JPH0561478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application This invention relates to a pump control device for a well, etc., and particularly to a pump control device having an antifreeze function.

(b) Conventional technology A well-known well pump control device is
A pressure switch is installed on the water output side of the pump, and when the faucet is opened and water is released, the pressure drops and the pressure switch is turned on, which drives the pump motor to pump water, and when the pressure rises, the motor stops. .
Furthermore, when the faucet is closed while the motor is running, the pressure increases and the pressure switch is turned off, stopping the operation of the pump motor. In addition, when using this type of well pump control device in winter or in a cold region, it is possible to suppress the temperature drop by turning on a light bulb or energizing a heater to prevent the pump motor from freezing and breaking. Some products have been treated to prevent them.

Furthermore, a system has been proposed in which a flow rate switch is provided in addition to the pressure switch, and the pressure and flow rate are detected and the pump motor is controlled according to the status.

(c) Problems to be Solved by the Invention The above-mentioned conventional water supply pump control device is equipped with a light bulb and a heater to prevent freezing, but these are only used to prevent freezing, and during seasons when there is no risk of freezing. There was a problem in that it became completely unnecessary and the cost of the entire device increased.

On the other hand, measures to prevent freezing are especially necessary when the water faucet is fully closed and the flow rate is zero.

In view of the above, an object of the present invention is to provide a pump control device that can prevent freezing when a faucet is fully closed without using a special anti-freezing means such as a heater.

(d) Means for solving the problem The pump control device of the present invention includes an AC power source 7,
a pump motor 1 including a main coil 2 and an auxiliary coil 3 and driven by the AC power source; a first switching circuit 5 connected in series to the main coil for controlling energization of the main coil; a second switching circuit 6 connected in series to the auxiliary coil for controlling energization of the auxiliary coil;
A pressure switch 18 that turns on in response to a decrease in pressure in the pump system, a flow rate switch 19 that turns on in response to a flow rate in the pump system, a temperature sensor 22 that detects the temperature near the pump motor, and this temperature sensor. a low temperature detection circuit 23 that outputs an output when the temperature detected by the circuit is below a predetermined value; and the first switching circuit when the pressure switch is off, the flow rate switch is off, and the low temperature detection circuit has an output. logic control means 20 for controlling the phase of the switching circuit and turning off the second switching circuit;
25, 26, 28, and 29.

(e) Effect In this pump control device, when the pressure switch is off (high pressure) and the flow switch is off (faucet fully closed), the temperature detected by the temperature sensor is detected by the low temperature detection circuit to be below a predetermined value. When a low temperature is detected, the first switching circuit is phase controlled and the second switching circuit is turned off. Therefore, no current flows through the auxiliary coil and the pump motor is not driven, but a current flows through the main coil in accordance with the phase angle, and the heat generated by the main coil itself keeps the temperature above a certain level, thereby preventing freezing.

(F) Examples Hereinafter, the present invention will be explained in more detail with reference to Examples.

FIG. 1 is a circuit block diagram of a well pump control device showing one embodiment of the present invention.

In this embodiment of the well pump control device, a pump motor 1 includes a main coil 2, an auxiliary coil 3, and a capacitor 4, one end of the main coil 2 is commonly connected to the auxiliary coil 3, and the other end is connected to a first switching circuit 5. connected in series. Further, the auxiliary coil 3 is connected in series to a second switching circuit 6 via a capacitor 4.

The series circuit of the main coil 2 and the first switching circuit 5 and the series circuit of the auxiliary coil 3 and the second switching circuit 6 are both connected in parallel to an AC power supply 7 via a thermostat 1a for coil protection. There is.

The first switching circuit 5 includes a triax 8, anti-parallel connected diodes 9 and 10, a tripod transformer 11, and the like. tripod transformer 11
consists of a primary coil L ₁ , a secondary coil L ₂ and a tertiary coil L ₃ . The tripod transformer 11 is
When the secondary coil _L2 side is short-circuited, a low voltage is generated in the tertiary coil _L3 , and the anti-parallel connected diodes 9 and 10
A voltage higher than the trigger gate voltage is applied between the terminal T ₁ of the triac 8 and the gate G via the triac 8, and the triac 8 is ignited.

The second switching circuit 6
2, an ignition circuit 13 for igniting this triac 12, etc., and the ignition circuit 13 includes a photoconductive element 15 of a photocoupler 14.

