CA2061842A1 - Hydro-massage tub control system - Google Patents

Abstract

HYDRO-MASSAGE TUB CONTROL SYSTEM

ABSTRACT OF THE DISCLOSURE
A control system for hydro-massage tub systems in which water is circulated through a pump and heater from the tub back to a plurality of jets in the tub to create a turbulent massaging action. The system is comprised of an activating device, a pump, a switch activating circuit, a heater with proportional control and a water level sensing safety system.
The pump is controlled by a switching and timing circuit that limits the time the pump is on which is slaved to a heater control circuit to prevent operation of the heater unless the pump is circulating waker. The proportional heater control circuit maintains the water temperature within a degree or two of a preset temperature by proportionally reducing power as the temperature approaches the preset limit. The activating device transmits a signal to the switching and timer circuit when a mechanical plunger isolated from electrical circuits is operated. The level sensing device monitors the water level in the tub and interrupts or prevents operation of the switching and timing circuit unless water is at a level which activates the level sensing signal transmission circuit.

Description

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1 ¦ Docket No. 185gCP

2 ¦ HYDRO-MASSAGE TUB CONTROL SYSTEM

3 ¦ SPECIFICATION

4 ¦ Field of the Invention ¦ This invention relates to hydro-massage ox whirlpool 6 ¦ bathtubs, and more particularly relates to a control system for 7 ¦ such bathtubs~
8 ¦ Backqround of the Invention 9 ¦ Hydro-massage bathtubs provide a therapeutic massaging ¦ action by delivering water through a plurality of jets in the 11 ¦ tub wall to create a circulating flow of turbulent water. The 12 ¦ tub water is circulated through a heater and pump back to the 13 ¦ tub through the jets to provide a warm circulating flow. Air 14 ¦ can be added to the circulated flow at a controlled rate to ¦ increase the turbulence and massaging action of the water 16 ¦ exiting from the jets.
17 ¦ As with any such system having electricity in proximity to 18 ¦ water, all electrical components must be isolated from the user 19 ¦ to prevent in~uries due to electrical shock. To prevent ¦ accidents, extraordinary ef~orts are made to provide electrical 21 ¦ components and wiring, which are completely isolated by using 22 ¦ mechanical controls linked to electrical circuits. However, 23 ¦ these devices, though effective, are not as stable, efficient 24 ¦ and reliable as desired.
¦ An additional problem with these types of control systems 26 1 is that of inadvertent operation when the water level is low.
27 ¦ Such occurrences can result in the jets splatteriny water 28 ¦ throughout the area resulting in a damaging, messy and 29 ¦ unsanitary condition, or the pump running dry and burning out the shaft seals.
31 Some systems employ level sensors to make a system 32 inoperable if levels are below a pre-selected level, however, ~^~ 3 ~

1 ¦ they suffer rom a numh~r of problems. One such system uses a 2 ¦ float which can bind, thereby preventing operation~ Further, 3 ¦ such floats being in contact with dirty trashy water can 4 ¦ interfere with the system operation requiring frequent ¦ maintenance. Other systems use pistons which can freeze or 6 ¦ stick, thereby interfering or preventing operation~ A system 7 ¦ that uses no hinged parts, pistons or ~loats would be 8 ¦ advantageous as it could be isolated from the water used in the 9 ¦ system resulting in improved stability, reliability and ¦ efficiency.
11 ¦ These systems also suffer from ~requent electrical 12 ¦ failure, due to the corrosive environment created when there is 13 ¦ a high degree of moisture present. System components often 14 ¦ corrode and fail and require replacement or repair.
¦ It is therefore one object of the present invention to 16 ¦ provide a hydro-massage bathtub control system having a 17 ¦ reliable, stable and safe design by using all solid-state 18 ¦ construction.
l9 ¦ Still another object of the present invention is to ¦ provide a hydro-massage tub control system having improved 21 ¦ electrical controls.
22 ¦ Yet another object of the present invention is to provide 23 ¦ a hydro-massage tub system having an operating switch s~stem 24 ¦ minimizing the potential for failure by using an electrically 1 isolated switch for safety.
26 ¦ Another object of the present invention is to provide a 27 ¦ hydro-massage tub control system having a water level sensor 28 ¦ safety system which will prevent operation below a pre-selected 29 ¦ water level.
¦ Still another object of the present invention is to 31 ¦ provide a hydro-massage tub control system having an improved 32 ¦ heater design using all solid-state circuits.

1 Yet another object of the present invention is to provide 2 a heater systPm ~or a hydro-massage tub, providing proportional 3 control to the heater for improved efficiency, stability and 4 temperature regulation.
Yet another object of the present invention is to provide 6 a hydro-massage tub system with a heater system having a fail-7 sa~e thermal fuse and fail indicator.
8 Another object of the present invention is to provide a 9 hydro-massage control system having a heater control minimizing overheating to provide more accurate operation. The 11 proportional control of power to the heating system provides 12 very little potential overshoot and maintains temperature at a 13 very reliable pre-selected level.
14 Still another object of the present inventibn is to provide a hydro-massage tub control system having a modular 16 construction, connect-ed by modular cords and plugs, allowing 17 guick disconnect and replacement or repair of solid state 18 circuits.
19 Another object o~ the present invention is to provide a water level sensing safety system for a hydro-massage tub 21 having a positive acting optical switch isolated from the water 22 in the tub by an air column.
23 Still another object of the present invention is to 24 provide a water level sensor safety system for a hydro massage control system having a positive acting switch isolated from 26 tub water, that operates almost instantaneously to stop the 27 system when the water drops below a pre-selected level.
28 Another object o~ the present invention is to provide a 29 water level sensing safety system that avoids the use o~
¦ unreliable mechanical or hinged parts.

1 Brief Description o~ the Invention 2 The purpose of the present invention is to provide a 3 hydro-massage bathtub control system that has arl improved all 4 solid-state construction and features which improve accuracy, reliability and safety.
6 The hydro-massage bathtub control system according to thP
7 invention has an all solid-state control for the system pump, a 8 magnetically operated on and off switch signaling device that 9 isolates electrical components and wiring from the user, an improved solid-state proportional heater control system, and a 11 water level sensing safety system having improved saf~ty and 12 reliability. The pump control circuit is an all solid-stake 13 system including a solid-state timer to set the length of time 14 for operation of the pump. After the period of time set by the timer, the pump will ~ycle off preventing continuous unattended 16 operation of the system.
17 A magnetically operated solid-state Hall effect switch 18 transmits a signal to start the cycle time by acti~ating the 19 pump, circulating water to a plurality of jets in the tub causing a turbulent massaging actionO Air vents on the tub rim 21 allow air to be added at a controlled rate and circulated to 22 the jets to increase the turbulence and provide a flow of 23 stimulating bubbles. When the magnetic Hall effect signaling 24 device switch is activated the pump draws water from the tub through a heater and recirculates it to the plurality of jets 26 in the tub.
27 The water in the tub is heated as it is drawn from the tub 28 by the pump through an in-line element controlled by a solid-29 state circuit providing proportional temperature control. The solid-state heater control has adjustments to preset the 31 temperature range and the maximum temperature of the water.
The proportional temperature control activates the heater and ~l ;~J

