Ramsey Electronics COMPUTEMP CT255 - Manual (Page 20)

CT255
• 20
ˆ 16. Install C2, 10 uF electrolytic capacitor. Remember to observe polarity
with electrolytic capacitors! Check the parts placement diagram for correct
orientation.
ˆ 17. Install R34, 10K ohm (brown-black-orange).
ˆ 18. Install R30, 10K ohm (brown-black-orange).
ˆ 19. Install R4, 10K ohm (brown-black-orange).
ˆ 20. Install R2, 10K ohm (brown-black-orange).
ˆ 21. Install C1, 1 uF electrolytic capacitor. Remember to observe correct
polarity!
ˆ 22. Install R1, 47K ohm (yellow-violet-orange).
ˆ 23. Install R15, 100K ohm (brown-black-yellow).
ˆ 24. Install C6, .1 µF disc capacitor (marked 104 or .1). Disc capacitors are
not polarized, so either direction is fine.
ˆ 25. Install R39, 1K ohm (brown-black-red).
ˆ 26. Install R37, a precision 1K ohm (brown-black-black-brown-brown).
ˆ 27. Install headers H2 and H1 by slipping the protruding pins on the short
side through the circuit board and soldering. Solder all three pins.
ˆ 28. Install C3, .1 µF disc capacitor (marked 104 or .1).
ˆ 29. Install R31, a precision 4.22K ohm (yellow-red-red-brown-brown).
ˆ 30. Install R27, a precision 1.43K ohm (brown-yellow-orange-brown-
brown).
ˆ 31. Install R40, the last 10K ohm (brown-black orange).
ˆ 32. Install R23, a precision 1.82K ohm (brown-gray-red-brown-brown-
brown).
ˆ 33. Install R22, a precision 10K ohm (brown-black-black-red).
ˆ 34. Install C5, .1 µF disc capacitor (marked 104 or .1).
Whew! That was some work. But we’re almost done and some decisions need
to be made before continuing. It’s a good time now to re-check all your work
up to this point. Carefully inspect the circuit board for stray leads or open
solder connections, trim and touch up any that need work.
Next, while we are at our best, we will install the LED segments for the
display. (L)ight (E)mitting (D)iodes are just that, a diode junction that emits
light of a particular wavelength when forward biased, so pay attention to the
polarity of the diodes as shown in the parts placement diagram. Remember
that this will be the most observed part of the entire kit, so take your time and