The primary coil L ₁ of the tripod transformer 11 is connected to the AC power supply 7 , and the AC voltage derived to the secondary coil L ₂ side is rectified by the rectifier circuit 16 and then connected to the constant voltage circuit 1 .
7, and the power supply voltage is supplied to each part of the electronic circuit.

On the other hand, the pressure switch 18 and the flow rate switch 19
The on/off signal is input to the heat retention operation detection circuit 20 and the power saving operation detection circuit 21. Also,
The temperature detected by the temperature sensor 22 installed near the pump motor is determined to be 2°C by the low temperature detection comparison circuit 23.
When the temperature is lower than 2° C., a signal indicating a low temperature is outputted and inputted to the heat retention operation detection circuit 20.

When the heat retention operation detection circuit 20 receives a low signal from the pressure switch 18, a low signal from the flow rate switch 19, and a high signal indicating that the temperature is below 2°C from the low temperature detection circuit 23, the heat retention operation detection circuit 20 outputs a signal indicating the heat retention operation. In addition to adding to circuit 25, OR circuit 3
4 to the firing phase angle control circuit 28. Further, a zero cross of the AC voltage derived to the secondary coil L ₂ side of the tripod transformer 11 is detected by a zero cross detection circuit, and is input to the ignition phase angle control circuit 28. When a zero cross signal is input under the condition that an energizing signal is applied from the heat retention operation detection circuit 20 or the power saving operation detection circuit 21, the ignition phase angle control circuit 28 controls the ignition phase angle control circuit 28 for a predetermined period (phase angle α) from the zero cross point. ) is low, and then outputs a signal that becomes high until the next zero-crossing point, and outputs a signal that goes to the logic circuit 25 and then to the logic circuit 2.
5, phase angle control is performed.

The oscillation circuit 24 oscillates a signal of several KHz to more than ten KHz and applies the signal to the logic circuit 25 . The logic circuit 25 adds the signal from the oscillation circuit 24 to the main coil switching circuit 26 according to the output state of the heat retention operation detection circuit 20 and the power saving operation detection circuit 21 and the signal from the ignition phase angle control circuit 28. ,
This oscillation signal turns on/off the main coil switching circuit 26, and short-circuits and opens the secondary coil _L2 of the tripod transformer 11.

The logic circuit 25 also includes a heat retention operation detection circuit 20.
The auxiliary coil switching circuit 29 is turned on/off according to the output state of the power saving operation detection circuit 21. Turning on/off the switching circuit 29 for the auxiliary coil
By turning off, the light emitting diode 3 of the photocoupler 14
0 lights up or goes out. The light emitted from the light emitting diode 30 sends light to the photoconductive element 1 of the ignition circuit 13.
5, the resistance value of the photoconductive element 15 decreases, and in response to this, the triac 12 of the second switching circuit 6 is ignited.

A current transformer 31 is connected to the first switching circuit 5, which derives the current flowing through the main coil 2 of the pump motor 1, and an inrush current inactivation circuit 32 disables excessive values due to inrush current, etc. On the other hand, the operating current comparison circuit 33 compares whether the current is greater than or equal to a predetermined value, and if the current is greater than or equal to the predetermined value, a signal indicating this is input to the power saving operation detection circuit 21.

Next, the operation of this embodiment device will be explained.

First, assuming that the faucet is opened appropriately and the pump motor 1 is rotated to pump water, in this case, the pressure switch 18 is turned on and the flow rate switch 19 is turned on.
is also on, and the warming operation detection circuit 20 outputs a signal indicating normal operation to the logic circuit 25, but the ignition phase angle control circuit 28 is not energized. Therefore, if the signal waveform rectified by the rectifier circuit 16 is the waveform shown in FIG. 2a, and the signal from the oscillation circuit 24 is shown in FIG. is shown in Figure 2c. That is, it is turned on and off throughout the entire cycle of the AC signal. And the secondary coil of the tripod transformer 11
_L2 is repeatedly shorted and opened. This secondary coil
Due to the short circuit of L ₂ , the triax 8 of the first switching circuit 5 is ignited and current flows through the main coil 2 . In addition, the logic circuit 25 also turns on the auxiliary coil switching circuit 29 and turns on the light emitting diode 30.
is turned on, the triax 12 of the second switching circuit 6 is also fired, current also flows through the auxiliary coil 3, and the pump motor 1 is driven.

