If I remember correctly the Super or TRF Crown also have an illuminated rangefinder focus system. Is that right?
The TRF Speeds and Crowns did, but I don't think the Super had it, which defies understanding. I'll see when it gets here tomorrow. If it does not, you can bet I'll dream up a way to retrofit one somehow.
The main reason they used a 22.5V battery with a capacitor was due to the poor retention of voltage compared to today's batteries. Flashes of sizes including the monsters F-33 and Mazda 75 would trip with a minimum of 4.5 volts, but nobody wanted to risk a shot with a poor battery. I do not know if today's replicas are better. Shame if they are not. Perhaps someone could inform us.
That was a variant of the Focuspot and worked with 3V to 4.5V. More to 22.5V plus didn't hurt with the proper bulb.If I remember correctly the Super or TRF Crown also have an illuminated rangefinder focus system. Is that right?
Fast electronics 101. Diode is an on off switch. Reverse direction it is a open until you exceed the prv. At that point it becomes a carbon short then burns open if your lucky. In the forward direction the on state voltage drop is approx. half a volt. 90 - 0. 5=89.5 volts to the circuit. E=I *R or in this case I=E/R. E=90 ... everything was designed
for battery voltage that dropped over time. I know you want to try it. Variable transformer to drop active to 45 vac or two Door bell type 24 volt (hardware store should have them, used in heating cooling for thermostats control voltage) transformers would be much less of a Smoke Test situation. If I get a chance tonight I will check the ohms of my Crowns solenoid. Trouble with smoke tests is the release of smoke from micro parts burning is nearly instant. Enjoy your learning experience.
Jac... That may be true of many flash units of the 50s and 60s, but the battery on a SuperGraphic does not trip the flashbulb... it only operates the shutter solenoid. The 2 or 3 D-cell batteries in the battery case trip the bulb.
Re: focuspot... it really is too bad that the Super never offered that!
Thanks gleaf. I've been restoring and working on radios, TV's tape recorders, test equipment--most everything for years, but I seriously doubt I'd pass Electronics 101. I get the part about PRV, but I just did not follow what you said. The mail lady will be showing up with my Super any minute, and it will be some time before I could have any batteries shipped in for it. I'm itching to find a way to hook up my tapped isolation xformer to it, but not entirely sure what I need to do. I can tap off anywhere between 25-125VAC. And I have a leftover diode I bought to experiment with a wave-clipping experiment for my soldering iron to run it at half voltage when I wasn't using it immediately. (The idea was to keep it warm when idling, and flip a toggle switch to give it full wave 117 when I pick it up to solder something). Thanks.
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