1-4. (canceled)
5. A semiconductor light emitting device comprising:
a conductive support substrate;
a metal layer disposed on the conductive support substrate;
a light emitting part disposed above the metal layer, the light emitting part including an n-type current spreading layer, an n-type cladding layer, an active layer emitting light, a p-type cladding layer, and a p-type current spreading layer in this order;
a first thin ohmic electrode partially covering the p-type current spreading layer; and
a second thin ohmic electrode partially provided between the metal layer and the n-type current spreading layer, wherein
each layer of the light emitting part is made of an AlGaInP-based semiconductor layer,
the first thin ohmic electrode and the second thin ohmic electrode are disposed so as not to overlap when seen from an upper surface of the semiconductor light emitting device, and
the n-type current spreading layer is a semiconductor layer whose lattice constant matches a lattice constant of the n-type cladding layer.
6. The semiconductor light emitting device according to claim 5, wherein the lattice constant of the n-type current spreading layer matches the lattice constant of the n-type cladding layer at a lattice constant mismatching rate of 0.5% or less.
7. The semiconductor light emitting device according to claim 5, wherein the light emitting part has a total thickness of 10 \u03bcm or less.
8. The semiconductor light emitting device according to claim 6, wherein the light emitting part has a total thickness of 10 \u03bcm or less.
9. A method of producing a semiconductor light emitting device according to claim 5, comprising:
forming the light emitting part on a GaAs substrate;
forming the second thin ohmic electrode on the light emitting part;
forming the metal layer on the second thin ohmic electrode;
bonding the metal layer and the conductive support substrate such that a metal bonding layer is interposed between the metal layer and the conductive support substrate;
removing the GaAs substrate; and
forming the first thin ohmic electrode on a surface of the light emitting part from which the GaAs substrate is removed, wherein
the step of forming the light emitting part includes epitaxially growing the p-type current spreading layer, the p-type cladding layer, the active layer, the n-type cladding layer, and the n-type current spreading layer on the GaAs substrate in this order.
10. A method of producing a semiconductor light emitting device according to claim 6, comprising:
forming the light emitting part on a GaAs substrate;
forming the second thin ohmic electrode on the light emitting part;
forming the metal layer on the second thin ohmic electrode;
bonding the metal layer and the conductive support substrate such that a metal bonding layer is interposed between the metal layer and the conductive support substrate;
removing the GaAs substrate; and
forming the first thin ohmic electrode on a surface of the light emitting part from which the GaAs substrate is removed, wherein
the step of forming the light emitting part includes epitaxially growing the p-type current spreading layer, the p-type cladding layer, the active layer, the n-type cladding layer, and the n-type current spreading layer on the GaAs substrate in this order.
11. A method of producing a semiconductor light emitting device according to claim 7, comprising:
forming the light emitting part on a GaAs substrate;
forming the second thin ohmic electrode on the light emitting part;
forming the metal layer on the second thin ohmic electrode;
bonding the metal layer and the conductive support substrate such that a metal bonding layer is interposed between the metal layer and the conductive support substrate;
removing the GaAs substrate; and
forming the first thin ohmic electrode on a surface of the light emitting part from which the GaAs substrate is removed, wherein
the step of forming the light emitting part includes epitaxially growing the p-type current spreading layer, the p-type cladding layer, the active layer, the n-type cladding layer, and the n-type current spreading layer on the GaAs substrate in this order.
12. A method of producing a semiconductor light emitting device according to claim 8, comprising:
forming the light emitting part on a GaAs substrate;
forming the second thin ohmic electrode on the light emitting part;
forming the metal layer on the second thin ohmic electrode;
bonding the metal layer and the conductive support substrate such that a metal bonding layer is interposed between the metal layer and the conductive support substrate;
removing the GaAs substrate; and
forming the first thin ohmic electrode on a surface of the light emitting part from which the GaAs substrate is removed, wherein
the step of forming the light emitting part includes epitaxially growing the p-type current spreading layer, the p-type cladding layer, the active layer, the n-type cladding layer, and the n-type current spreading layer on the GaAs substrate in this order.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A pump control apparatus, comprising:
a power circuit connectable to and controlling power to a pump;
a current sensing circuit for monitoring current flowing at the pump;
a controller connectable to and receiving at least one input from the current sensing circuit wherein the at least one input includes a rectified current waveform and is derived from sensed current data and does not depend on voltage data, and determining from the at least one input a baseline operating current and a plurality of operating conditions affecting an operation of the pump, wherein the baseline operating current is calculated from an area under the rectified current waveform; and
an alarm circuit connectable to and receiving at least one output from the controller, the alarm circuit providing a plurality of alarm indications corresponding to the plurality of operating conditions determined by the controller.
2. The apparatus according to claim 1, further comprising a level sensing circuit for sensing a liquid level and providing a further input to the controller.
3. The apparatus according to claim 1, wherein the current sensing circuit further comprises a current transformer being arranged so that current flowing through the current transformer is proportional to the current flowing at the pump.
4. The apparatus according to claim 3, wherein the current sensing circuit further comprises a rectifier circuit connectable to the current transformer and the controller for providing the rectified current waveform to the controller.
5. The apparatus according to claim 4, wherein the controller calculates the baseline current from the area under the rectified current waveform over four complete 5060 Hertz cycles.
6. The apparatus according to claim 1, the alarm circuit includes at least one of visual and audible alarm indications.
7. The apparatus according to claim 1, wherein the power circuit further comprises an electrical switch connectable to the controller, wherein the switch is regulated by the controller for controlling the power to the pump.
8. A pump control system, comprising:
a power supply connectable to and providing primary power to a pump; and
a pump controller, the controller comprising:
a power circuit for regulating a connection between the power supply and the pump;
a current sensing circuit for monitoring current flowing to the pump;
a central controller connectable to and receiving an input from the current sensing circuit wherein the input includes a rectified current waveform and is derived from sensed current data and does not depend on voltage data, and determining from the input a baseline operating current and a plurality of operating conditions affecting an operation of the pump, wherein the baseline operating current is calculated from an area under the rectified current waveform; and
an alarm circuit connectable to and receiving at least one output from the central controller and providing a plurality of alarm indications corresponding to the plurality of operating conditions determined by the central controller.
9. The system according to claim 8, further comprising a level sensing circuit for sensing a liquid level and providing a further input to the central controller.
10. The system according to claim 9, wherein the level sensing circuit includes an electrical sensor located at a predetermined level in a liquid collection area that establishes a complete electrical path in the level sensing circuit when the liquid level contacts the sensor.
11. The system according to claim 10, wherein the pump is located outside the liquid collection area.
12. The system according to claim 11, wherein the liquid collection area is a sump pit.
13. The system according to claim 8, further comprising a general computer system connectable to the pump controller.