Next, assume that the faucet is fully closed, the pressure in the pump system is high, and the flow rate is 0. In this case, the pressure switch 18 is low (off) and the flow rate switch 19 is low (off).
are also low (off), and these signals are input to the warming operation detection circuit 20. However, if the temperature detected by the temperature sensor 22 is around normal temperature, the detected temperature is higher than 2° C., and therefore, in this case, the low temperature detection comparison circuit 23 outputs a low signal. Therefore, all the signals input to the heat retention operation detection circuit 20 become low, and these logic state signals are applied to the logic circuit 25. In this state, the faucet is fully closed and the temperature is at room temperature, so there is no need to drive the pump motor 1 and no need to pass current through the main coil 2 and auxiliary coil 3. Therefore, the logic circuit 25 is a switching circuit for the main coil. 26 and the auxiliary coil switching circuit 29 are not turned on. Therefore, the first switching circuit 5 and the second switching circuit 6
Both remain off.

If the faucet is fully closed and the temperature near the pump drops below 2°C, the water in the pump system may freeze.

In this case, since the temperature detected by the temperature sensor 22 is lower than 2° C., the low temperature detection comparison circuit 23 outputs a high (ON) signal indicating that the temperature is low. The heat retention operation detection circuit 20 receives the high signal indicating the low temperature and the low signals from the pressure switch 18 and the flow rate switch 19, and detects the state of these signals.
In other words, a signal indicating the heat retention operation is output to the logic circuit 25. Further, the ignition phase angle control circuit 28 is energized by a signal indicating the heat retention operation. Therefore, the ignition phase angle control circuit 28 receives the zero-crossing signal shown in FIG. 2d, and inputs into the logic circuit 25 a signal that turns on after a period of α and turns off at the zero-crossing point (see FIG. 2e). . As a result, the logic circuit 25 inputs the signal of the oscillation circuit 24 to the main coil switching circuit 26 from after the α period to the next zero cross point, as shown in FIG. 2f. Therefore, the output of the main coil switching circuit 26 becomes as shown in FIG. 2g, and the secondary coil _L2 of the tripod transformer 11 is short-circuited and
Open. When a short circuit occurs, a voltage is induced in the tertiary coil _L3 of the tripod transformer 11, and the triax 8
fires. In other words, the first switching circuit 5
is phase controlled. As a result, the pump motor 1
A current flows through the main coil 2 of the main coil 2, and the main coil 2 itself generates heat due to this current, thereby performing a heat-retaining action. Therefore, freezing of the pump system is prevented.

In this case, the logic circuit 25 turns off the auxiliary coil switching circuit 29. Therefore,
Since the second switching circuit 6 is off and no current flows through the auxiliary coil 3, the pump motor 1 is not driven.

In the above embodiment, the setting of the ignition phase angle α is adjusted to determine how much current is passed through the main coil to prevent freezing.

(G) Effects of the Invention According to this invention, when a low temperature below a predetermined temperature is detected with the pressure switch turned off and the flow rate switch turned off, the main coil is turned on while the auxiliary coil of the pump motor is turned off. By passing current through the main coil itself, the heat generated by the main coil itself and its heat retention function can prevent the temperature of the water in the pump system from dropping, making it possible to prevent freezing without using any special means.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of a pump control device showing one embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the same device. 1: Pump motor, 2: Main coil, 3: Auxiliary coil, 5: First switching circuit, 6: Second switching circuit, 7: AC power supply, 18: Pressure switch, 19: Flow rate switch, 20: Heat retention operation Detection circuit, 22: Temperature sensor, 23: Low temperature detection comparison circuit, 25: Logic circuit, 26: Main coil switching circuit, 28: Firing phase angle control circuit, 29:
Switching circuit for auxiliary coil.

Claims (1)

[Claims] 1 Including AC power supply, main coil and auxiliary coil,
a pump motor driven by the AC power supply; a first switching circuit connected in series to the main coil for controlling energization of the main coil; and a first switching circuit for controlling energization of the auxiliary coil. a pressure switch that is turned on in response to a decrease in pressure in the pump system; a flow rate switch that is turned on in response to a flow rate in the pump system; a low temperature detection circuit that outputs an output when the temperature detected by the temperature sensor is below a predetermined value, and a low temperature detection circuit that outputs an output when the pressure switch is off, the flow rate switch is off, and the low temperature detection circuit has an output A pump control device comprising logic control means for controlling the phase of the first switching circuit and turning off the second switching circuit in this state.