GB2253286A - Testing apparatus for timing devices - Google Patents

Abstract

A testing apparatus for timing devices, especially quartz-movement wrist watches, that include electronically driven mechanical movements comprises a battery tester probe 18 for assessing the operative or inoperative condition of a battery; and an electronic driver tester 16 that detects the electromagnetic field variations produced by the electronic movement driving components of the timing device. <IMAGE>

Description

TESTING APPARATUS FOR TIMING DEN ICES Field of the Invention The present invention relates to testing apparatus for timing devices.

Background to the Invention There are currently a wide variety of watches and other timing devices on the market. The principles behind the mechanical movements within such devices have been appreciated for centuries. However, only recently have timing devices including mechanical movements, especially watches, been accurately driven electronically. The now well-known method of accomplishing this is to use a vibrating quartz crystal to generate a knon regular frequency pulse. The pulse in such devices is used to control the actuation of a stepper motor that itself drives the mechanical movement. Generally, in watches, the electric power is supplied from an internal battery (which includes all suitable portable power cells). It is with the testing of watches such as these that the present invention is particularly, though not exclusively, concerned.

The faults that cause such a timing device to malfunction may be divided into two main areas. Firstly there are power failures, usually as a result of the internal battery having simply run down to an inoperative condition. Secondly there is the possibility of movement faults that are usually caused by either electronic or mechanical problems. Electronic problems include short circuits, circuit breaks and component failures. Mechanical faults include damaged or dirty gear trains.

Excluding one of these faults from the possible causes of a breakdown is clearly a useful, and often necessary step as a precursor to the repair of the device.

Testing apparatus is known for testing a timing device battery, the apparatus normally used is a conventional multimeter.

Typically these multimeters do not place a substantial -load across the battery and therefore do not reflect the true state of the battery condition as it would be when fitted in a working timing device. For commercial purposes a multimeter display can be confusing to a lay-customer which leads to the possibility of detrimental customer relations. Additionally, the flying lead probes of conventional multimeters are difficult to apply to the often small (e.g lcm diameter by 0.5cm thickness) batteries used in these timing devices.

However, determining to whatever degree of accuracy, the operative of inoperative condition of the battery does not resolve the question of whether or not the mechanical movement is operational, nor whether or not the electrical driving means are in working order.

Testing apparatus is known for electronically determining the operative or inoperative condition of the electronic driving means.

This does not assist in determining the condition of the battery, nor in determining the condition of the mechanical movement.

Furthermore, these apparatus are not generally customer-friendly.

Thus there is no testing apparatus currently available that can be used to narrow down the range of possible faults occurring in an inoperative timing device to the level of: battery, electrical driving means or mechanical movement. This creates a problem for those involved in the testing and repair of such timing devices.

Furthermore, the known testing devices are generally cumbersome, expensive and confusing to any onlooking customers.

It is an object of the present invention to provide a testing apparatus that obviates or mitigates these problems.

Summary of the Invention According to the present invention there is provided a testing apparatus for timing devices that include electronically driven mechanical movements; the apparatus comprising a battery tester for assessing the operative or inoperative condition of a battery; and an electronic driver tester that detects the electromagnetic field variations produced by the electronic movement driving components of the timing device.

The timing devices will normally be battery driven.

The testing apparatus is preferably readily portable, and more preferably pocket sized.

For convenience the testing apparatus will normally include its own power source, especiallY when the apparatus is readily portable or pocket sized.

The invention will now be described, by way of example only, with reference to the drawings that follow; in which: Brief Descristion of the DrawlnEFs Figure 1 is a plan view of a testing apparatus in accordance with the present invention.

Figure 2 is a front view of the apparatus shown in Figure 1.

Figure 3 is a flow chart illustrating the diagnostic procedure to be followed using the present invention.

Figures 4 to 6 are circuit diagrams illustrating the electronic configuration of the apparatus shown in Figures 1 and 2.

Descrintion of the Preferred Embodiment Referring now to Figures 1 and 2 of the drawings that follow, there is shown a testing apparatus 2 comprising a substantially cuboidal casing 4 with one of the major faces of the casing 4 being detachable to allow access to the casing interior for inserting e.g a battery to enable the apparatus to have its own internal power source.

The whole apparatus 2 is readily portable, i.e it can be carried about by hand without assistance from other devices or persons.

