# US 8,233,301 B1 · Impedance dropping dc power supply having an impedance controlled converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,233,301 B1 - Document ID: US8233301B1 - Status: Granted - Kind: B1 - Application number: 12/317,354 - Filed: 2008-12-20 - Granted: 2012-07-31 - Earliest claimed: 2008-12-20 - Assignees: Sensorlink Corporation - Inventors: Zhijiang Guo - Web page: https://patentgrep.com/patent/US8233301B1 ## CPC - H02M 7/217: using semiconductor devices only - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract An impedance dropping dc power supply having an impedance controlled converter whose impedance adaptively changes as a function of the power supply's load impedance, to maintain the ac voltage across the primary winding of its power transformer below a predetermined maximum level, and to minimize the waste heat generated by the power supply that would otherwise have to be dissipated. ## Claims ### Claim 1 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises an ac switch, a dc switch, a power transformer, a diode, a controller, a rectifier, and a driver; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; wherein said converter is operable to decrease said average converter input impedance as said load impedance increases, and is operable to increase said average converter input impedance as said load impedance decreases; wherein said converter is operable to control said primary winding ac input voltage as a function of said load impedance, is operable to decrease said primary winding ac input voltage as said load impedance increases, and is operable to increase said primary winding ac input voltage as said load impedance decreases; wherein said controller comprises a Schmidt trigger and at least one controller capacitor; wherein a discharge rate of said at least one controller capacitor is at least partially a function of said load impedance; wherein said Schmidt trigger circuit is operable to generate controller control signals as a function of said load impedance; wherein said driver is operable to generate driver control signals as a function of said controller control signals; wherein said power transformer is operable to convert said primary winding ac input voltage into a secondary winding ac output current; wherein said rectifier is operable to convert at least some of said secondary winding ac output current into a rectifier dc output current; wherein said ac switch is operable to selectively permit and prevent a receipt by said rectifier of at least some of said secondary winding ac output current; wherein said ac switch is operable to periodically open and close as a function of said driver control signals; wherein said dc switch is operable to selectively permit and prevent a receipt by said controller of at least some of said rectifier dc output current; wherein said dc switch is operable to periodically open and close as a function of said controller control signals; wherein said at least one controller capacitor is operable to continue to supply electrical energy to said load, to said ac switch, to said dc switch, to said Schmidt trigger and to said driver for a period of time while said ac switch is operable to selectively prevent a receipt by said rectifier of at least some of said secondary winding ac output current and while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current; and wherein said diode is operable to block at least some of a flow of electrical current from said controller to said dc switch while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 2 (depends on 1) The power supply of claim 1, wherein said predetermined maximum voltage is about 600 V ac. ### Claim 3 (depends on 1) The power supply of claim 1, wherein said predetermined maximum voltage is about 1 kV ac. ### Claim 4 (depends on 1) The power supply of claim 1, wherein said predetermined maximum voltage is about 2 kV ac. ### Claim 5 (depends on 1) The power supply of claim 1, wherein said primary winding ac input voltage is less than about 1/10th of said high ac input voltage. ### Claim 6 (depends on 1) The power supply of claim 1, wherein said primary winding ac input voltage falls in a range of from about ½ to about 1/10th of said high ac input voltage. ### Claim 7 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises a controller, a dc switch, a rectifier, an ac switch, and power transformer; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; wherein said controller is operable to generate controller control signals as a function of said load impedance; wherein said power transformer is operable to convert said primary winding ac input voltage into a secondary winding ac output current; wherein said rectifier is operable to convert at least some of said secondary winding ac output current into a rectifier dc output current; wherein said ac switch is operable to selectively permit and prevent a receipt by said rectifier of at least some of said secondary winding ac output current; wherein said ac switch is operable to periodically open and close as a function of said controller control signals; and wherein said dc switch is operable to selectively permit and prevent a receipt by said controller of at least some of said rectifier dc output current; wherein said dc switch is operable to periodically open and close as a function of said controller control signals. ### Claim 8 (depends on 7) The power supply of claim 7, wherein said converter further comprises a diode; and wherein said diode is operable to block at least some of a flow of electrical current from said controller to said dc switch while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 9 (depends on 7) The power supply of claim 7, wherein said predetermined maximum voltage