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Hag's House _ Homemade Trail Camera _ Vivitar 2800

Posted by: 212 Feb 25 2005, 09:58 AM

First I need to say I do not know why this works and maybe you should not try this. Also if you don't know... the flash capacitor will bite ...real hard...do not touch the contacts.

Here is how I have modified the Vivitar 2800 flash unit.

An original 2800 will charge the capacitor and then turn off the charging circuit to save power. If the flash is not used before the voltage drops too low, you have to turn it off and back on again for it to charge again, even if you disconnect the batteries. If you do flash it, it will recharge and then turn off like before. It is hard to put into words but if you have one, you will understand.

To make the flash recharge itself again when just sitting idol, I connect a 220k~470k resistor across the switch terminals. When this is done, the flash will charge as before and cut off when the voltage goes to about 335v. .. Now when the voltage drops below about 250v the charging circuit will charge it back up.

You may or may not find this usefull...212

Posted by: 212 Feb 25 2005, 09:59 AM

You can put the resistor on the back if you want to, I drilled through and put it on top.

Posted by: djc68 Feb 25 2005, 10:17 AM

Just to let everyone know, the 2800's are selling at good prices on ebay...

Posted by: blackie Feb 25 2005, 01:31 PM

212,

Can I ask how these compare to the Viv 2000? (Flash strength etc)

Dave

Posted by: 212 Feb 25 2005, 01:45 PM

blackie, they both have a guide number of 79~80 depending on which version of the 2000 you get...The problem is, there are so many versions of the 2000. Some of them are only rated at guide number 60. Hard to tell what you have without opening it up.

Ebay? No...No those are all mine

Posted by: pntfrmr Feb 26 2005, 11:19 AM

Hey 212 good work if i understand this keeps it from going into sleep mode and having to be turned off then back on after a few hours correct. I haven't had time to play with mine anymore, and was wondering how to defeat the shut off.

Posted by: 212 Feb 26 2005, 11:49 AM

Yes, just as it nods off a little, it wakes up again.

Posted by: pntfrmr Feb 26 2005, 08:05 PM

Hey 212 have you ran a battery test on it yet? If SO HOW LONG DID THE 4 AA'S last?

Posted by: 212 Feb 26 2005, 08:25 PM

Tests were inconclusive, I did not do a long enough test. I am pretty sure they went 2 weeks but I would not swear to it. Once Brian made it possible to turn it on and off with the board, it no longer was important to me. It is a bonus though, the flash will not overcharge, and should last a long time.