Home About us Products Technical Info Samples Distribution News Contact Parametric Search
ImprintPrint page
Products:
SMD Capacitors
Capacitors in PCM 2.5 mm 
Capacitors in PCM 5 mm 
Film/Foil Capacitors in PCM 7.5 - 15 mm 
Metallized Capacitors in PCM 7.5 - 37.5 mm 
Pulse Capacitors 
RFI Capacitors 
Snubber Capacitors 
GTO Capacitors 
DC-Link Capacitors 
SuperCapacitors 

You are here: HomeProductsSuperCapsConstruction

Overview

 

SuperCap C

 

SuperCap MC

 

SuperCap R

 

SuperCap MR

 

Function

 

Construction

 

Application

 
 

Construction of WIMA Double-Layer Capacitors

WIMA SuperCap R in Rectangular Case

 

WIMA SuperCaps in rectangular case make space-saving serial and parallel arrays possible. Undesired cavities can be avoided, and the energy density can almost be doubled depending on the construction. The WIMA SuperCap has a laser welded sealing withstanding the permissible temperature range from -30° C to +65° C without problems. Due to the large case surfaces of the cells heat being generated by the continuous current flow can better be drawn off.


WIMA SuperCap C in Cylindrical Case

 

Cells of cylindrical construction can be manufactured more efficiently since there are technically mature production processes of well established products, e.g. electrolytic capacitors, which can be used as a guidance. Moreover, round cells in constructive terms permit an improved symmetrical arrangement of the current path in the cell playing an important role in the high current field (several 1000 A as a peak) because of electrical phenomena e.g. the proximity effect and path inductivity. Beyond that this series offers options to conveniently substitute brands of other manufacturers.

 

WIMA SuperCap R

  WIMA SuperCap C    


WIMA SuperCap R double-layer capacitors
with rectangular casing

 
WIMA SuperCap C double-layer capacitors
with cylindrical casing
   

 

All WIMA SuperCaps will be offered with plastic-sheathed insulation of high electric strength up to 300V. Additional insulation is to be provided for applications with higher voltages.

 

Cascaded SuperCap Modules

 

Despite the limitations of its maximum operating voltage of 2.5 V, several cells can be built up to enormous capacitance of the desired voltage by means of series or parallel connection (cascade). When cascading SuperCaps, the voltage of single cells must not exceed 2.5 V (decomposition of the electrolyte!) Hence, series connections need in any case to be balanced since a possibly slightly different aging of the individual cells due to temperature may over time cause deviating capacitances and thus different voltage drops at the cell. The balancing will be factory-mounted into the module. This can be made passively and in a cost-efficient way by simple resistors in those cases where additional losses as bypass current through the balancing resistors can be tolerated by the application. Alternatively, an active balancing can be made by keeping each cell at a certain voltage by means of a reference source. That means if the comparator circuit detects a commencing overload of any cell individual discharge is initiated by a bypass resistor. Except the leakage current of the cells there are no considerable losses created during active balancing.

 

WIMA SuperCap Module   WIMA SuperCap modules    

 

WIMA SuperCap Cascade

 

Passive balancing.
Without resistor: U reciprocal-effect to C - thus local overvoltage easily can occur
With resistor: U proportional-effect to R - thus voltage is fixed

 

WIMA SuperCap balancing

  Active balancing.
Comparator compares voltage at the capacitor
by a reference voltage and switches in order to
discharge through a bypassing resistor until
overvoltage has declined.