Electronic – AC/DC Adapter for Camera Flash Mod

accameradc

I'm trying to modify a Nikon SB-26 camera flash to use AC power instead of batteries. I have a setup similar to this with two dummy batteries connected to wires that lead out of the battery housing. Instead of hooking up the wires to an external battery pack though, I've connected the dummy batteries to this variable voltage 300mA AC adapter. My results with different voltages are as follows:

  • 1.5V: nothing
  • 3V: the unit turns on and all of the menu options work, but the flash itself doesn't charge
  • 4.5V: the unit does not turn on but beeps about once per second
  • 6V: the unit beeps at about once per second and also quickly turns on
    and off at the same interval.

I was about to call this experiment a failure when I decided to hook the flash up to some of the outputs on this Radio Shack electronics learning lab (which is powered by AA batteries.) Sure enough, when I plugged it into 4.5 volts, the flash was powered and worked normally (although the flash charged a little more slowly than normal)

This leads me to believe that I'm using the wrong AC adapter. My ideal solution would be charging the flash much faster than it does with the electronics learning lab and closer to how quickly it charges normally. Does anyone have any recommendations for what adapter I should be using instead? Even if you don't have a specific answer, any information on a good troubleshooting/honing path to proceed with would be extremely helpful.

Best Answer

The problem is that your "AC adapter" can't supply enough current. It is only rated for 300mA, which way to wussy. I don't know about the SB-26 stobe in particular, but other strobes I have looked at will happily draw 1 A or more after a strong flash.

Get a proper power supply rated for at least 1A. Don't play games and experiment with the voltage if you value your strobe. You can safely apply about 1.5 V times the number of AA cells the strobe is intended to take. If it's two cells, then 3 V. If 4 cells, then don't exceed 6V. 1 A may not be enough for short periods right after a flash, but is probably enough to get thru the tough charging phase a little slower to where it will draw less current after a few seconds. A little voltage sag is OK since the strobe has to be designed to at least not get hurt by low batteries. I would probably get a 2 A 6 V power supply (assuming 4 AA batteries) to get good quick recharge time.