Patent ID: 7427851

Claim:
A capacitor unit comprising: a capacitor block formed by incorporating a plurality of capacitors into a holder with body portions of the capacitors sandwiched and electrically connecting the capacitors in series or in parallel; a control circuit portion including a charging and discharging circuit for charging or discharging the capacitor block; a relay connector for electrically connecting the capacitor block and the control circuit portion; and a case housing the capacitor block, the control circuit portion and the relay connector, wherein the control circuit portion comprising: a circuit board; a circuit component forming the charging and discharging circuit; a heat radiator for suppressing heat generation of the circuit component in charging and discharging; a microcomputer for detecting and controlling states of the charging and discharging circuit and the capacitor block; and a connector connected to an external load; and wherein the control circuit portion is incorporated into the case in a way in which the circuit board is housed in the case in an upright position with respect to the case and the circuit board is out of direct physical contact with the case; wherein the heat radiator has a fixing hole, the case has a fixing boss corresponding to the hole formed on the heat radiator, and the hole and the boss are screwed to be fixed in the case; wherein the circuit component is pressure welded to the heat radiator by using an elasticity of a leaf spring attached to the heat radiator; and wherein the leaf spring is processed in a rectangular U shape, in which one end has a surface that is brought into contact with a rear surface of the heat radiator and another end has a pressure welding portion that allows the circuit component to be pressure welded to the heat radiator, and a center portion thereof is fixed to the heat radiator with a screw.