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Assembly and Operating Instructions for Kits


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Operating Instructions for the Multi-Trigger System (versions 2 & 3)


Assembly instructions for other kits


MTE-PCB assembled




Powering the Multi-Trigger

The delay unit

The photogate

The sound trigger

The instant flash output

The external input

Triggering a camera with the Camera Opto-Switch

Using the Opto-Switch to trigger a flash unit

Using wireless transmitters


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The starting point for this manual is that you've already assembled and tested your Multi-Trigger enclosure (assembled unit shown above) and that you've also prepared the input and output cables. For reference, all components of the Multi-Trigger system are shown below. Those that are not included with the MTE-PCB kit are indicated as accessories. However, use of all the components will be described in this manual.


Click on any image for a larger view.

Included with the MTE-PCB (assembly required)

Interrupter photogate cable

Photogate cable (interrupter type) with 3.5mm stereo connector

Individual emitter and detector photogate cable

Photogate cable (individual emitter and detector type) with 3.5mm stereo connector

Microphone cable

Microphone cable with 3.5mm mono connector

Accessories for the Multi-Trigger system

Trigger cord for flash PC

RCA to flash PC

Trigger cord for hot shoe

RCA to flash foot adapter

Trigger cord for Vivitar 283/285/2700

RCA to Vivitar 283/285/2700

A trigger cable such as one of the three shown above is needed to connect the flash outputs of the MTE-PCB to a flash unit. The RCA to flash foot adapter is the most nearly universal.

External input cable

External input cable

(The 3.5mm mono connector is supplied with the MTE-PCB.)


Female RCA to 3.5mm mono male adapter


This adapter can be used to convert a 3.5mm mono jack to an RCA jack.

(This adapter is available here.)

AC-to-DC 9V adapter

AC-to-DC 9V adapter

(This adapter is available here.)

The row below shows the components of the Camera Opto-Switch Kit for using the MTE-PCB to actuate a camera shutter.

Camera Opto-Switch

Camera Opto-Switch box

RS-60E3 shutter cable

Canon RS-60E3

RS-80N3 shutter cable

Canon RS-80N3

MC-30 shutter cable

Nikon MC30

Trigger cable for Opto-Switch


Trigger cable to connect TRIG output of Camera Opto-Switch

to camera output of the MTE-PCB

Cable to connect Camera Opto-Switch to camera shutter

(Use the connector type for your camera model.)


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


MTE-PCB controls


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Note: It's best to have the unit turned off when inserting plugs into the input jacks.


Powering the Multi-Trigger


The Multi-Trigger circuit is powered by 9V DC. This can be supplied either with a 9V battery or an AC-to-DC 9V adapter. The AC/DC jack on the enclosure accepts a standard 2.1mm plug such as the one on the adapter shown above.When the AC-to-DC adapter is plugged into the MTE-PCB, the battery is automatically disconnected internally.


When the on-off switch is flipped to the ON position, the LED next to the switch will light. If you're operating on battery power and the light is dim, that may indicate a weak battery. When the battery is weak, the unit may still function but demonstrate erratic behavior. That's a sign to replace the battery or use an AC-to-DC adapter.


The Delay Unit


You can test the operation of the delay unit without connecting an input. Use this starting configuration:

  • Power switch ON

  • Input selector switch on MIC (Note that when no input cable is connected to the enclosure, this test of the delay unit only works with the input set to MIC.)

  • DELAY/10 switch on 0.5s

  • TIMEOUT knob turned fully counterclockwise

  • All other knobs turned to their halfway positions

  1. Press and release the TEST button. You should see the TRIG LED light momentarily. This indicates that the delay unit triggered.

  2. Turn the COARSE DELAY all the way clockwise. Press the TEST button. You'll notice a longer delay before the trigger indicator lights. Turning the FINE DELAY clockwise also increase the delay. However, you're not likely to notice this visually, since the FINE DELAY control provides about 0.05s of delay at the most.

  3. Turn the TIMEOUT knob all the way clockwise and press TEST. TheTRIG LED will remain lit for about a second. During this period of time, the delayed output of the delay unit is inactivated. When using a flash, setting a long timeout prevents multiple exposures. This comes in most useful when using the sound trigger. Loud sounds that last for a while or that produce echoes can set off the sound trigger repeatedly. Setting a long timeout provides time for the sound to decay before the flash can discharge a second time. When triggering a camera, a long timeout prevents the shutter from actuating repeatedly.

