Viv 2000 mod and data (31657 board version)., Eliminate external components and low power mod. Options

[dkirk]

Have been digging into various versions of the Vivitar 2000 in an attempt to understand existing mods, and to develop new mods (if possible) to further reduce capacitor discharge rates and to also remove external components that are no longer used.

Below are my updated mods for the Vivitar 2000 that uses the 31657 board. The mods include the low power mod that has been previously posted by others (steps 1 & 2 below), along with my new mod to remove the external 3.3ufd capacitor that just takes up space. The 3.3 ufd capacitor can be removed since the trail camera builders are not using the bounce back feature of the Vivitar 2000 flash unit.

Basic Modification Steps
1) Remove or clip one leg of the 1 Meg ohm resistor that feeds the Neon Bulb (see picture).
2) Remove or clip the 10 K ohm resistor (see picture).
3) Remove or clip the 22 K ohm resistor (see picture).
4) Clip the wires that go to the 31657 board that come from the external bounce back sensor (see picture).
5) Clip the wires that go to the 31657 board that come from the externally mounted 3.3 ufd (yellow) capacitor (see picture).
6) Jumper the pins 1 and 2 of the large SCR (CR3AMZ) (see pictures).

 Viv2000_31657_board_pic_1.jpg ( 103.19K ) Number of downloads: 255

 Viv2000_31657_board_pic_2.jpg ( 72.79K ) Number of downloads: 185

 Viv2000_31657_board_pic_3.jpg ( 59.74K ) Number of downloads: 157


I have also attached capacitor discharge data for the above mentioned flash unit using both a 6 Volt SLA battery and 4 AA NiMH batteries to charge the flash unit.
 Vivitar_2000_with_31657_board_discharge_data.pdf ( 12.87K ) Number of downloads: 79


(As always modification of commerical products is done at your own risk. Use extreme caution since high voltage exists within flash units. Take proper steps to assure all energy has been discharged (from the capactiors, etc.), before touching any component within the flash unit.)

(Thanks to Hags member willraygreen for providing various Vivitar 2000 units for my analysis, and for his trust in me to not blow up his flash units).

Enjoy,
Don

This post has been edited by dkirk: Aug 9 2006, 10:07 AM

[livz2hunt]

I read everywhere that you should discharge energy from the flash units, but no one says how to do it. Being the electronic genius that I am, give me a few ponters here.

[dkirk]

Hello livz2hunt,

I first try and manually fire the flash unit by touching the two flash trigger wires together (these wires also have high voltage, so make sure you don't touch them with your bare hands). Then I place a low resistance across the large capacitor to discharge it the rest of the way. The value of resistance is not really cricital. I use 15 ohms (two 30 ohm wire wound resistors in parallel, 10 watts each). The capacitor will discharge in under a second using the 15 ohm resistor combo. Again be careful that you don't touch any bare connections/wires with your hands/fingers.

When I don't have my handy little resistor combo available, I place a piece of wire across the capacitor to discharge it (after I fired the strobe tube), but this still causes a large spark and pop.

Don

[212]

Good advice, also be aware the resistor can tend to get hot! Put some wire on the resistor to hold it with just in case

[oddball64]

Hello livz2hunt,

I first try and manually fire the flash unit by touching the two flash trigger wires together (these wires also have high voltage, so make sure you don't touch them with your bare hands). Then I place a low resistance across the large capacitor to discharge it the rest of the way. The value of resistance is not really cricital. I use 15 ohms (two 30 ohm wire wound resistors in parallel, 10 watts each). The capacitor will discharge in under a second using the 15 ohm resistor combo. Again be careful that you don't touch any bare connections/wires with your hands/fingers.

When I don't have my handy little resistor combo available, I place a piece of wire across the capacitor to discharge it (after I fired the strobe tube), but this still causes a large spark and pop.

Don

Yea, and the blue spark and "big" pop scares the crap right out of you!

[Matt in MO]

Don:

Do steps 3,4,5 &6 have any performance advantage or are they simply done for the convience/space?

I've been bit by a D380 and can't imagine getting hit by the 2000's cap. Besides discharging I also tape over anywhere I can.

Matt

[dkirk]

Hello Matt,

Great question.

I tested the original low power mod (steps 1 & 2) before I did the rest of my modifications, and there appears to be no additional performance gain (no additional reduction in discharge rate) when you do the rest of my mods. Therefore steps 3 through 6 only buy you real estate (no change in performance) for this version of the Vivitar 2000.

Don

This post has been edited by dkirk: Aug 9 2006, 11:35 AM

[212]

dkirk, I hate to embarrass you here, but every time I read your posts I have to comb my hair and sit up straight because I know it is important.

Thank you soooo much!

[tree sight]

I'll second that.

tree sight

[Matt in MO]

THIRD!

just for everyone's FYI, I had an issue with a 2000/Peanut that usually wouldn't flash when it was supposed to, but would if you so much as breathed on it. Turned out to be a defective jack that the peanut plugs in to.

[treetop]

I took a picture of what I made to discharge the flash and It works Great !!
I used
2.2k ohm resistor
12 " piece of scrap wire
2 wire connectors Just bent the ends to make a sort of point
1/4" heat shrink

heres a pic

[novascotiahunter]

I took a picture of what I made to discharge the flash and It works Great !!
I used
2.2k ohm resistor
12 " piece of scrap wire
2 wire connectors Just bent the ends to make a sort of point
1/4" heat shrink

heres a pic

thanks Treetop for the pic, I'll definately make one of these up, got to be better then the last thing I used to discharge the flash....my fingers Ouch!!!

[treetop]

Don did I do okay ?? It did work !! I am ready for a reply I brushed my hair and cleaned up for you !!

[dmach8]

Dkirk, nice work I have the df 500 and some of us members fried them with the low power mods, I believe it blew a transistor, not sure now, but replaced it with part numbers others had posted and I cant get it to charge now.. Any way to go about troubleshooting it or get another one and start over

[dkirk]

Don did I do okay ?? It did work !! I am ready for a reply I brushed my hair and cleaned up for you !!

Hello Treetop,

When you use the 2.2 K ohm resistor, the capacitor will take a little time to discharge, so we need to make sure the resistor is left connected long enough in order to discharge down to a safe level.

Here is a chart showing the amount of time to discharge various capacitors using your 2200 ohm resistor.

 Cap_Discharge_Using_Resistor.jpg ( 22.44K ) Number of downloads: 3


Note : after 1 time constant the capacitor will be discharged to approximately 37% of its starting value, and after 5 time constants it will be discharged to approximately 0.7% of its starting value.

In both your case and my case we are far exceeding the normal power rating of the resistors based on the peak current we generate during discharge. That is why I normally check the temperature of my discharge resistor after discharge to see how badly it's being abused (if it gets too hot, then you need to use a higher power rated resistor, or change to a resistance value that is more suitable). This is one good reason why we should try and avoid discharing a fully charged capacitor with the resistor, and try and dump most of the energy stored in the capacitor by first firing the flash tube.

Since both of our set ups must discharge the same amount of energy, I suspect the body of your resistor (which appears to be a 1/4 or 1/2 watt resistor) gets much warmer than mine since you have so much less thermal mass due to the physical size of your resistor body compared to the two large wire wound resistors that I use.

Regardless of what resistor we use to discharge the capacitor, it's a good idea to place a wire across the capacitor after we think we have safely discharged the capacitor just in case our discharge resistor device has failed (or measure the capacitor voltage with a known good volt meter).

Sorry for my rambling, but suspect your getting used to it by now.

Don