Systems and methods for immobilization with repetition rate control

1. An apparatus for impeding locomotion by a human or animal target by conducting a current through the target, the apparatus comprising:

a battery;

a circuit that charges a capacitance to a predetermined voltage, and that discharges the capacitance to provide a pulse of the current, wherein charging occupies a first interval having a duration, the duration affected by an operating condition of the battery;

a processor that controls the circuit to provide a first series of pulses of the current, the first series having a first pulse repetition rate, the first pulse repetition rate being compensated by the processor for variations in the duration of the first interval.

2. The apparatus of claim 1 wherein the operating condition of the battery comprises a temperature of the battery.

3. The apparatus of claim 1 wherein:

the circuit charges the capacitance in response to a signal; and

the processor provides the signal to control the circuit.

4. The apparatus of claim 3 wherein the circuit is responsive to an oscillation frequency of the signal.

5. The apparatus of claim 3 wherein the circuit is responsive to an oscillation frequency of the signal of about 500 Hz.

6. The apparatus of claim 5 wherein the processor compensates by delaying provision of the oscillation of the signal.

7. The apparatus of claim 1 wherein, after providing the first series of pulses, the processor further controls the circuit to provide a second series of pulses having a second pulse repetition rate, the second pulse repetition rate being compensated by the processor for variation due to the operating condition of the battery.

8. The apparatus of claim 1 wherein:

the circuit further comprises a spark gap having a breakdown voltage; and

the predetermined voltage is substantially the same in magnitude as the breakdown voltage.

9. The apparatus of claim 8 wherein:

the capacitance further comprises a first capacitor and a second capacitor;

the circuit charges the first capacitor sufficient to cause the gap to conduct; and

the circuit charges the second capacitor to a voltage sufficient for impeding locomotion by the target.

10. A method, performed by an apparatus, the apparatus for impeding locomotion by a human or animal target by conducting a current through the target, the method comprising:

charging a capacitance of the apparatus with energy from a battery of the apparatus to a predetermined voltage, charging occupying a first interval having a duration, the duration in accordance with an operating condition of the battery;

discharging the capacitance to provide the current;

repeating charging and discharging to provide the current at a repetition rate having a period; and

delaying, before repeating, to provide the period compensated for variations in the duration of the first interval.

11. The method of claim 10 wherein charging further comprises providing a signal to a circuit of the apparatus that charges the capacitance.

12. The method of claim 11 delaying comprises providing the signal to the circuit after a delay.

13. The method of claim 10 wherein a delay of delaying consists essentially of the period minus the duration of the first interval.

14. The method of claim 10 wherein charging further comprises:

charging a first capacitor of the capacitance to a voltage sufficient to cause a spark gap of the apparatus to conduct; and

charging a second capacitor of the capacitance to a voltage sufficient for impeding locomotion by the target.

15. The method of claim 10 wherein discharging further comprises causing a spark gap of the apparatus to conduct.

16. The method of claim 10 wherein discharging further comprises:

coupling a first capacitor of the capacitance to a voltage multiplier of the apparatus, wherein the voltage multiplier is coupled to an electrode of the apparatus that conducts the current;

discharging the first capacitor;

coupling a second capacitor of the capacitance to the electrode; and

discharging the second capacitor.