JPS627992B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital electronic watch for automobiles that turns on and off a clock display in conjunction with an engine key, and more particularly to a digital electronic watch with an alarm function.

Generally, digital electronic clocks installed in automobiles use a battery as a driving power source, so the clock display is turned on and off in conjunction with the engine key. That is,
When the engine key is on, the clock circuit main unit performs timekeeping operation and clock display, and when the engine key is off, that is, when the engine is stopped, only the timekeeping operation is performed with the clock display turned off. It is designed to minimize battery loss when stopped. and,
A display switch is provided for displaying the clock while the engine is stopped, and a function is added in which the clock is displayed for a predetermined period of time when the display switch is turned on.

Incidentally, with the recent practical use of high-density integrated circuits, digital electronic watches have been equipped with various functions, one of which is a digital electronic watch with an alarm function that is installed in automobiles. This type of electronic clock emits an alarm sound for several 10 seconds when the alarm setting time arrives, and in some cases the alarm sound can become annoying, so it is necessary to stop the alarm sound midway through. It is necessary to add a switch to stop the alarm. However, when this switch is added, the number of switches increases and the number of time setting switches in addition to the display switch is disposed on the panel surface of the conventional electronic clock as described above. It had drawbacks such as downsizing and impairing operability.

The present invention has been made in view of these points, and by making the display switch that displays the clock when the engine key is turned off also have the function of stopping the alarm, it is possible to eliminate the need for a special switch for stopping the alarm. The present invention provides a digital electronic timepiece for automobiles that can reduce the size of the panel and improve the operability of switches. Hereinafter, the present invention will be explained in detail based on examples.

The figure is a circuit configuration diagram showing an embodiment of a digital electronic timepiece according to the present invention. In the figure, reference numeral 1 denotes a well-known clock circuit body constructed from a semiconductor integrated circuit and equipped with an alarm function, and the hour adjustment, minute adjustment and hour adjustment terminals (hereinafter referred to as
Time setting switches S ₁ to S ₃ consisting of make contacts are connected to the H/S, M/S, and Z/A terminals, respectively, and "H" level signals are supplied when they are turned on. There is. and V _DD and V
"H" and "L" level signals are respectively supplied to _{the SS} terminal, and a Zener diode ZD ₁ is connected between these V _DD and V _SS terminals with the polarities shown. The anode side of this diode ZD ₁ is resistor R ₁
The anode side of the Zener diode ZD ₂ is connected to the connection point between the connected GND terminal and the ground side, and the cathode side of the Zener diode ZD ₂
is connected to the connection point between the cathode side of R2 and one end of resistor _R2 . The other end of resistor R ₂ is connected to the connection point between one end of display/alarm stop switch S ₅ and the cathode side of diode D ₁ , and a constant voltage is supplied from a battery (not shown) to the anode side of diode D ₁ . connected to the C ₊ terminal. The other end of the switch _S5 is connected to the alarm stop terminal (A _OFF terminal) of the clock circuit main body 1, and is also connected to the diode _D2.
The cathode sides of D 3 and D ₃ are connected to the anode side of the commonly connected diode D ₂ . diode
The cathode side to which D ₂ and D ₃ are commonly connected is connected to the set enable terminal (SE terminal) of the watch circuit main body 1, as well as the G terminal of the fluorescent display tube 2 as a digital display and the resistor R ₃ , R ₄ is connected to the input end side of the resistor R ₃ of the constant voltage circuit 3 consisting of the Zener diode ZD ₃ . The anode side of the diode _D3 is connected to a D ₊ terminal to which "H" and "L" level signals are supplied in connection with the on _/ off operation of an engine key (not shown). An "H" level signal is supplied when the engine key is turned on or the accessory (ACC) is turned on, and an "L" level signal is supplied when the engine key is turned off or the ACC is turned off.

In addition, an "H" level signal is supplied to the alarm terminal (A terminal) of the clock circuit main body 1 via an alarm time display switch _S4 , and the dimming terminal (L terminal) is supplied via a resistor _R5 . "H", "L" in connection with the on/off operation of a dimming switch (not shown)
The L ₊ terminal, to which the level signal is supplied, and the alarm output terminal (A _OUT terminal) are connected to the speaker SP, respectively. Furthermore, the output information accompanying the timekeeping operation of the clock circuit main body 1 is input to the fluorescent display tube 2, and the filament terminal (F ₊ terminal) as the operating terminal that enables the display operation of the display tube 2 is input to the fluorescent display tube 2. It is connected to the output end side of the resistor R ₄ of the constant voltage circuit, and its F _-
The terminal is grounded. Note that a crystal oscillator Q and a capacitor are connected to the _φ1 and _φ0 terminals of the clock circuit body 1.
Standard time signals having predetermined frequencies generated from a crystal oscillation circuit 4 consisting of C ₁ and C ₂ are respectively input.

