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Assembly and Operating Instructions for HiViz.com Kits

 

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Assembly Instructions for a Light-Activated Trigger on a Breadboard (legacy LAT-BB)

 

Note: These instructions are for kits before v10.

 

Assembly instructions

 

These instructions may be used in combination with the instructions for building a delay unit in order to provide a light-activated trigger with a selectable delay.  For instructions on building the delay unit, go here.

 

Parts List

The following parts are included with the LAT kit.   (If you purchased the LAT in combination with a delay unit, then a single set of wires was provided with the combination.)

 

NPN phototransistor, visible

555 timer IC
556 timer IC
3 400-V SCRs (EC103D)

 

Breadboard

Resistors
1 100 Ω (brown-black-brown)
1 1-kΩ (brown-black-red)1
1 10-kΩ (brown-black-orange)
1 100-kΩ (brown-black-yellow)
1 1-MΩ (brown-black-green)
4 22-kΩ (red-red-orange)

100-kΩ potentiometer (brown knob)
1-MΩ potentiometer (blue knob) 

Capacitors
2 0.0047-µF (472 or 0047)
2 0.01-µF (103)
2 0.047-µF (473 or 047)
1 0.1-µF (104)
1 0.47-µF (cylindrical metal case)
1 10-µF (cylindrical metal case)

Wires
6-ft of 2-conductor cable
Hookup wire
9-V battery cable2

 

1We are now providing 2 additional 1-kΩ resistors with delay units. This is to address an issue with some Canon flash units. The use of these resistors is described in Step 5. If you need these resistors, contact HiViz.com.

 

2A fresh 9-V battery is required but not included with the kit.  You'll also need a wire cutting and stripping tool such as the one shown to the right.

 

 


Click for larger view

 

Click on the thumbnails below in order to view full-size images of the breadboard with the components that have been added in each step.

 

 

Using the Breadboard

 

bb_002.jpg (81633 bytes)
click to view

The breadboard offers an easy way to build electrical circuits without soldering. The 2"x3" breadboard provided with your kit contains an array of holes where wires and components are to be inserted. The holes in the center portion of the breadboard are identifiable by row (vertical in the photos) and column (horizontal).  There are two sets of 30 rows numbered by 5's, and each set of rows has 5 columns labeled a-e and f-j. The 5 holes on each row are electrically connected to each other (but not across the center channel), so any components inserted into the same row would be connected just as if they had been soldered.  However, the components can be removed and replaced with other components at any time, without the hassle of unsoldering and resoldering parts.

 

On either side of the breadboard are two columns marked by blue and red lines. The 25 holes in each column are electrically connected, but the columns aren't electrically connected to each other.  The outermost column marked with the red line at the top will be used for all +9 V connections, while the outermost column marked with the blue line at the bottom will used for all ground (negative) connections.

 

Assembling the delay circuit

 

bb_003.jpg (82207 bytes)
click to view
Step 1: Adding the 556 Timer

 

The 556 timer is an integrated circuit (IC) with 14 pins that need to be seated in the breadboard.  Look at the top of the IC (with pins held away from you) and locate the semicircular notch at one end. The locations of pins 1 and 14 are shown in the figure to the right. Pins 1-7 are numbered consecutively right-to-left, and pins 8-14 are numbered consecutively left-to-right. Face the notch toward the right of the breadboard so that Pins 1 and 14 are also facing to the right. Now find Row 27 and look across to where it meets Column f. Place Pin 1 there. Pin 14 should easily fit in Row 27, Column e.

 

Don't press the IC down until all the pins are lined up with holes. Once they're lined up, press as evenly as possible across the top of the IC in order to make sure that none of the pins are bent as the IC is seated.  Press firmly to make sure the pins go in as far as possible.

bb_004.jpg (82428 bytes) click to view
Step 2: Adding the Potentiometer

 

The 1-MΩ potentiometer (blue knob) allows you to adjust the time delay of your circuit.  It has three legs, two in the front and one in the rear. Place the two front legs over Rows 28 and 30 on Column j, and the rear leg over the nearest hole on the nearby positive column. The front legs should be facing the center of the breadboard, while the rear leg is facing the outside of the breadboard. Press the legs in firmly as far as they will go, but avoid bending them. (Note that in the connections to follow, the left leg will not be connected to anything else.)

bb_005.jpg (83333 bytes)
click to view
Step 3: Adding the SCRs

SCR pin diagram

A = anode (+)
G = gate
C = cathode (-)

 

Two of the silicon-controlled rectifiers (SCRs) labeled EC103D are the output stages of the delay circuit. The SCRs allow you to to discharge a flash with or without a delay.  To identify the leads of the SCR, hold it as in the diagram to the right.

