JPH0396674A - Three-phase electronic float switch - Google Patents

Abstract

PURPOSE:To make relays and transformers entirely unnecessary and to make the whole device compact and lightweight by carrying out the turning on and off of the three-phase AC with noncontact output circuits, and carrying out the power source feeding necessary to operate a starter circuit and the like with a rectifier circuit and a wide scope rating constant voltage circuit. CONSTITUTION:When the water-level is raised to the first specific value, for example, the contact output of a starter float switch S1 is changed. As a result, a self-holding circuit 16 is set by a starter circuit 18, operation directing signals 16u and 16w are activated, and noncontact output circuits 12u and 12w are turned on through ignition circuits 15u and 15w. Consequently, an underwater pump motor 13 is started to rotate, and the water is started to exhauste. In this case, while the turning on and off of the three-phase AC is carried out with the noncontact output circuits 12u and 12w, the power source feeding to the starter circuit 18 and the like is carried out with a rectifier circuit 14 and a wide scope rating constant voltage circuit 17. Consequently, relays and transformers are made entirely unnecessary, and the whole device is made compact and light-weight.

Description

[Detailed Description of the Invention] The present invention is a three-phase electronic device that controls the start and stop of electrical equipment such as a three-phase submersible pump motor, an opening/closing door for water level adjustment, and a valve. Regarding float switches.

Submersible bombs used to adjust the water level in civil engineering work, water receiving facilities, etc. must be activated when the water level exceeds a predetermined level, and must be stopped when the water level drops due to activation. Therefore, an electronic float switch is equipped to control this starting and stopping. Conventional three-phase electronic float switches detect the water level using both a start float switch and a stop float switch placed in the water, and this detection signal operates a relay sequence circuit or an electronic circuit including a relay. The basic structure is to control the three-phase AC power supply of the underwater bomb motor, which in turn controls the starting and stopping of the underwater bomb.

However, when using an electronic float switch with a built-in relay sequence circuit, many large-sized relays are used, and the shape of the relay that connects and disconnects power to the submersible pump motor is difficult. In particular, since the device is large, the main body of the device becomes large and there is a problem in that it is inconvenient to handle.

In addition, when using an electronic float switch with a built-in electronic circuit including a relay, a transformer that steps down the commercial three-phase AC is essential in order to obtain the low DC voltage necessary to operate the transistors and ICs. The size of the transformer also poses a problem, and in both cases it is a major obstacle in promoting miniaturization of devices.

The present invention was created to solve the above problems, and its purpose is to provide a three-phase electronic float switch that can be downsized.

The three-phase electronic float switch according to the present invention for reducing the amount of electricity has a non-contact output circuit that connects and disconnects the three-phase AC power supplied to electrical equipment according to an external command, and a circuit that rectifies the three-phase AC power. A rectifier circuit that supplies power to each circuit component, a startup circuit that outputs the detection result of the startup float switch as a first water level detection signal, and a stop circuit that outputs the detection result of the stop float switch as a second water level detection signal. and turning on the non-contact output circuit in response to the first water level detection signal,
and a self-holding circuit that controls the non-contact output circuit to be in an OFF state in response to the second water level detection signal.

When the three-phase AC power source is turned on, power is supplied to each circuit component through the rectifier circuit, and the startup circuit etc. operate.

When the water level at the location where the start float switch and stop float switch are located exceeds the first water level, the first water level detection signal is output from the start circuit, and the non-contact output circuit is turned on by the operation of the self-holding circuit. state, and three-phase alternating current is supplied to electrical equipment.

Then, when the water level stops and the water level drops below the second water level, a second water level detection signal is output from the stop circuit,
Due to the operation of the self-holding circuit, the non-contact output circuit is turned off, and the supply of three-phase alternating current to the electrical equipment is stopped.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a three-phase electronic float switch according to the present invention will be described as an embodiment installed in a submersible pump.

FIG. 1 is a block diagram showing the electrical configuration of a three-phase electronic float switch.

