DE29718066U1 - Electrolytic capacitor with low self-inductance - Google Patents

Description

PATENT ATTORNEY .·, .:. .:.·..* aägiSHusum/Federal Republic of Germany

* D1PL.-CHEM. DR. EVA RUHTZ ^Market5

&psgr; Telephone {04841) 50 76 and 5077

Fax (04841) 61201 Also admitted to the European Patent Office

Dr. Eva Ruhtz · Markt 5 · 25813 Husum

German Patent Office Husum, 10.10.1997

80297 Munich

Applicant _: F & T Kondensatoren GmbH Nedderweg 25813 Husum Electrolytic capacitor with low self-inductance

The invention relates to an electrolytic capacitor with low self-inductance.

It is known that electrolytic capacitors are advantageously used in fast electronic controls IGBT (isolated gate bipolar transistor) due to their low self-inductance. It is also known that the inductance of the electrolytic capacitor is determined by the length of the connection between the cover connection and the winding.

The invention is based on the object of making the internal connection and the distance between the cover and the winding as short as possible.

This object is achieved according to the invention in that metal strips 8, 8' on the aluminum parts 7, 7' below the cover 6 are connected in a manner known per se to the connection lugs 9, 9' of the winding 5.

The advantages achieved with the invention consist in particular in the fact that when welding the flexible aluminum flags 9, 9 ^' of the roll 5 to the metal strips 8, 8' of the cover 6 do not have to lie flat. The aluminum flags 9, 9' can be printed directly onto the rigid metal strips 8, 8'.

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An embodiment of the invention is shown in the attached drawing and is described in more detail below. It shows

Figure 1 Parts of an old type electrolytic capacitor,

Figure 2 Parts of an electrolytic capacitor according to the

Invention,

Figure 3 an aluminium connection part in perspective, Figure 4 an aluminium part with flag in section,

Figure 5 an aluminium connector with metal strip and

Figure 6 an aluminium connector with metal strip and

Connection flags.

In the old-style electrolytic capacitor shown in Figure 1, the winding contained in an aluminum cup (not shown) is designated 1 and the plastic lid of the cup is designated 2. The aluminum connection parts for the anode and cathode 3, 3' are located therein and pass through the lid 2; they are shown in perspective and in section in the detailed Figures 3 and 4. The connection lugs 4, 4' of the winding 1 welded to the connection parts 3, 3 ¹ of the lid are shown in Figures 1 and 4.

The electrolytic capacitor part shown according to the invention according to Figure 2 consists of winding 5, cover 6 with the aluminum connection parts 7, 7', the metal strips 8, 8' and the connection lugs of the winding 9, 9'. These are shown in perspective and enlarged in section in Figures 5 and 5'.

Fischer & Tausche GmbH

The embodiment according to the invention leads to the following results:

The length of the windings determines the harmful inductance and the harmful ohmic loss components:

For example, a capacitor of 220,000 F and 25 volts has 20 nH inductance and 1 milliOhm flag resistance. According to the invention, a reduction of 80% can be achieved: With a cover diameter of 90 mm, a flag length of at least 45 mm is required according to the old design; by using a metal strip 8, 8' on the connecting parts 7, 7' inside the cover 6, flags 9, ⁹¹ of 10 mm length can be attached. This reduces the inductance from 20 nH to 4 nH and the ohmic loss components from 1 milliOhm to 0.2 milliOhm.

Protection claims

Fischer & Tausche Capacitors GmbH

Claims (1)

Claim for protection Electrolytic capacitor with low self-inductance made of an aluminum cup with a plastic lid, through which aluminum parts (7, 7') with threaded connection are guided, characterized in that (7, 7') below the lid (6) carry metal strips (8, 8') which are connected in a manner known per se to the connection lugs (9, 9 ¹ ) of the winding (5). Fisherman & Swap