JPS596365B2 - bath buzzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides, for example, when water in a bathtub reaches a certain set water level.
This relates to a bath buzzer that emits an alarm when the water temperature in the bathtub reaches a certain set temperature or when water leaks to a certain set level while heating the bathtub water.The purpose of the buzzer is to:
To obtain a bath buzzer which operates reliably, has few failures, has a long life, and whose alarm sound is easy to recognize.

Hereinafter, the present invention will be explained based on drawings showing embodiments thereof.

In FIG. 1, an outline of the entire circuit will be explained first, and then its details will be explained. 1 is a DC power source consisting of dry batteries, 2
3 is a 3-circuit, 4-contact interlocking changeover switch; 3 is a transistor for water leakage detection; 4 is a transistor for battery test, water level operation, and water leakage operation; 5 and 6 are transistors forming a Schmitt circuit.

Reference numerals 7 and 8 denote transistors constituting one of the astable multivibrator circuits, and the switching transistor 9 is turned on and off according to the on-off period of these transistors T and 8.

10 and 11 are transistors constituting the other astable multivibrator circuit, and a speaker 1 is connected to one of its output terminals.
2 is connected.

13 is a water leakage electrode, 14 is a water level electrode, 15 is a common electrode,
These electrodes are made from rust-resistant steel materials, such as stainless steel, which do not rust in water.

16 is a negative characteristic thermistor; this negative characteristic thermistor 16
The above-mentioned parts including the sensor 17 are resin-molded in the relevant positions as shown in FIG.

Fixed contacts 1a, 2a of the switch. 3a has a movable contact 1e,
When 2e and 3e are in contact, it is in the off state, and if you turn it one step to the right from this state, the battery test position 1b, 2b
, 3b, and when the battery is new and the voltage is high, transistor 4 operates and generates an intermittent sound from the speaker 12. However, when the battery is exhausted and the voltage drops below a certain level, transistor 4 does not operate and the speaker 12 does not operate. 12 doesn't ring. When this happens, the battery will be notified that it has reached its age and must be replaced with a new one. Next, turn the switch one more step to the right to reach the water level positions 1c, 2c, and 3c, and the sensor 1 shown in Figure 2
When the water level of the bathtub rises and the water level electrode 14 is immersed in the water at step 7, a minute current flows between the water level electrode 14 and the common electrode 15, activating the transistor 4 and notifying the speaker 12 that the bathtub is full.

Further, turning the switch one step to the right will set the temperature to 1d, 2.
d and 3d, and when the water temperature in the bathtub rises to a certain set temperature, the resistance value of the thermistor 16 decreases, the Schmitt circuit is activated, and the speaker 12 emits an alarm sound.

If water leaks from the bathtub during heating at this temperature and the water level drops below electrodes 13 and 15 in FIG. 2, a minute current flows between the water level electrode 13 and the common electrode 15 stops flowing and the transistor 3 is turned off from on, so the transistor 4 is activated and a water leakage alarm is emitted from the speaker 12.

Next, to explain the above configuration in more detail, a capacitor 18 is connected between the collector of the transistor 10 and the base of the transistor 11 to configure the other astable multivibrator circuit, and a capacitor 18 is connected between the base of the transistor 10 and the collector of the transistor 11. A capacitor 19 is connected between them, and a collector resistor 20 and a base resistor 2 are connected between the collector and base of the transistor 10, respectively.
1 is connected.

Further, a parallel load of a speaker 12 and a capacitor 22 and a base resistor 23 are connected between the collector and base of the transistor 11, respectively. In addition, this circuit has a power of approximately 2kHz.
The circuit constants are set so that the single tone z is generated from the speaker 12. Also, transistors 7 and 8 constitute one astable multivibrator circuit as above,
The collector resistor 24 of the transistor 8 is connected so that the switching transistor 9 is turned on when the transistor 8 is turned on.
, 25 are connected to the base of the switching transistor 9.

In this case, the base resistor 26 of the transistor 8 is connected to the collector of the off-side transistor 6 when the Schmitt circuit is set, and one of the transistors 8 of the astable multivibrator circuit transistors 7 and 8 is turned off. There is.