1 then proportionally reduces power as the ~emperature of the 2 water approaches the pre--selected maximum. This proportional 3 control improves temperature accuracy and effectively prevents 4 overshoot. This is a substantial improvement over the typical on-off heater control systems w~ich gives either full power or 6 no power when they are Oll or off.
7 The proportional control system of the present invention 8 reduces power levels to the heater to maintain the temperature 9 within an adjustable range of ~ 2 F, preferably within 1 F, or bett~r. As the temperature falls below the set point 11 temperature proportional power is applied to the heater to 12 reheat the water until it approaches the set point. Power is 13 ~proportionally reduced as the temperature approaches the set 14 point temperature so that overshoot, or temperature "inertia", is substantially eliminated preventing any substantial 16 overheating of the tub water being circulated through the 17 heater and pump.
18 The system also includes an improved water level sensing 19 safety system that effectively prevents operation unless water is at a predetermined level~ The water level sensing safety 21 system is a completely closed tubular container foxming an air 22 colu~n with an inlet positioned in the tub at a level above the 23 water jets. This construction prevents contaminatiny water, 24 soap or trash from reaching the controls. If the water level is not at the level of the inlet, the system cannot operate.
26 When the level is above the inlet, water enters the closed 27 water level sensing safety system applying pressure to an air 28 column which activates a switch sendiny a signal to allow the 29 system to operate.
Preferably the signaling system is an electro-optical 31 device comprised of a light emitting diode and a photo 32 detector, or photocell. A diaphragm at the upper end of the d3 ~3 ~ ~ g ~

1 air column of the closed container has a flag, or barrier, 2 which occludes th~ path of the light emitting diode 3 inkerrupting the beam when the dlaphragm is expanded thereby 4 allowing the system to operate. When the water level falls below the inlet of the level sensing system, the barrier is 6 retracted allowing the light beam to impinge on the photo cell, 7 sending a "hard" reset to keep the system switching circuit 8 o f. Thus, the water level sensing safety system is 9 substantially fail-safe.
The diaphragm in the closed water level sensing safety ll system isolates the electrical components preventing any 12 moisture from contaminating or interfering with their 13 operation. Additionally, the diaphragm is specially 14 constructed to have a central thin membrane portion which causes positive operation with hysteresis when the pressure in 16 the air column is above or below a pre-determined amount. As 17 water enters the inlet causing an increase in pressure in the 18 ¦ air column the diaphragm bulges until the conically shaped 19 ¦ central membrane snaps up, providing a positive quick acting ¦ extension of the flag or barrier into the path of the light 21 ¦ beam. Conversely, when the water level drops below the inlet 22 ¦ and the pressure in the air column drops below a pre-determined 23 ¦ amount, the thin center membrane of the diaphragm snaps back 24 ¦ retracting the barrier allowing the light beam to impinge on ¦ the photo cell, thereby generating a reset signal~
26 ¦ The functions of the systems are all interconnected using 27 ¦ modular plugs and signal transmitting cords to provide a 28 ¦ modular system in which any part of the system may be easily 29 ¦ removed for repair or replacement. A control box containing ¦ the heater, pump control and switching circuits is mounted on 31 ¦ top of the motor and provides power to the heater and pump.

32 ¦ Grounded sockets are provided in the control box ~or receiving 2 ~

1 ¦ power cord plugs from the heater and the pump. Addltionally, 2 ¦ indicator lights on the control box provide diagnostic 3 ¦ information on the operation of the system. A green light 4 ¦ emitting diode indicates system power is on, and red light ¦ emitting diode indicating impropex electrical installation, a 6 ¦ yellow light emitting diode on the control box indicates heater 7 ¦ duty cycle on time. The yellow indicating light emitting diode 8 ¦ will cycle on and off indicating the proportional power being 9 ¦ applied to the heater element. The on cycle shortens as the ¦ preset temperatur~ is approached, indicating the proportional 11 reduction in power. When the temperature of the water drops, 12 the heater will be energized and increased power proportional 13 to the temperature decrease is applied until the temperature is 14 brought back up to the set point temperature. A proportional reduckion in power as the temperature approaches the set point 16 temperature, reduces the amount of temperature overshoot and 17 increases the efficiency of operation and maintenance of the 18 temperature at the operating level.
19 The above and other objects and features of this invention will ~e more fully understood from the following detailed 21 description and the accompanying drawings, in which:
22 Brief Description of the Drawinas 23 ~IGURE 1 is a top view of the hydro-massage tub control 24 system accordiny to the invention;
FIGURE 2 is an end view of the pump mounted control system 26 taken at 2-2 of Figure 1;
27 FIGURE 3 is a sectional view taken at 3-3 of Figure l;
28 FIGURE 3a is a sectional view taken at 3a 3a of Figure 3;
29 FIGURE 4 is a sectional view of the activating device for use in the invention taken at 4-4 of Figure 1;
31 FIGURE 5 is a sectional view of a water level sensing 32 safety system taken at 5 5 of Figure 1, appearing with FIGS. 2, 33 5a and 5b;
34 FIGURE 5(a) is a sectional view taken at 5a-5a of Figure 5, fl ~

1 ¦ appearing with FIGS. 2, 5 and 5b;
2 ¦ FIGURE 5(b) is a perspective view of a diaphragm for use 3 ¦ in the invention, appearing with FIGS. 2, S and 5a;
4 ¦ FIGURE 6 is a block diagram of the hydro-massage tub ¦ control system.
6 ¦ FIGURE 7(a) an 7(b) are a schematic diagram of the hydro-7 ¦ massage tub control system.
8 ¦ FIGURE 8 is a partial schematic diagram showing a 9 ¦ switching circuit modification.
¦ FIGURE 9 is a schematic diagram of an alternate level 11 ¦ sensing safety system.
12 ¦ FIGURE 10 is a side view of the level sensing system of 13 ¦ Figur~e 9 mounted on a whirlpool bathtub.
14 ¦ FIG~E 11 is a top view of the level sensing system of ¦ Figure 10.
16 ¦ FIGURE 12 is a schematic diagram of an alternate touch 17 ¦ sensitive safety activating device for the hydro-message tub 18 ¦ control system.
19 ¦ FIGURE 13 is a sectional view similar to Figure 4 of the ¦ alternate touch sensitive safety activating device of Figure 21 1 12.
22 ¦ Fi~ure 14 is a schematic diagram of an alternate ~3 ¦ activating device for the hydro-message tub control system.
24 ¦ Figure 15 is a plan view of the installation of a tap 1 switch shown in the schematic diagram of Fiyure 14.
26 Figure 16 is a sectional view taken at 14-14 of Figure 15.
27 Detailed Description of the Invention 28 A hydro-massage tub control system is shown generally in 29 Figure 1 with tub 10 being shown in phantom for purposes of clarity. The hydro-massage tub control system is comprised of 31 a pump 12 for delivering water through a flow disbursement 32 manifold 14 to flexible pipes 16 for delivery to a plurality of JI ~ 2~$~

