The invention relates to a portable mini AC generator/DC accumulator for a mini power capacity as used e.g. for e wrist, a pocket or s necklace watch, a pacemaker or a battery powered hearing-aid, in which, under the influence of the individual movement of the bearer, a mass inertia or a rotor, set into motion with respect, to a stator not moving simultaneously therewith, and under the application of the pricipal of generating magnetic induction ^' currents and via a rectifier known per se, transferring a mini AC into a mini DC, servicing the purpose of supplying directly or temporarily accumula¬ ting respectively a mini current. There is a growing need for stopping the replacement of batteries in a battery powered mini equipment, such as for a watch or a pacemaker. At the most inconvenient moments a battery is exhausted and it is even sooner replaced than is strictly necessary just to avoid the risk of being empty e.g. for a pacemaker.

It is the purpose of the invention while using means known per se, to provide for for the generation and accumulation respectively of a mini power capaci¬ ty, no longer depending upon repiaceble mini battery cells such as from Hg batteries, Li batteries or Ni batteries.

According to the invention this is achieved in that a mini AC generator/DC accumulator contains a mutually cooperating selective magnetic system of a rotor and a stator, provided with a permanent magnet having at least 4 poles.

Extensive researches which were carried out by the Technological University of Eindhoven, Electrotechnics Department, Section of Electromechanics and Power electronics, have shown the above requirements for a mini genera¬ tor/accumulator to be used for a quartz generator watch. According to the invention there is further a need to connect the rectifier to a discharge protection for the accumulator in order to prevent an inadmissible discharge, caused e.g. if the watch is not used for a longer duration, comparable with a lack of movement impulses.

In a preferred embodiment of the invention a lithiumcell can be applied, which by its characteristic prevents a discharge of the accumulator.

The main problem is to generate a sufficiently powerfull and high grade magnetic field and thus the required high voltage remaining within the res- tricted available space. Supreme material for permanent magnets is extremely

expensive. For mini-use however material costs are less decisive for the ultimate price, so that for the mini generator/accumulator of the invention succesfull use can be made of a permanent magnet of the samarium-cobalt type pereformed in its isotropic or anisotropic version. Where samarium-cobalt can be mixed with resins (plastic bonded material), even a disadvantage of less magnetic field strength can be compensated by the greater freedom of design engineering. This also makes it possible to apply a permanent mag¬ net with radial or axial magnetisation for the rotor/statαr.

Calculations and research show that a very effective embodiment of the generator/ accumulator is achieved if the abovementioπed permanent magnet is circumferentially provided with an iron yoke having claw poles. Under such circumstances there are no restrictions for the magnet material and the best available quality of samarium-cobalt can be chosen. According to the invention a very favourable embodiment of a permanent magnet is effec- ted by an ellipsoide, being provided with an iron yoke that a cylindrical assembly is obtained. By this choice it can be expected that the magnetic saturation, which otherwise would be caused at critical points, does not occur.

Since the available space for a battery in existing watches becomes now available for the generator/accumulator of the invention, a loose unit appears to be most effective. Specifically for a quartz watch the sizes of the unit must measure between a thickness of at least 1.5 mm and at most 4 mm, whereas the diameter will be between 5mm and 11.5 mm at the most.

The invention will be explained by means of the drawing of a quartz watch with its parts.

Fig. 1 shows the schematic drawing αf a selfloading quartz generator watch.

Fig. 2 shows perspectively a similar watch in which the invention is embodied.

Fig. 3 is a modified version according to Fig. 3 of a quartz generator watch.

Fig. 4-9 each show various embodiments of the construction of the generator/ accumulator in a top view and in a vertical cross section respectively;

Fig. 10 is a cross se tion of a permanent magnet.

In Fig. 1, the principle is shown in which a quartz generator watch 1 is powered by an accumulator 2. This mini accumulator is charged by a mini

DC generator 3 which converts kinetic energy into electric energy and by meihs of a rectifierblock 4, a voltage regulates 5 and a discharge protection

6 a mini DC is given to the accumulator 2. The watch 1 is, by resorption of kinetic energy provided by its bearer powered by the mini generator/accu¬ mulator, no battery replacement being required and thereby enjoying the advantages of the invention.

In Fig. 2 and 3 various parts of a quartz generator watch according to the scheme of Fig. 1 can be found back. The usual parts of the analog quartz watch consist of the battery 7, the oscillating circuit with quarz crystal 8, the coil 9 of the step by step motor 10 with its rotor. Further the watch is provided with a rotor 11 and a stator 12 and on the rotor 11 there are mounted a number of permanent magnets 13, which magnets also provide for the mass inertia causing the rotor 1 1 to be brought out of balance. The way of generating energy shall not be discussed hereinafter since this is supposed to be known.

While in Fig. 2 the rotor 1 1 is provided with permanent magnets 13, a rotor can also in it self be selectively become magnetised and the stator instead of containing a single coil, can consists of a number of self inductions or otherwise be made of a self inductive element. For the application of the invention it makes no difference if the rotor is selectively magnetic and the stator is selectively inductive or reversely, it is only necessary to take the generated current away to the accumulator 7 via the rectifier ccircuit, see Fig. 1. To generate a mini power, caused by the bearer's kinetic energy, in stead of a rotating movement also an alternating movement can be used, in the plane of the rotor but also perpendicular thereto.

Fig. 3 shows a perpective view of another quatrs generator watch, the shape of the generator rotor 14 being different whereas the accumulator 15 and the combined rectifier circuit/voltage regulator/discharge protection 16 are shown as a single unit. From the difference in design between the genera¬ tor 1 1 and 14 some freedom in design is apparent, this being the result of the application of permanent magnets of the samarium-cobalt type in its isotropic or anisotropic version. It appears that this material is highly suitable for the mini power aimed at, despite its relatively high price, in combination with the advantages already discussed before.

In Figs. 4-9 there are shown some constructional embodiments of the mini generator making it possible to provide for a loose unit having minimum and optimal dimensions respectively.

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In various design embodiments a stator 17 with an induction coil 18 and a permanent magnet 19 of samarium-cobalt have been applied, together with a rotor 20 which is turnable around a fixed shaft 21. The embodiments shown in the Figs, enable to give the complete loose unit for use in a quartz watch a minimum thickness of 1,5 mm with a diameter of 5mm and having a thickness of at most 4 mm with a diameter of 11 ,5 mm.

This makes it possible to build the individual unit in existing battery powered watches.

The already mentioned researches and calculations show how optimal results are obtained while using permanent magnets with at least 4 poles, whereby, depending on the constructional choice, use can be made of radial or axial magnetisation.

It also appeared that preference may be given to a permanent magnet, provi¬ ded with at least 4 poles, circumferentially provided with an iron yoke having claw poles.

Fig. 10 shows a possible embodiment in a cross section of a permanent magnet in the shape of an ellipsoide, having such an iron yoke, that magnetic satura¬ tion is just being prevented. This can e.g. be done by making the iron thicker at the critical points. In Fig. 10 the permanent magnet 22 is surrounded fay the iron yoke 23 which provides for a cylindrical assembly.

It appears to be very well possible to produce the unit referred to for an attractive price which is lower than the price of a replaced battery. Surely for use with a pacemaker the advantages with the generating mini power are more remarkable and also while applying this for hearing-aids, etc., total independency exists with respect to replacement batteries.

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