1. Die roller for use in manufacturing, from plastic, Fresnel lens angular lens segments for a Fresnel lens solar collector, the die roller having a roller surface and a roller radius, the die roller comprising:
one or more segment dies on the roller surface; and
a plurality of curvilinear Fresnel facet dies formed in the roller surface, the Fresnel facet dies having a facet die collar with a facet die collar slope, the facet die collar slope being varied according to a die algorithm based on one or more facet factors.
2. The die roller recited in claim 1 wherein the Fresnel facet dies have a facet die peak and the facet die peak of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
3. The die roller recited in claim 1 wherein the Fresnel facet dies have a facet die base and the facet die base of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
4. The die roller recited in claim 1 wherein the roller surface has a surface base plating and the Fresnel facet dies are etched in the surface base plating.
5. The die roller recited in claim 4 wherein the surface base plating is further plated with a finish plating after the facet dies are etched in the surface base plating.
6. Die roller for use in manufacturing, from plastic, Fresnel lens angular lens sub-segments for a Fresnel lens solar collector, the die roller having a roller surface and a roller radius, the die roller comprising:
one or more segment dies on the roller surface; and
a plurality of curvilinear Fresnel facet dies formed in the roller surface, the Fresnel facet dies having a facet die collar with a facet die collar slope, the facet die collar slope being varied according to a die algorithm based on one or more facet factors.
7. The die roller recited in claim 6 wherein the Fresnel facet dies have a facet die peak and the facet die peak of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
8. The die roller recited in claim 6 wherein the Fresnel facet dies have a facet die base and the facet die base of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
9. The die roller recited in claim 6 wherein the roller surface has a surface base plating and the Fresnel facet dies are etched in the surface base plating.
10. The die roller recited in claim 9 with a finish plating after the facet dies are etched in the surface base plating.
11. Method for making a die roller for use in manufacturing, from plastic, Fresnel lens angular lens segments for a Fresnel lens solar collector, the die roller having a roller surface and a roller radius, the method comprising:
a) forming one or more segment dies on the roller surface;
b) forming a plurality of curvilinear Fresnel facet dies on the roller surface, the Fresnel facet dies having a facet die collar with a facet die collar slope, the facet die collar slope being varied according to a die algorithm based on one or more facet factors.
12. The method recited in claim 11 wherein the Fresnel facet dies have a facet die peak and the facet die peak of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
13. The method recited in claim 11 wherein the Fresnel facet dies have a facet die base and the facet die base of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
14. The method recited in claim 11 wherein the roller surface has a surface base plating and the Fresnel facet dies are etched in the surface base plating.
15. The method recited in claim 14 wherein the surface base plating is further plated with a finish plating after the facet dies are etched in the surface base plating.
16. Method for making a die roller for use in manufacturing, from plastic, Fresnel lens angular lens sub-segments for a Fresnel lens solar collector, the die roller having a roller surface and a roller radius, the method comprising:
a) forming one or more segment dies on the roller surface;
b) forming a plurality of curvilinear Fresnel facet dies on the roller surface, the Fresnel facet dies having a facet die collar with a facet die collar slope, the facet die collar slope being varied according to a die algorithm based on one or more facet factors.
17. The method recited in claim 16 wherein the Fresnel facet dies have a facet die peak and the facet die peak of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
18. The method recited in claim 16 wherein the Fresnel facet dies have a facet die base and the facet die base of one or more of the Fresnel facet dies is rounded according to the die algorithm based on one or more facet factors.
19. The method recited in claim 16 wherein the roller surface has a surface base plating and the Fresnel facet dies are etched in the surface base plating.
20. The die roller recited in claim 19 wherein the surface base plating is further plated with a finish plating after the facet dies are etched in the surface base plating.
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 semiconductor device comprising:
a semiconductor chip including a load current path that conducts a load current in response to an input signal activating a load current flow;
a current sensor arrangement that provides a measurement signal representing the load current; and
an evaluation circuit that is configured to compare the measurement signal with a first threshold and to signal an over-current when the measurement signal exceeds the first threshold after a delay time period that starts from the activation of the load current flow.
2. The semiconductor device of claim 1, wherein the evaluation circuit is configured to trigger an over-current switch-off of the load current flow when the measurement signal exceeds the first threshold after the delay time period.
3. The semiconductor device of claim 1, further comprising a control circuit that is configured to
activate and deactivate the load current flow in accordance with the input signal; and
limit the load current to a maximum current value.
4. The semiconductor device of claim 3, wherein the first threshold is lower than the maximum current value.
5. The semiconductor device of claim 3, wherein the control circuit is configured to blank the input signal in response to an over-current signal generated by the evaluation circuit so as to deactivate the load current flow.
6. The semiconductor device of claim 1, wherein the evaluation circuit is configured to maintain the over-current signal until a reset signal signals to reset the over-current signal.
7. The semiconductor device of claim 6, wherein the reset signal is generated by an external controller.
8. The semiconductor device of claim 6, wherein the input signal that activates the load current flow is used as the reset signal.
9. The semiconductor device of claim 1, wherein the evaluation circuit comprises a latch that is configured to store the occurrence of an exceedance of the first threshold by the load current and correspondingly to signal an over-current until the latch is reset in response to an appropriate reset signal.
10. The semiconductor device of claim 1, further comprising a power semiconductor switch conducting the load current.
11. A method for operating a semiconductor device that comprises a semiconductor chip including a load current path for conducting a load current, the method comprising:
activating the load current flow in response to an input signal;
measuring the load current so as to provide a measurement signal representing the load current;
comparing the measurement signal with a first threshold; and
signalling an over-current when the measurement signal exceeds the first threshold after a delay time period that starts from the activation of the load current flow.
12. The method of claim 11, further comprising triggering an over-current switch-off of the load current flow when the measurement signal exceeds the first threshold after the delay time period.
13. The method of claim 11, further comprising limiting the load current to a maximum current value, wherein the first threshold is lower than the maximum current value.
14. The method of claim 13, further comprising blanking the input signal in response to an over-current signal thus deactivating the load current flow.
15. The method of claim 11, further comprising receiving a reset signal; and
maintaining the over-current signal until a reset command is identified in the reset signal.
16. The method of claim 15, wherein the input signal activating the load current flow is used as the reset signal.