JPS6241271Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic timepiece circuit with an alarm, and more particularly to an electronic timepiece circuit having an auxiliary oscillation circuit.

In general, an electronic clock circuit with an alarm that uses the commercial frequency as a reference frequency and counts it in a clock circuit to obtain the time and outputs an alarm signal when a preset time has arrived depends on connecting a capacitor, etc. to the external terminal. An auxiliary oscillation circuit is provided for oscillation, and the oscillation output of the auxiliary oscillation circuit or its frequency-divided output is used as an alarm signal to drive a speaker, etc., and is also applied to the timekeeping circuit as a reference frequency during a power outage. However, in such an electronic clock circuit with an alarm, the alarm output terminal can only output an alarm signal that drives a speaker, etc., and, for example, a DC signal that turns on or off the power of a radio, etc. I couldn't take it out. Further, in order to extract this DC signal, a switching terminal must be added.

The present invention has been devised in view of the above-mentioned points, and provides an electronic timepiece circuit with an alarm that switches and outputs an alarm signal and a DC signal without adding any terminals. The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the present invention,
1 is an auxiliary oscillation circuit, 2 is a frequency dividing circuit, 3 is a switching circuit, 4 is a clock circuit, and 5 is an alarm output circuit.

The auxiliary oscillation circuit 1 includes a resistor R and a P-channel MOSFET (hereinafter referred to as P-MOS) 6 connected in series between a negative power supply -Vss and ground, a Schmitts inverter 7 continuously connected, and ordinary inverters 8, 9,
The connection point between the resistor R and the P-MOS 6 is connected to the external terminal A and to the input of the Schmitt inverter 7. The Schmitt inverter 7 has the input/output characteristics shown in FIG. 2a,
The low limit level has a level of -1/2Vss, and the high limit level has a level of -Vp.
Further, the output of the inverter 10 is applied to the gate electrode of the P-MOS 6 and the input of the frequency dividing circuit 2. The frequency dividing circuit 2 divides the frequency of the output of the auxiliary oscillation circuit 1 until it becomes the same as the commercial frequency, and its output is applied to the switching circuit 3. Switching circuit 3 is a control signal
Depending on the SL, a signal with a commercial frequency of 50 or 60 Hz is normally applied to the clock circuit 4, but in the event of a power outage, the output from the frequency divider circuit 2 is applied. Alarm output circuit 5 includes Schmitts inverter 11 and NAND gate 1
A signal from the auxiliary oscillation circuit 1 is applied to the input of the Schmitt inverter 11, and a 1Hz signal to make the alarm an intermittent sound is applied to one input of the NAND gate 12. 4, and one input of the AND gate 13 receives an alarm coincidence signal ALIN, which is output from the clock circuit 4 when a preset time has arrived.
is applied. Schmidt inverter 11 is the second
It has the input/output characteristics shown in FIG. b, with a low limit level of -1/4Vss and a high limit level of -Vp.

A capacitor 14 and a switch 15 serving as short-circuiting means are connected to the ground in parallel to the external terminal A, and the capacitor 14 determines the oscillation frequency of the auxiliary oscillation circuit 1 depending on the time constant with the resistor R. When the switch 15 is closed, the potential of the external terminal A is set to the ground level, and the oscillation is stopped.

The oscillation operation of the auxiliary oscillation circuit 1 will be explained with reference to FIG. First, when negative power supply -Vss is applied, the potential of external terminal A gradually decreases from the ground level to negative power supply -Vss.
When the Schmitt inverter 11 reaches the low Schmitt level -1/2Vss, the Schmitt is turned on and the charge stored in the capacitor 14 is discharged. As a result, the potential of external terminal A rises, and when it reaches the threshold level -1/2Vss, inverters 7, 8, 9, and 10 are inverted, and after a delay of time T, output B becomes "1" and turns off P-MOS6. state. By repeating the above operations, oscillation is maintained, and the waveforms shown in FIG. 2 are obtained at external terminal A and output B. On the other hand, the inverter 1 of the alarm output circuit 5 to which the signal of the external terminal A is applied
When the threshold level of 1 is set to -1/4Vss, the waveform shown in FIG. 3C is outputted to the output C.

Also, if the capacitance of the capacitor 14 is appropriately selected and the oscillation frequency of the auxiliary oscillation circuit 1 is set to 1KHz, the NAND
The output of gate 12 is a composite output of 1Hz and 1KHz,
That is, a 1KHz signal is output for 0.5 seconds per second. Now, a composite output of 1Hz and 1KHz shown in Fig. 3, that is, a 1KHz signal is output for 0.5 seconds per second. As shown in Fig. 4, when the alarm coincidence signal ALIN is output from the clock circuit 4, the alarm output terminal
A combined signal of 1Hz and 1KHz is output to ALM, which drives the speaker connected to the alarm output terminal ALM to emit an intermittent sound.

On the other hand, when the switch 15 connected to the external terminal A is closed, the potential of the external terminal A is fixed at the ground level, that is, "1", so the oscillation of the auxiliary oscillation circuit 1 is stopped, and the oscillation of the alarm output circuit 5 is Since the output of the inverter 11 is always fixed at "0", the output of the NAND gate 12 is always "1". Therefore, the alarm match signal ALIN becomes “1”
Then, a DC signal as shown in FIG. 4 is output to the alarm output terminal ALM. Such a DC signal is used as a signal to turn on or turn off the power of a radio or the like.

In this way, when external terminal A is not shorted, an alarm signal suitable for driving speakers etc. is output, and when external terminal A is shorted, a DC signal suitable for controlling the power supply is obtained. , these changes can be made by the switch 15. In addition, the switch 15 can be linked with the control signal of the switching circuit 3 so that an alarm signal and a DC signal can be selected arbitrarily when the power is on, and only the alarm signal can be output when the power is turned on or when the drive is powered by a battery or the like. can. It goes without saying that the switch 15 can be an electronic switch such as a transistor or FET.

As described above, according to the present invention, the output signal of the alarm output terminal can be switched by simply connecting a shorting means to the external terminal to which the capacitor that determines the oscillation frequency is connected, and the number of terminals can be increased. Furthermore, a single integrated circuit implementing the present invention can be used in various electronic clocks, and the effect is particularly great when built into a radio, etc. There is.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIGS. 2 and 3 are waveform diagrams showing the operation, and FIG. 4 is a waveform diagram showing the state of alarm output. 1... Auxiliary oscillation circuit, 2... Frequency dividing circuit, 3...
Switching circuit, 4... timing circuit, 5... alarm output circuit.

Claims (1)

[Scope of utility model registration request] a clock circuit that obtains time by counting the reference frequency;
The auxiliary oscillation circuit is equipped with an auxiliary oscillation circuit that performs oscillation by connecting a capacitor or the like to an external terminal, and the oscillation output of the auxiliary oscillation circuit or its portion is adjusted depending on the coincidence signal output from the timer circuit when a preset time has arrived. In an electronic watch circuit with an alarm that outputs a frequency output as an alarm output, a gate circuit is provided that outputs a signal at a predetermined level when the auxiliary oscillation circuit stops oscillating, and the external terminal is short-circuited by a short-circuiting means, and the An electronic clock circuit with an alarm, characterized in that a DC signal is output from an alarm output terminal when oscillation of an auxiliary oscillation circuit is stopped.