As shown in the figure, a submersible pump motor 1 as an electrical device
A commercial three-phase alternating current of 200V is supplied to the primary side of No. 3 through a thermostat l1 and non-contact output circuits L2u and 12v. That is, the operation of the non-contact output circuits 12u and 12v, whose main components are triacs, connects and disconnects the three-phase alternating current supplied to the submersible pump motor l3. It should be noted that the thermostat 11 is provided to protect the submersible pump motor 13 from overcurrent, restraint current, and to prevent the equipment from overheating.

Further, the three-phase AC V- phase voltage is guided to a rectifier circuit 14 configured by a diode bridge. The output stage of this rectifier circuit 14 includes a wide range rated constant voltage circuit l.
7 is connected, and this output voltage is supplied as a power source to circuit configurations such as a starting circuit 18, a stopping circuit 19, and a self-holding circuit 16 for controlling the non-contact output circuits 12u and 12v. There is.

The wide range rated constant voltage circuit 17 is equipped to handle commercial three-phase AC other than 200V, and when the three-phase AC is 200V or more, the output voltage of the rectifier circuit 14 is divided by a transistor, It is designed to always output a specified voltage.

This has the advantage that even when submersible pump motors l3 having different rated voltages are used, it is not necessary to change the design of each circuit component.

The starting circuit l8 is a circuit that outputs the detection result of the starting float switch S1 connected to this input terminal via the resistor Rl as a first water level detection signal 18a, and the input section is composed of Darlington-connected transistors. It operates as a high input impedance circuit. The l-th water level detection signal 18a is led to a self-holding circuit 16, which will be described later.

The stop circuit 19 is a circuit that outputs the detection result of the stop float switch S2 connected to this input terminal via a resistor R2 as a second water level detection signal 19a, and the input section is composed of Darlington-connected transistors. It is designed to operate as a high-power impedance circuit. The second water level detection signal 19a is led to a self-holding circuit 16, which will be described later.

The starting float switch SL and the stopping float switch S2, which are connected to the starting circuit 18 and the stopping circuit 19 via cables not shown, are arranged at predetermined locations of the water whose water level is to be adjusted, and When the lower side is the first water level and the lower side is the second water level, the first water level is detected by the start float switch S1, and the second water level is detected by the stop float switch S2.

The self-holding circuit 16 is configured by Cyrisk or the like, and a first water level detection signal 18a is introduced into the set human power terminal, and a second water level detection signal 19a is introduced into the reset human power terminal. The operation instruction signals 16u, 16W, which are the output signals of the self-holding circuit 16, are guided to the control terminal side of the non-contact output circuits 12U, 12W via ignition circuits l5υ, 15W configured by photocouplers. There is.

Next, the operation of the three-phase electronic float switch as described above will be explained. FIG. 2 is an explanatory diagram showing changes in water level.

When a power switch (not shown) is turned on, three-phase alternating current is energized, and the rectifier circuit 14, wide range constant power circuit 1
DC voltage is supplied to the starting circuit 18, the stopping circuit 19, the self-holding circuit 16, etc. through the starting circuit 7, and these circuit components operate.

Now, when the water level at the location where the start float switch S1 and the stop float switch S2 are located rises ((as shown by the old figure in Figure 2)) and that water level becomes the first water level.
At (time Tl), the contact output of the startup float switch SL changes. Then, the first water level detection signal 18a output from the starting circuit 18 is sent to the self-holding circuit 16,
The self-holding circuit 16 enters the set state. Therefore, the operation instruction signal 16u, 1 output from the self-holding circuit 16
6- becomes active, and the non-contact output circuits 120, 12W are turned on through the ignition circuits 150, 15-. At the same time, the submersible pump motor 13 starts rotating and drainage starts.

With the start of this drainage, the water level begins to fall, and when the water level falls below the first water level, the contact output of the starting float switch S1 changes again, but due to the latching operation of the self-holding circuit l6, the non-contact output circuit 120, 12 tl is kept on and drainage continues.

