HiViz.com breadboard trigger circuits have SCR outputs to act as electronic
switches for flash units. In some cases, you may wish to
trigger a camera rather than a flash unit. The Camera Opto-Switch
Kit is designed to trigger electronic camera shutters from
the outputs of HiViz.com breadboard circuits. The Opto-Switch would also be used to trigger a camera with the SK3 Sound Trigger and the PCB for Multi-Trigger (MT-PCB3). In order to check whether your trigger circuit requires an Opto-Switch, see this chart.
While the Camera Opto-Switch can also be used to trigger
flash units, some older flash units may have several
hundred volts across the PC terminal. This voltage may
burn out the optoisolator IC. Therefore, we only recommend
using the Camera Opto-Switch with flash units if you're sure that the flash unit has low voltage (<80
V) across its terminals.
When wired and connected correctly, the Camera Opto-Switch
can't damage your camera. The optoisolator provides electrical
isolation for the camera. The customer assumes liability
for any consequences of incorrect wiring. Most likely,
these would simply be that the trigger wouldn't work but
with no damage to the camera. The fact that the input
and output sides of the PC board are separate minimizes
the possibility of an inadvertent electrical connection
across the optoisolator.
For wire cutting, trimming, and stripping:
wire strippers, needle-nose pliers, small diagonal cutter
(recommended for snipping wire ends after soldering)
Wire cutters and
For soldering: 15-30 watt soldering iron,
solder, wet sponge, magnifying glass recommended (to
view solder connections up close)
For project box assembly: small wrench or
For drilling holes in the project box lid: drill motor, 3/32", 1/4", 9/32" bits (The 1/4" bit can be used in place of the 9/32" bit and the hole widened with a file.)
Solder in a well-lit, well-ventilated, open
area. Avoid contact with all metal surfaces
on the iron.
Keep the tip of the soldering iron clean
by wiping it against a wet sponge or towel
before and after each use. A clean tip should
look shiny and silvery; any yellow or black
material on the tip will get into the solder
and may weaken your solder joint.
Once the tip of your soldering iron is clean,
touch a bit of solder to the tip just before
use. This is called tinning, and helps the
solder run more evenly.
Heat the connection to be soldered by holding
the soldering iron to it, until solder applied
at the junction between the two melts and
flows freely. This ensures the connection
and the solder are both hot enough to yield
a good solder joint. This should take no more
than 10-15 seconds. After the connection is
heated, try to get solder along the entire
length of the connection by briskly moving
the solder and iron along.
Avoid touching only the solder to the connection,
and then the soldering iron to the solder
to melt it onto the connection. The connection
will be cooler than the melted solder and
won’t form a good solder joint.
Let new solder joints cool for several seconds
before examining them. There should be solder
all the way around the connection, forming a
rigid joint. When done, unplug your soldering
iron and let it cool.
About the images: Clicking on any image will open a larger version on top of the page. If you prefer to have the larger images open in a different tab or window, right click on the image and make the appropriate selection.
Switch box and circuit board assembly
1: Adding the 8-pin IC socket
Insert the 8-pin IC socket into the holes in
the unplated side of the PC board as shown to
2: Crimping and soldering the legs of the IC socket
Turn the PC board over to show the plated side.
Bend the legs of the IC socket outward to hold
it in place (see the upper photo).
Solder each leg of the IC socket to the corresponding
copper strip as shown in the lower photo. In order
to get a good solder joint, make sure the solder
runs freely on the copper contact and covers the
leg. Also make sure the solder doesn't bridge
across to a neighboring contact. A magnifying
glass comes in handy here. Solder bridges can
be extremely fine and hard to see. If you get
a solder bridge, you can remove it by running
the tip of the soldering iron between the contacts
that are bridged.
If the solder beads up and seems to sit on top
of the copper, it's possible that you have a cold
solder joint. Such connections do not conduct.
You may think that you've made the connection
when, in fact, no current will flow. You can guard
against cold solder joints by heating the copper
with the tip of the soldering iron and then touching
the solder to the copper rather than to the tip
of the soldering iron. If you think you may have
a cold solder joint, reheat the solder and try
to draw off the solder bead. Then resolder.
3: Adding the resistor
Insert the legs of the 100-Ω resistor through the non-plated side of
the PC board as shown in the upper image. Then
turn the board over and solder the legs onto the
copper contacts as shown in the middle image.
Snip the legs off down to the solder. The completed
solder joints are shown in the lower image.
Step 4: Adding the input wires
Strip back the insulation on the red and black
hook up wires about 1/8 inch.
Insert the wires into the board as shown in
the upper photo.
