For individual photos of the parts supplied in the kit, see the Parts List.
If you would like to refer to a circuit schematic while you work, download one here.
In these instructions, click on any image for a larger view. (In order to open the image in a new tab or window, right click and select open in new tab or window.)
Tools that you'll need
Having the right tools will make the job easier. You'll need to provide your own. Here's what we recommend.
15-30 W soldering iron and solder
Wire stripper (photo below)
A small diagonal cutter (photo below) makes it easy to trim stray wires, but other kinds of snipping tools such as scissors may work.
Needle-nose pliers (photo below) make it easier to handle wires, especially if you have big fingers.
A magnifying glass is useful to inspect solder joints.
A lighter or matches to shrink heat-shrink tubing, if the project requires it.
A drill motor and these drill bit sizes: 3/32, 1/8, 1/4, 5/16 in
Rubber or contact cement to affix the label to the project box lid
Hammer and a pointed instrument such as a large needle or a punch
Stencil or razor knife and a straightedge
Hole punch such as that used for punching paper for binders
Mild solvent such as denatured or rubbing alcohol and soft, clean cloth
Be sure to solder in a well-ventilated area. Keep the tip of your soldering iron clean by wiping it against a wet sponge. Once the tip is clean, touch a bit of solder to the tip to tin it and improve heat conductivity. Inspect your solder joints to see if the solder flowed well to make good electrical contact. If it looks like the solder formed a bead, that's likely a bad joint and will not conduct. Reheat to flow the solder.
Adding Components to the PCB
Step 1. Adding the IC sockets to the PCB
Photo 1a: This photo shows the upper side of the PCB for the project.
Photos 1b,c: Two 8-pin sockets will be soldered to the board. Note in Photo 1b how the notch in the end of a socket corresponds to the notch in the corresponding figure on the PCB. Seat both of the sockets in their respective locations on the board as shown in Photo 1c.
Photo 1d: The photo shows the underside of the PCB. Crimp the pins of the sockets over in order to hold the sockets in place and prepare for soldering.
Photo 1e: Solder the pins, being careful not to bridge solder between pins. If this happens run the tip of the soldering iron between the pins to remove the bridge. This may take several tries.
Step 2. Adding the resistors to the PCB
Photos 2a,b: Start with a 1k resistor (see photo to the right). The resistance value is indicated by the sequence of band color, brown-black-red in this case. Insert the legs of the resistor into the location labeled R1 on the PCB. Note that the resistors aren't polar and can be placed in either of the two possible orientations. Solder the leg of the resistor to the back side of the PCB and then clip off the excess. The completed solder connections, surrounded in yellow circles, are shown in Photo 2b.
Photo 2c: There are 6 remaining resistors. (One of these, R3, will be soldered on the lid in a later step.) Solder these as given below:
R2, R5 = 470 (yellow-violet-brown)
R4 = 1k (brown-black-red)
R6, R7 = 680 (blue-gray-brown)
Photo 2d: The back of the board after the resistors legs are soldered and clipped is shown.
Photos 2e: Select the 0.1-uf capacitor (labeled 104) and seat the legs in location C1. Like the resistors, the capacitors are non-polar. Seat the 0.01-uf capacitor (labeled 103) in location C2. Solder the legs under the board and clip.
Photo 2f: This shows a different view of the board with the sockets, resistors, and capacitors added.
Step 3. Adding the SCR and fuse holder to the PCB
Photo 3a: Insert the SCR into the location labeled SCR1 on the PCB. Align the flat side of the SCR with the corresponding shape on the board. Push the component down to seat the legs firmly. Solder the legs on the underside of the PCB. Avoid overheating the SCR as damage could be caused to the component. If you take too long soldering on a particular leg, wait for the SCR to cool before moving onto to another leg. Be careful to avoid bridging the solder between legs. Clip the protruding legs when finished.
Photos 3b,c: The last component to solder to the board is the fuse holder See Photo 3b. It'll take a bit of force to snap the 2 legs into place. See Photo 3c for a side view showing the legs protruding under the board. Once in place, solder the legs.
Photo 3d: This photo a shows a view of the board with all components in place with the exception of the ICs and fuse, which will be added as the final step.