 

The two SCRs fit into consecutive rows on Column a, except for their cathodes, which should fit into the nearest available hole in the negative (blue) column. Here's what to do. Insert the gate of one SCR into Row 15 of Column a, and the anode into Row 16 just beside it. The cathode goes to the negative column. Next, insert the gate of the other SCR into Row 17, and its anode into Row 18 just beside it. Its cathode will also go to the negative column.

bb_008.jpg (85007 bytes)
click to view
Don't be concerned if some of the capacitors shown in the photo have different physical sizes from those in your kit.  What is important is that the numbers on the capacitors are correct.
Step 4: Adding the Capacitors 

 

First, gather together all the capacitors. You should have 9 total. All but two of them have round, tan heads.  The other two have cylindrical heads. These are the electrolytic capacitors, and unlike the others have polarity. Look at the cylindrical case and find the light-colored strip bearing a negative sign. The lead on the side of this strip is the negative lead, while the other lead is the positive lead.  Note that this is also the longer of the two leads.

 

Locate the 10-µF electrolytic capacitor, which will have 10 µF written on its case. Insert the positive lead into Row 26, Column a. The negative lead will go to the nearest hole on the nearby negative column. Now locate your 0.47-µF electrolytic capacitor. Insert the positive lead into Row 27, Column j, and insert the negative lead into Row 25 of that same column. (See this note regarding a a discrepancy between these instructions and the circuit schematic provided with the kit.)

 

Locate the two capacitors labeled "472" or "0047." These have values of 0.0047 µF. Take one and insert one end (it doesn't matter which this time) into Row 19, Column b. Insert the other end into Row 21 of that same column. For the other 472 capacitor, insert one end into Row 18 of Column i, and the other end into Row 22 of that same column.

 

Finally, locate the two capacitors labeled "473" or "047." These have values of 0.047 µF. Take one and insert one end into Row 25, Column g, and the other end into Row 29 of the same column. Insert one end of the next capacitor into Row 24, Column c. The other end should reach over to the nearest hole of the negative column. 

 

You should have three capacitors remaining.  The 0.1-µF capacitor and one of the 0.01-µF capacitors may be substituted for the 0.47-µf capacitor in order to obtain different delay ranges.  This will be discussed in Step 9.  The other 0.01-µF capacitor will be used for the photogate circuit.

 

You may wish to trim the leads of the capacitors so that they sit closer to the breadboard.  This will reduce the chance that the leads of two components accidentally touch each other and create a short.  When you add the resistors in the next step, you may wish to trim their leads also.

bb_038.jpg (2767964 bytes)
click to view
Step 5: Adding the Resistors

 

Each resistor is marked with four bands that are a code for the value and tolerance of its resistance. You should have 10 resistors; lay them out so that the gold band on each is always facing right (so it's the fourth band). The colors should now be read from left to right.  In the following instructions, the resistors will be identified by the first three bands, ignoring the gold band.  The gold band indicates the tolerance of the resistance value, while the other three bands indicated the value of the resistance.

 

There are 4 resistors with the color code red-red-orange. These each have values of 22 kΩ. Insert one end of the first into Row 15, Column d, and the other end into Row 19 of the same column. Insert one end of the second into Row 21, Column a, and the other end into Row 30 of the same column. Insert one end of the third into Row 17, Column c, and the other end into Row 22, Column c. Lastly, insert one end of the fourth into Row 22, Column g, and the other end into Row 24, Column j.

 

Note for users of Canon flash units 430ex and 580ex.  In order to correct a problem in using these flash units with the delay circuit, substitute a 1-kΩ resistor (black-brown-red) for the 22-kΩ resistor for the these two resistor placements:  19d to 15d and 22c to 17c.

 

Locate the brown-black-red resistor (1 kΩ).  Insert one end into Row 26, Column b, and the other end into Row 30 of the same column.

 

Locate the brown-black-green resistor (1 MΩ); insert one end into Row 18, Column j, and the other end into Row 22 of the same column.

 

Locate the brown-black-brown resistor (100 Ω); insert one end into Row 26, Column h, and the other end into Row 30 of the same column.

