The B32529-V (RM 5) and B32521-V (RM 10) series, available from Ramelec Electronics , feature EPCOS CombiSuppressor packaging technology that is suitable for EMI suppression in DC motors in motor vehicles. The CombiSuppressor packaging technology comprises a film capacitor and a multilayer ceramic varistor connected in parallel in a plastic case. This packaging technology offers mechanical protection for the components and facilitates automatic picking and placement.
The items are designed for operating temperatures from -55°C to 125 °C. The capacitors are characterised by high pulse load capability of up to 250 V/µs and meet ISO 7631. These components are available for operating voltages ranging from 22 to 45 VDC and threshold voltages of the varistor from 44 to 90 V. Their capacitances cover a range from 0.47 to 2.2 µF. All types have a leakage current of less than 50 µA.
Top-range vehicles now employ more than 100 electric motors, all of which must operate interference-free in a sensitive environment. In order to eliminate electromagnetic interference directly at the motor and to assure interference-free operation of other electronic units in automobiles, more EMI suppression components must be built into the same space.
The EPCOS CombiSuppressor packaging technology has the functionality of two components in a single package and offers users benefits in space required, placement costs and logistics expenditures. Typical applications for the CombiSuppressor packaging technology include windshield wipers, electrical seat adjusters, electrical windows, electrical sun-roofs, gasoline and oil pumps as well as central locking systems.
The CombiSuppressor packaging technology is a leaded component supplied in bulk with varied leads, packaged on reels or in an Ammopack. To weld the components directly onto a carrier frame when no separate circuit board is used, the leads can also be supplied bent, as specified by the customer.
As an alternative to the film capacitors, EPCOS have also extended their range of super high-capacitance varistors (SHCVs) and offer the SHCV SR6 series in the case size of 1206. SHCVs are leaded components combining a multilayer varistor with a multilayer ceramic capacitor for overvoltage protection and radio interference suppression.
Similar to the CombiSuppressor, the SR6 series was also developed for interference suppression in DC motors. EPCOS satisfy requirements for improved technical properties such as constant capacitance with X7R ceramic, an extended temperature range from -55 to +125°C, significant miniaturisation of standard EMC components and cost reduction. SHCV SR6 types are available with ratings of 220 nF/14 V and 470 nF/35 V as well as 1 µF/20 V and 1 µF/35 V.