Re: [EVGRAY] charging a coil like a cap

Body

Were they lithium or zinc oxide
On May 28, 2018 1:45 PM, "[email protected] [EVGRAY]" <
[email protected]> wrote:

>
>
> Yes, indeed, Ole.
>
> That would be perfect for charging large  batteries.
> The circuit I have, works perfectly good for up to  9V small batteries and
> does it's magic on watch batteries.
> Yesterday, I recharged 2 watch batteries that had been in a closet inside
> the watches for over 10 years!
> They were completely dead.
> Both watches are now up and running and batteries were measuring way over
> 1.6V after removing them from charger, which were charging for a period of
> 2+ hours.
> I really want to do the higher voltage circuit. Time is my main obstacle
> now (work)
>
> Thanks!
>
>
> ---In [email protected], <onielsen@...> wrote :
>
> Hi Karl,
>
> "The 73 volts is measured open circuit  across the coil from collector to
> top of coil. Not from top of coil to base of transistor."
> Then from 0V (emitter) to collector is the voltage across the coil (73V)
> plus the voltage across the voltage supply (5V) minus the voltage across
> the rectifying diode.
>
> If the peak voltage is a smooth half sine wave (bottom up parable) the
> transistor doesn't go into avalanche mode. Then it's the parasitic
> capacitance of the coil that limits the peak voltage.
>
> If a higher flyback voltage is wanted a high voltage transistor like the
> ones used to drive the flyback transformer in old CRT screens could be
> used. Some of these have breakdown voltages above 1kV like the BU208
> <http://www.alltronics.com/mas_assets/acrobat/BU208A.pdf> or BU508
> <http://pdf.datasheetcatalog.com/datasheets/savantic/787.pdf>. The
> flyback voltage were further stepped up by using a high tension secondary
> winding on the flyback transformer and then feeding a voltage tripler
> <http://www.interfacebus.com/Glossary-of-Terms-Voltage-Quadrupler.html>
> to reach the extremely high tension for accelerating the electron beam.
> When using a step up winding this down transforms the current at the same
> ratio as the voltage step up ratio. The peak current of the flyback pulse
> is the current reached when breaking the input cycle assuming no secondary
> winding is used.
>
> Regards
> Ole
>
>
> 
>