WordClock-3 Assembly Guide 2/25/20 Version 0.6
Page 4
Build the 30v and 1.65v power supplies. Install R1-R8, L2, L3, D3, D4, C4-C7, U2, and
U3. Note that D3, D4, C6, C7, U2, and U3 must be installed in the direction noted on
the board.
Connect a temporary jumper between Q1 pins 2 and 3. For version 5 and above,
temporarily connect the ENABLE pad to +5v. Connect the power supply, and check the
test points for approximately 30v and 1.65v. Do not continue assembly if these
voltages are not present at the test points. Remove the temporary jumper.
Install the components on the bottom of the board, starting with the surface mount ICs,
U6-U10. The line or dot on one side of the chip must be installed toward the cutout on
one side of the silkscreened pattern. The best way to install a surface mount chip is to
add a very small amount of solder to one of the corner pads on the board. Then quickly
and carefully solder the corresponding pin to the pad. Check the alignment of all pins
and if correct, solder the opposite corner pin. Check the alignment again, then solder
the remaining pins quickly and carefully. Always use a magnifier to check for solder
bridges and bad solder joints.
Install the remaining surface mount parts on the bottom of the board, C8, and C13-
C18.
Install the SD card connector next. Be sure to solder all leads to the board. Solder
quickly and carefully. The plastic chassis can easily be damaged by too much heat.
Several pins on one side of the connector are very close to the grounded case. Be
careful that they are only soldered to the pc board, not the case. Then install J3, the
GPS connector.
Install all of the remaining parts on the top of the board,
except for the RGB LEDs
,
LED1-LED8. These will be installed last.
The ambient light sensor, Q2, should be installed about 10mm above the board. The
shorter lead goes toward the back of the board.
Install the remaining parts to the main board. J4 is not used.
Insert the microcontroller, U4, into the headers, aligning the direction of the USB
connector and the antenna with the marks on the board.
Step 2 – Build the Tube Boards
Cut the leads of all six IV-17 tubes progressively smaller, to make insertion of the leads
into the tube boards easier.
