after a power outage), the coil (Re) of the relay (Ry) is energized by the initial settings of the microcomputer (50), and its contact (Ra) closes to connect the AC motor (24). is driven. With this drive, the first cam (27) rotates, and at this time, the protrusion (40) of the swing arm (31)
), the reed switch (32) is off, the position detector (56) is at low level (L), and the protrusion (4o) is in contact with the small arc surface (34) in FIG. B)
When it is in contact with the large arc surface (33) of the first cam (27) as shown in FIG. Even so, the timer section (58) starts counting when the position detection section (56) goes from high level (H) to low level (L). That is, as shown in Fig. 4, when the count end time is set to, for example, 16.5 seconds as the reference value, the frequency is 18 seconds and 60 seconds per cycle of the first cam (27).
At the frequency H2, it takes 15 seconds for one period of the first cam (27), so when the reference value is reached, the position detection section (56) is at high level (H) or low level (L).
), it is possible to detect an appropriate power supply frequency by having the determining section (58) determine whether the power supply frequency is the same or not.

(G) Effects of the Invention In the above-described power frequency detection device of the present invention, when the power is turned on, the AC motor constituting the damper device is rotated for one cycle or more, and the AC motor is used to rotate the first cam. Since the power supply frequency can be detected using the clock count number of the timer section operated by the position detection section that detects the position of one cam as a reference value, there is no need for a waveform rectification circuit and it is possible to eliminate the need for a damper device that is caused by noise mixed in the power supply. Malfunctions and malfunctions can be prevented.

[Brief explanation of the drawing]

The drawings all show embodiments of the power frequency detection device of the present invention, with Fig. 1 being a perspective view of the main parts, Figs. A circuit diagram, FIG. 4 is a time chart showing frequency detection, FIG. 5 is a vertical sectional view of a refrigerator equipped with the device of the present invention, and FIG. 6 is a sectional view taken along line A-A in FIG. 5. (17) Damper device, (24) AC motor, (27) First cam, (31) Swing arm, (32) Reet switch, (SO)
...Microcomputer, (56) ...Position detection section, (58)
...Timer section. Applicant Sanyo Electric Co., Ltd. and one other representative Patent attorney Takuji Nishino To one other person Figure 5 Figure 6

Claims (1)

[Claims] 1. An AC motor that rotates in synchronization with the power supply frequency and performs a predetermined periodic operation is provided, and when the power is turned on, the AC motor is driven to perform at least one period of the predetermined periodic operation, and the time of this one cycle is A power frequency detection device that measures the power frequency and detects the power frequency.