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Assembly and Operating Instructions for Kits


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Instructions to Replace the Multi-Trigger Enclosure Breadboard with a PCB (MTEconv)


Assembly instructions for other kits


For reference, the instructions for building the Multi-Trigger Enclosure for a breadboard (MTE) are here.




What you need

Parts guide (opens in new tab or window)

Soldering the fixed-value resistors to the PCB

Soldering the IC sockets to the PCB

Soldering the capacitors to the PCB

Soldering the semiconductors to the PCB

Connecting the enclosure lid to the PCB

Completing the assembly


Operating manual (opens in new tab or window)


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What you need


PCB for Multi-TriggerThese instructions show how to replace the breadboard in a Multi-Trigger Enclosure with a PC board. The MTEconv kit comes with the PC board and additional parts that you need for the conversion. The PC board is shown to the right. You'll see that the locations for the components are labeled with symbols like R1, C1, etc. This makes it easy to find where to place the components. You'll take components from your breadboard assembly, insert them into the holes on the PCB, and solder them to the back (non-printed side) of the PCB. We'll provide guidelines for getting good solder joints, but we recommend that you have previous experience soldering on a PC board. With soldering, you can't make changes easily like you can with a breadboard. If you solder something in the wrong place, repair can be time-consuming.


Having the right tools will make the job easier. You'll need to provide your own. Here's what we recommend.


For soldering

  1. 15-30 W soldering iron (with a new or pointed tip) and solder
  2. Wire stripper (photo below)

  3. A small diagonal cutter (photo below) makes it easy to trim the legs of the components after you solder them to the PCB, but other kinds of snipping tools such as scissors may work.

  4. Needle-nose pliers (photo below) make it easier to handle small components, especially if you have big fingers.

  5. A heat sink (photos below) protects heat-sensitive components while soldering.

  6. A desoldering tool (photos below) helps in clearing solder from a hole. The cylindrical type works better than the bulb.

  7. A magnifying glass is used to inspect solder joints.

  8. A lighter or matches to shrink heat-shrink tubing

    Wire cutters and stripper

    Small diagonal cutter

    diagonal cutter

    Needle-nose pliers

    needle-nose pliers

    Heat sinks

    heat sink clip heat sink clip

    Desoldering tools

    desoldering tool desoldering bulb


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.


Parts guide


Click here for a detailed, illustrated list of all the parts you'll need. You can use this list to identify the parts and make sure you have them all. Most of the parts will come from your existing Multi-Trigger and will be transferred from your breadboard to the PCB.


A helpful reference


It will be helpful to print this pdf document for reference while you work. There are lists of component placements and jumper wire connections. For those who like to use circuit schematics, there's a complete schematic of the circuit.


Soldering the fixed-value resistors to the PCB


If you don't have your soldering iron heated up, do that now, because you'll be soldering next. You'll be doing some detailed soldering work, so an iron with a good tip will make it easier. Start with R1, a 100-kΩ resistor.

  1. Insert the legs of resistor R1 over the rectangular space labeled R1 on the PCB. See Figure 1. (Click on it for a closeup view.) You can flip the resistor either way in the holes; the orientation doesn't matter for resistors, since resistors work the same no matter which way current flows in them.

  2. Push the resistor in until it's flush with the surface of the PCB. Then flip the PCB over. Figure 2 shows the legs protruding from the back of the board.

  3. Next you'll solder. Tin the tip of the soldering iron by melting some solder on it. Then bring the point and the solder down to one of the holes where the resistor protrudes as in Figure 3. Melt some solder around the base; it doesn't take much. The solder should flow down into the hole around the leg of the resistor to make a good electrical joint. Now solder the other leg.

  4. Turn the board over to verify that solder filled the holes. See Figure 4. If you don't see that solder melted through to the upper side, it's probably a good idea to melt some more solder into the hole from the back of the board.

