JPS592630Y2 - Notification circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a notification circuit that uses an annunciator such as a buzzer to notify the completion of a predetermined operation of a load operated by power supply.

In this type of alarm circuit, it is required to operate an alarm such as a buzzer simultaneously with the completion of a predetermined operation of the load.

Conventionally, the timing for sounding the buzzer was set in terms of time using a mechanical timer circuit, etc., which had the disadvantage that it was difficult to make the notification timing coincide with the end of operation, and the timer circuit was also complicated.

In view of this, the present invention provides an alarm circuit that can operate an alarm such as a buzzer at the same time as the end of a predetermined operation of the load.An embodiment of the present invention will be described below with reference to the drawings. .

1 is an AC power supply, 2 is a load such as a washing pump for a dishwasher, and 3 is a control circuit such as a timer connected via a transformer 4. After a predetermined time has elapsed since the power is turned on, a switch 3a is opened to turn off the power. 1 and cuts off the power supply to load 2.

Furthermore, the voltage taken out from the control circuit 3 is DC.
A bias resistor 8 is connected between the power supply line 5 and the e-power supply life 6 to control the base bias of the switching transistor 7.
and 9 are connected.

Also, a diode 10, a resistor 11. Connect capacitor 12 in series, diode 10 → resistor 11 → capacitor 12
The charging circuit 13 is formed by the path.

Furthermore, a diode 10, a resistor 11. Resistor 14 and resistor 15 are connected in series, capacitor 12 → resistor 14 → resistor 15
A discharge circuit 16 is formed by the path.

Further, the collector of the switching transistor 7 and the gate of the thyristor 17 are commonly connected to the midpoint between the resistors 14 and 15.

A DC voltage rectified by a rectifier 18 is applied from a power source 1 to the anode and cathode of the thyristor 17, and a buzzer 19 is connected to the supply path of the power source 1.

Note that the resistor 14 used is one that is sufficiently larger than the resistor 11.

Next, the operation of the notification circuit configured as above will be explained.

When the power is turned on, the load 2, for example, the washing pump of a washing machine, operates and performs a washing operation.

Further, the control circuit 3 also operates via the transformer 4.

Furthermore, a base current flows through the switching transistor 7 by the bias resistors 8 and 9, and this transistor 7 becomes conductive, so that the power supply line 5-→diode 10→resistor 11-→resistor 14→1--the collector of Ranjistaf-1-the emitter of Ranjistaf-- A current flows through the power supply line 6, and on the other hand, a charging circuit is formed along the path of the power supply line 5, the diode 10, the resistor 11, and the capacitor 12, and the capacitor 12 is charged.

Therefore, at this time, no trigger signal is generated at the gate of the thyristor 17, and the thyristor 17 is not conductive.

Then, after a predetermined period of time has elapsed, the control circuit 3 switches the switch 3a.
The circuit is opened to cut off the power supply to the load 2, and, for example, the cleaning pump becomes inoperable and the cleaning operation ends.

Further, when the switch 3a is opened, the voltage of the lines 5 and 6 is no longer supplied, and the switching river/Ranjistaf becomes non-conductive.

At this time, the resistor 15 and the gate and cathode of the thyristor 17 are opened, so that the charge stored in the capacitor 12 is discharged through the resistor 14 and the resistor 15, and a voltage appears across the resistor 15, causing the gate of the thyristor 17 to be discharged. When triggered, the cyrisk 17 becomes conductive and sounds the buzzer 19, so that it is possible to notify that the load 2 has finished its predetermined operation.

The current due to the charge in the capacitor 12 flows through the thyristor 1.
When the holding current becomes lower than the holding current of 7, the thyristor 17 becomes non-conductive and the buzzer 19 stops sounding.

In the embodiment shown in the drawings of the present invention, the buzzer 19 is connected to the power source side from the switch 3a to maintain the operation of the buzzer 19, but in other embodiments, the buzzer 19 is connected to a power source different from the power source 1 (see the figure (not shown) to maintain the operation of the buzzer 19.

As described above, the present invention includes a switching element such as a transistor that is conductive when power is supplied, a charging circuit that is formed when power is supplied, and a power supply to the load when the load completes a predetermined operation. A control circuit including a switch circuit configured to cut off the supply; a discharging circuit that makes the switching element non-conductive and discharges the charge of the charging circuit when the power supply is cut off by the control circuit; a thyristor that is non-conductive when conductive and conductive in the discharge circuit when the element is non-conductive; and a thyristor that operates when the thyristor is conductive and maintains this operation after the thyristor is conductive from the switching means to the power source side or to the power source. Since the alarm circuit consists of an alarm such as a buzzer connected to a separate power source, it is possible to easily synchronize the timing of sounding the buzzer with the end of the load's predetermined operation, and the timing to sound the buzzer can be easily matched with the end of the load's predetermined operation. It has the advantage of being able to alert you by sounding a buzzer at the same time.

Furthermore, since the buzzer starts sounding when the power supply to the load is cut off, the circuit has the advantage of being simplified.

Furthermore, as mentioned above, if the load is the washing pump of a dishwasher, the operator can reliably confirm that washing has been completed, and the present invention has many applications.

[Brief explanation of the drawing]

The figure is an electrical circuit diagram showing an embodiment of the notification circuit of the present invention. 1...Power supply, 2...Load, 3...Control circuit, 3a
... switch, 7... switching transistor,
13... Charging circuit, 16... Discharging circuit, 17...
Sairisk, 19...buzzer

Claims (1)

[Scope of utility model registration request] In a notification circuit that uses an alarm such as a buzzer to notify the end of a predetermined operation of a load operated by power supply, switching elements such as transistors that are conductive when power is supplied, and switching elements such as transistors that are conductive when power is supplied and a control circuit including a switch circuit that opens to cut off the power supply to the load when the predetermined driving operation is completed; a discharging circuit discharging the charge of the charging circuit while discharging the charging circuit; a thyristor that is non-conductive when the switching element is conductive and conductive in the discharging circuit when the switching element is non-conductive; An alarm circuit comprising an annunciator such as the buzzer connected to the power source side of the switch means or to a power source separate from the power source so as to maintain this operation after the thyristor is activated and conducts.