facelets: custom component and custom converter

[arne anka]

hi,
i got my custom component (faclets based, not tomahawk or trinidad,  
extending UIOutput) working so far -- but my converter is not executed.
if i attribute the converter to, say, h:outputText it works, so it seems  
to be ok.
my idea is, because i use my own rendere (getRendererType() returns null)  
maybe i need to call it myself?
if so, how do i get hold of the converter?
both with

<my:component value="foo" converter="contentConverter" />

and with

<my:component value="foo">
        <f:converter converterId="contentConverter"/>
</my:component>

getConverter() always returns null

thanks in advance