Ramsey Electronics LEDS1, Quick Reference Page Manual

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LEDS1
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23. Install C9, .47 uF electrolytic capacitor under VR1. Watch the polarity.
Make sure the band on the cap lines up with the right hole on the board.
Only “+” is marked on the board, the band on the cap could be “+” or “-”.
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24. Install R5, 1K ohm resistor [brown-black-red], next to C9.
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25. Install C11, 1 uF electrolytic capacitor, next to R5. Watch polarity.
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26. Install C12, 10 uF electrolytic capacitor just above C11. Watch polarity
again.
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27. Install U3, NE555 timer IC, to the left of C12. Line up the notch at on
end with the notch on the board drawing. U3 is the oscillator that flashes the
LEDs in stroboscope mode.
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28. Install D11, 1N4002 silicon diode, to the left of U3. Make sure the band
at one end of the diode lines up with the band on the board drawing.
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29. Install C10, 33 uF electrolytic capacitor above D11. Watch that polarity.
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30. Install D10, the other 1N4002, above U3. Line up the band again.
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31. Install R18, 330 ohm resistor [orange-orange-brown] next to D10.
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32. Install R10, 10K ohm resistor [brown-black-orange], just above D10.
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33. Install U2, the other NE555 timer IC, next to R10. U2 flashes the LEDs
in audio mode.
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34. Install R11, 470K ohm resistor [yellow-violet-yellow], next to U2.
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35. Install C7 .1 uF capacitor next to R11. You’ll see that the PC board
layout shows the outline of an electrolytic capacitor but that we’ve supplied
a disc cap. You’ll have to bend the leads with so that they fit into the smaller
spacing; ignore the polarity markings since disc caps are not polarity
sensitive. It looks tight but it can be done! Solder as usual.
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36. Install C8, 1 uF electrolytic capacitor. Follow the silkscreen layout for
orientation.
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37. Install R15, 68 ohm resistor [blue-gray-black], up and to the left of U2.
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38. Install R19, 100K ohm potentiometer up at the top of the board. This
controls the flash rate in stroboscope mode.
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39. Install R7 and R16, both 300 ohm resistors [orange-black-brown], at the
top of the board.
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40. Install S1, S2, and S3, pushbutton switches, at the top of the board.
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41. Install Q1, 71F7034_H N channel MOSFET, in the middle left of the