new hamfest finds

From: Rob O'Donnell <classiccmp.org_at_irrelevant.fsnet.co.uk>
Date: Sun Jun 6 08:22:56 2004

At 23:56 05/06/2004 +0100, Tony Duell wrote:

> > My dad had (probably still has, knowing him) a big camera flash unit that
> > features one of these batteries. Big unit the size of a handbag with a
> > shoulder strap, with the accumulator in this, and flash gun on the end
> of a
> > spiral cord. I was always fascinated with it as a kid, so I guess that
> > places it earlier than the '70s...
>
>These sort of units were quite common at one time (and often used
>lead-acid 'wet cell' accumulators). Actually, I'd not be suprised if the
>batteries were still available somewhere..
>
>Sometimes there were 2 or 3 plastic balls of different densities inside.
>They floated or sank depending on the density of the eletrolyte, which in
>turn depended on the state of charge of the cell. Interesting idea.

Yep, his had the balls ... As a kid, I'd watch them when he had it on
charge to see if I could spot them moving! The battery was exposed on the
flash unit so you could monitor it's state as you used it.


>Getting the HT for the 'electronic flash' tube was something of an
>entertainment before transistors (which took all the fun out of it, due
>to the ease of making an oscillator that would run off a 6V battery).
>Some manufacturers used a mechanical vibrator, like the one in a car
>radio [1] to chop up the DC from a battery to feed it into a transformer.
>Others used HV (250V or so) batteries. The Voigtlander Vitrona, one of
>the first cameras to have built-in electronic flash, did this -- a
>handle containing an HV battery plugged into the bottom of the cammera.


I remember, also as a kid, so mid to late 70's, pulling apart an old valve
radio I picked up at a jumble sale. Battery operated, with spaces for
about three different sort of huge batteries... I think one of those was
supposed to be an HV battery - I never came across one though.


>[1] I am showing my age. This was how they got the HT (B+) voltage for
>valves (tubes) in car radios about 50 years ago...
>
>-tony
Received on Sun Jun 06 2004 - 08:22:56 BST