  5. When your solder joints are complete, you can snip off the legs of the resistor down to the solder joint or you can wait to snip legs until after you've added more components.

inserting R1 R1 from back of PCB Soldering a leg of the resistor R1 from back of PCB
Figure 1. Resistor R1 inserted into dedicated space on PCB Figure 2. Legs of resistor R1 protruding from back of PCB Figure 3. Soldering a leg of the resistor Figure 4. Inspecting the finished solder joints


Something to be aware of before you do any more soldering is that there are two kinds of holes on the board: solder holes and via holes. The solder holes are for the component legs. The via holes, which are smaller than the solder holes, are places where there are connections between the upper and lower conducting layers of the board. To see what we mean, click on Figure 5, which shows a small section of the board. The via holes have been circled in yellow. Don't try to solder components into via holes. If, however, you get solder in a via hole, don't worry about it.
  1. In addition to R1, solder the following fixed-value resistors to the PCB: R2 - R6, R9, R10, R12, R17 - R19. Note that you will not solder R7, R8, R11. These resistors are already soldered to the lid of your enclosure. Note also that R13-R16 are the pots that are already mounted on the project box. One other note: R12 is the extra 1-kΩ resistor supplied with your conversion kit. The corresponding resistor on the breadboard is a 100-Ω resistor. While either resistor will work on the PCB, the higher-value resistor draws less current in operation and therefore provides longer battery life.

  2. When you've finished soldering the resistors, your board should look similar to Figure 6.

via holes board with all resistors
Figure 5. Via holes (circled in yellow) and solder holes Figure 6. PC board with fixed-value resistors mounted


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Soldering the IC sockets to the PCB


The 8-pin and 14-pin IC sockets will be used to seat the 555 and 556 timers. The latter won't be added to the sockets until later, since the ICs can potentially be damaged by heat.

  1. See Figure 7. Note that the socket has a notch on one end. You'll line this notch up with the one on the PCB when you seat the socket into the board.

  2. Place the 8 pins of the socket into the corresponding holes on the PCB as shown in Figure 8.

  3. Turn the board over and bend the pins down to the side to hold the socket in place as shown in Figure 9.

  4. Solder the 8 pins to the board. The finished result is shown in Figure 10. Check with a magnifying glass to make sure there are no solder bridges or hairs between pins. If so, remove them by running the tip of the soldering iron between the pin.

  5. Solder the 14-pin socket to the board similar to how you did the 8-pin socket.

8-pin socket notch seating the 8-pin socket Crimping the 8-pin socket 8-pin socket soldered to PCB
Figure 7. Notches on the socket and the PCB Figure 8. 8-pin socket seated on PCB Figure 9. Crimping the pins of the 8-pin socket Figure 10. 8-pin socket soldered to PCB


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Soldering the capacitors to the PCB


0.0047-uf capacitorThere are two kinds of capacitors, ceramic and electrolytic. We'll start with the ceramic capacitors. There are 6 of these; they all have a disc shape and are orange or yellow in color. A number on the disc identifies the capacitor. The capacitor on the right, for example, has the number 473. From the Parts Guide, you can determine that this is a 0.0047-μf capacitor. Note that one of the ceramic capacitors, a 0.047-μf capacitor, is already soldered to the enclosure lid. This is C8.Therefore, you will not solder C8 to the PCB.


  1. Ceramic capacitors, like resistors, are non-polar. So it doesn't matter if you flip them one way or the other other in the solder holes. Slip the ceramic capacitors in the holes now as shown in Figure 11. Seat them down to about the height of the pots. Remember to omit C8.10-uf capacitor

  2. Turn the board over and solder the capacitor legs like you did the resistor legs. It may seem like you're not getting solder in the holes even when you are; turn the board over to inspect. Resolder if necessary. Wiggle the capacitor to make sure both legs are seated firmly. The legs are close together, so check carefully for solder bridges. Note the solder bridge in Figure 12. This was removed by drawing the tip of the soldering iron through the legs.

  3. There are two electrolytic capacitors. These have cylindrical metal cases with the value of the capacitance printed on them. See the photo of a 10-μf capacitor to the right. These capacitors are polar; that is, they have a positive and negative side. Therefore, there's only one way to mount them in the PCB. You'll see that the locations of the positive and negative sides for an electrolytic capacitor are marked on the PCB. Note the negative (-) sign for C6 in Figure 13. The corresponding negative side of the capacitor has a negative sign--it's a hollow rectangle--printed on one side. This is also the side with the shorter leg. One of the electrolytic capacitors, a 0.47-μf capacitor, is already soldered to the enclosure lid and so will not be soldered to the PCB. This is C3. Place C6 on the board now as shown in Figure 14. Then turn the board over and solder the legs. Figure 15 shows the PC board with all components mounted so far.

