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Assembly and Operating Instructions for HiViz.com Kits

 

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Assembly Instructions for the Transistor Photogate with Delay Unit on a Breadboard (TPG-DU-BB)

 

Note: These instructions are for kits before v10.

 

Assembly instructions

Parts List

 

The following parts are included with the kit.  

 

Infrared phototransistor (PT)
Infrared emitter (LED)

 

2N2222 transistor (or PN2222A)
556 timer IC
3 400-V SCRs (EC103D)

 

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

Resistors
1 100 Ω (brown-black-brown)
1 470-Ω (yellow-violet-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)

Capacitors
2 0.0047-µF (472 or 0047)
1 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
3-ft of 2-conductor cable
3-ft of 3-conductor cable
Hookup wire
9-V battery cable
2

Breadboard

 

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.  If you do any soldering, you'll need a soldering iron, solder, and a heat sink.


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)
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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)
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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)
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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.

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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 8 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 two capacitors remaining.  The 0.1-µF or 0.01-µF capacitor may be substituted for the 0.47-µf capacitor in order to obtain different delay ranges.  This will be discussed in Step 9.

 

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.

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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.

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Cable to Output 1 for quick discharge; click to view
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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.

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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.  Contact us 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.

 

Assembling the Photogate

 

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Step 10: Adding the Potentiometer

 

The 100-kΩ potentiometer (gray knob) allows you to adjust the sensitivity of your photogate. It has three legs, two in the front and one in the rear. Place the two front legs over Rows 7 and 9 on Column j, and the rear leg over the 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_121.jpg (92352 bytes) click to view

Step 11: Adding the SCR and Transistor

 

The silicon-controlled rectifier (labeled EC-103D) is the output stage of the sound trigger. Putting in the SCR is easy since all three leads go in consecutive rows along Column c. Put the cathode into Row 8 on Column c. The gate will then go into Row 9, and the anode into Row 10 of that column. (For information on identifying the leads of an SCR, see Step 3 in "Assembling the Delay Circuit" above.)

Transistor pin diagram

E = emitter (-)
B = base
C = collector (+)

The transistor looks identical to the SCR but is labeled PN2222A (or 2N2222A). Its three leads go in consecutive rows along Column g.  To identify the leads of the transistor, hold it as in the diagram to the right.  Put the emitter into Row 8 on Column g.  The gate will then go into Row 9, and the collector into Row 10 of that column.

bb_122.jpg (89053 bytes) click to view

Step 12: Adding the Resistors

 

Locate the brown-black-orange resistor (10 kΩ).  Insert one end into Row 9, Column d, and the other end into Row 8, Column f.  Next, find the yellow-violet-brown (470 Ω) resistor.  Insert one end into Row 3, Column g. The other end should reach over to the nearest hole in the positive column.

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Step 13: Adding the Wires

 

Two short wires are needed for this step.  Strip about 1/4" of insulation off each end. One wire should join Row 8, Column b to the nearby negative column.  The other should join Row 10, Column h to the nearby positive column.

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Photogate connections shown with
3-conductor cable; click to view
Note that for some versions of this kit, the colors of the wires in the 3-conductor cable are red, black, and green.  In that case, simply replace the word white with green in the instructions.

 

 

 

 

Step 14: Connecting the LED and phototransistor

 

The photogate has a light-emitting and a light-sensing component.  The former is a light-emitting diode (LED), which emits an infrared beam.  The sensing component is an infrared phototransistor (PT). When the beam is broken by an object, the blockage causes the voltage to rise across the PT, which gates the SCR at the output of the circuit.

For the TPG kit, the PT and the LED are the individual components shown to the right. The LED is the component with a blue case, and the PT has a clear case. (In an earlier version of this kit, the PT and LED both had clear cases. If you have this version, note that the LED has longer legs than the PT.) For both components, one leg is shorter than the other. The shorter leg is positive on the PT, while on the LED, the longer leg is positive. The wiring instructions given later in this section will ensure that the correct polarity is maintained.

To begin wiring, use the gray 3-conductor cable. The 4 legs of the PT and LED will be soldered to these three conductors.

 

Strip 1" of insulation from each of the conductors on one end of the cable. The PT and LED 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.

 

Wrap the red wire around the longer leg of the LED, and the white (or green) wire around the shorter leg of the PT.  Next prepare a jumper wire that will go from the shorter leg of the LED to the longer leg of the PT.  The length of this jumper will depend on how far apart you want to separate the PT and LED for your photography.  Strip the wire back about an inch on each end wrap it onto the legs of the components.  Now wrap the black wire of the 3-conductor cable to either one of the legs onto which you wrapped the jumper wire.

 

Connect the free ends of the 3-conductor cable to these holes on your breadboard:

Black to the negative column
White (or green) to Row 9, Column h
Red to Row 3, Column f

You may want to wait to solder the leads until you've tested the circuit (see next section).  When you do get around to soldering, here are some tips.

 

Note about soldering:  When you connect a wire to a leg of the PT or LED, 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 the 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.

 

Final Connections and Testing

 

bb_126.jpg (89537 bytes) click to view
Step 15: Connecting the Photogate Trigger to the Delay Unit

 

Add a wire from Row 10, Column a, the output of the photogate trigger, to Row 18, Column h, the input of the delay unit. This will allow the photogate trigger to trip the delay unit.

 

Note that the photogate trigger can be used to trigger a flash directly rather than going through the delay unit. Go to step 16a to see how to make connections for direct triggering.  Otherwise, skip to step 16b.

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Step 16a: Connecting the Photogate Trigger to a Flash Unit

 

In order to trigger a flash unit directly with the photogate trigger, make the following connections with the output cable that you prepared in Step 8.  Insert the red wire of the cable into Row 10, Column e and the black wire to the negative column.

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Step 16b: Connecting the Delay Unit to a Flash Unit

 

Step 8 described how to connect either output of the delay unit to a flash unit using an output cable.  The photograph to the left shows the output cable connected to Output 2.

 

Step 17: Operating the Circuit

 

Connect a 9-V battery to the battery clip.  Lay the PT and LED down on a table a few inches apart, pointing at each other.  You may wish to tape them in place so the components can't shift positions.  Run your finger between the PT and LED quickly in order to break the photogate beam.  (If you pass your finger through too slowly, the photogate may not respond.)

 

If your flash cable is connected directly to the photogate or to Output 1, 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 you don't get a discharge, one possible reason is that the sensitivity isn't adjusted correctly.

 

Adjusting the sensitivity: Turn the 100-kΩ potentiometer in one direction or the other until the flash discharges spontaneously. Then back up the dial just before the point of spontaneous discharge.

 

If you change the distance between the PT and LED or if the orientation of either component changes slightly, you may need to readjust the sensitivity.  The maximum separation is about 6 inches. The larger the separation, the more care you need to take in aligning the components.

 

 

 


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