1 jets 18 which create turbulence in the water in tub 10. The 2 turbulence created in tub 10 provides a therapeutic massaging 3 action. The massaging action can be enhanced by the addition 4 of air through air vents 20 connected to the jet heads 18. Air vents 20 are ogten each separately adjustable to regulate the 6 amount o~ air provided to each o~ the jets.
7 The water in tub 10 is drawn into pump 12 through suction 8 inlet 22 and pipe 24. An in-line heater 26 heats the water 9 being drawn into pump 12 as it flows through the heater and pipe 28. Heater 26 is controlled by a heater control circuit 11 in control box 30, as will be described in greater detail 12 hereinafter.
13 The system also includes an activating device 32 14 mechanically isolated from the electrical components and the electrical wiring for activating the control system. A timer 16 in control box 30 times the period of operation of the pump as 17 will be described in greater detail hereinafter. Also included 18 in control box 30 is an external temperature adjustment 34 for 19 presetting the maximum water temperature over a temperature ranye of about 15 F delivered from pump 12.
21 The system also includes a unique water level sensing 22 safety system 36 attached to tub 10 at 38, slightly above the 23 level of jets 18. Water level sensing safety system 36 24 inactivates the hydro-massage system i~ the water level is below the inlet 38, as will be described in greater detail 26 hereinafter.
27 Figure 2 is a view taken at 2-2 of Figure 1 illustrating 28 the mounting of the control box 30. Control box 30 is mounted 29 on top of pump motor 12 for controlling operation of the pump, heater, water level sensing safety system, as well as the 31 operation of activating device 32 and to use the pump housing 32 as a heat sink for power components. The control box 30 also $ ~

