Graflex.org Forum Index Graflex.org
Get help with your Graflex questions here
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Graflex BC-Cartridge

 
Post new topic   Reply to topic    Graflex.org Forum Index -> Flash Help
View previous topic :: View next topic  
Author Message
hmartin@tns.net



Joined: 04 Sep 2001
Posts: 83

PostPosted: Tue Sep 04, 2001 7:46 am    Post subject: Reply with quote

Hi
I just bought a Graflite battery case #2773 plus a reflector off eBay. The battery case has a Graflex BC-Cartridge plus a dummy size D battery in it. CAT. No. 2795 and uses 22 1/2 volt battery. Can you tell me anything about it and are 22 1/2 volt batteries still available?
Thanks in Advance, Harry

Okay, this is an answer to Les's question below. The dummy D cell is a 1 1/4" diameter painted black wood sized D cell with a 1/4" diameter hole drilled through the dowel's center. There is a 2 1/2" long paper clip with 3/16" wide metal legs. I tested it with an OHM meter and it is not a capacitor. (I don't have the capacitor that Stephen mentions below.)(Yes I do! See UPDATE#2) It appears to only fill the empty space and conduct current.
The BC Cartridge is about 4 1/2" long, blue plastic and has provisions for a 22 1/2 volt battery in the hollow space of the cartridge. The BC Cartridge Cat. No. is 2795.
I hope this helps, Harry

UpDate: I have checked a Radio Shack as Stephen suggested. The store I visited didn't carry any 22 1/2 volt batteries but their catalog lists several of them. I don't know which is the right one yet. As soon as I fine out I'll report it here. I'm guessing that replacing 4 1/2 volts of batteries with one 22 1/2 volt battery is to fire off multiple flashbulbs together? I do have two slave units with 7" reflectors that came with the BC-Cartridge and battery case with reflector. It's all beginning to come together!

UPDATE#2 I was wrong, I do have a capacitor built into the blue BC-Cartridge. It is 250 MFD and it is rated for 25 VDC. I still don't have the 22 1/2v battery. But I have been told that it should be a photographic rated battery.

UPDATE#3 I have been unable to find a source for size 'B' batteries with 22.5-volts. I have checked Radio shack, all the large local photogaphic stores and the internet without any luck. 22.5-volt batteries are available, but not in the size 'B' that my B-C Cartridge requires.

UPDATE#4 I decided to make do with the battery that I had ordered from Radio Shack (RSU 9600437, Eveready NO. 412, NEDA 215, 22.5 volts, and 1"x5/8"x 2" high). I used double stick carpet tape and wood shims to fill the voids in the round battery cavity of the cartridge. The battery will now remain straight. I had to shorten the dummy D battery by about 3/4". I put it all back together and test fired it with a 5B flashbulb. It works great! Thanks for all the help, Harry
P.S. The total battery cost was $10.01 which includes sales tax plus postal charges to my home.


[ This Message was edited by: hmartin@tns.net on 2001-09-04 18:33 ]

[ This Message was edited by: hmartin@tns.net on 2001-09-09 21:23 ]

[ This Message was edited by: hmartin@tns.net on 2001-09-16 00:56 ]

[ This Message was edited by: hmartin@tns.net on 2001-10-10 17:55 ]

[ This Message was edited by: hmartin@tns.net on 2001-10-10 17:56 ]

[ This Message was edited by: hmartin@tns.net on 2001-10-14 18:57 ]

[ This Message was edited by: hmartin@tns.net on 2001-10-14 22:17 ]
Back to top
View user's profile Send private message Send e-mail Visit poster's website
stephen



Joined: 09 May 2001
Posts: 11
Location: Florida Space Coast

PostPosted: Tue Sep 04, 2001 9:19 pm    Post subject: Reply with quote

The BC stands for Battery/Capacitor.

The dummy D cell is a capacitor for the flash. It stores a charge to help supply more current to ignite the flash bulb, which results in less misfires.

One place to get the battery is Radio Shack. They carry one type of 22.5v battery and their catalog lists the other ones for special order. Search the web and you might find cheaper places to get the battery.

Once you have the battery in, be careful of that capacitor. It will bite when charged.

Stephen
Back to top
View user's profile Send private message Send e-mail
Les



Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI

PostPosted: Tue Sep 04, 2001 9:43 pm    Post subject: Reply with quote

I'm trying to recreate exactly what you have! Can you tell me what numbers (if any) are on the capacitor/Dummy D cell?

Les
Back to top
View user's profile Send private message
crvogt



Joined: 23 May 2001
Posts: 27
Location: Rochester, NY

PostPosted: Mon Sep 10, 2001 8:37 pm    Post subject: Reply with quote

Today, I stopped by the local ACE hardware, would you believe they had 3 of the 22.5 photo batteries on the battery rack. I was very surprised to actually see these batteries on the shelf. They must be used in something else, like garage door openers or something!! Check out your local ACE hardware...

_________________
Regards
Carl

Carl@carlvogt.com
http://www.carlvogt.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
jdman



Joined: 13 May 2001
Posts: 302
Location: Midwest

PostPosted: Fri Sep 14, 2001 5:19 am    Post subject: Reply with quote

My B-C unit which is a tilt a mite uses the 22.5 volt battery and a 200 MFD cap. The cap. is about the size of the 22.5 volt battery. No voltage rating on the cap. but I would think that double the working volt, 50 volts would be ok. The cap. needs to be photoflash grade. The use of the cap. rather than just the battery increases the current and prolongs the battery life. Same reason that a 3 d cells works better than an 2 d cells.Russ
Back to top
View user's profile Send private message Send e-mail
hmartin@tns.net



Joined: 04 Sep 2001
Posts: 83

PostPosted: Tue Oct 09, 2001 3:31 am    Post subject: Reply with quote

I found a couple paragraphs on B-C Cartridges in a 1973 book titled 'The Amateur Photographer's Handbook'
by Aaron Sussman. Quote.....
"The battery-condenser (or capacitor) system of flash (introduced by Busch, Jen, and Kodak in 1951) has been a real breakthrough for flash photography. It not only gives the photographer more power (as many as seven bulbs can be perfectly flashed on 100 feet of cord, provided they're wired in series), but it also makes him practically independent of such uncertain factors as age of battery, condition of metal contacts, and temperature. Besides, the peaking time of flash lamps fired by a B-C circuit is much more uniform.


Ordinary flash works on a direct circuit between batteries, bulb, and solenoid; that's why the batteries have to be at peak strength for efficient operation. B-C, on the other hand, works this way: A small 22.5 volt B battery (the kind they use in hearing aids) feeds power to a condenser which stores the power until you're ready to make the exposure. The circuit is so ingeniously wired that no current flows between battery and condenser until a flashbulb is inserted into the flashgun socket. Then the condenser begins to fill up (it takes no more than two seconds!) and you are ready to flash. Though the small B battery replaces the three large batteries normally used, it delivers fifteen times the voltage wallop of those regular 1.5-volt flashlight batteries. Long life (up to two years and thousands of shots) and consistent synchronization are among the advantages of this new power supply. You can buy either a complete B-C flashgun unit (such as the Busch, Kalart, Polaroid, Jen, Kodak, Standard) or you can buy B-C cartridges which, with a B battery, will convert your present gun to a B-C unit. Heiland, Kodak, and Linhof manufacture these inexpensive conversion cartridges. Almost all the new flash units are now made B-C."
Harry

Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Graflex.org Forum Index -> Flash Help All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group