Function Overview

Flash Power Control

The power pack is divided into two channels, A and B, and each is fitted with one head socket. An LED display for each channel indicates the available power in watt/seconds available at the head fitted to that channel.

A single Overall Power Selector reduces the pack’s total power by one or two f/stops and individual Channel Variator controls reduce each channel’s power by a further three f/stops in 1/3-stop steps. The Overall Power Selector has settings for both Asymmetric (A/B) and Symmetric (A+B) modes.

The selected power in Asymmetric mode is available independently from each channel whether or not any head is fitted in the other channel. The power available is controllable by using the appropriate Channel Variator and the associated display.

The full selected power in Symmetric mode is only available from Channel A, providing that no head is fitted in the Channel B socket. The total power available is shown on the Channel A Power Level Display and is controllable by means of the Channel A Variator only.

In general, the Overall Power Selector should be set to the lowest setting and the Channel Variator(s) set to the highest, consistent with the flash power and the distribution between heads required. This method provides the shortest flash duration for a given power output.

Whenever the power levels are changed, the pack automatically dumps any excess energy. The Test Button will flash while this is occurring. The time for the Ready Indicator to light up can be reduced by using the Test Button to flash the pack.

Modelling Control

The Modelling Mode Selector provides a common control for the modelling lamps of all fitted heads. Note that most heads are fitted with a modelling lamp On/Off Switch that overrides the control on the power pack. As well as Off, the pack provides three modelling modes, each available with Intermittent flash indication:

1.Off turns all lamps off.

2.Intermittent extinguishes the lamps when the pack is fired and turns them back on again when the pack is 100% recycled and Ready Indicator lights up. This provides a visual indication that the pack has been successfully triggered and has recycled.

3.Continuous turns the Intermittent mode off.

4.Proportional sets the lamp brightness in proportion to the appropriate Channel Variator setting.

5.MAX sets all lamps to full brightness.

6.Automatic 100% sets the modelling lamps of the head plugged into the channel with the highest flash power setting to 100% and the modelling lamps of the head plugged into the other channel in proportion to its variator setting.

HINT: The unit can be set to display power in terms of a decimal reading where 10.0 represents full

power. This display mode can be set by holding down the test button at switch on.

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Function Overview

Test Button and Ready Indicator Light

The green Test Button is lit whenever the power pack reaches 100% charge and is ready to be triggered. This light flashes when the pack is automatically dumping excess energy after a power-level adjustment.

Press the Test Button to:

1.Trigger the power pack for test purposes whenever the Test Button is lit.

2.Dump excess energy quickly while the Test Button is flashing. This avoids having to wait a few seconds for the pack to automatically dump energy.

Audio Indicator

An Audio Ready Signal is provided to beep when the generator is 100% recycled. Turn the Audio Switch On with the rocker switch. The red LED lights up when the Audio is on.

Photocell

A Photocell is provided to trigger the power pack from another flash source or IR Trigger. Turn the Photocell On with the rocker switch. The red LED lights up when the Photocell is on.

Fast/Slow Charge

The power pack has the facility to adjust the charging times. Turn the Fast/Slow Switch to Slow if:

1.Only a poor quality AC supply is available.

2.Several power packs are to share the same supply.

3.Fast recycling is not required.

Using the Slow setting whenever possible will prolong the life of the power supply.

Triggering System

The power pack may be triggered from the following sources:

1.An external sync source plugged into either of the Sync Sockets. This will trigger the power pack if the Ready Indicator is lit. The Sync Socket line is nominally +5V and designed for low voltage camera operation. These sockets may also be used with radio and IR triggers to provide a synchronised trigger.

2.The Test Button will fire the power pack only if the unit is charged and the Ready Indicator is either lit or flashing.

3.When the Photocell is switched on, the power pack will trigger in response to an external flash of light, if the Ready Indicator is lit. For best results, be sure that the red Photocell window is clearly exposed to the triggering light source.

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Bowens BW-7620 manual Function Overview, Triggering System