Monday, March 28, 2011

Taking Apart The LP160

So, I've been poking and prodding at the LP160 to figure out the best way to build mods for the flash. In doing so, I get to see the underlying guys and figure out what all is in the flash unit!


Some material/parts specs:
  • 1100 uF 330V Photo Flash Capacitor
  • 600V, 100A MOSFET IGBT
  • MicroChip PIC MCU
  • All LED(s) are surface mount LED(s)
Operational Specs:
  • Capacitor is charged to approximately 325V
  • 6V operation expected from batteries, based on silk screen on board


6 comments:

  1. Hi,
    Please can you elaborate some more about how to take apart the lp160? I'm trying to do it by myself but did't come too far :) becouse didn't want to break something..

    Thanks

    ico

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  2. Hi ico,

    You mainly just need a screw driver of the right size. However, like most flash units, there are quite a few screws and once some parts open, like the flash head, some pieces will fall out and be hard to put back into place.

    Unless you really need to open up your flash and have high voltage safety in mind, I would not recommend it. Also, it will invalidate your LP160's warranty.

    However, if you really do want to open up the unit:

    * Screws on the underside of the flash head(x4)
    * Screws at points around the hinge/swivel(x4) (might need to swivel head to the side to see the screws)
    * screws on the body(from the bottom and from in back)

    Note/warning:
    * high voltage capacitor is in the hinge part of head
    * consider everything in the flash head part to be high voltage
    * the wires connecting to the hot shoe part are tiny and weak. They can break off VERY easily.
    * There is on screw behind the back display sticker.
    * There are some latch bits on the side of the hinge(round circle areas).

    Basically, the one LP160 I've taken apart completely, I've not been able to put back together and don't expect it to ever go back into full operation. It is totalled.

    The remaining LP160 I have is only going to be modified in a limited manner, when I've figured out the key solder points for what I want to do.

    Currently, I'm working on trigger circuits and testing them on a Vivitar 283. But because the two use different technologies to start and stop the flash power, I'm not 100% sure I can "back-port" the solution from the 283 to the LP160.

    LP160 - IGBT voltage up/down for start/stop of the current to the flash tube.

    Vivitar 283 - Thyrister/SCR to start the flash, and another thyrister/scr to dump the remaining power into a neon bulb/mini flash tube to stop the flash. Yes, the lower the power level, the more of the energy/power is wasted. ;_;

    Think of it this way: If you open it... you need to be prepared that something may break. If you can't take that chance, don't open it.

    ReplyDelete
  3. Woow this is what I call quick answer! :)

    I tried to open just the bottom part. What I want to do is to be able to use AC adapter to power the flash. I have some 5V adapter and matching connector which should go between batteries and PCB. This way when I connect AC adapter, the battery gets disconnected (if battery present). The electric part isn't problem for me, opening the plastic case and not break it is. BTW I tried to remove the sticker and didn't find the screw :)

    Another solution would be to use some dummy AA batteries and power the flash that way.

    3rd solution would be to use some crocodile connectors and just connect them to springs down in the battery socket. That would look really bad :)

    The 1st solution seems to be the best to me. I tried again to take it apart... but didn't have the nerve to try to open latches where the 2 parts of flash can turn around...

    I would probably use the dummy AA batteries and somehow combine them wich connector placed on another side from PC&jack connectors. That seems to be less invasive method and the way to go for me.

    But still, thank you for info. Especially the thing about not to be able to put it again together. :)

    ReplyDelete
  4. Ah, external power. Nice.

    I would avoid the alligator clips and avoid opening the LP160 entirely. Not necessary.

    Make some dummy AA batteries, like shown here:

    http://photo.net/photography-lighting-equipment-techniques-forum/00VoM0


    Then, modify the battery door of the LP160 by drilling a hole through the door, between the two metal spring connectors. Solder your cable to those two metal tabs, add in a protection diode to avoid reverse voltage, then string the cable out through the hole towards your external power source.

    So what you end up with is: 4 dummy AA batteries inside the LP160. A modified sliding door that has a cable running out, leading to your power source.

    Your external power source can then be:

    - sealed lead acid battery (6V variety)
    - AA/D battery packs
    - Walwart AC->DC adapters. (beware, not sure what the amp draw of the flash is while it is charging. Would be good to get an ammeter there and measure it between flashes to make sure you don't risk burning out the AC adapter)

    Voila, no need to crack open the LP160 if the goal is external power!

    ReplyDelete
  5. * the wires connecting to the hot shoe part are tiny and weak. They can break off VERY easily.

    mmmm yes. I wish I had read this before hand....
    Can you please tell me which wire goes where? The solder fell off with the wires...and I do not know where to solder.

    Thanks very much, Yuriy Floppypancreas@gmail.com

    ReplyDelete
    Replies
    1. Hi Cricket,

      ** 1st off, warning, high voltage inside of the flash unit. Take precautions. **

      The LP160 hotshoe has several pins, however, only 2 contact points are relevant, since the unit has a straightforward "SHORT-TO-SYNC" operation.

      What you will need is a multimeter with continuity or resistance testing.

      1) Switch your meter to continuity test mode.
      2) place one probe tip against the external GND plate of the hotshoe "foot".
      3) With the other probe of your meter, test the pins on the inner side of the hot shoe plate. The one that registers low resistance or continuity will be the "GND" Note this in your notebook.
      4) Do the same with the center or SYNC pin on the outside part of the hotshoe. This will be the SYNC pin.
      5) Once you know which two pins are the GND and SYNC, you can then solder the wires back.

      You can test which lead goes to ground by test triggering your flash by shorting the GND and SYNC with a diode. That will indicate direction of current flow and thus which is GND.

      Then, just solder back in place to the pins you had marked off, and it should work fine.

      Delete