Preparing the Project Box
Step 4. Drilling the lid and the bottom of the box
Note that Photos 4a-c show the veiw from the underside of the project box lid.
Photo 4a: Cut out the drilling template and place it in the underside of the project box lid. Using a hammer and a sharp, pointed instrument such as a large needle or a punch, mark the centers of the holes on the template.
Photo 4b: Remove the template. Drill 3/32-in starter holes at each of the locations that you marked.
Photo 4c: Drill the starter holes to the sizes indicated on the template.
Step 5. Adding the label
Photo 5a: Trim around the black border of the lid label. A stencil or razor knife with a straightedge will help to get straight cuts, but sharp scissors will also serve.
Photo 5b: Pull the backing off one of the laminate sheets, and lay the sheet, sticky side up, on a table. Carefully place the lid label, label side down, onto the sticky side of the laminate sheet. In order to avoid getting air bubbles, apply the shorter edge of the label first and gradually push it down onto the laminate with a finger.
Photo 5c: Remove the backing from the other laminate sheet and carefully apply it, sticky side down, to create a sandwich of the two laminate sheets with the label in the middle. Use the technique described above to avoid getting air bubbles. When the laminate is in place, rub a finger over the laminate and around the edges of the label to ensure a good seal.
Photos 5d,e: Use a stencil or razor knife or sharp scissors to trim the excess laminate from around the label. Then use a 1/4-in hole punch to punch out the 1/4-in and 5/16-in holes on the label as shown in Photo 5d. If you don't have a hole punch, the point of a sharp knife can be used to carve out the holes. Don't worry if some edges are ragged. These will be covered by the components later. The label with holes punched is shown in Photo 5e. The 1/8-in holes will be punched later.
Photos 5f,g: Now it's time to glue the label to the top of the lid. First cut the 2-in section of plastic tubing into two 1-in pieces. For glue, use rubber cement or other repositionable adhesive. Spread the adhesive over both the lid and the underside of the label (not shown). Place the label in position on the lid, and align it using the two pieces of plastic tubing. Push one piece of tubing through the On-Off hole and the other through the Flash hole. Flatten the label by rubbing a finger over it and hold in position for a minute or so to insure adhesion. Then carefully remove the plastic tubing to avoid shifting the position of the label. Any glue that extends beyond the edge of the label can be rubbed off with a finger. If there is glue smeared on the label that can't be rubbed off, use a mild solvent such as denatured or rubbing alcohol and a soft, clean cloth to clean the label. Finally, place the label under a stack of books or other weight to press it for a few hours. When completed, the lid with label should look like Photo 5g.
Photo 5h: Use a knife to expand the punched holes for the Power In and Sensitivity pots to 5/16 in. Then check the underside of the lid to see if portions of the label overlap any of the 1/4-in holes. If so, use a stencil knife, razor, or knife blade to trim the label back to the boundaries of the hole. This will make it easier to insert components later.
Photo 5i: Using a small knife, cut an X in each of the 1/8-in holes. Then use a small screwdriver or pencil point to push through the holes. It's not necessary to clean the paper out of the holes. This will be covered by the bolts later.
Adding Components to the Lid of the Project Box
Step 6. Adding the jacks and LEDs
Photo 6a. The photo shows the underside of the box lid. Mount the RCA jack in the lower left-hand corner. Note the orientation of the tab of the jack.While this orientation isn't essential, it will help in wiring later.
Photos 6b,c: Mount the three 3.5mm mono jacks (cream colored) and the 3.5mm stereo jack (black) in the locations shown. Orient the tabs as shown in Photo 6b. Photo 6c shows the upper side of the lid with the components mounted so far.
Photos 6d-f: The LED holder has two parts shown to the right. The first step in mounting an LED is to snap the collar of the LED holder into the hole from the upper side of the lid as shown in Photo 6d. Then, from the underside of the lid, insert each LED into its collar as shown in Photo 6e. Note that one leg of the LED is longer than the other. Orient the LEDs so that the longer leg is the one nearer the outside of the lid. Push each LED into the collar until the LED snaps into place. This may require quite a bit of force, depending on how tight the fit is. You can use a small, blunt instrument to push on the base of the LED until you hear it snap into place. The final part of the LED assembly is to place the ring over the collar on the underside and push it into place as shown in Photo 6f.
