Thursday, March 20, 2008

Vivitar 283 Flash Hacking (again)

High- to low-voltage flash trigger circuit, from Sam Goldwasser's Electronics Repair FAQ:



Parts List:
5.1V zener diode
4M carbon resistor, 1/4 W (2)
22nF, 1000V capacitor
1N4148 signal diode
400V 1A triac (any will do)

I paid a visit to Alexan and, wonder of wonders, they had a new display: 22 nF, 1000V capacitors. In this photo (taken with a reversed 50mm lens), frolicking with zener diodes, Teccor triacs, and resistors:



I also bought correct-valued resistors and zener diodes (4.3M-ohms, 5.1V zeners), although the circuit worked fine previously with values that were way out of line.

A completed circuit (much neater than my earlier attempt):





Low-voltage trigger circuit installed inside Vivitar 283 (trigger voltage is now 3.5 volts, down from 110 volts, which is extra-extra safe):



The flash in all its glory..



With infinitely-variable power! (see hand-labeled "infinitely variable flash power adjustment"):



Professional external power supply cord! (some discarded extension cord, soldered directly to the flash main board):



And the non-Quantum power supply (saves a ton on AA batteries, and lasts forever):

9 comments:

Danny said...

hi, i need the complete list of parts for make my circuit. i´m have one Vivitar 283 with 276volts in the hot shoe. This 283 not working with my cactus wireless trigers, the cacutus only work with 12v and lower. You can List the component, in the image not understand the code for Triac and the transisor.
Thanks.
Danny

orly_andico said...

You can get the original circuit here:

http://repairfaq.cis.upenn.edu/sam/zpaofu1.pdf

I just used some random generic 400V, 1A TO-92 triac. You don't have to follow the model in the schematic.

Mark Hoy said...

Thanks for sharing. Does it make the PC sync port voltage safe?

Can you post or email me a larger version of photo number 4 (the one where you've installed the circuit)?

Thanks.

Alex said...

the original diagram doesn't mention the 22nf capacitor voltage, mine is much smaller than that, does it really need to be 1000v?

orly_andico said...

Doesn't have to be 1000V, anything over about 300V should be fine.

That said, a Yongnuo YN-460 is under $40. At some point, your time is precious and an unreliable hacked-together Viv 283 will just enrage you compared to the (new) Yongnuo.

Hafiz said...

My 22nF capacitor is rated 50V only, because the voltage across it is never higher than 5.6V (because the voltage is clamped down by the zener).

G. Hardy said...

I appreciate the hack for the Viv. 283. I have a question. I've got five 283s. I've measured the trigger voltages of each, and most they are past 400v. Doesn't your hack top out at 400v? What parts to I need to get their voltages down? I want to use them with my Cybersync radio triggers which have a limit of 300 volts.

Here are the voltages of my Vivitar 283 flashes:

349, 492, 517, 447, and 489v.

Thanks!!

orly_andico said...

G. Hardy,

You'd need a higher-voltage triac (like the STMICROELECTRONICS Z0103MA 1AA2 TRIAC, 0,8A 600V TO-92) and capacitor to go over 400V.

evandam said...

I tend to agree with Hafiz, the Voltage rating of the capacitor of 50V should be fine. The 5.6V ZD will clamp it way lower than that. orly_andico, could you explain why you think you need such a high rated capacitor? Want to make sure I'm not missing anything.