S series: aluminium electrolytic capacitors of the old school

Aluminium electrolytic capacitors of the S series are among the vintage products of the FTCAP portfolio: the manufacture of this type has all but died out. They are designed with threads to allow mounting on a mounting plate, for example. Today these capacitors are in demand primarily as spare parts in railway technology.

Aluminium-Elektrolytkondensatoren S-Serie

TCAP, part of the Mersen Group, is one of the only companies that still manufacture capacitors of this type. These capacitors are from an era before the invention of the printed circuit board, which is commonly used for mounting of capacitors today. The threads of the S series make it possible to screw them directly onto a mounting plate.

As spare parts these aluminium electrolytic capacitors are still in high demand – especially for use in railway technology. They are installed for example in older relay signal boxes, where they ensure trouble-free operation of switching and linking components. But they can also be found in tube radios and amplifiers. A few years ago FTCAP donated capacitors of the S series for a Zuse computer of type Z-22 from the year 1959 – one of the first commercially available computers. One of three models existing worldwide is still in use today at the Suderburg University of Applied Sciences – thanks to capacitors from FTCAP.

The S series comprises three models – the standard version, the SZ series with double or even triple capacitance, and the SH series for high temperatures up to 105 °C. Customisation of these older models is thoroughly conceivable: a capacitor of this type could easily be designed to operate with the high capacitances and electric strengths that are common in modern applications.