Photos 6g,h: Photo 6g shows the power jack, inverted. Note the numbering of the lugs. We'll refer to these numbers in mounting the jack. Remove the nut and washer from the power jack, and insert the jack through the bottom of the lid as shown in Photo 6h. Orient the three lugs with the numbers corresponding to those in Photo 6g. Slip the washer and nut on the threads on the upper side of the lid and tighten. The upper side of the lid with the components mounted so far is shown in Photo 6i.
Step 7. Adding the switches, pot, and standoffs
Photos 7a-d: The switches will be mounted next. In Photo 7a showing the On-Off switch, notice the ring with the tab pointing toward the base of the switch. When you mount the switch on the lid of the project box, point the tab the opposite direction. Then when you insert the switch through the 1/4-in hole on the underside of the lid, the tab will slip into the 3/32-in hole, serving to prevent the switch from turning. Photo 7b shows the underside of the lid with the switch mounted. Mount the TPDT switch in a similar fashion as shown in Photo 7c. Be sure to align the tab with the 3/32-in hole. This is essential for correct wiring. The upper side of the lid with both switches mounted is shown in Photo 7d.
Photos 7e-h: The final component to mount is the variable resistor, also known as a potentiometer or pot. Note that there are 2 washers under the nut. Remove the nut and one of the washers. Note also that there's a metal tab beside the shaft. We recommend snipping off about one-third of the tab so that it doesn't create an indentation in the lid label when mounted. See Photo 7e. Slip the pot through the underside of the lid as shown in Photo 7f. On the upper side of the lid, place the remaining washer and the nut on the shaft and tighten. See Photo 7g. Before adding the knob, turn the shaft of the pot all the way counterclockwise. This is the 0 position. Loosen the set screw on the knob and mount on the shaft with the white indicator mark pointing to zero. Tighten in place. Photo 7h shows the lid with the knob mounted.
Photos 7i,j: Push the four 4-40 bolts through the 1/8-in holes from the upper side of the lid as shown in Photo 7i. Then add the four standoffs to the underside as shown in Photo 7j.
Wiring the Project Box Lid
Step 8. Wiring the resistors and component-to-component wires
Refer to this graphic to identify pins and part IDs in wiring the lid. Note that the black wires shown in the graphic are white wires in actual use.
Photo 8a: Note the numbers on the 9 lugs of the TPDT switch shown in Photo 8a. These are the same numbers as on the graphic above. We'll refer to these numbers in making connections to the switch; however, we won't duplicate the numbers on subsequent photos. Instead, refer to the graphic. Begin by bending over the longer legs of the two LEDs and loop them through lug 4 of the switch.
Don't solder any connections until instructed to do so.
Photo 8b: The red wires will be connected next. Cut and strip the needed lengths to make the following connections.
Lug 3 to lug 4 of the TPDT switch
Lug 3 of the TPDT switch to lug 3 of the Power In jack, J6
Lug 3 of the TPDT switch to lug 3 of the LED jack, J5.
Photo 8c: The remaining 1k (brown-black-red) resistor is wired between components on the box lid. Connect the resistor between lug 2 of the TPDT and lug 2 of the Sensitivity pot (RV).
Photo 8d: Connect the white wires next. Cut and strip the needed lengths to make the following connections.
Lug 1 to lug 9 of the TPDT
Lug 9 of the TPDT to lug 1 of the Pulse jack, J1
Lug 1 of J1 to the side tab of the Flash jack, J3
Photo 8e: Connect the green wires next. Cut and strip the needed lengths to make the following connections.
Lug 7 to lug 6 of the TPDT
Lug 6 of the TPDT to lug 1 of the Sensitivity pot, RV
Lug 2 of the Power jack, J6, to lug 2 of the On-Off switch, SW1
Photo 8f: Connect the blue and yellow wires next. Cut and strip the needed lengths to make the following connections.
