초록 ▼

A battery equalization circuit for equalizing charge between at least first and second series-connected batteries, where each battery has a positive end and a negative end, with the positive end of the second battery coupled to the negative end of the first battery at a common node, and using: a swi

A battery equalization circuit for equalizing charge between at least first and second series-connected batteries, where each battery has a positive end and a negative end, with the positive end of the second battery coupled to the negative end of the first battery at a common node, and using: a switching circuit connectable to the positive end of the first battery at a positive node and the negative end of the second battery at a negative node; a transformer having first and second magnetically coupled windings, each with a first end defining a polarity of the winding and a second opposing end; and a transformer reset circuit coupled from the windings of the transformer to the positive and negative nodes. The switching circuit acts to simultaneously couple the first and second windings in parallel with the first and second batteries, respectively, in the same polarity such that a charge is transferred between the first and second batteries as a function of a charge imbalance therebetween. The transformer reset circuit couples one of the first and second windings in parallel with one of the first and second batteries in an opposite polarity to direct reset current from the transformer to that battery to decrease the charge imbalance therebetween.

대표청구항 ▼

[ What is claimed is:] [1.]1. A battery equalization circuit for equalizing charge between at least first and second series connected batteries, each battery including a positive end and a negative end, with the positive end of the second battery being coupled to the negative end of the first batter

[ What is claimed is:] [1.]1. A battery equalization circuit for equalizing charge between at least first and second series connected batteries, each battery including a positive end and a negative end, with the positive end of the second battery being coupled to the negative end of the first battery at a common node, the battery equalization circuit comprising:a switching circuit connectable to (i) the positive end of the first battery at a positive node, and (ii) the negative end of the second battery at a negative node;a transformer having first and second magnetically coupled windings, each winding having a first end defining a polarity of the winding and a second opposing end; anda transformer reset circuit coupled from the windings of the transformer to the positive and negative nodes,the switching circuit being operable to simultaneously couple the first and second windings in parallel with the first and second batteries, respectively, in the same polarity such that a charge is transferred between the first and second batteries as a function of a charge imbalance therebetween, andthe transformer reset circuit being operable to couple one of the first and second windings in parallel with one of the first and second batteries in an opposite polarity to direct reset current from the transformer to that battery to decrease the charge imbalance therebetween. [11.]11. A method of equalizing charge between at least first and second series connected batteries, each battery including a positive end and a negative end, where the positive end of the second battery is coupled to the negative end of the first battery at a common node, the method comprising the acts of:simultaneously connecting first and second magnetically coupled windings of a transformer in parallel with the first and second batteries, respectively, in the same polarity such that one of the first and second batteries having greater charge drives a current into a corresponding one of the first and second windings;causing an induced current to flow out of the other of the first and second windings and into the other of the first and second batteries having a lesser charge such that charge between the first and second batteries tends to equalize;simultaneously disconnecting the first and second windings of the transformer from the first and second batteries; andproviding a current path for a reset current to flow through the corresponding one of the first and second windings and into the other of the first and second batteries having lesser charge such that charge between the first and second batteries tends to equalize.12. The method of claim 11, wherein the act of simultaneously disconnecting the first and second windings from the first and second batteries is carried out using the first and second switching transistors.13. The method of claim 11, wherein the act of simultaneously connecting the first and second windings in parallel with the first and second batteries is carried out using:a first switching transistor coupled at one end to the positive end of the first battery at a positive node; anda second switching transistor coupled at one end to the negative end of the second battery at a negative node;wherein each winding of the transformer includes a first end defining a polarity of the winding and a second opposing end such that: (i) the first end of the first winding is coupled to an opposing end of the first switching transistor, (ii) the first end of the second winding is coupled to an opposing end of the second switching transistor, and (iii) the second end of the first winding is coupled to the first end of the second winding.14. The method of claim 13, wherein the act of providing a current path for a reset current to flow through the corresponding one of the first and second windings is carried out using:a first diode having an anode coupled to the second end of the second winding and a cathode coupled to the positive node; anda second diode having an anode coupled from the negative node and a cathode coupled to the first end of the first winding.15. A battery equalization circuit for equalizing charge between at least first and second series connected batteries, each battery including a positive end and a negative end, where the negative end of the first battery is connectable to a negative node of the equalization circuit, the positive end of the first battery is coupled to the negative end of the second battery and connectable to a common node of the equalizer circuit, and the positive end of the second battery is connectable to a positive node of the equalizer circuit, the battery equalization circuit comprising:a transformer having first and second magnetically coupled windings, each winding having a first end defining a polarity of the winding and a second opposing end;a first capacitor;a transformer reset circuit coupled from the first winding of the transformer to the positive node; anda switching circuit operable during ON times to (i) simultaneously couple the first and second windings in parallel with the first and second batteries, respectively, in the same polarity; and (ii) couple the first capacitor in parallel with the first winding.16. The battery equalization circuit of claim 15, wherein, during the ON times, one of the first and second batteries having greater charge drives a current into a corresponding one of the first and second windings, and an induced current flows out of the other of the first and second windings and into the other of the first and second batteries having a lesser charge such that charge between the first and second batteries tends to equalize during the ON times.17. The battery equalization circuit of claim 15, wherein the second battery drives a current into the second winding and an induced current flows out of the first winding and charges at least one of the first battery and the first capacitor: (i) during ON times; and (ii) when the second battery has a greater charge than the first battery.18. The battery equalization circuit of claim 17, wherein respective magnitudes of the current driven into the second winding and the induced current flowing out of the first winding are functions of a parallel combination of impedances of the first capacitor, the first winding, and the first battery.19. The battery equalization circuit of claim 17, wherein:the switching circuit is operable to simultaneously disconnect the first and second windings of the transformer from the first and second batteries during OFF times; andthe transformer reset circuit is operable to provide a current path for a reset current to flow through the second winding and into the first capacitor such that the first capacitor charges during OFF times.