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Assembly and Operating Instructions for Kits


Operating Instructions for the AstroSplash Drop Controller


Assembly instructions for other kits


For our Guide to Drip Photography, click here.


See below for details of the functions and operation of the AstroSplash Drop Controller.


Refer to the following photo of the AstroSplash for the locations of the knobs, switches, jacks, and LEDs.

AstroSplash trigger cable 12VDC wall transformer
Trigger cable Power supply
valve 2.1mm power plug
Valve 2.1mm power plug


Powering the AstroSplash


The AstroSplash circuit and valves are powered by a 12V DC external source. There is no battery. The wall transformer shown above is the one that we provide for use with the unit. It accepts 120-240VAC at 50-60 Hz and has a power rating of 25W. It will provide up to 2 A of current, which is sufficient to power the AstroSplash timing circuit and three of our valves. If a current of 2A is exceeded, the fuse will blow inside the AstroSplash. This protects both the AstroSplash and the wall transformer. Note that the wall-side plug of the transformer is a standard 2-pin non-polarized US plug. An adapter may be needed for some countries.


If you use your own power supply, make sure it provides a 12VDC regulated output and is rated for at least 24 W. If you use your own valves, the total current draw of the valves must not exceed 1.5A in order to avoid blowing the fuse in the AstroSplash. Note that the connector for the power jacks is a standard 2.1mm plug shown above.


Plug the power source into the 12V IN jack at bottom right.


Replacing the fuse


If your unit stops working, you may have blown the fuse. Check by removing the lid and inspecting the fuse to see if it the wire inside the fuse is intact. If not, replace the fuse with one having a rating of 2A. These can be purchased at hardware/home improvement stores. Do not exceed the 2A rating; otherwise, you run the risk of burning out components in the AstroSplash circuit or the wall transformer itself.


Valve Outputs


The valves we provide are rated for 12V, 6W operation. If you use your own valves, they need to have these voltage and power ratings. The plug for the valve is a standard 2.1mm plug shown above. Valves may be plugged into any of the VALVE1, VALVE2, or VALVE3 jacks. Up to 3 valves may be operated at one time by the AstroSplash.


Trigger cable


The trigger cable is plugged into the TRIG jack at upper left. Pressing the push button on the cable initiates the timing sequence that triggers the valves and opens the camera shutter.


Camera Outputs


There are three outputs for cameras or other devices such as flash units and wireless transmitters. These are on the left side of the AstroSplash below the TRIG jack. All of the outputs are optically-isolated from the AstroSplash power train. This protects electronic equipment that you connect to the outputs. The outputs all act like simple circuit closures, which is what most camera shutters, flash units, and wireless transmitters require. The outputs are not identical, however. Descriptions follow.


3.5mm stereo plug

CAM: This is a stereo output that can be used for camera makes such as Nikon that require a half-press of the shutter button before the shutter will open. (Note that for Nikons, the half press is required even when the camera is used in full manual mode.) For this mode of operation, a 3-conductor cable with a 3.5mm stereo plug is required (see photo to the right). See this page if you need a shutter release cable.

3.5mm mono plug


The CAM output may also be used by devices, including cameras, that require only a single circuit closure for operation. In that case, use a cable with a 3.5-mm mono plug to connect to the AstroSplash. See the photo to the right.


AUX1, AUX2: These are mono outputs that can be used for camera makes such as Canon that do not require a half-press of the shutter button when operated in manual mode. These outputs may also be used for other devices that require a single circuit closure for operation.


Note that the auxiliary input of a Multi-Trigger 3 (or the external input of a Multi-Trigger 2) can be connected to any of the camera outputs. This will trigger the delay circuit of the Multi-Trigger.


Turning on the unit


The switch next to the 12V IN jack powers the unit on. The LED next to the switch will light and remain lit as long as the switch is in the ON position.


Clearing the water path


The CLEAR button is used to help clear the water path of air. With a valve or valves connected, holding the button down will keep the valve(s) open. Releasing the button will close the valve(s).


Pulses and timing


The AstroSplash works by producing a series of pulses when the TRIG button is pressed. Each pulse actuates all the valves simultaneously, and up to 3 pulses can be produced. There will always be at least one pulse produced. The two switches at the top are used to select whether you want a second or third pulse. With a valve connected and a water supply to the valve, a drop will be released with each pulse. Whenever a pulse is produced, the corresponding LED along the top edge of the box flashes.


The duration of each pulse is adjusted with the corresonding TIME ON knob. A longer duration will result in the valve remaining open longer and releasing a larger volume of water per drop.


The time interval between the end of the previous pulse and the beginning of the next is adjusted with the corresponding TIME OFF knob. Thus, this adjusts the time between successive drops. Note that there is no TIME OFF knob for Pulse 3, since the interval of time after the last pulse is irrelevant.


All time durations and intervals have ranges of 8 to 120 ms ( 1 ms = 0.001 s). The scale values for TIME ON and TIME OFF are accurate to ~5%, but the reproducibility is much better than that. For accurate time readouts of the signal voltage, an oscilloscope may be connected to the TEST jack.


The camera outputs are closed coincident with the onset of Pulse 1 when the trigger is pressed. Some electronic devices connected to a camera output will have a lag time in their function. A camera shutter, for example, may take 50 ms or more to open. For a typical drip apparatus, this isn't an issue, because the shutter will open while the drop is still falling toward the pool. Wireless transmitters respond much quicker with a lag of just a few milliseconds, while flash units are, for all practical purposes, instantaneous.





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