Hi everyone! First post on this really awesome forum! I'm thinking of an AC-adapter for hot-shoe flashes, which are usually powered with batteries. Here a guy describes his unsuccessful attempt: he built a wooden battery pack with contacts at the right place and connected to a universal power supplier giving 300 mA @ 6V. The flash does not even switch on. The reason is simple: the current is not enough. My first thought was: high current is only needed to charge the capacitor of the flash. How about I add an external capacitor that stabilizes the 6V at higher currents? But how big does it need to be? Easy to calculate. A flash takes about 5 seconds to reload after a full discharge. A flash can flash about 120 times with 4 AA batteries of 2500 capacity connected in series. Then, the discharge current during reload must be about 2.5 Ah / (120 x 5s / (3600 s/h) ) which makes 15 A (massive!). So, even if I allow a drop of 2 V, I still need a 7.5 F capacitor, which is pretty expensive (although easily available on car hifi stores). Am I doing something wrong? Is what I'm trying to do impossible? Is it necessary to SKIP the low-voltage stadium and connect the output of the AC/DC converter to the high-voltage section of the flash, so that the required currents are lower? (there is a product on the market, which I can't mention because it would be spam, which does exactly that, but it only works with flashes that have a plug for an optional external battery pack) What sucks, though, is that flashes that can use power from an external supply are twice as expensive as the ones that don't! Is there a way to "hack" into the flash and connect an external power supplier even if the flash does not natively accept it? Thanks a lot!