Creating new electronics for Super Graphic?

Ok. Basically all that's needed is to replace the 45v battery in the circuit with the 9v battery plus inverter board. The output of the inverter connects to where the 45v battery is shown in the cct diagram.

 

I was going to suggest putting a diode in reverse across the inverter output, but I see there's already one in place. Its purpose is to absorb the back-EMF from the solenoid coil.

 

Modern advances in capacitor technology probably mean that a single capacitor of 220 uF/50v can be fitted in the space of one of the old 80 uF ones. The capacitance value isn't critical - the original capacitors only act as a current booster to trip the solenoid.

 

It's all workaday stuff. No need to get too hung up on precise voltages and component values. The capacitors are there because the original 22.5 v batteries couldn't deliver enough current on their own to trip the solenoid. So the capacitors act like a 'bucket' to collect a trickle of current over a few seconds. When the shutter switch is pressed, those capacitor 'buckets' empty a gush of current into the solenoid, and (hopefully) the shutter fires.

 

Edit: Capacitors are commonly sold only in 'preferred values', and 80 uF isn't a modern preferred value. Nearest preferred value these days would be 100 uF. No harm will come from using two 100 uF capacitors, or a single one of 220 uF. The tolerance on electrolytic capacitors is at least +/- 20% anyway.

Edited January 27, 2018 by rodeo_joe|1

Two of these would do the job:

 

100µF 63V 85°C Radial Electrolytic Capacitor | maplin

 

Ignore the picture! The idiots have obviously used a generic picture that shows an entirely different value.

Rodeo_Joe has good advice. Just play with things and see how you go.

Update: I've ordered 2 different circuit boards from the chinese distributor linked above. Hopefully I can figure out something that will get this idea off the ground. I've already discovered that if I go the 9V route that the batteries will have to be cut open and the metal case discarded. 9V batteries are a tad thicker than the 22 1/2V ones and don't quite fit the battery bay of the camera. No big deal. I'll report later. It will probably be a while for that slow boat from China to get the boards here.

A modern electrolytic capacitor will last so much longer than the old ones before getting leaky. But don't leave the batteries in there. (Applies to all cameras.)

"A modern electrolytic capacitor will last so much longer than the old ones before getting leaky."

 

- Whoa! That's a leap of faith. I've had a lot of modern kit go 'phut' due to a faulty electrolytic in the switch-mode PSU.

 

I just remembered about little 12v 23A batteries, and the even smaller versions that fit in car remotes etc. Maybe those would save on size enough to fit in the existing battery bay?

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Flashbulbs throw a LOT of light for their size-significantly more than an electronic flash. One of my favorite photographers-O. Winston Link-used an array of 50-100 bulbs to illuminate trains at night.

 

I would've hated to be a crew member of a train he was taking a picture of, as you would probably see nothing for quite a while afterwards.

I'm not sure what relevance the previous post has, but while this thread is resurrected.

 

How's it going Henry?

 

Any joy with the modification?

I'm not sure what relevance the previous post has, but while this thread is resurrected.

 

How's it going Henry?

 

Any joy with the modification?

I'm assuming that, that much light must be blinding.