That is, when the Schmitt circuit transistor 6 is turned on, the transistors 8 of the astable multivibrator circuit transistors 7 and 8 are activated, and one astable multivibrator circuit is activated. In this case, if the oscillation period of the transistors 7 and 8 for one of the astable multivibrator circuits is set to 5 to 7 Hz, the output from the speaker 12 is 2k.
A Hz oscillation sound is generated intermittently at the oscillation cycle of 5 to 7 Hz. Also, transistors 5 and 6 of the Schmitt circuit
Of these, the transistor 6 is off when the water level is set and the temperature is set (however, if the common electrode 15 and the water leakage electrode 13 are not underwater when the temperature is set, the base resistor 27 of ρ, which turns off and turns on, is the collector of the transistor 5). The emitters are each coupled to an emitter-coupled resistor 28. Also, one end of the resistor 29 is connected to the base of the transistor 5, one end of which is connected to the other end of the resistor 29, and the other end is connected to the negative terminal of the DC power supply 1. A silicon diode 31 for compensating for reduced voltage is connected between the connection point with the resistor 30 connected to the side and the positive side of the DC power supply 1.Furthermore, at the base of the roller JW star 6, A collector resistor 32 of the trigger transistor 4 is connected to turn on the transistor 6 during a battery test, water level, or water leak.

Further, a capacitor 33 and a resistor 34 are connected in parallel between the emitter and the base of the transistor 6 to stabilize the pulse voltage input from the astable multivibrator circuit when the switch 2 is switched. Trigger transistor 4
A resistor 35 is connected between the emitter and base of the switch 2, and its base is connected to the common point 2e of the switch 2.

When the switch 2 is in the battery test positions 1b, 2b, and 3b, the common point 2e that becomes the base of the trigger transistor 4 is the connection between the resistors 38 and 39 in the series resistors 16, 36, 37, 38, 39, and 40. It is connected to the point via the fixed contact 2b. In addition, 16 is a negative characteristic thermistor for temperature detection, 36 is a semi-fixed polyurethane for temperature setting, and 37 is a polyurethane for temperature adjustment. Now, the voltage of DC power supply 1 consisting of dry batteries is V.

, where the voltage between the emitter and base of the trigger transistor 4 is Veb, where R3 is the resistance value of the resistor 35.

The same applies below. If Eb in equation (1) is greater than or equal to the threshold voltage of the trigger transistor 4, the trigger transistor 4 operates and drives the Schmitt circuit.
The voltage V of the DC power supply 1, which generates intermittent sound from the speaker 12 and is also composed of a dry battery.

The voltage V at which the voltage has disappeared. When the voltage drops to ', Veb becomes below the threshold voltage, and as a result, the trigger transistor 4 does not operate, so no sound is emitted from the speaker 12. That is, resistors 16, 36, 37, 38, 39, 4
If the resistance value of 0 is set appropriately, the desired voltage V can be obtained. ', the alarm sound can be prevented from being generated, and it is possible to know when the lifespan of the DC power supply 1 consisting of a dry cell battery has come to an end. Also R3,》Rl
By making 6+R36+R37, Polyuum 37
, VO' can be set regardless of the resistance value of the thermistor 16, and when the circuit of the thermistor 16 is disconnected within the sensor 17, Eb becomes Veb-. regardless of the battery voltage. This prevents the use of dry batteries, even if they are new, and prevents accidents caused by malfunctions in the temperature alarm.

When the switches 1c, 2c, and 3c are in the water level set state, the resistor 41 connected in series to the water level electrode 14 is
This is a resistor for protecting the base of transistor 4.

In this state, when the water level rises and the common electrode 15 and the water level electrode 14 are immersed in water, a minute current flows and the transistor 4 is activated, so that the speaker 12 generates an intermittent sound as described above. The positions of the switches 1d, 2d, and 3d are in a state where the temperature is set, and the common point 2e, which is the base of the transistor 4, is connected to the collector l of the transistor 3 via the fixed contact 2d. A collector resistor 42 is connected to the collector, a resistor 43 is connected between the emitter and the base, and a protective resistor 44 is connected to the base.When the temperature is set, the common electrode 1
5 and the leakage electrode 13, a small current flows between both electrodes, and the voltage between the collector and emitter of the transistor 3 becomes less than the threshold voltage between the emitter and base of the trigger transistor 4, and the voltage between the emitter and the base of the trigger transistor 4 is lowered. Transistor 4 is not activated.

If water leaks from the bathtub in this state and both electrodes 15, 1
If there is no water between the transistors 3 and 3, the base current of the transistor 3 will no longer flow.

Therefore, the transistor 3 is turned off, and the voltage between the collector and the emitter becomes higher than the threshold voltage between the emitter and the base of the transistor 4, and the transistor 4 is activated to notify the leaker 12 that water has leaked. Furthermore, when the water in the bathtub is heated without water leakage, the water temperature in the bathtub rises, and when the resistance value of the thermistor 16 drops to the resistance value set by the temperature regulating polyurethane 37, the voltage between the emitter and the base of the transistor 5 increases.
As a result, the transistor 5 is turned off, and the speaker 12 notifies that the water is hot.