Preferably the apparatus 2 is pocket sized, i.e none of the linear (e.g length, width or depth) dimensions are greater than 20cm.

The testing apparatus 2 also comprises a switch 6 mounted on a long side of the casing 4, and mounted on, or in, the substantially planar upper face 8 a voltage display 10, a battery tester contact area 12, an electronic driving means condition indicator 14 and an electronic driving means test area 16. Mounted in a short side of the casing 4 is a flying lead battery probe 18.

The switch 6 is a push-to-make, release-to-break type manual movement switch.

The voltage display 10 comprises a plurality of light emitting diodes (LEDs) 20, in this case there is a row of ten LEDs 20a-20j that provide a progressive indication of the voltage measured in steps of 0.3 volts and are labelled accordingly. There is also an 'ON' LED 22 at one end of the row of LEDs 20. All of the LEDs 20, 22 are mounted in the casing 4 so that they protrude above the substantially planar upper face 8. In order to assist a user of the apparatus 2 the LEDs 20, 22 are colour-coded. The 'ON' LED 22 is a first colour, the LEDs 20a-20d and 20f-20i are a second colour and LEDs 20e and 20j are a third colour. In this case the colours are yellow, red and green respectively.

The contact area 12 is a substantially circular conducting plate (e.g steel) recessed below the level of the upper face 8 and substantially flush against the lower surface of the face 8 (see dashed lines in Figure 2) so that the casing 4 forms an up standing rim 24 around the contact area 12.

The electronic driving means condition indicator 14 comprises three LEDs 26a, 26b and 26c. These LEDs 26 are driven in response to signals from the electronic driving means test area 16 that is an identified area of the upper face 8.

The flying lead battery probe 18 may be of any convcntional type well known in the art.

The operation of the testing apparatus 2 will now be described with additional, and especial, reference to Figure 3. It is to be noted that references to "watches" are not to be tal;en as limiting the present invention to just this type of readily portable, pocket sized timing device, but rather are used by way of example.

Figure 3 may be properly understood with reference to the following key: 28 START 30 Place suspect battery on contact area positive side down.

32 Check whether battery is 1.5 volt silver oxide or 3 volt lithium cell.

34 Place the probe on the centre of the battery and switch on unit.

36 Is battery OK? 38 Fit new battery to watch.

40 Go to 'A'.

42 Check watch contacts for corrosion.

44 Is corrosion apparent? 46 Remove the corrosion and refit the battery.

48 Electronic fault.

50 Is there is a polarity change? 52 Pulse intervals will depend on movement type.

54 Are the hands moving? D6 Mechanical fault.

58 Watch OR 60 Is it moving? 62 Is there a second hand? 64 Place watch on the test area and switch on unit.

66 Go to 'B'.

68 STOP The diagnostic procedure set out in Figure 3, which uses standard flow chart symbols, can be best understood by following through three hypothetical examples: ExamPle 1 - Batterv Fault Oniv Beginning at START (28) the battery condition is first assessed.

The watch battery (none of the battery components are shown) is first removed from the watch and placed on the contact area 12, positive side down; the positive side of the battery is normally clearly marked and will typically be the larger end-face of the battery. It is then necessary to determine whether the battery is a 1.5 volt silver oxide or a 3 volt lithium type battery (32) these are the two main battery types now used for which this embodiment of the present invention is adapted.

Since the contact area 12 is recessed below the level of the upper surface 8, the upstanding rim 24 provides a retaining surface for the battery. This avoids the problem encountered with multimeter battery testers because the battery is effectively confined to a small area. The contact area 12 is large enough to accommodate all usual battery sizes; particularly small batteries may be pushed against the upstanding rim 24 to effectively locate them in the contact area 12.

The flying lead battery probe 18 is then placed on the centre of the upper face of the battery - which will be the negative side and the apparatus 2 is energised (34) using switch 6. Upon the apparatus 2 becoming energised the 'ON' LED 22 is illuminated.

The contact area 12 and the probe 18 form the two terminals of a voltmeter to determine the voltage of the battery, the voltage being signified by the voltage display 10. For the silver oxide and lithium type batteries the correct voltages are displayed by the illumination of LEDs 20e and 20j respectively (the green LEDs); if the voltage is below that required by more than 0.3 volts one or the other (red) LEDs 20a-20d or 20f-20i are illuminated depending on the battery type. Thus a quick and simple indication of the operative or inoperative condition of the battery is given. Once an indication is obtained the apparatus is switched 'OFF' by releasing the switch 6.

