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NOTE: All CT-2 controllers are now sold as an assembled and tested board.  Assembly instructions on this page are for reference only.



Assembly and Initial testing of the W2DRZ CT-2 Controller

Before starting assembly, prepare a clean, uncluttered workspace and floor area. This will make it much easier to find the small parts should any of them be dropped.  The CT-2K parts list is at the end of this page.
Recommended Tools
Solder 63/37 # 22 or smaller, this is a lower temperature solder than 60/40 (KESTER 44 RA or Radio Shack Pt. # 64-013)
Rosin solder flux Radio Shack Pt. # 64-021
Soldering work station About a 40 watt pencil iron. (Weller Pt. # WTCPT, Radio Shack Pt. # 64-2184)
Diagonal cutters 3.5 or 4 inch (prefer surface cutter)
A few wood toothpicks Used to hold in place some parts while soldering.
Magnifying glass  

Installing the SMT (surface mount) parts
The SMT resistors are all identified by a number printed on the body of the part. The numbers are referenced in the steps below, along with the part number. Find the part number silk screened on the board and solder in place. Another person helping will make it much easier to install the SMT parts. Have your helper hold down the part with a wooden toothpick while you solder it in place. Solder quickly, 63/37 solder “wets and flows” quickly, so a bright solder finish is normal. If too much heat is used it will be dull looking and gray; result is burned solder / flux and damaged board.

When soldering SMT parts, place the tip of the iron on the circuit board trace next to the component without touching the part itself. Allow the heat and solder to flow from the trace onto the part. If the iron is directly in contact with the chip part, the heat can "shock" the part and fracture it. The connection may look good and even work, but small vibrations can cause the board to intermittently fail. This is not as much of a concern when using a lower power (15 watt) iron.


The board is positioned with connectors away from worker and top (silk screen side) of board up. The five I/O connectors are at the back of board (see Figure 1).

We recommend installing the parts in the order outlined below, otherwise it will be very difficult to complete the assembly. View here to help with components identification.

1 Take a toothpick, a dab of solder paste/flux on end of toothpick; apply a bit to smt pads.
2 Select 2 SMT resistors # 474, 470K, R15 and R17, helper hold with toothpick, solder in place.
3 Install R2-R5, # 101, 100 ohm SMT resistors.
4 Install R6-R9, # 331, 330 ohm SMT resistors.
5 Install R10, # 221, 220 ohm SMT resistor.
6 Install R16, R18, # 103, 10k ohm SMT resistors.
7 Install R12, # 103, 10k ohm SMT resistor
8 Install D1, SMT 9.1 volt zener diode. Look closely, it is difficult to see the bar which must face the right side of board (facing away from IC1).
9 Install RN1-RN4 sip, 6.8k resistor pak, solder in place. These may be facing either direction.
10 Install C6 and C7, (marked 220), 15 or 22 pf. ceramic capacitors, solder in place.
11 Install R13, R14, R19, (wire lead), 47k 1/8 watt resistors, solder in place.
12 Install jumpers from pad1 to pad2 and from pad3 to pad4. The jumpers provide a 1:1 count for incremental encoders. Omitting the jumpers gives a 4:1 count and is not recommended.
13 Install C1, C2 and C3, 1mfd tantalum electrolytic capacitors, observe polarity, bar on body and the long lead is +, solder in place.
14 Install .1 mfd ceramic capacitors C4,5,8,9,10,11,12, and 13 (marked 104).  Do NOT install the 220 Mfd on the bottom of board at this time.
15 Note: that the RJ11 (6 pin) and RJ45 (8 pin) connectors snap into place with a small amount of pressure. Take care to have the leads aligned to prevent damage to the connectors, solder in place.
16 Note: The middle DB-9 (AUX) is a male connector, solder in place.
17 Note: The right DB-9 (COMPUTER) is a female connector, solder in place.
18 Install the 20 Mhz crystal. Solder the leads before cutting close to board. If leads are cut before soldering, the shock from cutting can fracture the crystal.
19 Install remainder of parts, except for Q1-Q6, U$1-U$6, D6, SV1-10 pin ribbon plug and 7805 regulator with the heatsink. For all IC sockets, pin 1 is toward the connectors at the back of the board.  Be sure socket is flush to board surface, hold flush and solder in place.
20 Install the 7805 voltage regulator and heatsink using a 6-32 by screw, flat washer, lock washer, and nut. NOTE: The 6-32 flat washer is located between the PC Board and the heatsink for spacing of trace under heatsink. The 6-32 nut is on the 7805 tab, do not solder 7805 until the 6-32 bolt is tightened. Then solder the 3 leads.
21 Install transistors Q1 through Q6. The white / part number side is to the left edge of the board, the collector is to back, towards the I/O connectors.
22 Install LED’s U$3,4,5, and 6. The long lead is +, and goes to the left side of board. The LED’s can be flush or otherwise mounted.
23 Install LED U$1. The long lead is +, and goes to the right side of board.
24 Now install the 220 mfd SMT electrolytic capacitor, C14. It goes on the bottom side of the board, at the center of the PICC (IC1).  The + side is the WHITE BAR, and goes toward the back of board (towards I/O connectors). Be careful to position C14 so that it is centered between the traces so as to allow soldering of both leads correctly.
25 Install D6, the 3 amp, 50 volt polarity protection diode.  We recommend no more than 15 volts be applied.
26 Note: The RELAY Transistors (ZTX614) are 800 milliamps at + 100 volts collector to emitter rating.
27 An additonal 1/8 watt resistor, 47k, is included in the kit, but not shown in the schematic. Install this resistor between pin 2 and pin 5 of JP1. JP1 is the 14 pin jumper set located between connector SV1 and the edge of the board. The JP1 pins are identified in this picture:

Initial Testing
Before installing the IC's in their sockets, we recommend some initial testing to be sure there are no serious shorts on the board and that the voltage regulator is working correctly.

Start by measuring resistance between ground and the three points shown in Figure 1. Be sure to connect the negative lead of your ohmmeter to ground. Point A should read close to infinity on a digital multimeter. Points B and C will show charging effects due to the electrolytic capacitors but the ending values should be greater than 1 megohm for Point B, and around 5Kohms for Point C. (Measurements were taken with a Fluke Model 75 DMM, other models may vary due to different internal voltage and resistance of the meter circuitry).

Next wire the 8 pin DIN connector to your 12 volt DC power source and apply power (DIN-8 pinout). Measure voltage from ground to Point C on the diagram, and ensure it is about +5 volts. After power has been applied for a minute, check the 7805 voltage regulator's temperature by touch. It should remain cool.

Now remove power and install all the IC's in their sockets. IC placement is shown in Figure 1.

WIth power removed, measure the resistance at Point C to ground again. It should be approximately 3K ohms.

For further testing and setup, proceed to the DrzTrack documentation.

 

Figure 1

 


 Kit Parts List for W2DRZ CT-2 CONTROLLER
1 ea S1 4 position dip switch 1 ea S2 N.O. Tact switch
1 ea Button 1 ea 10 pin ribbon plug male
1 ea 10 pin ribbon plug male 1 ea J1 6 pin Modular Connector
1 ea J2 8 pin Modular Connector 1 ea X1 DB-9 Female
1 ea X4 DB-9 Male 1 ea X3 Din 8 Connector Female
1 ea X2 Din 8 male plug cable 8 ea C4 - C13 .1 Mfd
3 ea C1 - C3 1 Mfd @ 16 v 2 ea C6-C7 18 pf
1 ea C14 220 Mfd @ 6.3v 1 ea R1 Trim pot 2.0k
4 ea RN1-RN4 SIP 6.8k 4 ea R2-5 100 ohm
1 ea R 10 220 ohm 4 ea R6-9 330 ohm
2 ea R16, 18 47k 2 ea R15, 17 470k
1 ea R12 10k 4 ea R13, 14, 19, 20 47k 1/8 w
5 ea U$1, 2, 3, 4, 5 LED 4 ea D2, 3, 4, 5 Diode 1N4148
1 ea D6 Diode 1N5400 / A05 1 ea D1 Zener 9.1v
1 ea JP-1 6 ea T1, 2, 3, 4, 5, 6 ZTX614
1 ea IC-1 18f4580 20 Mhz 1 ea IC-2 MAX202CPE
2 ea IC-3, 4 MAX381 / SN75176B 2 ea IC6, 7 LS7084
1 ea IC5 7805T 1 ea H1 HEATSINK
1 ea washer 6-32 flat washer 1 ea Bolt 6-32 x 3/8 inch bolt
1 ea Nut 6-32 nut x 5/16 1 ea Q1 Crystal 20 Mhz
1 ea IC Socket 40 pin 1 ea IC Socket 16 pin
4 ea IC Socket 8 pin 1 ea PCB PC board W2DRZ Controller bd.

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