DE2622860A1 - SECOND HAND CONTROL CIRCUIT FOR A QUARTZ CLOCK - Google Patents

Description

The invention relates to a second hand control circuit for a quartz watch according to the preamble of the claim.

For controlling or setting the second hand of a Clock is known to move the seconds hand mechanically to stop by means of a button attached to the watch, but this principle proves from the point of view of durability as well as disadvantageous for reasons of cost.

From an electrical point of view, a reset option at the frequency divider stage would be available to control the second hand Advantage. However, this sometimes indicates that it is currently commercially available Quartz watches did not use a CMOS IC device on.

For controlling a second hand of a quartz watch, at using such a CMOS IC device, it is known, for example, to control the oscillation by short-circuiting the input of the oscillator part to the negative connection of the power source

609850/0713

to interrupt, which, however, has the disadvantage that in the case of using a CMOS IC component for such a quartz watch, which works with a dynamic frequency division in the lower stages of the frequency divider stage, although the oscillation is brought to a standstill, the frequency divider stage itself due to the structure of the dynamic frequency divider section is extremely unstable, which affects the output signal and causes unnecessary movement of the second hand Has.

The object of the invention is therefore to create an electrical control for the second hand of a quartz watch which does not occur the disadvantages of the prior art mentioned.

According to the invention, this object is achieved by the subject matter of the claim solved.

Advantageously, according to the invention, this is used as a control circuit created for the second hand of a quartz watch, the one equipped with a quartz oscillator part, a Frequency divider stage, the lower stages of which as a dynamic frequency divider section are formed, and comprises an output stage arranged in the form of a bridge circuit, wherein between the Both output connections of the output stage a capacitor and a driver coil are connected in series and due to the through the coil of flowing current is set in rotation by a stepping motor, the output torque of which moves the second hand and is stopped for control by short-circuiting the drive coil by means of a switch.

In particular, due to the inventive Circuit arrangement a control circuit for a second hand which is simple in construction and inexpensive to manufacture and has the same power consumption as in normal operation even when the second hand is controlled.

An embodiment of the invention is in the drawing and is described in more detail below.

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Show it:

Fig. 1: an embodiment of the invention,

Fig. 2: a pulse plan to illustrate the mode of operation the circuit arrangement according to FIG. 1.

In Fig. 1, reference numeral 1 is an oscillation inverter, reference numeral 2 is a feedback resistor and the reference number 3 denotes a binary counter, the lower stages of which (not shown in the figure) as a dynamic frequency divider section are formed, while with Ql, Q2, Q3 and Q4 output transistors are designated, of which Ql and Q3 P-channel MOS transistors and Q2 and Q4 N-channel MOS transistors are arranged in the form of a bridge circuit, as shown in FIG. 1 can be seen.

The circuit part enclosed by dashed lines, So the oscillation inverter 1, the binary counter 3 and the output transistors Ql, Q2, Q3 and Q4, is normally used as a CMOS IC component implemented in the form of a single IC chip.

As can be seen from Fig. 1, the input and the output of the oscillation inverter 1 with a crystal oscillator or Quartz crystal X'tal and capacitors Cl, C2 connected, and with the output terminals a and b of the output transistors a capacitor Co and a coil M connected to drive the stepper motor, while a switch Sw connected in parallel to the drive coil M is normally open and closed by means of a button attached to the watch, e.g. when a setting or control of the second hand is to be performed.

The following is the mode of operation of this circuit arrangement to be discribed. The frequency of an oscillating output signal, that of the known, the quartz crystal X'tal, the oscillation inverter 1 and the capacitors Cl and C2 having Oscillator circuit is output, is successively by means of of the binary counter 3 down to 0.5 Hz. The one friend

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Signals 0 and 0 having a frequency of 0.5 Hz are fed to the control electrodes of the transistors Q1 and Q2 and Q3, Q4. (As can be seen from Fig. 2, the signals 0 and $ are each inverted in relation to one another, that is, if the signal 0 has the value 1, the signal $ has the value O, and if the signal 0 has the value O, the signal $ has the value 1.)

It is now assumed that the signal 0 has the value 1 and the signal j? has the value 0. As in this case the output transistors Q2 and Q3 conduct and the output transistors Ql and Q4 block, a current flows through the transistor Q3, the output terminal b, the drive coil M, the capacitor Co and the output terminal a through the transistor Q2. Take after one Second when the output transistors Ql and Q4 become conductive and the output transistors Q2 and Q3 block, the signal 0 has the value 0 and the signal $ has the value 1, so flows through the transistor Ql, the output terminal a, the capacitor Co, the drive coil M and the output terminal b, a current through the transistor Q4.

The current flowing between the output connections ä and b should be i. If now the resistance of the driver coil M becomes R, the sum of the saturation resistances of the output transistors Q2 and Q3 (or the sum of the saturation resistances of the transistors Ql and Q4) with R ¹ , the capacitance of the capacitor Co with C and the voltage of the electrical voltage source with E. denotes, it results:

C (RfR ¹ )

R + R ¹ (1)

In this way, as illustrated by formula (1), an oppositely directed current flows once every second through the drive or driver coil M, whereby the known

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te, not shown in the figure, the stepping motor rotates and moves the second hand by means of the torque it generates .

If the second hand is to be adjusted or controlled, the. Switch Sw closed, whereby the driver coil -M is short-circuited-and-the-stepping motor no longer delivers any drive torque, so that the second hand comes to a standstill.

Since the current, denoted by ^{i 1} , flowing at this point in time between the output connections a and b, flows through

_ t

is given, the peak value of the current is variable over time ^{according to (R + R 1} ) / R ^1. However, since the amount of electricity consumed by integrating the formula (1)

Γ ¹ ^

^ t = O

dt = 2 CE (3)

and by integrating the formula (2)

/ i ¹ dt = 2 CE (4)

* t = 0

is obtained, the power consumption is accurate in both cases same.

In FIG. 2, the waveforms of the voltages 0, 0, a and 'b described in connection with the circuit arrangement according to FIG. 1 and the waveforms of the current i flowing between the output terminals a and b when the switch Sw is open and the waveforms of the between the Output terminals a and b shown with the switch Sw flowing current i ¹ is closed.

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Claims (1)

-6- May 14, 1976 S-3926 Claim Second hand control circuit for a quartz watch, with an oscillator part having a quartz oscillator and a frequency divider stage for frequency division of the oscillating output signal of the Oscillator part, which is a dynamic frequency divider section as lower stages has, characterized in, that with two output connections (a, b) a built in the form of a bridge circuit, on the frequency divider stage following output stage a series connection of a capacitor (Co) and a drive coil (M) is connected, the drive coil (M) a stepper motor to move the second hand drives, and that a switch (Sw) of the driver coil (M) is connected in parallel and the driver coil (M) during control or setting of the second hand short-circuits. 609850/0713 Blank page