In this example the battery is in an inoperative condition (following the 'NO' path from 36), a new battery is therefore fitted (38) to the watch. At this stage the watch mag be returned to the customer, although for thoroughness the procedure may be continued with as shown by proceeding (40) to 'A'.

From 'A' the electronic condition of the watch is assessed. The watch is placed on the test area 16. Typically a watch will be generally disc shaped so that one of the major, substantially planar, surfaces of the watch will be placed on the test area 16 the apparatus is then switched 'ON' (64).

Assuming that there is a second-hand on the watch (62) it can be quickly determined whether or not this hand is moving (60); the non-second-hand case is dealt with below. In this case the second-hand will be moving since the only fault has been corrected, the watch is functioning properly (58) and the test procedure comes to a halt (68) with the fault readily identified and subsequently rectified.

Example 2 - Electrical F-ault Onlv The procedure outlined in Example 1 is followed until the operative/inoperative indication of the battery condition is given (36) in this case the battery is operative and the watch electrical contacts to the battery are checked for corrosion, dirt etc (42). If corrosion, or some other substantially non-conducting material, is apparent (42) the material is removed and a new battery fitted (46). In any event the procedure moves onto 'A' (40) as above.

Assuming, once again, that the watch has a second-hand that, in this Example, is not moving (60), attention now turns to the electronic driving means condition indicator 14 and the test area 16, which together detect and indicate polarity changes of the stepper motor within the watch as it drives the mechanical movement in normal operation. The method of operation and detection utilised by the indicator 14 and area 16 is more fully described hereinafter. As tlze test area 16 detects polarity changes within the watch the LEDs 26a and 26c of the indicator 14 are illuminated alternately, there is also a two-tone audio-signal that accompanies the alternate illumination to put the electronic condition of the watch beyond doubt.The LED 26b is illuminated at all times whilst the apparatus 2 is 'ON' to give a preliminary indication that the indicator 14 is operational.

In this Example there will be no polarity change detected (50); hence it can be concluded that the fault is electronic in nature (48) and the procedure halted (68). Once again the apparatus 2 enables the fault to be readily identified, the watch may now be taken in for repair or a new watch sold.

Example 3 - Mechanical Fault Onlv The procedure outlined in Examples 1 and 2 is followed, again assuming the presence of a second-hand. In this case there is a polarity change (50) but the hands of the watch, and especially the second hand since this is the most noticeable, are not moving (54). Thus, the battery is in an operative condition (36) and the electronic driving means is in an operative condition (50) which leaves only a mechanical fault outstanding (56). The testing procedure may then be halted (68) and the watch taken for repair or a new watch sold. Once again, the apparatus 2 enables the fault to be readily identified.

If, in any of the above Examples, the watch does not have a second-hand the duration between stepper motor polarity changes may vary significantly from watches with a second-hand (52).

Depending on the actual movement type the duration between stepper motor polarity changes may be at intervals of e.g i, 5, 10, 15, 20 or up to 30 seconds. Determining whether or not the hands of the watch are moving, (54) may also not be immediately apparent for a watch without a second-hand.

The apparatus 2 may be used to check that a watch is functioning properly even if a fault is not suspected, or if a recently repaired watch is to be re-checked. In this case the procedures outlined in Examples 1 to 3 are followed and the watch will be found to be in a properly operative condition (58) with respect to its battery, electronics and mechanical movement components.

The electronic circuitry used in this embodiment will now be described in more detail with reference to Figures 4-6.

Figure 4 shows a battery tester circuit diagram. The circuit is based around a LED barograph display-driver integrated circuit (IC) 70 which, in this case, is an LM 3914-N linear device.

The contact area 12 has a positive input 72, the flying lead probe 18 has a negative input 74 connected across a load resistor 76 (in this case being a 1,000 Ohm resistor) to ensure that an accurate voltage display is given since this resistor reasonably reflects the normal load encountered by the battery in use.

The analogue comparitors within the display-driver IC 70 are referenced to a 1.2 volt source within the IC and the output of these comparitors drives internal transistors, lighting the appropriate LEDs 20a-20j and displaying the voltage to the user.

