FM-100 Page 40
9K. Install D6, a 1N4002 type diode. Make sure the striped end is installed
correctly!
10K. Install D7, the last 1N4002 type rectifier diode. Again check the
striped end for correct installation.
11K. Install VR4, the 79L08 -8 volt regulator. Make sure the flat side of the
part is oriented as shown. This part “smoothes” out the raw DC from C55.
12K. Install C56, a 10uF electrolytic capacitor. Make sure the negative
side of the capacitor is installed on the opposite side of where the positive
side marked on the board is.
13K. Install C55, a 1000uF electrolytic capacitor. (Watch polarity!)
14K Install C89, another 1000uF electrolytic capacitor. (Polarity) The last
group of parts have formed a negative voltage multiplier to give us our
minus supply for the opamps.
15K. Install C50, a 100uF electrolytic capacitor. Again check the polarity
before installing.
16K. Install VR3, the 7805 +5 volt power regulator. We want to mount this
flat to the board as shown in the diagram. The tab side of the part should
be facing the board. Install HS1 between the tab and the PC board. Make
sure the heatsink is installed so that it doesn’t hit the leads of the
regulator. Use a 4-40x1/4 screw and a lock nut to secure the regulator,
heatsink and board together.
17K. Install C10, a .01uF ceramic capacitor (marked 103, .01 or 10n).
18K. Install T1, the power transformer (PC-20-500). Notice how the label
of the transformer has an orientation dot on one corner. A corresponding
dot is located on the PC board silk screen for T1. When installing T1,
ensure that the dot on the transformer is oriented to the same corner as
indicated on the board. Make sure you install this correctly! If installed
wrong, you will destroy your entire kit! You may need to bend the leads
around a little before installing in the board. Make sure all six pins are
through before soldering.
7805
PC Board
Topside
Heatsink
