1. A system for controlling an electronic component, having a control terminal for receiving a stepwise control signal and at least one other terminal adapted for reaching a given voltage level by effect of the application of said control signal, said system comprising a damping resistive element interposed between said control terminal and said at least one other terminal, said damping resistive element structured as a resistive element exhibiting a current saturated behavior as the voltage applied across its terminals increases towards said given voltage level.
2. The system according to claim 1, wherein said damping resistive element is a resistive element exhibiting a current saturated behavior as the voltage applied across its terminals increases towards said given voltage level in the order on hundreds of Volts.
3. The system of claim 1 wherein said electronic component is an IGBT, for which said control terminal and said at least one other terminal are the gate and the collector of said IGBT, respectively.
4. The system of claim 1, wherein said damping resistive element is an element showing:
a resistive behavior that is essentially linear in a first range of voltage values applied across its terminals, and a phenomenon of current saturation with an increasing resistivity value toward high values when the voltage applied across the terminals of the element increases over said first range of values.
5. The system of claim 4, wherein said range of values extends up to the vicinity of 50 V.
6. The system of claim 1, wherein said damping resistive element comprises:
at least one semiconductor layer with a first type of conductivity, and a buried region with a second type of conductivity, opposite to said first type of conductivity, defining the resistive element proper.
7. The system of claim 6, wherein said buried region is made by implantation and diffusion and preferably comprises a set of subregions which, upon implantation, are reciprocally distinct and made to be at least marginally connected one to the other by diffusion.
8. The system of claim 1, wherein the electronic component and the damping resistive element are mounted on a common conductive substrate;
said common conductive substrate comprising a connection between said resistive element and said at least one other terminal of said component.
9. The system of claim 8, comprising a bonding wire that makes the connection between said resistive element and said control terminal of said component.
10. The system of claim 1 wherein the electronic component is associated with an ignition circuit for spark-ignited engines.
11. The system of claim 10, wherein said at least one other terminal of said electronic component is included in a coil current power line in said ignition circuit.
12. The system of claim 11, wherein the electronic component is an IGBT connected with its collector-emitter line in series with the primary winding of said ignition coil.
13. A process for controlling an electronic component, having a control terminal for receiving a stepwise control signal and at least one other terminal adapted for reaching a given voltage level by effect of the application of said control signal, said process comprising the step of making a damping resistive element in the form of a resistive element exhibiting current saturated behavior as the voltage applied across its terminals increases towards said given voltage level;
and the step of interposing a damping resistive element between said control terminal and said at least one other terminal.
14. A control system for an electronic component having a control terminal for receiving a stepwise control signal and at least one other terminal adapted to reach a predetermined voltage level in response to the control signal, the control system comprising:
a damping resistor coupled between the control terminal and the at least one other terminal, the damping resistor configured to reach current saturation at the predetermined voltage level.
16. The control system of claim 15, wherein the predetermined voltage level is at least 100 volts.
17. A control system for an electronic component comprising an insulated gate bipolar transistor having a gate terminal for receiving a stepwise control signal, and a collector terminal configured to reach a predetermined voltage level in response to the control signal, the system comprising:
a resistive element coupled between the gate terminal and the collector terminal of the insulated gate bipolar transistor, the resistive element formed to have at least one semiconductor layer of a first conductivity type and a buried region of a second conductivity type opposite to the first conductivity type, and including a plurality of implanted subregions separated by and electrically connected by surrounding diffusion, the resistive element structured to reach current saturation at the predetermined voltage level.
18. An electronic ignition system, comprising:
an electronic component having a first terminal for receiving a control signal, a second terminal for reaching a predetermined voltage in response to the control signal, and a third terminal coupled to an ignition coil; and
a resistive element coupled between the first and second terminals of the electronic component, the resistive element configured to reach current saturation at the predetermined voltage level.
19. An electronic ignition system, comprising:
an insulated gate bipolar transistor having a gate terminal configured to receive a stepwise control signal, a collector terminal configured to reach a predetermined voltage level in response to the control signal, and an emitter terminal coupled to an ignition coil, with the collector and emitter terminals connected in series with a primary winding in the ignition coil; and
a resistive element coupled between the gate and collector terminals of the insulated gate bipolar transistor, the resistive element formed to have at least one semiconductor layer of a first conductivity type and a buried region of a second conductivity type opposite to the first conductivity type, and including a plurality of implanted subregions formed in the buried regions and separated by and electrically connected by surrounding diffusion, the resistive element structured to reach current saturation at the predetermined voltage level.