  4. If you haven't snipped off the legs of the components protruding from the back, do that now. Snip them at the solder joint. You don't want to have any legs that can be bent over and touch other legs to create short circuits.

mouting the ceramic capacitors Solder bridge between the legs of a capacitor location of C3 with polarity indicated electrolytic capacitors on PCB
Figure 11. Mounting the ceramic capacitors Figure 12. Solder bridge between the legs of a capacitor Figure 13. Polarity for C3 is indicated on the PCB Figure 14. Electrolytic capacitor seated on PCB (polarity indicated)
PCB with all capacitors mounted      
Figure 15. PCB with all capacitors mounted      


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Soldering the semiconductors to the PCB

  1. There are 5 semiconductors, one transistor and four SCRs. They look alike except for the lettering on the face. You'll mount the transistor first. Look for the part that says PN2222A on the face. Slip it into the PC board as shown in Figure 16. Note that the flat side faces toward the inside of the board. This orientation is required for correct operation of the circuit.

  2. Soldering the semiconductors takes special care, because the components can be damaged by getting too hot. A way to bleed off excessive heat is to use a heat sink as shown in Figure 17. The heat sink is just a metal clip that grasps the leg to be soldered. The alternative to a heat sink is to solder quickly. If you find yourself taking too much time, wait a while to allow the component to cool before continuing. Solder on the back side like you did for the other components. Avoid the temptation to linger while soldering; the hole will fill before you know it. Turn the board over to check the other side to make sure that too much solder hasn't bled through.

  3. When you finish soldering the three legs, inspect carefully for solder bridges on both the front and back sides of the board. The legs of the transistor are so close together that solder bridges are a likelihood. Inspect under a magnifying glass for fine solder hairs. See Figures 18 and 19 for how your finished solder joints should look.

mounting the PN2222A transistor Using a heat sink on a transistor leg Inspecting for solder bridges Transistor soldered to PCB
Figure 16. Mounting the PN2222A transistor. Note the flat side. Figure 17. Using a heat sink on a transistor leg Figure 18. Inspecting for solder bridges Figure 19. Transistor soldered to PCB
SCR for photogate output (front view) SCR for photogate output (back view) Sound trigger output SCR Delay unit output SCRs
Figure 20: D1 SCR positioned on board Figure 21: D1 SCR seen from the back Figure 22: D2 SCR Figure 23: D3 and D4 SCRs for instant and delayed outputs
  1. Now let's move on to the SCRs. These have EC103D written on the face. Insert the legs of an SCR into the D1 location as shown in Figure 20. Make sure the flat side faces toward the 8-pin socket. Note that the three legs are contained within the small square. The holes labeled A and C shown from the opposite side in Figure 21 are not used by the SCR. Go ahead and solder the legs of the SCR as you did for the transistor.

  2. Position SCR D2 for the sound trigger as shown in Figure 22 and solder into place.

  3. Position SCRs D3 and D4 for the instant and delayed outputs as shown in Figure 24 and solder into place. You may notice that we accidentally filled some of the A and C holes with solder. This won't hurt anything. These holes are for optional, external cables. The solder in the holes may be reheated, if necessary, to slip wires in.

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Connecting the enclosure lid to the PCB

  1. Before starting to solder, remove the 555 and 556 timers from your breadboard and insert them into the sockets on the PCB. It's a good idea to discharge yourself by touching a grounded pipe or even the wooden leg of a table before handling the 555 and 556 timers. These are static-sensitive parts. Remember the notches in the socket? Well, there's a corresponding notch in the end of each IC. When you put an IC in a socket, the notches must be at the same end. Start with the 555 timer. Place it on the socket and pinch the pins gently if necessary to guide them into the holes. When all the pins are aligned, push down firmly on the IC to seat the pins. Repeat with the 556 timer.

  2. You'll need to decide on a physical arrangement that you're comfortable with when soldering the jumper wires to the PCB. Two possibilities are shown below. Figure 24 shows the PCB lying face up on a table in front of the box lid, which is propped up vertical. Note the orientation of the PCB with respect to box lid. The output holes at the left end of the board are near the RCA jacks on the box lid. The advantage of this arrangement is that you can see the writing on the PCB. The disadvantage is that it's difficult to size the wires to optimum lengths. We prefer the arrangement shown in Figure 25 in which a clamp holds the PCB upside down above the box lid.. If you don't have a clamp such as the one shown, you can still use this method if you have some means--perhaps another person--to hold the board while you solder. After you've soldered several wires, you'll find that the springiness of the wires will be enough to hold the board up. This upside-down method makes it easy to size the wires correctly. While you don't have the PCB labels to help you locate holes, we have an aid that will be described in step 4.

  3. When you built the MTE enclosure for your Multi-Trigger breadboard, we referred you to Figure 26 in order to see where to connect the jumper wires from the box lid to the breadboard. For convenience, we'll use the same breadboard coordinates to refer to the connections that you'll make to the PCB. For ease of reference while soldering, you can download a full-page version of this photo for printing.