 

There should be three resistors remaining.  Two of these will be used in the photogate portion of the circuit.  The third, the brown-black-yellow resistor (100 kΩ), can replace the brown-black-red resistor (1 kΩ) later if you desire a greater reset delay. This will be described in Step 9.

bb_039.jpg (2846369 bytes) click to view
Step 6: Adding the Wires

 

Now you'll add wires to connect all your components together. Each wire only needs to be 2 inches in length or less. You can estimate how much you'll need to bridge across two holes before cutting, though it's better to have longer wires than ones that are too short. Note that the wires supplied with your kit won't necessarily be the same color as those in the photographs.

 

Strip about 1/4" of insulation off each end. The list below will tell you which rows and columns your wire ends should fit into. The longest wires are listed first so if you happen to cut a piece that's too short, you'll be able to use it later.

 

Longest wires (~2 inches) Shortest wires (1 inch or less)
End 1  End 2 End 1  End 2
Row 30, Column e positive Row 23, Column c Row 27, Column c
Row 21, Column g negative Row 27, Column d Row 30, Column d
Row 29, Column f negative Row 25, Column d Row 26, Column d
Row 24, Column i positive Row 26, Column g Row 27, Column g
Row 19, Column e Row 23, Column g
bb_040.jpg (2921782 bytes) click to view
Step 7: Adding the Battery Clip

 

Locate the battery clip.  Insert the red wire into the positive column and the black wire into the negative column.  Don't attach the battery yet.

bb_042.jpg (2876599 bytes)
Cable to Output 1 for quick discharge; click to view
bb_041.jpg (2881266 bytes)
Cable to Output 2 for delayed discharge; click to view
Step 8: Connecting the Output Cable

 

The 3 feet of 2-conductor cable may be used to connect either of the circuit's two outputs to the PC cord of a flash unit. Output 1 provides an almost immediate discharge, while Output 2 provides a delayed discharge. You’ll need to provide your own PC cord.

 

From one end of the 2-conductor cable, strip 1" of the gray insulation, being careful not to cut the insulation on the red and black wires.  Then strip 1/2" of insulation from each of the red and black wires.  These will connect to the breadboard.  Next, strip 2" of the gray insulation from the other end of the cable.  Strip each of the individual wires back 1".  These will connect to the PC cord.  One way to make this connection is to cut the socket off the end of the PC cable, strip the insulation on the individual PC wires back by 1", splice the red wire of the gray cable to the positive wire of the PC cable, and splice the black wire of the gray cable to the negative wire of the PC cord.  (The positive wire of the PC cord is usually the wire that goes to the center pin of the PC socket.  For more information on connecting to a PC cord, see this page: http://hiviz.com/tools/triggers/makeown.htm#connect.)

 

If using Output 1, insert the end of the red wire on your ½" end into Row 16, Column b, and the end of the black wire into the nearest hole on the negative column. If using Output 2, insert the red wire into Row 18, Column b instead.

bb_043.jpg (2929066 bytes)
A sample jumper cable from input to ground; click to view
Step 9: Testing and Operating the Delay Circuit

 

Important:  Before testing the circuits, double check that all components are connected in the correct locations and with the correct polarities. Some wiring mistakes can cause the 556 timer to burn out. 

 

In order to test your delay circuit before the photogate is added, its input can be shorted to ground.  First, connect your flash unit to Output 1 and connect a fresh 9-V battery to the battery clip. Then take a piece of wire and insert one end into Row 18, Column h.  (We'll call this the trigger wire.) Insert the other end to the nearest hole on the negative column (ground).  The flash should discharge immediately. Now disconnect one end of the trigger wire, and connect your flash to Output 2. Connect the trigger once again. The flash should discharge, but there may be a slight delay before it goes off. Increase the delay by turning the blue potentiometer counterclockwise. Disconnect and reconnect the trigger wire to test again. The further counterclockwise that you turn the potentiometer, the more of a delay that you should notice.  Note, however, that in the furthest counterclockwise position, the circuit may not respond. If that's the case, back off a little from the maximum position.

 

Troubleshooting:  If the delay unit doesn't discharge the flash unit, there are a number of things to check.

  1. Make sure the battery is fresh.
  2. Check whether the polarity of the cable to your flash unit is reversed.  This can be done simply by reversing the cable connections on the breadboard.  This won't damage the circuit.
  3. Double check that the polarities of the electrolytic capacitors are correct, that all components are connected in the correct locations, and that all wires and components are firmly seated in place.
  4. Make sure the potentiometer is seated completely in the breadboard. Try pushing down on it while testing the circuit. If this is the problem, you may want to solder some wire legs onto the potentiometer so that the wires make secure connections with the breadboard contacts.
  5. If there were wiring mistakes, it's possible that the 556 timer is burnt out.  In that case, contact tech support for a replacement 556 or check to see if your local electronics store carries the component.