As drainage continues, the water level gradually decreases (as shown by h2 in Figure 2), and when the water reaches the second water level (time T2), the stop float switch S2 is activated.
The contact output changes. Then, the second water level detection signal 19a output from the stop circuit 19 is sent to the self-holding circuit 16, and the self-holding circuit 16 enters the reset state. Therefore, the driving instruction signal 1 output from the self-holding circuit 16
6u, 16W becomes inactive, ignition circuit 15U
, 15W through the non-contact output circuit 120. ．． 12W
is in the off state. At the same time, the underwater pump moke 13 stops. After that, when the submersible pump motor 13 stops discharging water, the water level changes in the direction of increasing, but the same operation is repeated thereafter.

In the three-phase electronic float switch in this embodiment, the three-phase alternating current is switched on and off using non-contact output circuits 12U and 12K, while the power supply necessary to operate the starting circuit 18, etc. is provided by the rectifier circuit 14 and the wide range rating. Since this is performed by the constant voltage circuit 17 and does not use any relays or transformers, the entire device is extremely small and lightweight. In addition, the insulation of the cable electrically connected to the start float switch S1 or the stop float switch S2 may be destroyed, and one of the terminals of the start float switch S1 or stop float switch S2 may be exposed to water or the like. Even when a leakage current is allowed to flow, the leakage current flows through the resistors R1 and R2 and is limited to a small current value. That is, safety is also excellent.

Next, a modification of the three-phase electronic float switch will be described with reference to FIGS. 3 and 4.

FIG. 3 is a partial block diagram showing the electrical configuration of the three-phase electronic float switch, and FIG. 4 is an explanatory diagram showing changes in the water level.

A third water level corresponding to an intermediate point between the l-th water level and the second water level is detected by the alternate activation float switch S3. Then, the alternate starting float switch S3 is connected to another starting circuit 31 (same structure as the starting circuit 18) via a resistor R3.
Connect to the input terminal of The third water level detection signal 31a, which is the output of the starting circuit 3l, is introduced into the set terminal of the self-holding circuit 16a via the alternating operation circuit 32, which is a binary counter circuit. Note that the configuration other than the above is completely the same as that of this embodiment.

In the case of such a modification, the water level can also be controlled as shown in FIG.

It goes without saying that the three-phase electronic float switch according to the present invention can be applied not only to submersible pumps but also to electrical equipment such as opening/closing doors and valves for water level adjustment.

As a result, the three-phase electronic float switch according to the present invention does not require relays or transformers, which is extremely effective in promoting downsizing and weight reduction of the device. has great advantages.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the electrical configuration of an embodiment of the present invention, Fig. 2 is an explanatory diagram showing changes in water level, and Fig. 3 shows a partial electrical configuration of a modified example of the present invention. block diagram,
FIG. 4 is an explanatory diagram of a modified example showing changes in water level. 1211, 12-... Non-contact output circuit l3...
Submersible pump motor 14... Rectifier circuit l6... Self-holding circuit 16U, 17... l8... 18a 19... 19a S1... S2...

Claims (1)

[Claims] (1) When setting the higher side of the water level to be adjusted as the first water level and the lower side as the second water level, the start float switch and stop float switch that detect the first and second water levels. A three-phase electronic float switch that controls the start and stop of submersible pump motors, water level adjustment doors, valves, and other electrical equipment based on each detection result, which controls the three-phase AC power supplied to the electrical equipment. a non-contact output circuit that is turned on and off by an external command, a rectifier circuit that rectifies the three-phase alternating current and supplies power to each circuit component, and a starting circuit that outputs the detection result of the starting float switch as a first water level detection signal. , a stop circuit that outputs the detection result of the stop float switch as a second water level detection signal, and a stop circuit that turns on the non-contact output circuit in response to the first water level detection signal, and a stop circuit that outputs the detection result of the stop float switch as a second water level detection signal; A three-phase electronic float switch comprising: a self-holding circuit that controls the non-contact output circuit to be in an OFF state in accordance with the above.