Patent ID: 6243604
Filing Date: 2001-06-05
Classification: A61N

Abstract:
Apparatus for charging defibrillator capacitors, comprising:a transformer having a primary winding with primary connection means for connection to a power supply, to draw current therefrom and a secondary winding with secondary connection means for connection to said defibrillator capacitors to supply charging power thereto, said pulse transformer having a magnetic field which rises and collapses while charging said defibrillator capacitors;field monitoring means for detecting the collapse of magnetic field of said transformer and for sending a trigger signal in response thereto;transformer control means coupled to said transformer primary winding to control current flow therethrough in response to a control signal;a downstream pulse generator having an output coupled to said transformer control means to provide the control signal therefor, said downstream pulse generator also having an input for receiving a driving signal and a reset port for receiving a reset signal to reset said downstream pulse generator, said downstream pulse generator producing an output signal pulse of pulse width determined in response to said driving signal and resettable in response to the reset signal received at said reset port;a comparator having two inputs and an output which is coupled to said downstream pulse generator reset port;a reference signal means coupled to one of said comparator inputs;primary signal means coupled to the other of said comparator inputs, and producing a primary sensor signal in response to current flow through the transformer primary winding;a multivibrator delivering a series of pulses, comprising said driving signal, to an output coupled to said downstream pulse generator input, said multivibrator further having a reset port for receiving a multivibrator reset signal so as to reset the series of pulses in response thereto;an upstream pulse generator having an output coupled to said multivibrator reset port, an input for receiving an upstream input signal and an upstream pulse generator reset port for receiving a reset signal to reset said upstream pulse generator, said upstream pulse generator producing the multivibrator reset signal, comprising a series of reset pulses, in response to said upstream input signal;said upstream pulse generator input coupled to said field monitoring means for receiving the trigger signal therefrom and for resetting the series of reset pulses in response thereto, thereby synchronizing the downstream pulse generator and hence said transformer control means to said collapse of magnetic field of said transformer.