Changing the delay range:  A half second delay is long for many high-speed photography situations.  You can change the range of the potentiometer by removing the 0.47-µf capacitor and replacing it with one of smaller value.  Extra 0.1-µf and 0.01-µf capacitors have been provided for this purpose.  The 0.1-µf capacitor will provide delays up to about a tenth of a second, while the 0.01-µf capacitor will provide delays up to about a hundredth of a second.

 

Changing the reset delay: After the flash unit discharges, it will be inactive for a short time before it can be discharged again.  This amount of time is termed the reset delay.  The circuit is currently set for a reset delay of about a hundredth of a second.  (This is actually less than the recharge time of most flash units.)  For some photo situations, this may lead to multiple exposures.  In order to increase the reset delay, first locate the 1-kΩ resistor. Then replace it with the 100-kΩ resistor.  This will increase the reset delay to about a second.

 

Disconnect the battery and the flash before proceeding with the wiring of the photogate.

 

Constructing the Light-Activated Trigger

 

bb_087.jpg (101426 bytes) click to view

Step 1: Adding the 555 Timer

 

The 555 timer is an 8-pin IC that also has a notch and circle identifying Pin 1.  Orient the IC so that the notch faces the left side of the breadboard. Now find Row 4 and look across to where it meets Column e. Place Pin 1 there. Pin 8 should easily fit in Row 4, Column f. Press the IC firmly down in place; again, it should be seated across the center division of the breadboard.

bb_088.jpg (96288 bytes) click to view

Step 2: Adding the Potentiometer

 

The potentiometer allows you to adjust the sensitivity of your light-activated circuit. It has three legs, two in the front and one in the rear. Place the two front legs over Rows 11 and 13 on Column j, and the rear leg over the nearest hole on the nearby positive column. The front legs should be facing the center of the breadboard, while the rear leg faces the outside of the breadboard. Press the legs in firmly as far as they will go, but avoid bending them.

bb_089.jpg (102606 bytes) click to view

Step 3: Adding the Phototransistor

 

The phototransistor (PT) is the visible light-sensing component of the circuit. The component has three legs as shown to the right, but only two will be inserted into the breadboard.  Looking down at the top of the PT (legs facing away), locate the tab on the case.  With the tab pointing up, the leg to the left of this tab goes into Row 1, Column i.  The leg to the right of the tab goes into Row 3, Column h.  The last leg can be bent outward, away from the breadboard.

 

If you wish to mount either phototransistor away from the breadboard for more flexibility, it can be soldered to a 3-ft length of the included 2-conductor cable.  This is described in a later step.

Visible light phototransistor

bb_090.jpg (103409 bytes) click to view

Step 4: Adding the SCR

 

The silicon-controlled rectifier is the output of the light-activated circuit and can be connected to the input of the delay circuit.  Putting in this SCR is easy since all three leads go in consecutive rows along Column e. Put the cathode into Row 11 on Column e. The gate will then go into Row 12, and the anode into Row 13 of that column.

SCR pin diagram

A = anode (+)
G = gate
C = cathode (-)

bb_091.jpg (98599 bytes) click to view

Step 5: Adding the Capacitor

 

One lead of this capacitor should fit into Row 7, Column h, and the other lead into Row 9 of the same column.

 

You may wish to trim the leads of the capacitor so that it sits closer to the breadboard.  This will reduce the chance that the leads of two components accidentally touch each other and create a short.  When you add the resistor in the next step, you may wish to trim its leads also.

bb_092.jpg (100828 bytes) click to view

Step 6: Adding the Resistor

 

Insert one end into Row 6, Column c, and the other end into Row 12 of the same column. 

bb_093.jpg (103256 bytes)
Completed LAT, not joined to delay unit
(click to view)

 

 
bb_095.jpg (106427 bytes)
LAT joined to delay unit via green wire (click to view) 

Step 7: Adding the Wires

 

Now connect all your electronic components together. Each wire only needs to be 2 inches in length or less. You can estimate how much you'll need to bridge across two holes before cutting, although it's always better to have longer wires than ones that are too short.

 

Strip about 1/4" of insulation off each end. The list below will tell you which rows and columns your wire ends should fit into. 