is about 600 V ac. ### Claim 10 (depends on 7) The power supply of claim 7, wherein said predetermined maximum voltage is about 1 kV ac. ### Claim 11 (depends on 7) The power supply of claim 7, wherein said predetermined maximum voltage is about 2 kV ac. ### Claim 12 (depends on 7) The power supply of claim 7, wherein said primary winding ac input voltage is less than about 1/10th of said high ac input voltage. ### Claim 13 (depends on 7) The power supply of claim 7, wherein said primary winding ac input voltage falls in a range of from about ½ to about 1/10th of said high ac input voltage. ### Claim 14 (depends on 7) The power supply of claim 7, wherein said controller comprises at least one controller capacitor; wherein a discharge rate of said at least one controller capacitor is at least partially a function of said load impedance; and wherein said at least one controller capacitor is operable to continue to supply electrical energy to said load for a period of time while said ac switch is operable to selectively prevent a receipt by said rectifier of at least some of said secondary winding ac output current and while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 15 (depends on 14) The power supply of claim 14, wherein said at least one controller capacitor is also operable to continue to supply electrical energy to said ac switch and to said dc switch for a period of time while said ac switch is operable to selectively prevent a receipt by said rectifier of at least some of said secondary winding ac output current and while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 16 (depends on 14) The power supply of claim 14, wherein said controller comprises a Schmidt trigger circuit; wherein said Schmidt trigger circuit is operable to generate said controller control signals as a function of said load impedance. ### Claim 17 (depends on 16) The power supply of claim 16, wherein said at least one controller capacitor is also operable to continue to supply electrical energy to said Schmidt trigger circuit for a period of time while said ac switch is operable to selectively prevent a receipt by said rectifier of at least some of said secondary winding ac output current and while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 18 (depends on 14) The power supply of claim 14, wherein said converter comprises a driver; wherein said driver is operable to generate driver control signals as a function of said controller control signals; and wherein said ac switch is operable to periodically open and close as a function of said driver control signals. ### Claim 19 (depends on 18) The power supply of claim 18, wherein said at least one controller capacitor is also operable to continue to supply electrical energy to said driver for a period of time while said ac switch is operable to selectively prevent a receipt by said rectifier of at least some of said secondary winding ac output current and while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 20 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises a power transformer; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; and wherein said converter is operable to decrease said average converter input impedance as said load impedance increases, and is operable to increase said average converter input impedance as said load impedance decreases. ### Claim 21 (depends on 20) The power supply of claim 20, wherein said converter is operable to decrease said primary winding ac input voltage as said load impedance increases, and is operable to increase said primary winding ac input voltage as said load impedance decreases. ### Claim 22 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises a power transformer; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; wherein said converter comprises a controller, a dc switch, and a rectifier that is operable to convert a rectifier ac input current into a rectifier dc output current; and wherein said dc switch is operable to selectively permit and prevent a receipt by said controller of at least some of said rectifier dc output current; wherein said controller is operable to generate controller control signals as a function of said load impedance; and wherein said dc switch is operable to periodically open and close as a function of said controller control signals. ### Claim 23 (depends on 22) The power supply of claim 22, wherein dc switch is connected in parallel with said controller; wherein said dc switch is open said dc switch is operable to permit a receipt by said controller of at least some of said rectifier dc output current; and wherein when said dc switch is closed said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 24 (depends on 23) The power supply of claim 23, wherein said converter further comprises a diode; and wherein said diode is operable to block at least some of a flow of electrical current from said controller to said dc switch while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 25 (depends on 22) The power supply of claim 22, wherein said controller comprises at least one controller capacitor; wherein a discharge rate of said at least one controller capacitor is at least partially a function of said load impedance; and wherein said at least one controller capacitor is operable to continue to supply electrical energy to said load for a period of time while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 26 (depends on 25) The power supply of claim 25, wherein said at least one controller capacitor is also operable to continue to supply electrical energy to said dc switch for a period of time while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 27 (depends on 25) The power supply of claim 25, wherein said controller comprises a Schmidt