  4. In order to aid in routing wires from the box lid to the PCB, use Figure 27 or 28, depending on which of the physical soldering arrangements you're using. Figure 27 shows the top of the board, while Figure 28 shows the bottom. Both figures have an overlay of the same breadboard coordinates as used in Figure 26. Note that B(+) indicates the red wire of the battery pack. Like Figure 26, full-page versions of Figures 27 and 28 can be downloaded and printed.

  5. Go ahead now and solder the jumper wires. Solder B(+) last so that you can arrange the battery holder the way you like. Trim down some of the wires to shorter lengths so that you won't have so much wire to compress when you place the completed assembly on the box.

  6. Snip off any wires extending from the bottom of the PCB.
One possible arrangement for working on PCB connections Another possible arrangement for working on PCB connections Box lid and jumper wires PCB (top side) with overlay of labeled locations for jumper wires from the box lid
Figure 24. One possible arrangement for working on PCB connections Figure 25. Another possible arrangement for working on PCB connections

Figure 26. Jumper wires from box lid labeled with former breadboard coordinates

Download full-page photo

Figure 27. PCB (top side) with overlay of labeled locations for jumper wires from the box lid

Download full-page photo

PCB (bottom side) with overlay of labeled locations for jumper wires from the box lid      

Figure 28. PCB (bottom side) with overlay of labeled locations for jumper wires from the box lid

Download full-page photo



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Completing the Assembly


Now you can reassemble your box. See Figure 29 for how everything fits together in the project box. Place a fresh battery in the battery holder before closing the box. Then gently work the lid down, compressing the wires gradually and making sure that they don't get pinched by the box lid. Finally, screw down the lid. The final assembly shown in Figure 30 will look identical from the outside as your original breadboard enclosure.


Seating the battery holder and PCB in the project box Multi-Trigger box with labels    
Figure 29. Seating the battery holder and PCB in the project box Figure 30. Multi-Trigger enclosure with labels    




Your Multi-Trigger Enclosure with PCB should function identically to when you had the breadboard installed. Run through the tests below to verify functions.


Power test

Flip the On-Off switch to the right to verify that the power LED lights.


Photogate test

Turn the PG SENS to the middle of its range. Plug in the interrupter photogate cable and verify that the photogate alignment LED comes on. Run your finger through the slot to see if the LED goes out momentarily. Turn PG SENS all the way clockwise to see if the LED goes out. Then turn the knob back to the middle position.


Delay unit test

Turn the COARSE DELAY pot all the way clockwise. Flip the INPUT selector switch to MIC and the Divide/10 switch (also called Delay Range) to the 0.5s position. Flip the TIMEOUT switch to 1s. Push the Test button. After a delay of about a second, the TRIG LED should turn on and stay on for about a second. Now flip the Timeout switch to 0.01s. When you push the Test button, you'll get the same delay as before, but the delay unit LED should flicker briefly


Flip the Divide/10 switch to the 0.05s position. When you push the TEST button, there won't be noticeable delay. Flip the Divide/10 switch back to the 0.5s position.


Photogate with delay test

Now plug in one of your photogate cables again, and flip the INPUT selector to PG. You should get all the same results as above if you break the photogate beam instead of pushing the test button.


Delay unit with external input test

If you have an external trigger that you want to use with the Multi-Trigger and you've already prepared a cable for it, plug the cable into the external input (EXT IN) jack. The delay unit should function the same with an external trigger as it did with the photogate.


Test of sound trigger input

Remove the photogate cable and connect the microphone cable. Flip the input selector to MIC. Turn SND SENS all the clockwise. Tapping the microphone or snapping a finger should trigger the delay unit and your flash the same as with the photogate.


Test of flash outputs

Connect the trigger cable for your flash unit to each of the flash outputs (ST OUT and DELAYED FLA) to verify that you can discharge your flash.


Test of camera outputs

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.


If you're using a Camera Opto-Switch to trigger your camera, connect the TRIG jack of the Opto-Switch to either the INSTANT or DELAYED CAM output, and connect the shutter cable from your camera to the CAM jack of the Opto-Switch. (See your Opto-Switch instructions if necessary.) A triggering event should actuate your camera shutter.


This completes testing. If any of your tests failed, you'll need to open the box and check your connections. If you have questions, you may contact us and we'll do our best to troubleshoot by email.


Operating Manual




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