20. The system of claim 19, wherein the predetermined voltage level is at least 100 volts.
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 composite support comprising:
an ordered mesoporous carbon comprising mesopores having an average diameter of about 2 nanometers to about 8 nanometers; and
a silicon carbide dispersed in the ordered mesoporous carbon,
wherein the ordered mesoporous carbon is in the form of a framework including walls which define the mesopores, and
wherein the silicon carbide is in the form of a particle and is disposed on an inner surface of the walls of the framework of the ordered mesoporous carbon.
2. The composite support of claim 1, wherein the silicon carbide is disposed on an inner surface and on an outer surface of the walls of the framework of the ordered mesoporous carbon.
3. The composite support of claim 1, wherein the silicon carbide is bound to the ordered mesoporous carbon.
4. The composite support of claim 1, wherein the silicon carbide has a shape of least one selected from a spherical, platelet, amorphous, and an acicular shape.
5. The composite support of claim 1, wherein the ordered mesoporous carbon and the silicon carbide are in a weight ratio of about 1:99 to about 30:70.
6. The composite support of claim 1, wherein the composite support has a specific surface area of about 300 square meters per gram to about 600 square meters per gram.
7. A method of preparing a composite support, the method comprising:
contacting an ordered mesoporous silica template and a carbonaceous precursor-containing mixture to prepare a first mixture;
thermally treating the first mixture at a temperature of about 1300\xb0 C. to about 1500\xb0 C. to form a pre-composite comprising an ordered mesoporous carbon comprising mesopores having an average diameter of about 2 nanometers to about 8 nanometers, a silicon carbide dispersed in the ordered mesoporous carbon, and the ordered mesoporous silica template; and
removing the ordered mesoporous silica template from the pre-composite to prepare the composite support, wherein the composite support comprises the ordered mesoporous carbon comprising mesopores having an average diameter of about 2 nanometers to about 8 nanometers and the silicon carbide dispersed in the ordered mesoporous carbon,
wherein the ordered mesoporous carbon is in the form of a framework including walls which define the mesopores,
wherein the silicon carbide is in the form of a particle and is disposed on an inner surface of the walls of the framework of the ordered mesoporous carbon, and
wherein the silicon carbide in the pre-composite is derived from the ordered mesoporous silica template and the carbonaceous precursor of the first mixture.
8. The method of claim 7, wherein the ordered mesoporous silica template comprises at least one selected from MCM-48, SBA-1, SBA-15, KIT-1, and MSU-1.
9. The method of claim 7, wherein a carbonaceous precursor of the carbonaceous precursor-containing mixture comprises at least one selected from glucose, sucrose, fructose, benzene, naphthalene, anthracene, phenanthrene, pyrene, phenol-formaldehyde (PF) resin, urea-formaldehyde (UF) resin, quinoxaline, propylenediamine, 4,4\u2032-dipyridyl, phenanthroline, p-toluenesulfonic acid, and furfuryl mercaptan.
10. The method of claim 7, wherein the carbonaceous precursor-containing mixture further comprises a metal precursor and a solvent.
11. The method of claim 7, wherein the thermally treating of the first mixture is performed at a temperature of about 1350\xb0 C. to about 1450\xb0 C.
12. The method of claim 7, wherein the thermal treating of the first mixture is performed in an inert atmosphere.
13. The method of claim 7, wherein the removing of the ordered mesoporous silica template from the pre-composite comprises contacting the pre-composite with an acid or an alkali solution capable of dissolving silica.
14. An electrode catalyst for a fuel cell, comprising: the composite support of claim 1; and a catalyst particle disposed on the composite support.
15. A membrane-electrode assembly for a fuel cell, the membrane-electrode assembly comprising:
a cathode;
an anode disposed opposite to the cathode; and
an electrolyte membrane disposed between the cathode and the anode,
wherein at least one of the cathode and the anode comprises the electrode catalyst of claim 14.
16. A fuel cell comprising the membrane-electrode assembly of claim 15.