trigger circuit; wherein said Schmidt trigger circuit is operable to generate said controller control signals as a function of said load impedance. ### Claim 28 (depends on 27) The power supply of claim 27, wherein said at least one controller capacitor is also operable to continue to supply electrical energy to said Schmidt trigger circuit for a period of time while said dc switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 29 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises a power transformer; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; wherein said converter comprises a controller, an ac switch, and a rectifier; wherein said power transformer is operable to convert said primary winding ac input voltage into a secondary winding ac output current; wherein said rectifier is operable to convert at least some of said secondary winding ac output current into a rectifier dc output current; wherein said ac switch is operable to selectively permit a receipt by said power transformer of at least some of said primary winding ac input current to, in turn, selectively permit a receipt by said controller of at least some of said rectifier dc output current; wherein said ac switch is operable to selectively prevent a receipt by said power transformer of at least some of said primary winding ac input voltage to, in turn, selectively prevent a receipt by said controller of at least some of said rectifier dc output current; and wherein said controller is operable to generate controller control signals as a function of said load impedance; and wherein said ac switch is operable to periodically open and close as a function of said controller control signals. ### Claim 30 (depends on 29) The power supply of claim 29, wherein said ac switch is connected in parallel with said primary winding of said power transformer; wherein when said ac switch is open said ac switch is operable to permit a receipt by said primary winding of at least some of said primary winding ac input voltage to, in turn, permit a receipt by said controller of at least some of said rectifier dc output current; and wherein when said ac switch is closed said ac switch is operable to prevent a receipt by said primary winding of at least some of said primary winding ac input voltage to, in turn, prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 31 (depends on 29) The power supply of claim 29, wherein said controller comprises at least one controller capacitor; wherein a discharge rate of said at least one controller capacitor is at least partially a function of said load impedance; and wherein said at least one controller capacitor is operable to continue to supply electrical energy to said load for a period of time while said ac switch is operable to prevent a receipt by said primary winding of at least some of said primary winding ac input voltage to, in turn, prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 32 (depends on 31) The power supply of claim 31, wherein said at least one controller capacitor is operable to continue to supply electrical energy to said ac switch for a period of time while said ac switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 33 (depends on 31) The power supply of claim 31, wherein said controller comprises a Schmidt trigger circuit; and wherein said Schmidt trigger circuit is operable to generate said controller control signals as a function of said load impedance. ### Claim 34 (depends on 33) The power supply of claim 33, wherein said at least one controller capacitor is operable to continue to supply electrical energy to said Schmidt trigger circuit for a period of time while said ac switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 35 (depends on 31) The power supply of claim 31, wherein said converter comprises a driver; wherein said driver is operable to generate driver control signals as a function of said controller control signals; and wherein said ac switch is operable to periodically open and close as a function of said driver control signals. ### Claim 36 (depends on 35) The power supply of claim 35, wherein said at least one controller capacitor is operable to continue to supply electrical energy to said driver for a period of time while said ac switch is operable to prevent a receipt by said controller of at least some of said rectifier dc output current. ### Claim 37 An impedance dropping power supply that is operable to convert a high ac input voltage from an ac source into a dc output voltage for a load having a load impedance; wherein said power supply comprises an impedance controlled converter having an average converter input impedance; wherein said converter comprises a power transformer; wherein said power transformer comprises a primary winding that is operable to receive a primary winding ac input voltage from said ac source; wherein said converter is operable to control said average converter input impedance as a function of said load impedance to keep said primary winding ac input voltage at a voltage which is less than a predetermined maximum voltage; and wherein said power supply further comprises a temperature controlled fault control device that is operable to prevent a receipt by said converter of at least some of said ac input voltage when a predetermined temperature limit is reached by said fault control device. ### Claim 38 (depends on 37) The power supply of claim 37, wherein said fault control device is normally open when not triggered and is connected in parallel with said primary winding of said power transformer. ### Claim 39 (depends on 37) The power supply of claim 37, wherein said fault control device is normally closed when not triggered and is connected in series with said primary winding of said power transformer.