On 13/02/2014 19:53, Jim K wrote:
http://www.tlc-direct.co.uk/Products/SMFLA01.html

Coo how's it do it? Whatever it does? ;-)

It's just a capacitor, possibly with a shunt bleeder resistor for safety
and possibly with a small series resistor to reduce peak currents and
save the switch contacts.

Wired across the lights it will present a low impedance in comparison
with the leakage path through the stray capacitance in the wiring and
any semiconductor switch (triac). Hence the voltage appearing across
the lights when switched off will be too small to lead to any flickering
effects or the like.

It's a useful item to know about, with wider application then just the
Smiths/Timeguard products. Flickering CFLs, unwanted illumination of
neon indicators, etc.

--
Andy