In addition, when testing the battery (switch positions 1b, 2b, 3b)
In this state, the resistor 39 is connected to the connection point between the collector resistors 45 and 40 of the transistor 6 because the dry battery is exhausted and the voltage drops to V.

When approaching ', the voltage of the dry cell decreases to V due to the voltage recovery of the dry cell and the voltage drop during blowing. This was done to apply positive feedback to prevent this, since the period of the oscillating sound is disturbed as a result. In FIG. 1, 46 is a collector resistor connected to the collector of transistor 7 constituting one astable multivibrator circuit, 47 is an electrolytic capacitor connected between the collector of transistor 7 and the base of transistor 8, and 48 is a collector resistor connected to the collector of transistor 7 constituting one astable multivibrator circuit. A base resistor 49 is connected to the base of the transistor 7, an electrolytic capacitor 49 is connected between the base of the transistor 7 and the collector of the transistor 8, and a collector resistor 50 is connected to the collector of the transistor 5 constituting the Schmitt circuit.

As described above, according to the present invention, there is provided a Schmitt circuit having two emitter-coupled transistors, a resistor having one end connected to the base of one transistor, and one end connected to the other end of this resistor, and the other transistor having one end connected to the base of the other transistor. A connection point with a resistor connected to the negative side of a DC power source whose end is a dry battery,
Since a diode for compensating for reduced voltage is connected between the positive side of the DC power supply, fluctuations in operating temperature due to voltage fluctuations of the DC power supply can be reduced.

Also, during battery testing, part of the collector voltage of the other transistor in the Schmitt circuit can be arbitrarily switched to OFF, a fixed contact for battery testing, water level detection, temperature detection that also serves as water leakage detection, and these fixed contacts. Since positive feedback is made to the base of the trigger transistor through the fixed contact for battery testing of the changeover switch that has a movable contact, there is no disturbance in the sound near the predetermined voltage VO' of the DC power supply, and the sound is stable. can get. Furthermore, since the battery test is performed with a temperature detection circuit such as a thermistor connected, if the thermistor circuit etc. is disconnected, the battery test will not blow regardless of the voltage of the DC power supply. As a result, accidents caused by temperature, such as burns caused by dry heating or boiling, can be prevented.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a bath buzzer showing an embodiment of the present invention, and FIG. 2 shows a sensor for detecting water level, etc. in the same buzzer, where a is a front view and b is a side view. 2...Selector switch, 4...Trigger transistor, 5, 6...Transistor, 16
, 36, 37...Temperature detection circuit, 28...
... Emitter coupling resistance, 29, 30 ... Base resistance, 31 ... Silicon diode for compensating for reduced voltage, 32 ... Collector resistance.

Claims (1)

[Claims] 1 comprises a Schmitt circuit having two emitter-coupled transistors 5 and 6, one end of which is connected to the base of one of the transistors 5, a resistor 29, one end of which is connected to the other end of this resistor 29, and the other end of which is connected to a dry battery. A silicon diode 31 for compensating for reduced voltage is connected between the connection point with the resistor 30 connected to the negative side of the DC power supply 1 and the positive side of the DC power supply 1, and the base of the one transistor 5 A fixed contact 3d for temperature detection is connected to the connection point of the and resistor 29, and this fixed contact 3d for temperature detection and a temperature detection circuit such as a thermistor 16 connected to the positive side of the DC power supply 1 are connected to the first A trigger transistor 4 having a collector resistor 32 is connected to the base of the other transistor 6, and a trigger transistor 4 having a collector resistor 32 is connected to the base of the trigger transistor 4. The movable contact 2e of the second changeover switch that is interlocked with the
a, battery test 2b, water level detection 2 with water level electrode 14
c. Each fixed contact of the water leakage detection 2d is arbitrarily switched, and the battery voltage, water level detection input, and water leakage detection input of the transistor 3 having the water leakage electrode 13 are added, and the movable contact 3e of the first changeover switch is switched during the battery test. At the same time, a part of the collector voltage of the other transistor 6 of the Schmitt circuit is connected to the fixed contact 3b of the trigger transistor 4 through the fixed contact 2b for battery test of the second changeover switch and the movable contact 2e. A bath buzzer characterized by positive feedback to the base and output from the collector of the other transistor 6 of battery voltage, water level detection output, and temperature detection output that also serves as water leakage detection.