Turn the board over and solder the wires to the
copper contacts. Snip the wires off down to the
solder. (lower photo)
Step 5: Adding the output wires
Strip back the insulation on the yellow and one
of the blue hook up wires about 1/8 inch.
Insert the wires into the board as shown.
Turn the board over and solder the wires to the
copper contacts. Snip the wires off down to the
solder. (photo not shown)
6: Drilling the project box lid
A template is supplied to lay out the holes to be drilled in the lid of the project box. Lay the lid on a table with the underside facing up. Then place the template inside the lid as shown to the left. Use a nail or punch to mark the locations of the centers of the holes. Then remove the template and drill the holes to the indicated diameters.
7: Adding the first toggle switch to the project
After drilling the holes, turn the lid over.
It should look like the upper photo to the left. Take one of the toggle switches and remove the
nut, lock washer, and retaining ring. Slip the
switch into the lid from below as shown in the
lower photo. Lower the retaining ring onto the
switch so that the tab on the inside of the ring
slips into the channel on the switch. Then orient
the assembly so that the tab on the outer side
of the ring slips into the small hole on the project
box. While holding the assembly in this position,
drop the lock washer onto the switch and then
screw on the nut. Tighten with a wrench or pliers.
8: Adding the remaining components to the project
a. Add the second toggle switch to the project
b. Remove the nut and washer from the pushbutton
switch. Slip the pushbutton into the center hole
from below. Place the washer over the threads
and screw on the nut. Tighten with a wrench or
c. Remove the nut and the metal tab from the
RCA panel jack. Slip the jack down into the lower-right
hole on the project box. Then slip the washer and ring onto
the jack from below and screw on the nut and tighten.
d. Remove the nut from the 3.5mm stereo jack.
Slip the jack into the upper-right hole from below.
Then screw on the nut and tighten.
The completed assembly is shown from above (upper
photo) and below (lower photo).
9: Connecting the yellow wire
Now you'll connect wires between
the components on the lid of the project box.
Start with a 2-in section of yellow wire. Strip the wire back about
a quarter of an inch on both ends. Loop one end
of the wire through lug 2 of the
stereo panel jack as shown in the upper photo.
Note that the jack has three terminals. The lower
photo should help to identify the lugs.
Loop the other end of the
wire around the left lug of the upper toggle
10: Connecting the blue wires
For the next connections, you'll
need 1-in and 2-in sections of the blue
wire. Strip the ends. Loop both of the wires through lug 1 of the stereo jack.
Loop the other end of the shorter
wire through either lug of the pushbutton
Loop the other end of the longer
wire to the center lug of the upper toggle switch.
11: Connecting the white wires
For the next connections, you'll
need two 3" sections of the white
wire. Strip the ends. Loop both of the wires through
lug 3 of the stereo jack.
Loop the other end of one of the wires through the unused lug of the pushbutton
Loop the other end of the second wire through the left lug of the lower toggle switch.
Step 12: Soldering connections
You can solder some of the connections. These are the ones circled in green in the photo to the left. The connections that can be soldered now include all of the pushbutton and stereo jack connections and the left lugs of both switches. You'll be adding two more wires to the center lugs of the switches in a later step, and you'll solder those lugs at that time.
13: Soldering the optoisolator input wires to
the RCA panel jack
Now you'll start soldering wires
from the PC board to the components on the lid
of the project box. Strip back the free ends of
the red and black wires and loop them through
the contacts of the RCA panel jack as shown in
the upper photo. Note that the red wire is connected
to the center contact. A close up of the connections
is shown in the lower photo.
14: Soldering the optoisolator output wires to
Strip back the free ends of the
blue and yellow wires coming from the PC board.
Loop the yellow wire through the center lug
of the lower switch.
Loop the blue wire through the center lug of the upper switch. You can solder both connections now.
15: Adding the optoisolator
Place the optoisolator on the 8-pin
socket on the PC board as shown in the photo.
Note that the dot on the chip is to the lower
right. Make sure the legs of the chip are inserted
into the correct holes. Then push down gently
until the chip is firmly seated.
16: Assembling the box
Lower the PC board connected to
the lid into the bottom of the project box as
shown. Then screw the lid on with the 4 screws
17: Adding the labels
Cut the strip of labels into individual
labels, remove the backing, and stick on the box
lid in the locations shown.
This cable is only needed if you're connecting the Opto-Switch to a breadboard circuit. Otherwise, you can skip to the next section.
Step 1. Adding red and black wires to the female RCA connector
Unscrew the black jacket from the female RCA connector. Cut one 3-in length each of red and black wire and strip back one end 1/8 inch. Then thread the wires to the RCA connector. The red wire connects to the shorter lug. Don't crimp the tabs on the sleeve yet.