Next, the operation of the above embodiment will be explained. Here, the watch circuit main body 1 includes H/S, M/S, Z/A, A,
It is assumed that the device is set to operate with the corresponding function when an “H” level signal is supplied to each of the A _OFF and L terminals. First, when the engine key is on or the accessory (ACC) is on, when an “H” level signal is supplied to the D ₊ terminal, this signal causes the clock circuit main body 1 to emit output information associated with timekeeping. Input to display tube 2. At the same time, the fluorescent display tube 2 outputs the inputted output information.
A clock is displayed when the display tube 2 enters the light emitting state due to the filament voltage associated with the "H" level signal supplied to the F ₊ terminal. During this display, when the time and the alarm time preset by the alarm time display switch _S4 match, the clock circuit main body 1 sends an alarm signal to the speaker SP through the _AOUT terminal and sounds it. When the display/alarm stop switch _S5 is turned on during this ringing, the "H" level signal associated with this ON operation is supplied to the A _OFF terminal of the clock circuit main body 1, so that the clock circuit main body 1 The alarm signal is stopped by the "H" signal, and thereby the sounding of the alarm sound emitted from the speaker SP while the above time is displayed can be stopped by turning on the display/alarm stop switch _S5 . .

Next, when the engine key is off or the accessory (ACC) is off, no voltage is applied to the D ₊ terminal, and when a “L” level signal is supplied, the clock circuit main body 1 performs normal timekeeping operation. However, the fluorescent display tube 2 enters a non-display state due to the "L" level signal supplied to the F ₊ terminal and turns off. When the display/alarm stop switch S ₅ is turned on while the light is off, the filament voltage accompanying the "H" level signal is applied to the fluorescent display tube 2 through the switch S ₅ and the constant voltage circuit 3. Supplied to the F ₊ terminal. Then, the fluorescent display tube 2 changes from the off state to the clock display for a period corresponding to the ON state of the display/alarm stop switch _S5 , thereby causing the switch _S5 to display the time when the engine key is turned off. It has the function of Also, if the alarm time matches the alarm time preset by the alarm time display switch _S4 while the light is off, the clock circuit main body 1
Since the "H" level signal is supplied to the A _OFF terminal and the F ₊ terminal of the fluorescent display tube 2 via the switch _S5 , the alarm sound emitted from the speaker SP is stopped in the same manner as described above. At the same time, a clock can be displayed on the fluorescent display tube 2.

As explained above, according to the present invention, in a digital electronic watch for a car that has a clock circuit body with an alarm that turns on and off the clock display in conjunction with the engine key, the clock display is temporarily turned off when the engine key is turned off. Since the switch for turning on the alarm is configured to stop the alarm sound when the alarm sound is emitted from the clock circuit main body, 1.
A single switch can be used both to display the clock and to stop the alarm when the engine key is turned off.This has the effect of reducing the size of the panel and improving the operability of the switch.

[Brief explanation of the drawing]

The figure is a circuit configuration diagram showing an embodiment of a digital electronic timepiece according to the present invention. 1... Clock circuit main body, 2... Fluorescent display tube, 3...
...constant voltage circuit, 4...crystal oscillation circuit, S ₁ to _{S 3} ...
Time setting switch, S ₄ ... Alarm time display switch, S ₅ ... Display/alarm stop switch.

Claims (1)

[Claims] 1 The clock circuit body has an alarm function and has an alarm stop terminal that stops the alarm when voltage is applied, and an operation terminal that enables display operation, and the clock circuit body uses signals output from the clock circuit body. A digital electronic watch for automobiles equipped with a digital display means for displaying information, a switch connected in series between a battery power supply circuit and the alarm stop terminal, and an anode connected to the alarm stop terminal. a first diode, a second diode whose anode is connected to a terminal to which a voltage is applied when the engine key is turned on or the accessory is turned on, and whose cathode is connected to the cathode of the first diode; 1. A digital electronic timepiece for an automobile, comprising a circuit connecting a cathode of a diode and the operation terminal, and the switch is configured to both display a clock and stop an alarm when the engine key is turned off.