Macsense Connectivity Digital Wattmeter DWM-4 - Manual (Page 2)

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in the assembly instructions to assist the builder. These can be used for parts identification and PC
board placement.
Assembly: You will first install (locate, place, and solder in place) the parts on the DWM-4 Main
PC board. Use the silk screen layout in the back of this manual to assist in locating where parts
are to be installed.
___ Install all of the resistors, R2, 8, 22, 26, 29 and 30. Be sure to check the values with the parts list.
Most of the resistors are 1/8 watt and may be hard to read. Use an ohmmeter to verify the values if
you have trouble identifying them.
___ Install the 1N4001 diode, D1. Note the band polarity.
___ Install the 1N4148 diodes, D2-5. Note the band polarity.
___ Install the 10K 10-pin SIP resistor, RP1. Be sure to note the orientation of the SIP resistor. A small
line (or dot) on the side with writing marks pin 1.
___ Install the .01uf monolithic capacitors, C1, 3-5, 7-10, 12-15, 17-20, 22-25.
___ Install the ceramic capacitors, C6 100pf 1KV; C26 & 27 10pf 500v.
___ Install U2, the 7805. Align the .2" hole in the regulator with the .2" hole in the PC board. Solder
and clip the three legs. Then place one screw through the bottom of the PC board, through the
hole in the 7805 and tighten a nut on it from the top of the PC board.
___ Install the 2N3904 transistor, Q1. Note the correct orientation.
___ Install the variable resistors (100K pots), R5-6, 11-12, 17-18, 23-25.
___ Install the socket for U3, 14-pin DIP socket. Match the notch on the silk screen with the notch on
the socket. Do not install the U3 (the LM339) until later.