Yellow wire from lug 5 of the TPDT to lug 3 of the IR PT jack, J4
Blue wire from lug 8 of the TPDT to lug 1 of J4
Photo 8g: You may now solder some of the connections. Solder all the lugs of the TPDT and also the connections circled in yellow in Photo 8g. When soldering to the TPDT, avoid overheating and possibly melting the base.
In the next section, you'll add jumper wires to the unsoldered connections.
Connecting the Jumper Wires to the Lid and the PCB
Step 9. Connecting the jumper wires
to the lid and the PCB
Continue to refer to this graphic to identify pins and part IDs.
Except as indicated below, you may now solder wires as you connect them below or wait to solder until finished with all connections.
Photo 9a: Cut a 2.5-in section of white wire, a 2-in section of yellow wire, and a 1-in section of green wire. Strip the wires back by 1/4 inch on one end and 1/8 inch on the other. Connect the 1/4-in stripped ends as follows (also Photo 9a):
White wire to the side tab of the Flash jack, J3
Yellow wire to lug 1 of the IR LED jack, J5
Green wire to lug 1 of the Shutter jack, J2
Photo 9b: Place the PCB on the standoffs as shown in Photo 9b. As you lower the PCB, thread the shorter leg of LED2 through hole A of the PCB. You may solder the connection, but don't bolt down the PCB yet.
Photo 9c: Connect the following wires to the PCB. Solder as you connect so that the wires will remain in place.
White wire from the side tab of the Flash jack, J3, to hole C of the PCB
Green wire from lug 1 of the shutter jack to hole G
Yellow wire from lug 1 of the IR LED jack, J5, to hole L
Photo 9d: Here you'll cut some new wire sections to connect between components on the lid and holes on the PCB. As before, strip one end of each wire by 1/4 inch and the other by 1/8 inch. The longer stripped end connects to the component on the lid and the shorter end to the PCB. Make these connections:
1-in green wire from lug 3 of the Pulse jack, J1, to hole K on the PCB
1-in blue wire from the center lug of the Flash jack, J3, to hole I
2-in red wire from lug 3 of the IR LED jack, J5, to hole J
4.5-in blach wire from lug 3 of switch, SW1, to hole H
Photo 9e: You'll continue connecting wires from the lid to the PCB. Strip them as described in the previous step. Make these connections:
1-in yellow wire from lug 2 of the Shutter jack, J2, to hole F on the PCB
1.5-in blue wire from lug 3 of J2 to hole E
2-in green wire from lug 1 of the Sensitivity pot, RV, to hole B
Photos 9f,g: One wire is left to connect. This wire will connect from the shorter leg of LED1 to hole M on the PCB. Cut a 3-in section of green wire. Strip it back 1/2-in on one end and 1/8-in on the other. Wrap the 1/2-in end around a small nail or brad as shown in Photo 9f. Slip this spiral down over the shorter leg of LED1 and solder in place close to the base of the LED, but be sure to keep the two legs from touching. Then connect the shorter end of the wire to hole M on the PCB. See the LED connection circled in yellow in Photo 9g. Clip this leg of the LED down to the solder joint.
Wiring the Battery Holder and Completing the Box Assembly
Step 10. Wiring the battery holder and completing the assembly
Photos 10a,b: Cut 1-in sections of black and red wire. Strip each wire back half an inch on one end. Also strip the red and black wires of the battery holder by the same amount. See Photo 10a. Twist the black battery holder wire around the short, black section. Do likewise for the red wires as shown in Photo 10b. Then solder the connections.
Photo 10c: Cut two 1-in sections of the 3/32-in heat shrink tubing and slip over the soldered connections. Use a lighter or match to shrink the tubing. Note that the purpose of these extensions is to make the wire ends less likely to break when the lid is removed for battery replacement.
Photo 10d: Connect the black wire of the battery holder to lug 1 of the Power jack, J6, and the red wire to lug 3 of J6. Solder the connections.
Photo 10e: Bolt the PCB to the standoffs. Then insert the PS2501-2 chip into the lower of the 8-pin sockets. Note the location of the white dot on the optocoupler. Once the pins are aligned, push down, applying as nearly equal pressure as possible on the surface of the IC to seat all pins. Repeat with the 555 timer in the upper socket. Note that the notch in one end of the socket aligns with the notch on the IC. Insert the fuse into the fuse holder clips. The fuse isn't polar, so either orientation will work.