 

End 1  End 2 End 1  End 2
Row 1, Column g  negative Row 5, Column d Row 6, Column g
Row 11, Column c negative Row 7, Column d Row 4, Column g
Row 4, Column c negative Row 6, Column i Row 11, Column i
Row 9, Column f negative Row 3, Column j Row 6, Column j
Row 4, Column h positive *Row 13, Column c Row 18, Column h
    *This wire is only needed if you're connecting the trigger to a delay unit.
bb_094.jpg (106923 bytes)
Testing the LAT 

 

Step 8: Connecting the Cables

 

Cut the 6 ft of 2-conductor cable into two pieces.  The phototransistor can be soldered onto one of these cable lengths, while the other length of cable will be used to connect a flash unit to the output of this circuit.

 

Strip 1" of insulation from each of the conductors on one end of the phototransistor cable. The PT will be attached to this 1" end. Now strip ½" of insulation from each conductor on the other end of the cable. This ½" end will connect with the breadboard. Strip an additional 1" of the gray outer shielding from the ½" end so the individual conductors can reach to their destinations.

 

Note about soldering:  When you connect a wire to a leg of the PT, first wrap the wire tightly around the leg several times. Then clip a heat sink (a metallic alligator clip will work for this) to the leg just below the plastic case. This will prevent the component from heating excessively during soldering. Before starting to solder, make sure you're working in a well-ventilated area in order to avoid inhaling the solder fumes. A fan to blow the fumes away from you will help. Prepare the tip of the soldering iron by holding the solder to it so that solder can melt and flow over the tip. This will improve heat conductivity.  Touch the solder on the leg to which you're soldering the wire.  Hold the flat of the soldering iron tip on leg but not directly on the solder. As soon as the leg is hot enough, the solder will flow. Move the solder around so as to melt solder into the wire and onto the leg along the length of the leg.

 

You may want to wait to solder them until you've tested the circuit in Step 9.

 

Phototransistor Connection

 

Locate your phototransistor.  This component should already have been inserted onto the breadboard in Step 3.  The PT has a polarity that must be maintained when wiring. 

 

Looking down at the case of the PT (legs facing away), locate the notch on the case.  Make the following connections. 

Wrap the black wire around the leg to the left of the notch.
Wrap the red wire around the leg to the right of the notch.
The last leg is unused and can be bent outward.

Now connect the free ends of the 2-conductor cable to these holes:

Black to Row 1, Column i
Red to Row 3, Column h

Flash Connection

 

The remaining 3 feet of 2-conductor cable may be used to connect the output of either the LAT or the delay unit to the PC cord of a flash unit. You’ll need to provide your own PC cord. You may have already prepared your flash cable if you wired the delay unit. If not, follow the instructions in the next paragraph.

 

From one end of the 2-conductor cable, strip 1" of the gray insulation, being careful not to cut the insulation on the red and black wires.  Then strip 1/2" of insulation from each of the red and black wires.  These will connect to the breadboard.  Next, strip 2" of the gray insulation from the other end of the cable.  Strip each of the individual wires back 1".  These will connect to the PC cord.  One way to make this connection is to cut the socket off the end of the PC cable, strip the insulation on the individual PC wires back by 1", splice the red wire of the gray cable to the positive wire of the PC cable, and splice the black wire of the gray cable to the negative wire of the PC cord.  (The positive wire of the PC cord is usually the wire that goes to the center pin of the PC socket.  For more information on connecting to a PC cord, see this page: http://hiviz.com/tools/triggers/makeown.htm#connect.)

 

In order to connect the flash unit directly to the output of the light-activated circuit, connect the red wire to Row 13, Column b, and the black wire to the negative column.

 

In order to connect the flash unit to the delayed output (Output 2) of the delay circuit, connect the red wire to Row 18, Column b and the black wire to the negative column.

 

In order to connect the flash unit to the undelayed output (Output 1) of the delay circuit, connect the red wire to Row 16, Column b and the black wire to the negative column.

bb_096.jpg (107875 bytes)
LAT joined to delay unit, with Output 2 connected to flash (click to view) 

Step 9: Operating the Circuit

 

With a 9-V battery connected to the battery clip and your flash unit connected to the breadboard, you can now test your circuit.  Shine a flashlight or other bright light source at the phototransistor to activate the trigger.  If your flash cable is connected directly to the LAT circuit output or to Output 1 of the delay circuit, you should notice an immediate discharge of your flash unit.  If your flash cable is connected to Output 2, you may notice a short delay before discharge, depending on the setting of  your delay circuit.  If your flash unit doesn't discharge, you may need to adjust the sensitivity of the LAT.

 

Adjusting the sensitivity: Turn the 100-kΩ potentiometer clockwise to increase the sensitivity of the circuit but avoid turning it all the way in either direction.

 

 

 

 


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