A circular heatsink can include a thermally conductive cylinder with an outer circumferential surface and an inner circumferential surface. An emissive and convective and convective surface area can extend radially from the outer circumferential surface. At least one thermally conductive ledge can extend from the inner circumferential surface and be configured to support a planar substrate having heat-generating electrical components. Air flow over the emissive and convective surface area can cause thermal conduction away from the heat-generating electrical components and through the at least one thermally conductive ledge, the thermally conductive cylinder, and the emissive and convective surface area.