Photo 10f: Position the battery holder in the bottom of the project box as shown in the photo. Use the supplied hook-and-loop tape to affix the battery holder securely to the bottom of the box.If the power switch of the box is on, turn it off. Then insert a fresh battery into the battery holder.
Photo 10g: Place the lid on the box, being sure to seat it completely without any wires being pinched. Then the screw down the 4 corners of the box, or, if you wish, leave the screws off until after you've tested the box.
Wiring the Emitter and Sensor Cables
Step 11. Connecting the IR phototransistor to the sensor cable
Photo 11a: Cut the black 2-conductor cable into two equal lengths. For one of the sections, strip back the black insulation on one end only by 2 inches.
Photo 11b: The individual red and black conductors are surrounded by a sheath of metal foil. Remove this sheath. Then strip back the red and black conductors by 1 inch each. Finally, wrap the bare wire conductor around the stripped end of the black conductor.
Photo 11c: Cut a 1-inch section of the 3/32-in heat-shrink tubing. Slip this over the red conductor.
Photo 11d: Next you'll connect the infrared phototransistor. This is the component with a transparent housing. (The infrared LED has a blue housing.) Wrap the black conductor around the longer leg of the phototransistor and the red conductor around the shorter leg.
Photo 11e: Solder the wrapped wires to the legs of the phototransistor.
Photo 11f: Slip the heat-shrink tubing over the leg of the phototransistor. Use a lighter or match to shrink the tubing.
Photo 11g: Cut a 3-in section of the 3/16-in heat-shrink tubing. Slip this over the 2-conductor cable from the free end. Slip the tubing all the way up to the phototransistor. Then shrink into place.
Step 12. Connecting the 3.5mm mono plug to the sensor cable
Photo 12a: Unscrew the jacket from one of the 3.5mm mono plugs. Slip the jacket over the free end of the sensor cable. (The one to which you connected the phototransistor in the previous step.) Strip 1/4-in of insulation from the end of the cable. Then strip the red and black conductors back by 1/8 inch each.
Photo 12b: Wrap the bare wire conductor around the stripped black conductor.
Photo 12c: Connect the red conductor to the shorter leg of the 3.5mm plug and the black conductor to the shaft of the plug.
Photo 12d: Solder the two connections.
Photo 12e: Crimp the tabs of the shaft around the insulation of the cable.
Photo 12f: Screw the jacket onto the plug.
Photo 12g: The completed cable is shown.
Step 13. Connecting the IR LED to the emitter cable
The wiring of the emitter cable is very similar to the sensor cable, but there are a few differences.
Photo 13a: Use the remaining length of 2-conductor cable. Strip back the black insulation on one end only by 2 inches and remove the foil covering.
Photo 13b: Cut off the bare wire conductor. Then cut a 1-inch section of the 3/32-in heat-shrink tubing. Slip this over the red conductor.
Photo 13c: Next you'll connect the infrared LED. This has a blue housing. Wrap the black conductor around the shorter leg of the phototransistor and the red conductor around the longer leg. (Note that this is the opposite of the phototransistor connections.)
Photo 13d: Solder the wrapped wires to the legs of the LED.
Photo 13e: Slip the heat-shrink tubing over the leg of the LED. Use a lighter or match to shrink the tubing.
Photo 13f: Cut a 3-in section of the 3/16-in heat-shrink tubing. Slip this over the 2-conductor cable from the free end. Slip the tubing all the way up to the LED. Then shrink into place.
Step 14. Connecting the 3.5mm mono plug to the emitter cable
Photo 14a: Unscrew the jacket from the remaining 3.5mm mono plug. Slip the jacket over the free end of the emitter cable. Strip 1/4-in of insulation from the end of the cable. Cut off the bare wire conductor. Then strip the red and black conductors back by 1/8 inch each.
Photo 14b: Connect the red conductor to the shorter leg of the 3.5mm plug and the black conductor to the shaft of the plug.
Photo 14c: Solder the two connections.
Photo 14d: Crimp the tabs of the shaft around the insulation of the cable.
Photo 14e: Screw the jacket onto the plug. The completed cable is shown.