# US 11,444,454 B2 · Rectifier-based surge protection circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,454 B2 - Document ID: US11444454B2 - Status: Granted - Kind: B2 - Application number: 15/932,454 - Filed: 2018-03-07 - Published: 2019-11-14 - Granted: 2022-09-13 - Earliest claimed: 2018-03-07 - Assignees: Rantec Power Systems, Inc. - Applicants: Rantec Power Systems, Inc. - Inventors: Steve Isakson - Web page: https://patentgrep.com/patent/US11444454B2 ## CPC - H02H 9/042: {comprising means to limit the absorbed power or indicate damaged over-voltage protection device} - B64D 45/02: Lightning protectors; Static dischargers - H02H 9/025: {Current limitation using field effect transistors} - H02H 9/04: responsive to excess voltage (lightning arrestors H01C7/12, H01C8/04, H01G9/18, H01T) - H02H 9/041: {using a short-circuiting device} - H02M 1/32: Means for protecting converters other than automatic disconnection - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - 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 A surge protection circuit comprises a bridge rectifier having two input terminals coupled to an input source of electricity that may experience highly positively or negatively biased over-voltage and/or over-current, and two output terminals respectively coupled to a voltage surge blocking stage via a first bus line and to a return bus; a current surge protection stage that is series coupled in the first bus line between the voltage blocking stage and a voltage surge detection stage that is disposed between the first bus line and the return bus; two output terminals respectively coupled to the first bus line and the return bus, after the current surge protection stage. Embodiments can protect circuits or apparatus, such as DC-DC converters, that are sensitive to highly positively or negatively biased voltage/current surges by inverting negative pulses associated with a surge and outputting the inverted or rectified over-voltage/over-current to other protection circuitry. During events such as lightning strikes, apparatus such as DC-DC converters are effectively transiently powered by the strike, from which negative bias has been removed and passed through blocking and surge protection stages. ## Claims ### Claim 1 A surge protection circuit comprising: a bridge rectifier having two input terminals coupled to an input source of DC electricity that is subject to experience negatively biased over-voltage and/or over-current, and two output terminals, a first output terminal of the two output terminals coupled to a voltage surge blocking stage via a first bus line and a second output terminal of the two output terminals coupled to a return bus; a current surge protection stage that is series coupled in the first bus line between the voltage surge blocking stage and a voltage surge detection stage that is coupled between the first bus line and the return bus; wherein the voltage surge blocking stage comprises a transistor having a drain terminal, a source terminal, a channel and a gate terminal, wherein the first bus line is coupled across the source terminal and the drain terminal through the channel of the transistor, and the gate terminal of the transistor is coupled to the voltage surge detection stage; a holdup capacitor coupled across the first bus line and the return bus, after the voltage surge detection stage; a bias converter coupled across the first bus line and the return bus, and comprising a positive bias output and a negative bias output, the positive bias output coupled to the voltage surge blocking stage, the positive bias output and the negative bias output coupled to the voltage surge detection stage; the first output terminal of the two output terminals coupled to the first bus line and the second output terminal of the two output terminals coupled to the return bus, after the bias converter. ### Claim 2 (depends on 1) The surge protection circuit of claim 1, the bridge rectifier operable to invert negative pulses of negatively biased voltage/current surge input during a lightning strike into over-voltage/over-current that is positively biased, said bridge rectifier operable to prevent reverse currents to any of the two input terminals during a positive surge or a negative surge. ### Claim 3 (depends on 1) The surge protection circuit of claim 1, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike. ### Claim 4 (depends on 1) The surge protection circuit of claim 1, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike upon an aircraft. ### Claim 5 (depends on 1) The surge protection circuit of claim 1, wherein any over-voltage at the voltage surge blocking stage causes a pinch-off state of the channel of the transistor thereby at least in part blocking any over-voltage from reaching a protected unit that is coupled to two output terminals of the surge protection circuit. ### Claim 6 A surge protected DC-DC power converter system comprising: a DC-DC converter; a bridge rectifier having two input terminals coupled to an input source of DC electricity that is normally DC voltage and DC current for the DC-DC converter that is subject to experience positively or negatively biased over-voltage and/or over-current under a surge condition, and two output terminals, a first output terminal of the two output terminals coupled to a voltage surge blocking stage via a first bus line and a second output terminal of the two output terminals coupled to a return bus; a current surge protection stage that is series coupled in the first bus line between the voltage surge blocking stage and a voltage surge detection stage that is coupled between the first bus line and the return bus; wherein the voltage surge blocking stage comprises a transistor having a drain terminal, a source terminal, a channel and a gate terminal, wherein the first bus line is coupled across the source terminal and the drain terminal through the channel of the transistor, and the gate terminal of the transistor is coupled to the voltage surge detection stage; a holdup capacitor coupled across the first bus line and the return bus, after the voltage surge detection stage; a bias converter coupled across the first bus line and the return bus, and comprising a positive bias output and a negative bias output, the positive bias output coupled to the voltage surge blocking stage, the positive bias output and the negative bias output coupled to the voltage surge detection stage; after the bias converter, the first output terminal of the two output terminals coupled to the first bus line and the second output terminal of the two output terminals coupled to the return bus and to inputs of the DC-DC converter. ### Claim 7 (depends on 6) The surge protected DC-DC power converter system of claim 6, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike. ### Claim 8 (depends on 6) The surge protected DC-DC power converter system of claim 6, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike upon an aircraft. ### Claim 9 A surge protection circuit comprising: a bridge rectifier having two input terminals coupled to an input source of DC electricity that is subject to experience negatively biased over-voltage and/or over-current, and two output terminals, a first output terminal of the two output terminals coupled to a voltage surge blocking stage via a first bus line and a second output terminal of the two output terminals coupled to a return bus; a current surge protection stage that is series coupled in the first bus line between the voltage surge blocking stage and a voltage surge detection stage that is coupled between the first bus line and the return bus; wherein the voltage surge blocking stage comprises a transistor having a drain terminal, a source terminal, a channel and a gate terminal, wherein the first bus line is coupled across the source terminal and the drain terminal through the channel of the transistor, and the gate terminal of the transistor is coupled to the voltage surge detection stage; the first output terminal of the two output terminals coupled to the first bus line and the second output terminal of the two output terminals coupled to the return bus, after the current surge protection stage. ### Claim 10 (depends on 9) The surge protection circuit of claim 9, the bridge rectifier operable to invert negative pulses of highly negatively biased voltage/current surge input during a lightning strike into over-voltage/over-current that is normally biased. ### Claim 11 (depends on 9) The surge protection circuit of claim 9, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike. ### Claim 12 (depends on 9) The surge protection circuit of claim 9, wherein the bridge rectifier has a maximum voltage rating and a maximum current rating that are greater than corresponding over-voltage and over-current values that are experienced at the input terminals during a lightning strike upon an aircraft. ### Claim 13 (depends on 9) The surge protection circuit of claim 9, coupled to a DC-DC converter to provide surge protection of the DC-DC converter from a highly positively or negatively biased over-voltage/over-current source such as a lightning strike.