  4. Turn the TIMEOUT back to the original position, and flip the DELAY/10 to the 0.05s position. When you press the TEST button, there will be no noticeable delay even with the COARSE DELAY turned all the way clockwise. This is because all delays are divided by 10 from the original position. This is useful when you need particularly fine control of the delay for events for which the maximum delay needed is less than about 0.05s.

  5. Now flip DELAY/10 back to the 0.5s position. Using the appropriate trigger cable for your flash unit, connect the FLASH DELAYED output jack to your flash unit. Turn on your flash. When you run a finger through the photogate or push the TEST button, the flash should discharge.

The above functions will work the same when you have an input cable connected. That connection will be described next.


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The Photogate


With the unit turned off, insert the 3.5mm plug of the interrupter photogate cable into the PG jack. Be sure to push the plug in all the way; otherwise, the photogate won't work. Flip the input selector to PG and make sure the PG SENS knob is turned to its halfway position. Turn the unit on. The PG LED on the right side of the panel should light as soon as you turn on the unit. This LED indicates that the photogate beam is unbroken. Now run a finger through the interrupter. The alignment indicator will go out, and theTRIG LED will momentarily light and the flash unit discharge after whatever delay you've dialed in.


Now turn off the unit, remove the interrupter photogate cable, and insert the other photogate cable. Tape the emitter and detector to the table pointed at each other a few inches apart. Turn on the unit. The PG LED should come on. If it doesn't, check the alignment of the emitter and detector. If you wish, move one of them to the side to verify that the PG LED responds correctly. Now turn the PG SENS knob clockwise until the alignment LED goes out. This happens when the sensitivity is set too high. In order to set the sensitivity at the highest it can be without going over the threshold, dial the knob back to the point where the LED comes back on. If you're running on battery power, the sensitivity may drift as the battery runs down. So if you have the sensitivity adjusted to the threshold, you may have to readjust it as the battery weakens. You also need to readjust the sensitivity when you change the separation of the emitter and detector. Whenever you position the emitter and detector for an experiment, be sure to anchor them as rigidly in place as possible in order to maintain alignment as well as the sensitivity adjustment.


Turn off the unit and disconnect the photogate cable. Leave the flash connected for testing the sound trigger.


The Sound Trigger


Plug the microphone cable into the MIC jack and flip the input selector to MIC. Turn the SOUND SENS knob to the halfway position and turn the TIMEOUT all the way clockwise. Turn on the unit. Snap your fingers or tap the microphone. The TRIG LED should light and the flash discharge the same as in your tests of the delay unit and photogate. With the TIMEOUT set to 1s, the flash will remain inactive for about a second. This is the typical TIMEOUT setting to use with the sound trigger in order to avoid multiple images from repeated triggering of a flash. Of couse, you may use a smaller TIMEOUT if you wish.


If you want to adjust the sensitivity of the sound trigger, do the following. Turn the SOUND SENS knob clockwise until the flash will no longer discharge. The reason that the flash can't discharge at or beyond this point is because the sound trigger is holding the flash in an on state. Turn the SOUND SENS knob counterclockwise just enough so that you can discharge the flash again. This adjusts the sound trigger for maximum sensitivity. If you wish to have less sensitivity, turn the knob further counterclockwise. If the greatest sensitivity isn't a requirement, just leave the knob at its halfway position.


If you connected ST OUT rather than the instant flash (INSTANT FLA) output, you can trigger a flash using the direct output of the sound trigger. Since this output of the sound trigger bypasses the delay unit, the sound trigger is in its most responsive state. But first flip the input selector to PG. This disconnects the sound trigger output from the delay unit input. This is important if you're using a flash unit that has high-voltage (>80 V) terminals, as the flash can burn out the 556 timer otherwise.


Turn off the unit and disconnect the microphone.


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The Instant Flash Output


If you connect the instant flash output rather than ST OUT, then when you connect a flash unit to INSTANT FLA, the delay unit will discharge the flash unit immediately. With this output, the coarse and fine delays, timeout, and divide/10 switch have no effect. If you want to get flash double exposures a short time apart, you can connect flash units to both the instant and delayed outputs.


