PowerSlave 7 Hookup Information

Version 1.6, February 27, 2004

WARNING:  CONNECTION OF THIS DEVICE TO A CAMERA FLASH UNIT MAY INVOLVE HAZARDOUS VOLTAGES, AND SHOULD ONLY BE ATTEMPTED BY THOSE QUALIFIED.

These modifications are not recommended or condoned by Vivitar or any other manufacturer, and will void the warranty on the flash unit if made.

While I do not know that a shock from the flash capacitor could be lethal, I don't know that it CAN'T.  It can certainly cause one to hurt oneself.  Any attempt to duplicate the modifications described herein is done strictly at the risk of the party attempting the modifications.


The PowerSlave version 7 (PS7) is designed to connect to the "Vivitar Electronic Flash 2000 with bounce", part number 231544C or a compatible flash unit.  Apparently several different versions of the "Electronic Flash 2000" have been produced over the years, and I do not know whether any versions other than the one used for the prototype are similar enough to be compatible with the PowerSlave.  The Kalimar 175A flash unit as well as the Kodak Gear "Automatic Camera Flash" model 80030 have also been used successfully and appear to be electrically identical to the Vivitar unit.

A newer version of the Vivitar Electronic Flash 2000, part number 231544J, is also usable but somewhat different internally.  Disassembly of this version will not be detailed here at this time, but electrical connections are shown on a linked page below.

The PowerSlave serves two main functions:

    1.) It optically detects a camera flash to trigger a slave flash unit (either on the camera's first flash or second flash)
    2.) It measures the voltage on the flash capacitor and turns on the inverter only when needed to keep the capacitor charged with approximately a 7-volt range, allowing it to stay on and ready to flash for weeks at a time.

The design also measures the supply voltage, and if the batteries drop below about 3.9 volts for any period of time, the PS7 will stop charging the flash in order to avoid draining the batteries low enough to possibly damage them.  Optionally, a CdS photocell may be added to disable charging the flash during daylight hours.

Part of the installation involves cutting two resistors in the Vivitar unit to disable the "Ready" indicator as well as the automatic adjustment circuitry;  the unit will flash at nearly the full capacitor flash energy (which is basically the same as if the flash unit were set to "Manual").  This must be done to avoid their draining the flash capacitor, which would drastically reduce battery life.

Above is the basic hookup information for the PowerSlave version 7 (PS7).

If the Photocell Daylight Sensor is omitted, the PS7 will keep the flash unit's capacitor charged and ready to flash all the time.

If the 1st/2nd Flash Select Switch is omitted, the PS7 will trigger on the second flash (suitable for the Olympus D-370 and D-380 cameras, and probably others).  If operation is desired with cameras that use a single flash (i.e. film cameras), either a switch or a jumper connecting the two points must be installed.

Flash Unit Modification

Note: The following steps are valid for the older 231544C and 231544W models.  The 231544J is somewhat different and not detailed here.

Here's what the flash unit looks like in the packaging (click the images for larger views):

The first step for modification is to open the flash unit.  This is done by opening the battery compartment and slitting the battery direction labels along the dividing line of the two plastic "halves" of the case;  next the four screws can be removed that hold the hot-shoe "foot", and the case can be pulled open:

Once the case is open and the circuit board is accessible, the hot-shoe "foot" can be de-soldered, and the board removed from the case for access.

There are (at least) four different versions of the circuit board used in the flash unit having model numbers 231544C, 231544W, or 231544J.  Boards are numbered 31057, 31657, or DF500 on the bottom.  To see board-specific instructions, click the most closely-matching picture:


31057a


31057


31657


DF500


©2002-2004 Jon Barclay, all rights reserved.