TDK Debuts a Series of Screw Terminal Aluminum Electrolytic Capacitors

The Epcos B43706 and B43726 series are part of TDK’s wide selection of capacitors with screw terminals.

The B43706 (left) and the B43726 (right). Image courtesy of TDK

These devices feature a high-rated current capability (at 100 Hz, 85℃) of up to 56.1 amps. Screw terminal mounting makes the series applicable to high-performance situations presenting high ripple currents. Current capacity is increased by 25% over the figures for the previous series. Service life is spec’d at 12,000 hours @85℃.

Members of the B43706 series of Screw Terminal Aluminum Electrolytic Capacitors feature ring clip or clamp mounting. The B43726 devices offer threaded stud mounting with or without an insulated base.

 

Ripple Current Capability

Members of both series feature diameters of either 51.6, 64.3, 76.9, or 90 mm. Maximum permissible ripple currents (IAC, max) are:

• 51.6 mm: 55 amps
• 64.3 mm: 71 amps
• 76.0 mm: 100 amps
• 90 mm: 100 amps

Image courtesy of Series/Type: B43706, B43726 datasheet

However, with the availability of forced air around the capacitor body or the contact elements,  these limits can be exceeded upon consultation with TDK. This is also possible with a heat sink at the capacitor base, and both the B43706 and B43726 offer a variety of options for heat sink mounting. These devices also offer special terminals for reverse polarity protection.

 

Availability

Members of both the B43706 and B43726 are available with rated voltages (V_R) of either 400, 450 or 500 VDC.

 

400V Capacitors

Members of this series offer rated capacitances (CR) from 1,500 to 15,000 μF. Lengths vary from 80.7 to 220.7 mm.

Typical equivalent series resistances (ESR) are specced for 100 Hz at 20℃ and at 300 Hz at 60℃, with the former measuring between 50 to 5.1 mΩ, and the latter ranging from 14 down to 1.8 mΩ. In all, ESR is lower for capacitors featuring higher CR’s

Maximum impedance ranges from 70 mΩ for the 1,500 μF unit to 8 mΩ for the 15,000 μF device

Maximum ripple currents are 15.9 amps and 80.1 amps for the 1,500 μF and 15,000 μF capacitors, respectively.

 

450V Capacitors

These capacitors feature CR’s from 1,000 to 12,000 μF with lengths of 80.7 to 221 mm. Typical ESR’s for 1,000 µF units are 90 and 24 mΩ at 100 Hz at 20℃ and at 300 Hz at 60℃, respectively. For the 12,000 units, the figures are 7.7 and 2.4 mΩ

For the 1,000 μF capacitor, maximum impedance and ripple currents are 140 μF and 11.8 amps, respectively. For the 12,000 μF, the equivalent figures are 13 μF and 74.4 amps

 

500V Capacitors

These units’ CR’s range from 820 to 10,000 μF. Typical ESR’s at 100 Hz and 20°C starts at 80 mΩ for the 820 μF capacitor and decrease to 7 mΩ for the 10,000 μF unit. At 300 Hz and 60°C, the equivalent numbers are 24 mΩ and 2.3 mΩ

Maximum ripple currents are 9.7 amps and 67.5 amps for the 8200 μF and 10,000 μF capacitors, respectively. Impedances range from 110 to 10 mΩ.

 

Applications

• Wind power converters
• Solar inverters
• Uninterruptible Power Supply (UPS)
• Frequency converters
• Power supplies