The External Input


The external input jack can be used to connect other triggers to the delay unit. When a 3.5mm mono plug is inserted into EXT IN, both the photogate and sound trigger circuits are internally disconnected from the delay unit. You can connect as an external input any trigger that produces a short circuit as an output. Examples include the Amplified Sound Trigger as well as a simple contact trigger such as the one shown here. In order to see how this input works, plug the external input cable into the enclosure. Turn on the unit and simply touch together the two bare wires at the end of the external input cable. (If you haven't prepared a cable, you can unscrew the plastic jacket from the extra 3.5mm mono plug that comes with the MTE-PCB kit and jump a wire across the contacts.) The delay unit will operate the same as if using the internal sound trigger or photogate.


You can also trigger the unit externally from either the instant or delayed output of another delay unit. This means you can chain delay units for the purpose of triggering multiple flash units.


In the event that you want to plug an RCA-type cable into the external input jack, you can use an adapter such as the one shown in the last row of the table above.


Triggering a Camera with the Camera Opto-Switch


Important: Don't connect a camera shutter or wireless controller directly to either of the CAM outputs. You must use a Camera Opto-Switch with these outputs.


In order to trigger a camera, you'll need a Camera Opto-Switch and the associated cable. Connect the Opto-Switch according to the instructions for that unit. Connect the trigger cable of the Opto-Switch to either the INSTANT CAM or DELAYED CAM output jack of the Multi-Trigger. You can then trigger your camera the same as you would a flash unit by using the TEST button, a photogate, sound trigger, or an external trigger.


The Opto-Switch will not function from the flash outputs.


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Using the Opto-Switch to Trigger a Flash Unit


The Camera Opto-Switch can be used to trigger flash units as well as cameras. This makes it possible to trigger two flash units essentially simultaneously. You could connect one flash to the DELAYED FLASH output jack and a second flash through an Opto-Switch to the DELAYED CAM output. While there may a small time difference between the discharge of the two units, this will not be noticeable except for particularly high-speed events.


A requirement of triggering a flash unit using the Opto-Switch is that the flash unit may have no more than 80 V across its terminals. Higher voltages may burn out the optoisolator in the Opto-Switch. The requirement of having less than 80 V across the flash terminals is met by virtually all modern flash units. Older units, such as Vivitar 283s manufactured before 1984, have a few hundred volts across the terminals, but units manufactured after that time have only 10 V.


In order to trigger a flash unit with the Opto-Switch, you'll need to convert the CAM jack of the Opto-Switch to the RCA type so that it will accept a flash trigger cable. The adapter shown in the bottom row of the table above will work for this. Assuming you have the adapter in place, do the following:

  • Connect the trigger cable of the Opto-Switch from the TRIG input of the Opto-Switch to either of the INSTANT CAM or DELAYED CAM outputs of the Multi-Trigger.

  • Connect the flash trigger cable from the CAM jack of the Opto-Switch to the flash unit.

  • Flip the Shutter switch on the Opto-Switch box to ON. (The FOCUS switch isn't used in this application.) You can then trigger the flash using the TEST button, photogate, sound, or external triggers.

Using Wireless Transmitters


You can use the Multi-Trigger to trigger a wireless transmitter in order to discharge a remote flash connected to a wireless receiver. There are two ways to connect the transmitter to the enclosure.


Method 1. Connect either of the flash outputs (or ST OUT if you have it connected) of the Multi-Trigger to the input of the wireless transmitter. The cord needed for this will depend on the transmitter. As an example, the PocketWizard Plus II can be triggered either through a 3.5mm phone jack or a hot shoe. In that case, you could use the RCA to flash foot adapter shown in the table above. Alternatively, you could prepare a cable with a male RCA plug on one end and a male 3.5mm mono plug on the other.


Method 2. Connect either of the camera outputs of the Multi-Trigger to the TRIG jack of a Camera Opto-Switch. Then connect the CAM jack of the Opto-Switch to the wireless transmitter. You could use the adapter shown in the last row of the table above to convert the 3.5mm CAM jack to an RCA jack. Then you could use the RCA to flash foot adapter to connect to the wireless transmitter.


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