1 provides power to the heater through socket 40 and to pump 12 2 through socket 42 and cord 13. The sockets 40 and ~2 are shown 3 with the respective components unplugg~d for purposes of 4 clarity.
The heater temperature and control circuit, the on-off 6 switch, and the level sensor are connected to the control 7 circuits in control box 30 through mo~ular plugs (not shown) 8 which connect to modular sockets 46, 48 and 50 respectively.
9 Input power is provided to the control circuit through cord 52 connected to any convenient AC power supply, controlled by a 11 wall switch. The use of plugs 40, 42 and modular sockets 46, 12 48 and 50 allow each component of the system to be easily 13 removed for repair or replacement. They also allow easy 14 assembly and installation.
The heating system is shown in the sectional view of 16 Figure 3, and is comprised of a compact heater-26 connected to 17 a temperature sensing heater interface board 55, as will be l~ described in greater detail hereinafter. Power to heater 19 element 54 is supplied through cord 56 plugged into socket 40 on control box 30 which is protected by thermal fuse 53.
21 Temperature sensor 57 and heater interface board 55 is 22 monitored through signal cable 58 connected to modular plug 46 23 on control box 30. The entire heater assembly 26 is attached 24 to suction line 24 and 28 by couplings 60 and 62. Water, indicated by arrows 64, flows through conduit 24, heater 26 assembly 26 and conduit 28 to the pump, to be kept at a pre-27 selected operating temperature determined by adjustment of 28 temperature control 34. This sets the maximum temperature o~
29 water in tub 10.
The heating system 26 is uniquely constructed so that 31 heater 54 is approximately about one-half the size of heater 32 elements presently used. The reduction in the size of the 1 ¦ heater is made possible by removing the heater controls to 2 ¦ control box 30 with only the heat sensor ~nd thermal fuse being 3 ¦ on heater assembly board 55. The much smaller construction of 4 ¦ heaker 54 permits use o~ a housing having the same diameter as ¦ pipes 24 and 28 on either side of standard couplinqs 60 and 62 6 ¦ which allow easy removal and replacement. A further advantage 7 ¦ of this construction is that water retention, a problem 8 ¦ frequently encountered with prior systems is eliminated because 9 ¦ a smaller, shorter housing 27 can be used. The smaller ¦ diameter heater housing eliminates any traps which might be 11 ¦ foxmed by a housing larger than the diameker of the water pipe 12 ¦ and effectively eliminates water retention.
13 ¦ A unique activating device 32 is illustrated in Figure 4.
14 ¦ ~he activating device is connected to the system through signal ¦ cord 66 attached by a modular plug (not shown) to modular 16 ¦ socket 48 in control box 30. Activating device 32 is comprised 17 ¦ of a Hall effect solid-state switch 68 activated by magnet 70 18 ¦ on plunger 72 mounted in housing 76 on the rim of tub 10. The 19 ¦ system is turned on by pressing button 72 against khe force of ¦ spring 74 bringing magnet 70 in close proximity to Hall effect 21 ¦ switch 68 to transmit a siynal through signal transmitting cord 22 ¦ 66 to activate pump 12 and heater 26 through a switching and 23 ¦ timing circuit. Heater 26 will not operate unless pump 12 is 2~ ¦ also in operation. The pump 12 will remain on for a period set ¦ by a timer, as will be described hereinafter. Activating 26 ¦ device 32 is mounted in housing 76 securely mounted in the rim 27 ¦ of tub 10, as illustrated in Figure 1. The operation of 28 ¦ activating device 32 is completely isolated from any electrical 29 ¦ components and wires from the person using the hydro~massage ¦ tub. Alternatively, switch 68 ma~ be a momentary switch, 31 ¦ proximity switch, optical switch or mechanical switch.
32 ¦ The switch on timer circuit 104 combined with activating ~i ' 2 ~ 2 1 ¦ device 32 may be configured to be a three-way sequential 2 ¦ transmittiny device. The sequential operation o~ plunger 72 3 ¦ activatss the pump, then the pump and heater and finally turns 4 ¦ the system off (in a on/on/off operation). Thus, modified ¦ activation device 32 in conjunction with a heater control 6 ¦ circuit, to be described hereinafter, provides a three-way mode 7 ¦ of operation.
8 ¦ To prevent operation o~ the system in the event that the 9 ¦ water level is low in tub 10, a water level sensing safety ¦ system 36, shown in Figure 5, is provided. Water level sensing 11 ¦ safety system 36 is comprised of a closed tubular container 12 ¦ connected to tub 10 by a through wall fitting 78 secured to the 13 ¦ wall of the tub. Through wall fitting 78 provides an inlet 38 14 ¦ for water 80 to enter cavity 82 in the water level sensor.
¦ Inlet 38 should be at a level which is higher than the jets, to 16 ¦ assure that the level of water 80 covers the j-ets completely.
17 ¦ This prevents water from accidentally being splattered out of 18 ¦ the t~b should the system be turned on when the water level is 19 ¦ below the jets. Water level sensor safety system 36 provides ¦ an air column inside cavity 82. Since water level sensor 36 is 21 ¦ completely sealed, the air column in cavity 82 will be 22 ¦ compressed as water level 84 inside the water level sensor 23 ¦ rises. Thus, the water level must be above inlet 38 to cause 24 ¦ an increase in pressure sufficient to allow the hydro-massage ¦ system to operate.
26 ¦ Water level sensing safety system includes diaphragm 86 27 ¦ clamped by head 87 on neck 89 having a small post 88 receiving 28 ¦ a flag or barrier 90 moved up or down with diaphragm 86.
29 ¦ Barrier 90 is positioned to occlude light beam 92 from light ¦ emitting diode 94 impinging on photo cell 96. As long as 31 ¦ barrier 90 remains between light emitting diode 94 and photo 32 ¦ cell 96 the system can continue to operate because no reset 1 I signal is generated. This can only occur when water level 84 2 in the w~ter level sensing safety syst~m is s-~f~icient to 3 increase the pressure in the air column to deform or exp~n~
4 diaphragm 86. Should the water level fall below inlet 3B, the air column pressure will drop causing diaphragm 86 to retract 6 removing barrier 90 from between light sensing diode 94 and 7 photo cell 96. Beam 92 may now impinge on photo cell 96 8 transmitting a signal through siynal transmitting cord 98 to a 9 modular plug (not shown) connected to modular socket 50 at the control box 30 to reset a switching circuit shutting down the 11 system. The system will remain inopera~ive as long as the 12 level of water ~0 is too low, preferably below inlet 38.
13 Water level sensor 36 has a unique diaphragm 86, shown in 14 greater detail in Figure 5(b). Diaphragm ~6 has a central conical shaped thin membrane 100 supporting post 88. Thin 16 conical membrane 100 provides a positive displacement of post 17 88 and barrier 90 mounted on the post. Any increase in 18 pressure of the air column in cavity 82 causes membrane 100 to 19 bulge upward and then snap into a deformed, expanded position with barrier 90 interruptin~ the beam 92 from light emitting 21 diode 94. A reduction in the level of water 80 in tub 10 below 22 inlet 38 will reduce the pressure in air column in cavity 82 ~3 causing a reversal of membrane 100. The diaphragm will begin 24 to retract as pressure drops and then membrane 100 will.snap back retracting post 88 and barrier 90 from a position 26 interrupting the beam from light emitting diode 94. Water 27 level sensor safety system 36 provides a positive acting system 28 which almost instantaneously deactivates the system should the 29 water level fall below a safe margin.
The electronics of the system are shown in the block 31 diagram of Figure 6. The main control box 30 includes a main 32 control board 102, switching and timer circuit board 104 and a 1 proportional heater control circuit board 106. Heater and pump 2 motor are connected directly to a power supply through main 3 system control board through plugs ~o and ~2. Temperature 4 sensing board 108 in the heat and temperature sensor assembly is connected to the main pump and system control board through 6 modular plug 42. Activating device 72 and water level sensor 7 35 are connected to modular sockets 50 and 48 respectively.
8 ¦ The main system control board includes indicatiny lamps or 9 ¦ light emitting diodas (LED's) 116, 118 and 120, which provide ¦ an indication of system operation and diagnostics.
11 ¦ Green light emitting diode 120~1ights whenever the system 12 ¦ is enabled. Yellow LED 118 lights when heater 54 is on.
13 ¦ Yellow LED 118 blinks on and off indicating the proportional 14 ¦ power being applied to the heater. The longer the yellow LED
¦ is on, the more power is being applied to the heater. ~ed LED
16 ¦ 116 provides system diagnostics by indicating if the system is 17 ¦ correctly installed and connected. ~n additional red LED (not 18 l shown) indicates the failure of a thermal fuse 53 connected to 19 ¦ detect overheating of heater 54, as will be described in ¦ greater detail hereinafter. As can be seen from the block 21 ¦ diagrams of Figure 6, each modular component of the system is 22 ¦ easily connected and disconnected for repair or replacement.
23 ¦ The electrical operations of the system can be seen by 24 l reference t~ schematic diagram of Figure 7(a) and 7(b), where ¦ the reference numbers indicate the corresponding circuits in 26 ¦ the block diagram of Fi.gure 6. Main control circuit board 102 27 l is shown in Figure 7(b). Power is supplied to ths pump and 28 l heater through triacs Q7 and Q3, (Figure 7(a)) respectively.
29 ¦ Additionally, operation o~ motor 112 is controlled by an input ¦ from switch 32 to timer circuit 104 and triac Q7 to time the 31 length of operation of the motor. The upper terminal is the 32 110 volt AC low level connection, with the lower terminal being l the 110 AC high level connection. The middle terminal 2 connected to diode D2 is chassis ground for the system.
3 The main control and power supply circuit supplies DC
4 power of approximately 12 volts from transformer T1 through the bridge rectifier comprised of diodes D6 through Dg to all 6 solid-state circui~s. It also supplies the component voltag~s 7 and interconnections to timer board and temperature control 8 board, as well as gate power to the triacs that power the motox 9 and heater.
The system is turned on by operating activating device 32, ll comprised of Hall effect switch IC3 activated by moving magnet 12 70 toward or away from the Hall effect switch. This sends a 13 signal to activate flip flop IC4 and timer IC5 to turn on triac l~ Q~ through Q5 and Q6~ which supplies power to the pump motor.
Timer IC5 is set to a pre-selected cycle by the circuit l~ configuration, preferably 9 to 10 minutes. IC~ and its related 17 circuit acts as an on-off switch for pump motor 112, while ICS
18 controls the period of operation o~ the system.
19 Activating switch 32 a first time transmits a signal to set flip-flop IC4 high, turning off transistor Q5 and Q6~ which 21 turns on triac Q7 via current flow through resistor R26. This 22 activates pump 112 and simultaneously enables power controller 23 IC1. A second activation of switch 32 sends a signal to reset 24 flip-flop IC4 turning on Q5 and Q6 to divert current o~
resistor R26 from triac Q7 turning it off and stopping the 26 pump. Triac Q7 is simply an AC switch to apply AC power to 27 pump motor 112.
28 An optional but preferred arrangement of the system is to 29 provide a three way on/on/o~ selection with the activating 3Q device 32 (i.e. Hall effect switch or touch sensitive switch).
31 -The three way operation is achieved by modifying the connection 32 of integrated circuit IC4 a 4013 integrated circuit as a dual 1 flip-flop connected in tandem, shown in the partial schematic 2 of Figure 8 as IC4A and IC~B with the modi~ication of 3 connections to IC4. ~he first operation of activating switch 4 32 sets IC4A. A s~cond operation of switch 32 resets IC4~, sets IC4B then sets IC4A again through feedback circuit oP RF, 6 CF. This enables (i.e. turns on~ both the pump and heater. A
7 third operation of switch 32 resets IC~A and IC4B shutting off 8 the system. The first activation of switch 32 transmits a 9 signal to flip~flop IC4 turning on the pump. A second activation of switch 32 activates heater 54 presuming that the 11 temperature is sufficiently low that power will be enabled to 12 power controller ICl. A third activation of switch 32 sends a 13 reset signal to flip flop IC4A and IC~B to turn off the system 14 completely.
Transistors Q~ and Q2 provide a switch to slave the 16 operation of the heater control circuit to operation of pump 17 112. These transistors are slaved to operation of triac Q7 18 which, when on, enables power controller IC1.
19 The system has a power up reset system for initial connection of 110 AC voltage, or whenever there is a loss of 21 power. At initial hookup system power is applied through a 22 circuit comprised of diodes D2 and D3, resistor R17 and 23 capacitor C4 to the reset pin of flip-flop IC4 resetting the 24 system. Any loss of power will also apply a reset to the system when power returns. When timer IC5 counts down to zero 26 from its preset time limit a signal is applied to the reset pin 27 of flip-flop IC4, which in turn resets itself.
28 Additionally, at low water level or when there is no 29 water in the tub a beam from liyht emitting diode D1 impinges on photocell Q4 applying a "hard" reset to flip-flop IC4 which 31 will reset both the flip-flop and the timer disabling or 32 preventing operation of the system. A constant reset signal 3 ~ 3 ~