The 'ON' LED 22 is also shown between the power-rails in series with one of the circuit resistors 78.

There are many types of LED bargraph display-driver ICs available (some can drive more LEDs than others and may not be linear devices), and production is not limited to the use of only one type of driver, if an IC is actually used at all in the design.

Referring now to Figures 5 and 6 of the drawings that follow, there is shown an electronic driving means condition tester circuit diagram.

In Figure 5 it can be seen that the circuit is based around a first IC 80 and a second IC 82, the first IC 80 is a 4011 quad 2-input NAND and gate, and the second IC 82 is a 4093 quad 2-input NAND schmitt trigger device (both Complimentary Metal-Oxide Silicon, or CMOS, ICs).

The minute magnetic pulses, constituting electromagnetic field variations, emitted from the stepper motor of the watch under test must firstly be detected and the amplified before being processed by the remaining circuitry.

The magnetic pulses that the watch stepper motor emits from its field coil comprise two states that are as follows: N-S S-N N-S S-N N-S....

or, depending on the physical position of the watch on the test area 16: E-W W-E E-W W-E E-W....

These alternating magnetic field changes are picked up by a ferrite-cored inductor 84 and then amplified by a discrete component 2-stage transistor amplifier 86. The signal (now greatly amplified) is fed into the first NAND gate of the first IC 80 which is configured as an amplifier.

The further amplified output from this first gate is then directly coupled to a potential divider 88 between two more NAND gates.

These in turn are biased positive and negative by two equal value resistors 90, one to Vss and the other to Vdd. The negative going gate is preceded by the final NAND gate, configured as an invertor to balance the outputs.

The two outputs are then de-coupled by capacitors 92 and fed into the first two gates of the second IC 82. The de-coupling capacitors 92 also act a timing components for the Schmitt triggers (second IC 82). The outputs 94 from the Schmitt trigger gates are cross-coupled so that they reset one another and to provide feed back for the two preceding NAND gates of the first IC 80. The outputs also directly drive two LEDs 26a, 26c via a current limiting resistor 96 to indicate the stepper motor polarity to the user.

The final two gates of the Schmitt trigger are also fed from these outputs and are configured as oscillators running at separate frequencies. These drive a piezo-sounder 98 and provide the two audio-tones that coincide with the illumination of the LEDs 26a, 26c.

It is to be noted that the apparatus 2 is protected against incorrect battery connection by a series rectifier diode 100, the supply is also de-coupled.

Circuit resistors 102 and capacitors 104 are also shown in Figure D.

The circuit described above is shown in its logic-format in Figure 6 in which like numerals reference like parts.

It will be noted that other ICs may be used in place of those mentioned above, or discrete components may be substituted. For all of the ICs and discrete components reference should be made to the manufacturer's.

It will also be noted that the discrete components of the above circuits, i.e. resistors , capacitors, etc used in this particular circuit design are not critical and many different types and values of components may be used to provide the same or similar levels of accuracy and/or performance and/or function.

Many variations can be made to the described preferred embodiment within the scope of the present invention as will be appreciated by those skilled in the art. For the avoidance of doubt it is to be noted that other LED configurations and colours may be used and that the testing procedure described above is not to be taken as limiting the scope of the present invention with regard to the ordering of the steps in the procedure and the essential/inessential steps.

The upper surface 8 of the apparatus 2 will usually include symbols to guide the user, such as writing indicating the various purposes and methods of use of aspects of the apparatus and common electrical symbols. The square identifying the test area 16 is one such symbol. These symbols will normally be screen printed on to the upper surface 8.

Thus, the present invention provides a testing apparatus that is easy to use, readily portable (in fact pocket sized), accurate and which allows rapid fault determination to be carried out.

Claims (4)

1. A testing apparatus for timing devices that include electronically driven mechanical movements; the apparatus comprising a battery tester for assessing the operative or inoperative condition of a battery; and an electronic driver tester that detects the electromagnetic field variations produced by the electronic movement driving components of the timing device.

2. Apparatus according to Claim l and characterized by the feature that the apparatus is pocket-sized.

3. Apparatus according to Claim 1 or Claim 2 and characterized by the feature that the apparatus includes its own power source.

4. Apparatus according to any of the preceding Claims and in the form of a watch-testing apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.