On 01/07/2011 03:57, John Gardner wrote:
> Hi David -
>
> I could'nt get the links to work, but did manage to run down a circuit by
> one of the fellows mentioned on the page you referenced.
>
> http://www.portabletubes.co.uk/sitefiles/ausbatt.htm
>
> Interesting stuff...
>
>   Jack

I have perfectly good switchers. Been designing flyback, boost and buck=20
etc since 1978. I tend nowadays to use an IC. Though I made a boost=20
converter from an LM393 + FET or BJT. One 1/2 is relaxation osc and the=20
other 1/2 is comparator compare o/p to a reference. Both o/ps are=20
connected to switch (gate or base) with a single pullup. Works down to=20
0.9V if you have a suitable reference to give +45V. I used doubler=20
technique for +90V as the transistors and fets I tried as switches only=20
60V rated.

I want to use real batteries and have no transistors or ICs.  If this is=20
too ambitious  I will switch to using C or D cells at nominal 2.4V,=20
4.8V  or 9.6V  (2, 4 or 8 cells) The challenge with switcher is=20
filtering when it's a radio.
--=20
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