1 ¦ will remain on the reset pin of IC~ whenever light from light 2 ¦ emitting diode Dl impinges on photocell Q4 preventiny operation 3 ¦ of-the system when water is below a certain level or there is 4 ¦ no water in the tub.
¦ Water level sensor 36 is connected to flip-flop IC4 and 6 ¦ timer IC5 to act as a "supervisor" to determine whether the 7 ¦ system can operate. If the water level is su~ficient such that 8 ¦ barrier 90 blocks beam from L~D Dl, then the system can 9 ¦ operate. ~owever, if the water level is too low and the beam ¦ from LED Dl strikes photo cell Q4, then the water level sensor 11 ¦ will apply a hard reset to flip-flop IC4, the pump on-of~
12 ¦ switching circuit.
13 ¦ Thus, there are three resets for the system. One is when 14 ¦ a second signal is sent from activating switch 32, a second is ¦ when timer IC4 counts down to zero sending a reset and a third 16 ¦ is transmitted from the level sensor whenever the water level 17 ¦ is low or there is no water in the tub.
18 l A signal from activating switch 32 sets flip-flop IC4 19 l which removes the reset signal sent to timer IC5 causing it to l begin to count down from the preset time. Timer IC5 is a 4541 21 ¦ timer connected to control the running time of pump 112 and 22 ¦ heater to comply with safety regulations. A time period of 23 ¦ approximately 9 to 10 minutes is selected by the circuit 24 ¦ configuration.
l Timer IC5 times its operation by counting cycles ~rom the 26 l AC line supplied through resistor R22. Time is set in timer 27 l IC5 by pin connections. The timer uses a countdown scheme of 2% ¦ the AC cycles for long term stability, reliability and 29 ¦ accuracy.
¦ The heater control circuit, shown in Figure 7(a), is 31 l slaved to the motor switch circuit by transistors Q1 and Q2 to 32 ¦ prevent operation of the heater whenever the pump is of~. Main ~J ~ 2 ,;~ ~ ~ $ ~ ~
, 1 ¦ control and power supply circuit 102 also includes triac Q3 2 ¦ acting as an AC switch controlled by a proportional power 3 ¦ controller triac driver IC1. Proportional power controller 4 ¦ triac drive integrated circuit IC1 is connected to temperature ¦ ,sensor IC2 in heater assembly 108. Any rise and fall o~ the 6 ¦ temperature is applied to proportional control driver IC1 to 7 ¦ control the power applied to heater H1 through triac Q3. Thus, 8 ¦ the operation o~ heater H1 is proportionally controllcd to 9 ¦ maintain the temperature of water flowing through heater 26 at ¦ a nearly constant temperature varying only +1 to 2 F, or 11 ¦ better.
12 l Thermal fuss F1 in heater assembly 108 is connected in 13 ¦ series with heater H1 and burns out if the temperature in heater 14 ¦ H1 exceeds a pre-determined level. Thermal fuse F1 is ¦ preferably selected to prevent the temperature of heater H1 16 ¦ from exceeding approximately 150 degrees Fahrenheit, but could 17 ¦ be higher.
18 l Potentiometer R4 sets a temperature range of about 15 F
19 l for proportional control drive chip IC1. Potentiometer R1 sets ¦ the maximum upper limit o~ the temperature range for the water 21 ¦ ~lowing through heater 26. Preferably this temperature is in 22 ¦ the range o~ 104 deyrees, the maximum tolerable temperature for 23 ¦ most bathers.
24 1 Proportional controller ICl is a Motorola UAA1016B, ¦ integrated circuit, more specifically described as a 26 ¦ p.oportional band temperature control. It puts out pulses to 27 l turn on triac Q3 to power heater H1. Groups of pu1s~5 are 28 ¦ output from proportional controller IC~ proportional to inputs 29 l received from temperature sensor IC2. The output ~rom ¦ temperature sensor IC2 is a voltage level proportional to the 31 temperature and the set point voltage determined by 32 potentiometer R4 in IC1. The tempPrature sensor inputs are t~ 7~

