Abstract: A thermodynamic cycle apparatus is provided. The thermodynamic cycle apparatus includes: (i) a first reservoir containing a first storage medium; (ii) a second reservoir containing a second storage medium; (iii) a heat pump having a cold side thermally coupled to the first reservoir for cooling the first storage medium and a hot side thermally coupled to the second reservoir for heating the second storage medium; (iv) a first thermodynamic circuit of a first working fluid; (v) a second thermodynamic circuit of a second working fluid; (vi) an auxiliary heat input thermally connected to the first thermodynamic circuit so that auxiliary heat may contribute to the creation of the first pressurized vapor; and (vii) an auxiliary heat output thermally connected to the second thermodynamic circuit so that the second working fluid can lose heat to an auxiliary heat sink.

Abstract: A thermodynamic cycle apparatus is provided. The thermodynamic cycle apparatus includes: (i) a first reservoir containing a first storage medium; (ii) a second reservoir containing a second storage medium; (iii) a heat pump having a cold side thermally coupled to the first reservoir for cooling the first storage medium and a hot side thermally coupled to the second reservoir for heating the second storage medium; (iv) a first thermodynamic circuit of a first working fluid; (v) a second thermodynamic circuit of a second working fluid; (vi) an auxiliary heat input thermally connected to the first thermodynamic circuit so that auxiliary heat may contribute to the creation of the first pressurized vapor; and (vii) an auxiliary heat output thermally connected to the second thermodynamic circuit so that the second working fluid can lose heat to an auxiliary heat sink.

Abstract: An ORC heat engine including a working fluid circuit having an evaporator for heating and evaporating a working fluid, a condenser for cooling and condensing the working fluid, and a positive displacement expander-generator having an inlet in fluid communication with the evaporator and an outlet in fluid communication with the condenser. The ORC heat engine further includes a control system coupled to the positive displacement expander-generator having a switch and driving means, the switch being switchable between a first state and a second state, wherein in the first state the switch is coupled to the driving means, and the positive displacement expander-generator is drivable by the driving means, and in the second state the switch is not coupled to the driving means or the driving means is switched off, and the positive displacement expander-generator is not drivable by the driving means.

Abstract: A linear or rotary positive displacement expander (10) is fed by compressed gas or vapour from a reservoir (11) by means of a fast acting pulsed flow control valve (12) actuated by a PWM microprocessor (13) which receives input data from the expander (10) and the reservoir (11) to determine the correct operation of the valve (12). By injecting single or multiple controlled volume pulses of gas into the expander (10), the need for additional pressure regulation between the reservoir (11) and the expander (10) is eliminated, and the expander can operate efficiently within its built-in pressure ratio capability whereby the gas or vapour is expanded to be as close as possible to ambient pressure at the outlet of the expander.

Abstract: Apparatus for measuring displacement between two members. A scale is provided on one member and has an incremental pattern with at least one reference mark embedded in it. A read head is provided on the other member and comprises a periodic diffraction means for interacting with a light pattern modulated by the incremental pattern on the scale to produce interference fringes having movement relative to said readhead responsive to said displacement, first detecting means for detecting the movement of the interference fringes, imaging means for imaging the reference mark and second detecting means for detecting the image of the reference mark.

Abstract: Interferometry apparatus which comprises a measurement light beam (2a, 2b) and a reference light beam (2c, 2d) which interact with each other to cause a spatial fringe pattern (24). An optical device (12) is provided which interacts with the spatial fringe pattern (24), such that light is spatially separated into different directions (30, 32, 34, 36). The intensity modulation in two or more directions of the spatially separated light is phase shifted. The optical device may comprise, for example, a diffractive device, a refractive device or a diffractive optical element.

Abstract: A rotary ring for use in scale reading apparatus, comprises a flexible ring (10) which has scale markings (14) provided on a surface thereof. The rotary ring is mounted onto a machine part (22) by providing the machine part with a region of increased diameter (26) and stretching or shrinking the flexible rotary scale (10) over said region of increased diameter. The manufacturing tolerance of the rotary scale or differential e.g. thermal expansion is thus taken up by stretching or shrinking it into place. The region of increased diameter may comprise an annular protrusion or an O-ring, for example.

Abstract: A rotary ring system for use in scale reading apparatus comprises a rotary ring (12), provided with scale marks on its surface and at least one intermediate member (24). The at least one intermediate member (24) is fitted between the rotary ring (12) and the machine part (10) on which the rotary ring is to be mounted. Application of a force to the at least one intermediate member adjusts the effective radius of the rotary ring. The at least one intermediate member may be tangentially compliant.

Abstract: The invention provides a substrate treatment method and apparatus to produce a pattern on the substrate (10). Embodiments show a substrate (10) in the form of a rotary encoder ring (10) having a pattern of marks producable by means of a laser treatment device (122) controllable by a controller (100, 110) to produce the pattern in the correct manner whilst there is continuous relative displacement between the ring (10) and the laser treatment device (122).

Abstract: A method and apparatus is disclosed for producing precision marks (28) for a metrological scale in the form of a stainless steel ribbon (10). A laser (21) is used to produce ultra-short pulses, which have a fluence at the ribbon such that ablation takes place. The laser light can be scanned via scanner (25) and the pitch of the marks (28) can be controlled. The ablative technique causes little thermal input and improves the accuracy of the scale.