■ FIGURE 3
Construction
The components of the Proto Buddy are mounted on
a double-sided printed circuit board (PCB) as shown in
Figure 6. The side with PRB-1 printed on it is the
component side (C side). The other side is the solder side
(S side). As the names imply, components are mounted
on the C side and soldered on the S side. However, three
sets of mounting pins will be mounted on the S side and
soldered on the C side.
Start by inserting the 15 pin jacks into the PCB.
CAUTION: Make sure you have inserted them on the
correct side of the board before soldering. The pin jacks
sit loosely in their holes, so they must be held in place
before turning over the board to solder them. I used an
emery board held by a metal binder clip as shown in
Figure 7. You could use anything of that size as long as
the material doesn't melt; maybe a popsicle stick or a
piece of scrap PCB.
Once the pin jacks are soldered in place, mount the
two position DIP switch (S1 and S2) and bend the four
pins to secure it to the board. Insert S3 and S4; they have
springy leads that should hold them on the board without
bending the leads over. Turn the board over and solder all
the switches.
The LEDs must be oriented correctly before mounting.
One LED lead is longer than the other. The long lead is
the anode and the short lead is the cathode. The cathode
lead is closest to the pin jack. If you look carefully, you
might see a flat section on the plastic base of the LED
next to the cathode lead. (Refer to Figure 6).
Mount the two LEDs and bend their leads slightly to
hold them in place. Mount the two resistors and bend
their leads slightly. Turn the board over and solder the
leads. Clip off any excess lead length.
The three position terminal block is mounted next. Its
leads are too heavy to bend, so secure it to the board
with rubber bands. Make sure the bands are positioned
away from the pins so they don't melt, then solder them to
the board. Remove the rubber bands.
The two jumpers (designated jmp) are implemented
■ FIGURE 4
with pairs of header pins on 0.1 inch centers. Usually
header pins come in multiple pin strips (e.g., an eight pin
header strip). Such strips are designed to be snapped into
pieces, so snap off two pairs. You can use a bit of putty to
hold the pairs of pins to the board. Solder them to the
board and remove the putty. Push a jumper block onto
each pair of header pins.
Three pairs of header pins are used to hold the Proto
Buddy to the SBB; they are mounted on the S side of
the board and soldered on the C side. Follow the same
procedure used for the jumper pins.
The soldering is done. Use some rubbing alcohol and
an old toothbrush to remove any flux
■ FIGURE 5
■ FIGURE 6
■ FIGURE 7
January 2009 45