"
l I applied to sensing input pins "a" and "bi' of IC1. When the 2 ¦ water in the tub is cold or below the set point voltage (i.e~
3 ¦ temperature) determined by potentiometer R~, a continuous 4 ¦ stream of pulses from ICl allows triac Q3 to fire every cycle ¦ keeping heater H1 continuously on. When the température 6 ¦ reaches the control band, the output from proportional 7 ¦ controller IC1 is a burst o~ pulses and then a pause~ As the 8 ¦ temperature increases through the proportional band, the bursts 9 ¦ of pulses shorten and each pause between bursts lengthens, ¦ until the temperature reaches the set point voltage ll ¦ (i. e. temperature) and then shuts off. This is indicated by 12 ¦ light emitting diode D14 blinkiny on for shor~er periods 13 ¦ reflecting the shorter bursts of pulses from IC1 as temperature 14 ¦ approaches the set point.
l Power controller IC1 has a control band which is set to 16 ¦ control the tsmperature within a range of plus or minus 1 to 2 17 ¦ degrees Fahrenheit (F), or better. The difference between the 18 ¦ low level and high level of the control band is set by the 19 ¦ voltage at pin "c" of IC1. Maximum power is applied to the ¦ heater until it reaches the lower level of the power 21 ¦ controller band, and the controller then begins to cut down the ~2 l bursts of pulses and consequently the power to the heater H1.
23 ¦ This is in contrast to the usual full on or full off control 24 ¦ circuit presently used.
l The duty cycle of triac Q3 and heater H1 is controlled by 26 ¦ the pulses from power controller IC1. This can be visually 27 l percaived by yellow LED D12 (118 in Figure 6) blinking on and 28 ¦ off. The yellow LED blinks on for a longer period at the lower 29 ¦ end of the control band and blinks on for shorter periods ¦ indicating lower power, as the temperature approachPs the set 31 ¦ point or upper end of the control band. At the set point the 32 ¦ heater is turned off minimizing overshoot of the set 1 temperature. The proportional controller controls the 2 temperature, preferably within a plus or minus one degree 3 level. This maximum is adjustably set by potentiometer R4 and 4 may be approximately the maximum tolexable temperature of about 104 degrees Fahrenheit.
6 Temperature sensor IC2 puks out approximately 10 7 millivolts per degree Fahrenheit, which is applied through Rg 8 and R1o to pin "b" of power control IC1. Power controller IC
9 provides 100% power to heater H1 until it reaches the lower level of the control band, about one degree below the set 11 point, and then gradually reduces power until it's at zero at 12 the upper level of the control band.
13 Connected across heater Hl and thermal fuse Fl is an 14 indicating circuit to show the on cycle of the heater and to indicate whenever fuse Fl should fail. If heater H1 overheats 16 and thermal fuse Fl fails, red LED D14 goes off. Red LED D14 17 is not shown in the mechanical drawings, but could be mounted 18 in any convenient place on heater board 55.
19 Yellow LED Dl2 is illuminated whenever power i5 applied to heater H1 through triac Q3. The yellow LE~ will be on 21 constantly until the temperature level reaches the lower level 22 o~ power control band, or about one degree below the minimum 23 set point. The yellow lamp will then begin to blink on and off 24 indicating the duky cycle of the heater. The on cycle of the yellow lamp will indicate long on periods when the temperature 26 is near the lower level of the power control band and then will 27 blink for shorter periods as the power approaches the upper 28 level of the power controller band where the power to the 29 heater approaches 0%. Thus, the power is gradually reduced from 100% at the lower level of the power control band through 31 about 50% at the middle portion of the power control band to 0%
32 at the upper level of the power control band minimizing 1 overshoot of the temperature and maintaining constant accurate 2 temperature within + 1 to 2 F, or better.
3 Thermal fuse Fl is selected to provide a maximum 4 temperature in the range of approximately 150 F at which point ~ it will fail shutting down the heater.
6 Potentiometer R1 sets the maximum upper limit of the 7 temperature range over which the set point is controlled by 8 potentiometer R4. Potentiometer R1 is an internal adjustment 9 to preset a 15 F temperature range at an upper limit of 104 degrees. Potentiometer R4 allows an ad~ustment of the set 11 point temperature within the 15 F externally from 12 approximately 90 range up to the maximum of 104 degrees.
13 When wall switch (not shown) is turned on, green LED D4 is 14 turned on and remains on as long as the system remains activated. When the system is no longer being used and the 16 wall switch is turned off, it removes the power ~o the system 17 and the green LED D4 is extinguished.
18 Red LED D5 is a diagnostic indicator to be certain that 19 the lines are properly connected. If the high-low lines should be reversed when installing the circuit the red LED D5 will 21 illuminate indicating that the power lines have keen reversed.
22 They can then be properly connected. The system will run with 23 the lines reversed but is more subject to interference from 24 line spikes.
An alternate level sensing system for the hydro-message 26 tub sys~em of Figure 1 is shown in Figures 9-11. In the 27 schematic diagram of Figure 9 the system employs a sensing 2~ plate P1 mounted on the outside of whirlpool bathtub 10 as will 29 be described in greater detail hereinafter. The level sensing circuit of Figure 9 works on a "reach through" ePfect that 31 causes a oscillation amplitude drop that results in an output 32 to a control circuit that allows operation of the whirlpool tub 2 ~
1 control system. If the water level is ~elow the level of 2 sensing plate Pl there will b~ no output an~ ~he sy5tem cannot 3 operate.
4 The level sensing system of Figure 9 has a high Q tuned circuit comprised of capaci~or C1 and coil L1 that i5 loosely 6 coupled to field effect transistor (FET) Q1 with just 7 sufficient positive feedback ~rom the FEI~ source throuyh 8 resistor R3 and potentiometer R2 to the FET gate to cause 9 oscillation at about 5 mHz. The level of feedback is adjustable by potentiometer R6 and is set to produce a 11 reasonably undistorted sine wave. Sense plate P1 is connected 12 to the highest voltage point of the tuned circuit of C1 and Ll.
13 When a "lossy" substance (such as water or human tissue) is 14 brought near sense plate P1 energy is extracted from tuned circuit C1,L1 causing a rapid decrease in Q and concomitant 16 drastic drop in oscillation or a complete loss of oscillation.
17 Interposing a low loss dielectric (such as tub wall 10) 18 between sense plate Pl and a lossy substance causes capacitor 19 coupling to the sense plate producing a "reach through" effect as if sense plate P1 was physically moved to the opposite 21 surface of the dielectric material or tub wall 10. When tuned 22 circuit C1,L1 oscillates diode D1 rectifies the resulting RF
23 voltage and shuts off FET Q2 causing its drain voltage to rise 24 at output terminal J2 via light emitting dioda D2 producing a reset signal fGr use in the hydro-message tub control system.The 26 system shown in Figure 9 is extremely simple and effective. No 27 direct contact with the sensor plate is required because the 2B circuit has a l'reach khrough" effect that will cause a 29 reduction in oscillation amplitude. This reduction can be achieved through a substantially thick dielectric material such 31 as wall 10 of a hydro-massage tub. A very significant 32 reduction can result because of this "reach through" effect i ~ ~
2 ~
1 ¦ which acts as though sensor plate P1 had been moved to khe 2 ¦ other side of the dielectric material or tub wall 10 because of 3 ¦ capacitor coupling to the sensor plate through the dielectric 4 ¦ material. Any lossy substance making ~ontact wi~h ~he ~ub wall ¦ 10 on the other side of sensor plate P1 is capacitivel~ coupled 6 ¦ to the sensor plate resulting in a reduction in oscillation 7 ¦ amplitude and an output signal to allow the circuit to work. A
8 ¦ lossy substance can be any substance that will absorb RF energy 9 ¦ rather than act as a dielectric substance such as the tub wall.
¦ A lossy substance such as water or human tissue that is placed 11 l against the tub wall 10 on the other side of sensor plate P1 12 ¦ will absorb energy resulting in a drop in energy in the tuned 13 ¦ circuit of C1, Ll which has a high Q and is so loosely coupled 14 l to the drive circuit that includes FET Q1 it will cause a drop ¦ in oscillation amplitude. Because of the loose coupling 16 l through a few windings of coil L1 of the drive circuit of FET
17 l Q1 extraction of just a relatively small amount of energy ~rom 18 l tuned circuit C1, L1 reduces the energy enough to prevent 19 ¦ oscillations from being sustained which will disappear ¦ altogether or be reduced in amplitude significantly. This is 21 l seen by the circuit of diode D1 which then acts upon the FET Q2 22 ¦ output device.
23 l When the amplitude in tuned circuit C1, L1 is reduced 24 ¦ significantly or reduced to zero by the application o~ a lossy l substance to tub wall 10 on the opposite sid~ of sense plate P
26 l the rectified voltage disappears allowing FET Q2 to turn on 27 l light emitting diode LED D2 removing the reset signal from 28 l output terminal J2. The capacitor C2 filters the yate voltage 29 l of FFT Ql Resistor R4 establishes a ground ref2rence for the ¦ gate of FET Q2 basically bypassing the gate to the source.
31 l Resistor R5 furnishes drain current to FET Q2. Resistor R1 32 l prevents spurious oscillation while capacitor C3 filters the J~

