
PicoKeyer-Plus
05/25/2014 (Firmware V4.5)
Page 12 of 19
4.
Once the part is in place and the solder has cooled, use a pair of fine pointed cutters to trim the excess
component leads close to the PCB.
You can build your PicoKeyer-Plus kit to be powered by either the on-board coin cell battery or external DC
power. During normal use, the supplied battery should last at least a year or two. If you wish to use external
power, install the supplied Zener diode and resistor in Step 9 instead of the battery holder. Do not install both
power options! Connecting external power while a battery is installed can result in component damage and could
even cause the coin cell battery to heat up and explode or burn. If using external power, a source of 3-14 Volts DC
must be connected to JP1,
not
to the pads used for the battery holder.
Step-By-Step Assembly Instructions
Locate the printed circuit board (PCB). Orient the PCB with the
component side on top and the lettering right-side up as you look at
it.
Your board may or may not have the component designators (C1,
C2, C3, Q1, etc) marked. Since all of the same type of parts are the
same value, this shouldn’t cause you any problems at all.
Locate the three ceramic capacitors in your kit. These will be small
rectangular parts with two parallel leads. All three are .01 μF
(marked 103). Install the three capacitors in the locations shown for
C1, C2 and C3. The capacitors used in your kit are not polarity
sensitive (meaning, don’t worry – you can’t install them backwards).
Note:
If you have an older version of the printed circuit board, C1
may be in a different location. The boards are functionally identical,
and the three capacitors still get installed in C1, C2 and C3.
Install one of the 2N7000 MOSFET transistors in location Q1. Make
sure the flat side of the transistor is facing the direction indicated by
the silkscreen printed outline. Leave about 1/8” between the circuit
board and the bottom of the transistor to avoid putting too much
stress on the leads.
Install the second 2N7000 MOSFET in location Q2, making sure the
flat side is oriented as shown on the printed outline. It’s not installed
the same as Q1!