I have a Pentax 540 flash, and would like it to work with my Quantum Turbo external power pack. I have the cable for this set up. How can I make this work for me? There are no instruction in the manual that I can look at for guideance. Is there any out there, that have tried this and made it work? Help

[SOldBear]

It's pretty simple: put 4 AA battery cells in the 540. It needs the low voltage supply to run the low voltage circuitries (e.g. LCD). Connect the 540 to the Quantum Turbo with the cable (Quantum CN3). IME, the cable connector at the flash can be tricky. You have to make sure to push it all the way in.

That's it.

You may want to set "charging mode" as in the manual (image below). IME, with a Quantum Turbo, even PP1 is good enough with less than 2 sec. recycle time from full power strobe. PP2 is slightly faster, but not by much. This is different with the Pentax TR Power Pack, PP1 is about 3.5 sec, PP2 is about 2 sec.

Is it possible, to put 4 AA dummy pack in this compartment and make it work? I was under the impression that if the 4 AA battery got to hot they would explode. I also wanted to eliminate the possibility of corrosion on the terminal in the battery compartment. excuse my ignorance about charging. The Quantum power pack has the charger on its own, and can be charged independently. Could you explain for me about charging on your last statement. thank you

[mtansley]

The dummy pack would not work.

Your external power pack is not charging the AA batteries in the flash unit from what I understand.

The external pack ONLY charges the flash capacitor at a high voltage.

The AA batteries are still needed to power the flash unit electronics (LCD display, computer circuitry, etc) since the external battery pack does not power this part of the flash.

It's like your flash is divided into two parts, the flash capacitor and everything else.

When you use the AA batteries only, they run both parts.

With the external pack, the AAs power part of the flash and the external pack powers the other part (the flash charging) although you can still select a charging method in which the AAs still power both parts and the external pack still powers the flash part.

[SOldBear]

Read the manual page I posted above. Replace "the TR Power Pack-3" with "the Quantum Turbo" and follow the exact instructions.

The manual is clear that even with an external power source (Quantum Turbo), the 540 still needs 4 AA battery cells to operate.

The Quantum power pack has the charger on its own, and can be charged independently. Could you explain for me about charging on your last statement. thank you

In the last statement of my post above, I referred to section "Switching the Charging Mode" in the 540 manual. "Charging" here means charging the flash's capacitor, either only from the external power source, or from both the external power source and the 4 AA battery cells.