1 ¦ voltage (B+) supply.
2 ¦ The lev~l sensing circuit of Fiyure 9 is mounted in a 3 ¦ small rectangular box 136 secured to the wall of kub 10 at 4 ¦ about the level of water desired. As shown in the top view of ¦ Figure 11 the box 136 containing sense plate P1 can be secured 6 ¦ with an adhesive 138 to the tub wall. The sensitivity is 7 ¦ adjusted by rotatable adjustment 140 which adjusts 8 ¦ potentiometer ~2 in Figure 9. ~ three wire cable 142 connects 9 ¦ the level sensing system to the hydro-message tub control ¦ system. LED (i.e. diode D2 in Figure 9) 1~4 indicates when the 11 ¦ level sensing circuit is on allowing the hydro-message control 12 ¦ system to operate.
13 ¦ The l~vel sensing control system ~f circuit o~ Figure g 14 ¦ would be substituted for level sensor 36 shown in Figure 7b.
¦ Terminals J1~ J2 would be connected where the outputs of 16 ¦` transistor Q4 are shown. Gate terminal would be connected to 17 ¦ the line going to resistor R16 which would no longer be 18 ¦ necessary and would be removed from the circuit.
19 ¦ As another alternative, the mechanical tap switch ¦ illustrated in Figure ~ and schematically in Figure 7b can be 21 ¦ replaced by a compact efficient touch switch shown in Figures 22 ¦ 12 and 13~ The touch switch schematic shown in Figure 12 is 23 ¦ subs~antially the same as the level sensor circuit of Figure 9 24 l except that resistors R5 and R6 and diodes D2 and D3 are not ¦ needed. The level sensing circuit output produces a reset 26 l si~nal to IC4 as shown in Figure 7b. However, the touch switch 27 ¦ works differently in that it causes an output to turn on the 28 l system through transistors Q5 and Q6 and triacs Q3 and Q7.
29 ¦ That is when activated it produces a turn-on command to the ¦ control system. The differences between the two circuits are 31 ¦ relatively minor because the output of the two devices address 32 ¦ different circuits in the control system shown in Figure 7b.

2~

1 ¦ In the touch or proximity switch circuit shown in Figure 9 2 ¦ sense plate P~ is mounted ~or sensing human tissue on the other 3 side of a dielectric 1~6. As before the proximi~y o~ human 4 tissuP near sense plate P1 causes a reduction in amplitude of oscillations in tuned circuit c1, L1 producing an output to 6 terminal J2. Thus the first time dielectric is touched 7 proximate sensing plate P1 the system is activatedO A second 8 touch of the switch enables both the pump and the heater. A
9 third touch of the switch shuts off the system.
The touch switch is simple and easy to construct and very ll easy to operate, having no moving parts. The mounting is 12 ~ubstantially similar to that shown in Figure 4 for the tap 13 switch except that there are no moving parts. The electronic 14 circuitry of Figure 12 is mounted in a module or circuit enclosure 148 mounted in threaded housing 150 secured to tub 16 wall 152 by threaded nut 154. The upper end of threaded 17 housing 150 has a sealed dielectric plate 156 to which sensing 18 plate 158 is adhered by an adhesive or as a coating on the back 19 o~ the dielectric 156. The output of the circuit in the enclosure 148 is connected via cord 160 to the main circuit of 21 the system as described previously. As described above the 22 system is small, compact, and very efficient with no moving 23 parts or openings allowing any contact of electrical circuits 24 by the user or from water in the tub.
2~ To activate the system the dielectric plate 156 need only 26 be touched and sense plate 158 activates the circuit shown in 27 Figure 12 to provide an output to turn on the system. A second 28 touch of dielectric plate 156 activates both the pump and the 29 heater while a third kouch o~ the switch sends a reset si~nal to turn the system off completely.
31 A disadvantage of the touch sensitive sa~ety activating 32 device shown in Figures 12 and 13 is that it is sometimPs too . ` - 2 ~

1 easily ~ctivated~ Simply wipiny across the switch could 2 sometimes actlvate it when cleaniny or for some other purpose.
3 For that reason the system of Figure 14 was conceived. This 4 system employs a piezoelectric device that when mechanically disturbed or mechanically stressed will produce an output 6 signal. This system is illustrated in the schematic diagram 7 Figure 14. Since a damped sine wave from the piezoelectric 8 device is not a very good control signal, the signal is 9 conditioned by applying it to a one shot multi-vibrator. The circuit only uses the first or second half of the damped sine ll wave to activate the one shot and the remaining oscillations 12 are ignored because once the one shot multi- vibrator is 13 triggered, it will ignore any other inputs until the end of its 14 time delay. The time delay is chosen to be long enough to allow the damped sine wave output from the piezoelectric device 16 to subside. This provides a clean output signal to activate 17 the control electronics in the hydro-message tub 18 control system.
19 As shown in the schematic diagram of Figure 14 a light tap on piezoelectro device, Pl produces a damped sine wave output 21 to a one shot multi-vibrator comprised of NAND gates Gl and G2, 22 capacitor Cl and timing r~sistor R3. Resistors Rl and R2 23 supply proper bias to piezoelectro device P1. NAND Gate G3 24 serves as an output buffer.
Any mechanical distortion of piezoelectric device P1 by a 26 light tap as shown at 150 causes a dampe~ sine wave output to 27 NAND gate G1. The negative going signal triggers NAND gate G
28 which is then latched through capacitor C1, timing resistor R3 and MAND gate G2 by positive feedback to NAND gate G1 for a time period determined by capacitor C1 and resistor R3. The 31 resulting pulse is inverted by NAND gate G3 then routed to 32 output terminal J2. Supply voltage is provided by terminal J~

