Simple discrete single cell converter with small standby current?

[Peter Heitzer]

For some simple led curcuits I would like to use just a single AA cell.
Are there any simple low part count _discrete_ solutions for a converter that
has an efficiency of >50% with a standby current or no load current of
less than 1mA? Charge pump is preferred, but if it needs a single coil
it's also ok.
Thanks in advance.

 

[Slavek]

Connect BJT base through 1k to primary of small transformer (made on
small bead with a few turns and ratio 1:1). Other end of the same wind
connect to +1.5V. The other turn connect between +1.5V and the
collector. Emitter connect to the ground. LED connect between collector
and the ground in parallel with small cap. LED should for a few hours.
Replacing BJT with MOS with low Vgsth may even improve efficiency.
ed to /dev/null.