Flash strobe power supply system and method
First Claim
1. A flash strobe power supply comprising:
- an input filter;
a control circuit coupled to the input filter;
a first and second transistor operatively coupled to the control circuit;
a first and second transformer, each transformer operatively coupled to at least one of the first and second transistors; and
at least two circuits configured to sense an energy state of each transformer, the circuits coupled to the programmable control circuit, the control circuit configured to operate each transistor in response to at least one of the circuits to allow a dead time between cessation of energy in each transformer and an associated transistor turn on via synchronization code in the control circuit, the synchronization code periodically delaying operation of one or the other of the first and second transistors to maintain a 180 degree phase difference in switching cycles of the first and second transistors.
1 Assignment
0 Petitions
Accused Products
Abstract
A reliable strobe power supply is disclosed that provides requisite light energy for emergency uses without causing EMI problems. A two phase dual flyback power converter operating in transitional mode is disclosed containing a microcontroller that maintains a 180 degree displacement between the two phases by enabling a small, variable dead time between the cessation of stored energy in the flyback transformers and turn-on of the associated power switching transistor for one or the other phases. The power supply is capable of detecting a fault (neoning) and automatically correcting the condition by incrementing the flash capacitor charge off-time delay. The power supply is also capable of tolerating defective (persistently neoning) strobe tubes that cause an inordinate delay in capacitor charging by turning them off.
-
Citations
27 Claims
-
1. A flash strobe power supply comprising:
-
an input filter;
a control circuit coupled to the input filter;
a first and second transistor operatively coupled to the control circuit;
a first and second transformer, each transformer operatively coupled to at least one of the first and second transistors; and
at least two circuits configured to sense an energy state of each transformer, the circuits coupled to the programmable control circuit, the control circuit configured to operate each transistor in response to at least one of the circuits to allow a dead time between cessation of energy in each transformer and an associated transistor turn on via synchronization code in the control circuit, the synchronization code periodically delaying operation of one or the other of the first and second transistors to maintain a 180 degree phase difference in switching cycles of the first and second transistors. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A method for operating at least two power converters in at least two phases with transitional conduction mode for a strobe power supply, the method comprising:
-
determining which of the power converters has a higher frequency; and
periodically introducing enough dead time to the higher frequency power converter to displace the phases of the at least two power converters by a predetermined amount to maintain a displacement in the at least two phases. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for detecting a neon condition in a strobe power supply, the method comprising:
-
after a predetermined time, measuring a flash storage capacitor voltage;
comparing the voltage to a reference voltage;
determining whether the voltage has increased due to charge current; and
identifying a neoning condition if the voltage failed to increase. - View Dependent Claims (15, 16, 17)
-
-
18. A system for diagnosing and correcting neoning in a strobe tube power supply, the system comprising:
-
a programmable control circuit configured to operate computer code, the computer code including;
an anti-neon off-time delay variable configured to store a value capable of being incremented by a predetermined delay time;
an output from the programmable control circuit configured to supply a charge current to one or more flyback converters within the strobe tube power supply, the programmable control circuit configured to turn off the charge current for the predetermined delay time;
one or more flash capacitors coupled to the flyback converters, the programmable control circuit configured to test one or more voltages of the one or more flash capacitors, the code within the programmable control circuit configured to determine whether any flash capacitor voltage has failed to increase, the failure indicative of a neon condition, the programmable control circuit configured to respond to the failure by an alteration in the predetermined delay time. - View Dependent Claims (19)
-
-
20. A method for detecting and effectively disconnecting defective strobe tubes in a flash strobe power supply system, the method comprising:
-
selecting a flash tube from a list of active flash tubes within the system;
testing the selected flash tube to determine a delay for the selected flash tube or to turn off the selected flash tube;
repeating the testing for each flash tube in the list of active flash tubes; and
removing turned off flash tubes from the list of active flash tubes, the list of active flash tubes stored in a programmable control circuit. - View Dependent Claims (21, 22)
-
-
23. A method for diagnosing defective strobe tubes in a flash strobe power supply system, the method comprising:
-
individually firing each strobe tube in the system;
identifying whether any strobe tube is causing an extraordinary delay;
turning off any identified strobe tubes; and
determining a delay time suitable for any unidentified strobe tubes. - View Dependent Claims (24)
-
-
25. A method for synchronizing phases of a dual power converter in a flash strobe power supply, the method comprising:
-
dividing a period of a first phase of the dual power converter and obtaining a predetermined fractional period of time;
waiting for the predetermined fractional period of time;
issuing a turn on command; and
AND-ing the turn on command with a turn on command for a second phase of the dual power converter. - View Dependent Claims (26, 27)
-
Specification