Step 2. Soldering the wires
Solder the wires to the lugs. Be sure to heat up each lug before melting solder on it. You'll get faster flow if you tin the tip of the iron with solder first.
Step 3. Crimping the tabs
Now you can crimp the tabs over to hold the wires tightly.
Step 4. Completing the cable
Screw the black jacket on to complete the cable adapter.
The shutter cables are provided separately from the Camera Opto-Switch Box Kit. The cables include a 2.5mm to 3.5mm adapter to connect the shutter cable to the Opto-Switch box.
Compatible with Cameras
Canon EOS 7D, 10D, 20D, 30D, 40D,
50D, 5D Mark II, 1Ds Mark III, 1D Mark IV, 1D Mark
Canon EOS Rebel series, EOS
60D, 300D, 350D, 400D, 450D, 500D, 550D, 1000D,
Powershot G10, G11, G1; Pentax K20D, K7
The customer provides the cable. We provide the 3.5mm male and female stereo connectors shown to the right to modify your shutter cable for the Opto-Switch box.See these assembly instructions.
Operation of the
Figure 1. The Opto-Switch box
Figure 2. Connecting the Opto-Switch to an MT-PCB2, MT-PCB3, SK3, or MTE-PCB
Refer to the photo above. Begin with the Focus and Shutter switches in the
the OFF positions (to the left).
Turn off the camera before inserting the 3.5mm plug from your shutter cable
into the CAM jack on the switch box. Be sure to push
the plug in all the way.
Insert one end of the trigger cable (the RCA cable)
into the TRIG jack on the switch box.
Connect the other end of the trigger cable as described in the panels to the right.
Turn your camera on and set it in a mode that will
autofocus. Make sure that the subject of the photograph
is far enough away for the camera to focus on it.
Flip the Focus switch on the switch box to on. The
camera should autofocus. (See note below.)
Depress and release the pushbutton. The shutter
should actuate. (This is for testing purposes and
for manual operation of the shutter.)
Flip the Shutter switch on. Nothing should happen,
…when your trigger circuit fires, the camera shutter
As long as you have the Focus and Shutter switches
turned on and the switch box connected to the trigger
circuit, the shutter can actuate repeatedly with repeated
triggering events. If you want to decrease the repetition
rate and you're using a delay unit, increase the reset
delay (timeout). See your trigger instructions for how
to do that.
In order to view the photos you've taken, flip the
switches to their OFF positions. The LCD view
screen on your camera may be disabled as long as the
Focus switch is on.
Turn off the camera before disconnecting the 3.5mm
plug from the switch box.
Note about the FOCUS switch: Generally, you won't set your camera to autofocus for high-speed photography. We asked you to set the camera for autofocus above just for testing purposes. Even when your camera is set for manual focusing, you may still need to flip the FOCUS switch on the Opto-Switch to the ON position. Nikon camera models, for example, require this. Canon models, on the other hand, do not require the FOCUS switch to be on.
On the MT-PCB3, the instant and delayed pulse outputs may be used to trigger a camera via an Opto-Switch. The pulse output is connected to the TRIG input of the Opto-Switch with a male-to-male RCA cable.
For the SK3 Sound Trigger, the pulse output is connected to TRIG jack of the Opto-Switch.
For the discontinued products, MT-PCB2 and MTE-PCB, the pulse outputs are labeled as CAM outputs and are connected as above.
The MT2 and CBP2 triggers do not require an Opto-Switch.
Figure 3. Connecting the Opto-Switch to a breadboard
For the Multi-Trigger breadboard or other breadboard circuits, the male-to-male RCA cable is used together with the breadboard cable adapter as shown above. The connection points of the red and black wires for all of our breadboard circuits are given in the COS connections chart at the bottom of this page.
The breadboard version of the Crossed-Beam Photogate (CBP-O) does not require an Opto-Switch.
Chart for the Camera Opto-Switch
The trigger cable of the Opto-Switch connects to Hiviz breadboard circuits (v10) as given below.
Note that the hole placements for the SK2, SPG1, SPG2, TPG, LAT, and DU individually are the same as for the combinations SK2-DU, SPG1-DU, SPG2-DU, TPG-DU, and LAT-DU.
DU - Delay unit
SK2 - Sound trigger
You must also remove the wire from 5C to 8C to disconnect the SCR.
SPG1,2- Schmitt trigger photogate
TPG - Transistor photogate
LAT - Light-activated trigger
MT - Multi-Trigger
You must also remove the wire from 27D to 29D to disconnect the SCR.