1 while terminal J3 is common yround.
2 The installation of the Circuit of Figure 14 is shown in 3 Figures 15 and 16. Tap switch 160 is mounted on plate 162 in 4 ¦ the upper surface of tub deck 164. Light indicators 166, 168 ¦ and 170 show when the power pump and heater are on 6 ¦ respectively. Illumination is transmitted to the indicators by 7 ¦ light conducting fiber optics as will be described in greater 8 ¦ detail hereinafter. NAND gates G1, G2, and G3 can be provided 9 ¦ by an integrated circuit such as a quad, dual input NAND gate ¦ integrated circuit manufactured by Motorola under the model 11 ¦ number MC 14093 or similar device.
12 ¦ Tap switch 160 is comprised of housing 172 having thin 13 ¦ flexible membrane 174 at the upper end for receiving plastic 14 ¦ cap 176. Piezoelectric device 178 comprised of metal plate 180 ¦ and metallized ceramic 182 is attached beneath flexible 16 ¦ membrane 174 and connected by leads to circuit board 184. A
17 ¦ third insulator is provided by a mica plate or an adhesive tape 18 ¦ between thin membrane 174 and piezoelectric device 178.
19 ¦ Piezoelectric device 178 and circuit board 184 are secured in ¦ housing 172 by retaining sleeve 188 having a recess 190 at the 21 ¦ upper end to retain piezoelectric device 178 in housing 172 and 22 ¦ a second recess 192 for receiving circuit board 184. Cavity 23 ¦ 194 beneath circuit board 184 is then filled with a hysol 24 ¦ potting compound to seal and retain the circuit board 184 and ¦ piezoelectric device 178 in housing 172 . Housing 172 is then 26 ¦ secured in threaded tub wall fitting 196 for mounting in tub 27 ¦ deck 164 with retaining nut 198.
28 ¦ Light from LED's in the hydro-massage control box is 29 ¦ transmitted to indicators 166, 168 and 170 by light conducting ¦ fiber optic cables 200. Fiber optic cable 200 fits into sleeve 31 ¦ 202 and abuts lens 204 on the end of the sleeve. Each 32 ¦ indicator has a fiber optic cable 200 to transmit light Erom 1 ¦ each LED to indicate the on/off state for power, the pump and 2 ¦ the heater. When any of the LED~s in the control box 3 ¦ illuminate the light is then visible at the corresponding 4 ¦ indicator 166, lG8 and 170. Indicator 166 shows when there is ¦ power applied to the system. Indicators 168 and 170 show when 6 ¦ the pump and heater respectively are on. The pump is always on ¦ when the heater is on.
8 ¦ The tap switch circuit shown in Figur~ 14 would be 9 ¦ substituted ~or the Hall switch 32 illustrated in Figure 7b.
¦ Terminals Jl' J2~ and J3 would be connected where outputs 1, 2, 11 ¦ and 3 are illustrated in Hall switch 32. In operation a light 12 ¦ tap on cap 176 of tap switch 160 produces an output signal to 13 l IC4 (Fig. 7b). A first tap turns on the pump, a second tap 14 ¦ turns on the heater and a third tap turns the entire system I off.
16 ¦ In operation the system is acti~ated after fllling tub 10 17 l by pressing activating device 32 or 32' (Fig 13). This sends a 18 ¦ signal to activate flip-flop IC4 and timer IC5, turning on 19 ¦ motor 112 to start circulating water through heater 26 to ¦ flexible pipes 16 and jets 18. As the water flows through 21 l heater 26 temperature sensor IC2 sends a signal to proportional 22 l control driver IC1 to allow power to flow through triac Q3 to 23 ¦ heater H1. Of course, the system will remain inoperative 2~ ¦ unless the water level in tub 19 is first sufficient to ¦ interrupt the light beam from LED 94 in water level sensor 36 26 ¦ or activate the level sensing system of Figure 9-11. The 27 ¦ system will continuously circulate water throuyh pump 12 and ~8 flow disbursement manifold 14 ~or a period of time determined 29 by timer IC5. When the period of time set, usually in the range of 9 to 10 minutes, expires timer IC5 resets ~lip-flop 31 IC4 and itself shutting off pump motor 112 and deactivating 32 heater 26. The system can be restarted by again operating ~.3 1 activating device 32, if desired.
2 The system disclosed and described provides a unique 3 hydro-massage tub control system for circulating water to a 4 hydro-massage tub which has improved efficiency, stability, accuracy and reliability. The system also includes a unique 6 water level sensing safety system and a proportional 7 temperature control for highest efficiency and reliability, 8 The system is entirely solid-state for high reliability and the 9 electrical circuits are isolated for maximum safety.
This invention is not to be limited by the embodiment 11 shown in the drawings and described in the description which is 12 given by way of example and not of limitation, but only in 13 accordance with the scope of the appended claims.

I/
16 /l //

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Claims (22)

1. A control system for a hydro-massage tub comprising;
pump means for pumping water from said tub back to plurality of jets in said tub;
heating means for heating said water as it circulates through said pump means;
proportional temperature control means for applying proportional power to said heating means to maintain said water near a constant preselected temperature;
activating means for activating said control system;
level sensing means for sensing the level of water in said tub and interrupting operation of said control system when the water falls below a preselected level;
power supply means for supplying power to said control system, said power supply means including means for preventing operation of said heater means without operation of said pump;
whereby water is heated and circulated through jets in said tub to create a turbulent massaging action.

2. The system according to claim 1 in which said level sensing means comprises;
sensing means sensing the proximity of water;
mounting means mounting said sensing means at the water level desired; and circuit means responsive to said sensing means to provide an output signal when said sensing means senses water;
whereby said water level sensing means prevents operation of said hydro-massage tub without the desired level of water.

3. The system according to claim 2 in which said sensing means comprises a metal plate mounted on the outside of a hydro-massage tub; and circuit means responsive to the energy absorbed by the water sensed by said metal plate.

4. The system according to claim 3 in which said circuit means comprises a tuned circuit connected to said metal plate; whereby the amplitude of oscillations of said tuned circuit are reduced when said metal plate senses the proximity of water in said hydro massage tub.

5. The system according to claim 4 in which said circuit means includes a field effect transistor loosely coupled to said tuned circuit for driving said tuned circuit.

6. The system according to claim 5 including means indicating when said circuit means produces an output.

7. The system according to claim 6 in which said indicating means comprises a light emitting diode.

8. The system according to claim 1 in which said activating means comprises a touch switch mounted on said hydro-massage tub.

9. The system according to claim 8 in which said touch switch comprises; sensing means sensing the proximity of a lossy substance; and circuit means response to said sensing means to provide an output to operate said hydro-massage tub system.

10. The system according to claim 9 in which said sensing means comprises a sensing plate mounted in a dielectric material; and a tuned circuit responsive to said sensing plate sensing a lossy substance; whereby said touch switch provides an output to operate said hydro-massage when said dielectric material is touched by human tissue.

11. The system according to claim 10 in which said sensing means comprises a sensing plate mounted in a dielectric material; and a tuned circuit responsive to said sensing plate sensing a lossy substance; whereby said touch switch provides an output to operate said hydro-massage when said dielectric material is touched by human tissue.

12. The system according to claim 10 in which said circuit means includes a field effect transistor circuit loosely coupled to drive said tuned circuit; whereby when a lossy substance is detected said tuned circuit oscillation amplitude drops.

13. A water level sensing safety system for controlling the water level in a hydro-massage tub, comprising;
sensing means sensing the proximity of water;
mounting means mounting said sensing means at the water level desired; and circuit means responsive to said sensing means to provide an output signal when said sensing means senses water;
whereby said water level sensing means prevents operation of said hydro-massage tub without the desired level of water.

14. The system according to claim 13 in which said sensing means comprises a metal plate mounted on the outside of a hydro-massage tub; and circuit means responsive to the energy absorbed by the water sensed by said metal plate.

15. The system according to claim 14 in which said circuit means comprises a tuned circuit connected to said metal plate; whereby the amplitude of oscillations of said tuned circuit are reduced when said metal plate senses the proximity of water in said hydro-massage tub.

16. The system according to claim 15 in which said circuit means includes a field effect transistor loosely coupled to said tuned circuit for driving said tuned circuit.

17. The system according to claim 16 including means indicating when said circuit means produces an output.

18. The system according to claim 17 in which said indicating means comprises a light emitting diode.

19. The system according to claim 1 in which said activating means comprises a vibration sensitive switch mounted on said hydro-massage tub.

20. The system according to claim 19 in which said vibration sensitive switch comprises piezoelectric means; said piezoelectric means being mounted in a housing in said hydro-massage tub deck; whereby a tap on a surface of said housing activates said vibration sensitive switch.

21. A proportional heating system for heating water circulating to and from a hydro-massage tub comprising;
heater means for heating circulating water;
proportional temperature control means for applying proportional power to said heating means in response to a change of temperature in said circulating water;
adjustable temperature selecting means for adjusting the temperature range of said proportional temperature control means;
whereby said proportional temperature control means gradually reduces power as the temperature in said circulating water approaches the optimum maximum temperature selected by said adjustable temperature selecting means.

22. The system according to claim 21 in which said proportional temperature control means includes; an integrated circuit power controller configured to gradually reduce power to said heater means when the temperature in said circulator water is within 2° Fahrenheit of the maximum temperature set by said adjustable temperature selecting means.