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[OM] Re: OM-32 flash question

Subject: [OM] Re: OM-32 flash question
From: Tim Hughes <timhughes@xxxxxxxx>
Date: Wed, 13 Sep 2006 17:59:03 -0700 (PDT)
One of the clever features of the BG2 is that it uses the power switch in the 
T32 to switch on the
inverter in the BG (as well as in the flash if batteries are present in T32). 
So it is not
necessary, as it is with say Qturbo, to switch on the high voltage seperately. 

I have a schematic with some notes, I did a long time ago for the BG2.  I may 
post it to Mark's
repair site when I get around to it one day!

Many flashes are designed to work with only the external high voltage supply 
connected. Most
sunpaks for example. An exception is the Sunpak 622 which requires a special 
adapter with a tiny
battery inside to operate a small part of the low voltage trigger logic. 

Part of the reason they work off hv easily, is because in the mist of time 
somebody saved a few
parts, by using the big drop in voltage on the flash cap to suddenly power on 
(via a charged
capacitor)and hence start the auto flash sensor integrator circuits. The 
flashtube trigger circuts
have historically been powered by the hv side too, since you need to generate 
6-8kv to trigger the
tube and it is much easier to do that starting from 300V  or so. Highly 
integrated flashes with
many features to integrate control with the camera, other than just ttl quench, 
are a lot more
difficult to design to run by just stealing power off the high voltage side, at 
the time of flash.


Many older flashes with no external connector for external HV power, could 
easily be run with only
a HV connection if one were connected, because they all use very similar 
ccts(copied one another's
circuits?).

Tim Hughes

--- Chuck Norcutt <chucknorcutt@xxxxxxxxxxx> wrote:

> No, quite to the contrary.  One of the advantages of the T-32 over 
> lesser flash units is that it can run on a 330 volt high voltage supply 
> without needing 4 AA's to keep its brains in order.  If you carry a 
> flash unit on the end of a long mechanical advantage lever like a 
> Stroboframe you'll appreciate not having to carry the extra weight of 
> the AA's.  For a list of flashes that don't require AA's when on a high 
> voltage supply refer to Quantum's instruction sheet for Quantum power 
> cables <http://www.manuals.qtm.com/qtb_cbl_p119_7b.pdf>
> 
> There may be an error in the data sheet since I don't recall needing 
> AA's on my Sunpak 522's.  Of course, that may be an error in my head 
> which is prone to happening as well.
> 
> Chuck Norcutt
> 
> AG Schnozz wrote:
> 
> >>Actually, I think the reason that the BG-2 manual says 9
> >>seconds vs. the 
> >>T-32's 10 seconds is an assumption that the T-32 batteries are
> >>helping 
> >>out.  The spec give the times for alkaline and Ni-Cd's and
> >>then says 
> >>parenthetically (coupled with T-32 batteries...).
> > 
> > 
> > I thought the T-32 batteries were required for the "brains" and
> > the flash wouldn't operate on solely the BG-2.
> > 
> > AG-Is it Dark in Here?-Schnozz
> 
> 
> 
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