Capacitor discharge tool
Novel techniques are described for discharging high voltage components. For example, a tool is provided to discharge high-voltage capacitors in electrical appliances prior to servicing those appliances. The tool can include a handle structure electrically and physically isolated from a head structure by an elongated body. The elongated body can house at least a portion of a discharge circuit configured to discharge high-voltage components and to indicate (visually, audibly, etc.) whether voltage is present on components being discharged. The head structure can include multiple probes adapted to electrically couple the tool with the high-voltage components and through which to discharge the components.
1. A capacitor discharge system comprising:
a head structure having a first probe and a second probe;
a non-conductive handle structure;
an elongated body coupled and extending between the head structure and the handle structure; and
a discharge circuit housed at least partially by the elongated body, the discharge circuit having:
an indicator component to provide real-time indication of a presence of voltage across the first probe and the second probe;
a high-power load component coupled with the indicator component; and
a shunt component coupled with the indicator component.
2. The capacitor discharge system of claim 1 , wherein:
the indicator component has first and second indicator terminals, the first indicator terminal coupled with the first probe;
the high-power load component is coupled between the second indicator terminal and the second probe; and
the shunt component is coupled between the first and second indicator terminals.
3. The capacitor discharge system of claim 1 , wherein:
each of the high-power load component and the shunt component is rated for at least one mega-ohm of resistance; and
the high-power load component is rated for at least one watt of power.
4. The capacitor discharge system of claim 1 , wherein the head structure further comprises:
a first probe carriage coupled with the first probe; and
a second probe carriage coupled with the second probe,
wherein at least one of the first probe carriage or the second probe carriage is movably coupled with the head structure, so as to adjust a spacing between the first probe and the second probe.
5. The capacitor discharge system of claim 4 , wherein:
the first probe is removably coupled with the first probe carriage; and
the second probe is removably coupled with the second probe carriage.
6. The capacitor discharge system of claim 4 , wherein the head structure further comprises:
a cord funnel configured to receive the first and second probe carriages.
7. The capacitor discharge system of claim 6 , wherein the head structure further comprises:
a funnel cap configured to secure the first and second probe carriages in the cord funnel.
8. The capacitor discharge system of claim 6 , wherein the cord funnel comprises routing structure through which wires are routed to electrically couple the probes with the discharge circuit.
9. The capacitor discharge system of claim 1 , wherein the elongated body extends along an axis between the handle structure and the head structure, and further comprising:
a rotational coupling that couples the head structure with the elongated body, such that the head structure is rotatable about the axis with respect to the elongated body.
10. The capacitor discharge system of claim 1 , wherein the first probe extends along a first vector, and second probe extends along a second vector, the first and second vectors define a plane, and further comprising:
a pivot coupling that couples the head structure with the elongated body, such that the head structure is pivotable about an axis normal to the plane with respect to the elongated body.
11. The capacitor discharge system of claim 1 , wherein:
the indicator component comprises a neon indicator lamp.
12. The capacitor discharge system of claim 1 , wherein:
the indicator component provides a visual indication of the presence of voltage across the first probe and the second probe; and
the indicator component is disposed within the elongated body in such a way that the visual indication is visible through at least a portion of the elongated body.
13. The capacitor discharge system of claim 1 , wherein the elongated body is substantially cylindrical.
14. The capacitor discharge system of claim 1 , wherein the elongated body is a substantially hollow tube.
15. The capacitor discharge system of claim 1 , wherein the elongated body is made of polycarbonate plastic.
16. The capacitor discharge system of claim 1 , wherein the elongated body separates the head structure from the handle structure by a distance of N inches and has a dielectric strength that is at least 5,000 volts per N inches, where N is a positive real number.
17. The capacitor discharge system of claim 1 , wherein each of the first and second probes is a banana plug.
18. A method for discharging a capacitor, the method comprising:
positioning first and second probes of a capacitor discharge device each to be in electrical contact with a respective one of a first terminal and a second terminal of a capacitor, the positioning performed using a handle structure of the capacitor discharge device that is coupled with and electrically isolated from the first and second probes via an elongated body that houses a discharge circuit coupled with the first and second probes,
such that the positioning causes the discharge circuit to provide a first real-time indication that a voltage is present across the first and second probes, and
the positioning causes the discharge circuit to discharge the voltage;
maintaining the first and second probes in electrical contact with the first and second terminals of the capacitor until the discharge circuit provides a second real-time indication that no voltage is present across the first and second probes; and
removing the first and second probes from electrical contact with the first and second terminals of the capacitor in response to the second real-time indication.