JPH0313823A - Bathtub-water-level detecting apparatus - Google Patents

Abstract

PURPOSE:To elongate the life of a battery by transmitting a radiowave only when the water level in a bathtub is higher than a specified value based on the signal from a pressure sensor with a power control circuit. CONSTITUTION:A water level sensor is composed of a diaphragm 13, a movable electrode 14 which is linked to the diaphragm 13 and a fixed electrode 15 facing the electrode 14. When the hot-water feeding from a hot water feeding machine 4 is started, the diaphragm 13 is displaced by receiving the pressure of water in a bathtub 1. The interval between the movable electrode 14 and the fixed electrode 15 becomes narrow. The frequency of an oscillating circuit 17 becomes low by the change in capacitance 16 constituting a resonating circuit 17. A power control circuit 20 detects the frequency of the signal from the transmitting circuit 17. The power is supplied from a battery 21 to a transmitter 18 when the frequency is lower than a specified value. Namely, only when the water level of the bathtub 1 is higher than the diaphragm 13 by specified value or higher, a radiowave is transmitted. The radiowave is received with a receiver 22. The frequency is detected and the water level can be found. The hot-water feeding into the bathtub 1 is controlled in correspondence with a preset water level.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a bathtub water level detection device using a water level sensor that detects the water level in the bathtub as pressure, and is used in automatic baths that automatically fill the bathtub with hot water. This is particularly useful for remotely installed automatic baths where the water heater is installed away from the bathtub.

2. Description of the Related Art Conventionally, there is an automatic bathing device of this type as shown in FIG. In FIG. 3, a water level sensor 3 is installed in a part of a circulation adapter 2 connected to a bathtub 1, and a water heater 4 installed apart from the bathtub 1 is connected to the bathtub 1 through a circulation pipe 5 for supplying and circulating hot water. water level sensor 3 and water heater 4
is connected to the water heater 4 with a connection cord 6.

In the conventional example with the above configuration, hot water supply to the bathtub is started from one side of the circulation pipe, the water level sensor 3 detects the water pressure of the bathtub water, a signal is sent to the water heater 4 via the connection cord 6, and the control inside the water heater 4 is performed. The water level is compared with the set water level in the water tank, and the water supply to the bathtub is controlled.

Problems to be Solved by the Invention As mentioned above, conventional water level detectors require a connection cord between the bathtub and the water heater, making installation work complicated and causing the connection to be prone to high humidity. Since they are placed in the environment, they have poor reliability and are embedded in walls, making maintenance difficult.

The present invention solves the above problems and eliminates the connection cord of the conventional example, thereby improving reliability and facilitating maintenance.

Means for Solving the Problems In order to solve the above problems, the present invention provides a pressure sensor for detecting water level that is provided in communication with a bathtub, a wireless transmitter that is modulated by a signal from the pressure sensor, and a battery thereof.
and a power control circuit that supplies power to the radio transmitter when the signal from the pressure sensor is above a certain value.

Function: According to the present invention, the water level signal detected by the pressure sensor is transmitted on radio waves from the wireless transmitter, and the water level signal is transmitted to the outside of the water heater body or the like. The wireless transmitter is supplied with power from the battery only when the signal from the pressure sensor is above a certain value by the power control circuit.

EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 and 2. In FIG. 1, the adapter body 7 is fixed to the bathtub 1 with connection screws 8 and packing 9. A hot water pipe 10 and a return pipe 11 are connected to the adapter body 7,
On the other hand, the hot water supply pipe IO return pipe 11 is connected to the discharge/suction port 12.
leads to bathtub 1.

A water level sensor is constituted by a diaphragm 13 facing into the suction passage in the adapter body, a movable electrode 14 connected to the diaphragm 13, and a fixed electrode 15 opposed to it, and constituted by the movable electrode 14 and the fixed electrode 15. The oscillation circuit 17 by the capacitance 16 and the signal of the oscillation circuit 17
A radio frequency transmitter 1118 is provided, the output of which is connected to an antenna 19. A signal from the oscillation circuit 17 is input to the power control circuit 20, and a battery 21 is connected to the transmitter 18 via its output.

In FIG. 2, a receiver 22 is provided inside the main body 4 of the water heater.

With the above configuration, when hot water starts to be supplied from the water heater main body 4 through the hot water pipe 10, the diaphragm 13 is displaced in response to the water pressure of the bathtub water, the interval between the movable electrode 14 and the fixed electrode 15 is narrowed, and the resonant circuit 17 is The frequency of the oscillation circuit 17 decreases due to a change in the constituent capacitance 16. The power control circuit 20 detects the frequency of the signal from the transmitting circuit 17 and supplies power from the battery 21 to the transmitter 18 when the frequency is lower than a certain value. That is, radio waves are transmitted only when the water level in the bathtub is higher than the diaphragm 13 by a certain value or more, and radio waves are not transmitted when the bathtub is empty after the hot water has been drained.

The radio waves from the antenna 19 are received by the receiver 22, and the water level can be determined by detecting the frequency, and hot water supply to the bathtub is controlled according to the set water level.

In this way, there is no longer a need for a connection cord between the water level sensor installed in the adapter and the water heater, which simplifies installation work, and it is also possible to seal a portion of the water level sensor inside the adapter, reducing environmental concerns. It also has excellent chain properties. Since the power control circuit transmits radio waves only when the water level in the bathtub is above a certain value based on the signal from the pressure sensor, the life of the battery 21 is extended.

In the embodiment, the pressure sensor is a capacitance type, but it is also possible to use other types of pressure sensors.

Effects of the Invention As described above, the bathtub water level detection device of the present invention comprises: a pressure sensor for water level detection provided in communication with a bathtub; a wireless transmitter and its battery modulated by the signal of the pressure sensor; and a pressure sensor. By configuring the wireless transmitter with a power control circuit that supplies power to the wireless transmitter when the signal is above a certain value, the following effects can be obtained.

(1) No connection cord is required between the water level sensor and the water heater, which simplifies installation work, and it is also possible to seal part of the water level sensor inside the adapter, which provides excellent environmental reliability. It is something.

(2) Radio waves are transmitted only when there is hot water in the bathtub, thereby preventing unnecessary power consumption, extending battery life, and eliminating the need for maintenance.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a bathtub water level detection device according to an embodiment of the present invention, FIG. 2 is an overall configuration diagram of the same device, and FIG. 3 is a configuration diagram of a conventional water level detection device. l...Bathtub, 4...Water heater body, 7.
...adapter body, 13 ... diaphragm, 14 ... movable electrode, l5 ... fixed electrode, 18 ... transmitter, 20 ... ...Power control circuit, 21...Battery.

Claims (1)

[Claims] A pressure sensor for water level detection installed in communication with the bathtub,
a wireless transmitter that is modulated by a signal from the pressure sensor; a battery that supplies power to the wireless transmitter; and a power control circuit that supplies power to the wireless transmitter when the pressure sensor signal is above a certain value. A bathtub water level detection device consisting of: