3700 Portable Samplers
Section 6 Servicing
6-12
6.3.3 Pump Control Board
The pump control board (Figure 6-7) is an integral part of the
pump assembly and serves two functions: controlling the pump
motor and sensing pump revolutions.
The pump motor control consists of a 2-pole, double-throw relay
(K201) and transistor switches (Q201, Q202, and Q203). The
relay changes the pumping direction and will run the pump in
reverse when in the rest state. Each time the pump runs, the
microprocessor sends the pumping direction signal through pin 1
of P7, waits for the relay to change state, then starts the pump by
sending a high signal through pin 3 of P7. By waiting for the
relay to change state before applying power, you can prevent
arcing at the relay contacts.
The LED-photo transistor device (IC201) is a key element of the
pump revolution count sensor. Whenever the pump is running,
power is supplied to IC201. A rotating disk positioned between
the LED and photo transistor periodically interrupts the trans-
mitted signal. These interruptions create pulses, which are sent
back to the main board at pin 8 of P7 to be counted. The micro-
processor then uses these counts to determine the pumped
volume.
Figure 6-7 Optical Counter PCB Component Layout
201
202
203
204
205
206
207
20
8
209
210
211
212
IC201
K201
201
201
C
D
Q201
Q202
R201
R202
R203
R204
P201
Summary of Contents for 3700
Page 2: ......
Page 4: ......
Page 33: ...3700 Portable Samplers Section 2 Setup Procedures 2 9 Figure 2 7 Locked Sampler ...
Page 34: ...3700 Portable Samplers Section 2 Setup Procedures 2 10 ...
Page 144: ...3700 Portable Samplers Section 3 Programming Guidelines 3 110 ...
Page 152: ...3700 Portable Samplers Section 4 Options and Interfacing Equipment 4 8 ...
Page 164: ...3700 Portable Samplers Section 5 Routine Maintenance 5 12 ...
Page 180: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 2 ...
Page 181: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 3 ...
Page 182: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 4 ...
Page 183: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 5 ...
Page 184: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 6 60 3703 262 REV J 3 2 ...
Page 186: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 8 ...
Page 188: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 10 ...
Page 189: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 11 ...
Page 190: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 12 ...
Page 191: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 13 ...
Page 192: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 14 ...
Page 193: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 15 ...
Page 194: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 16 ...
Page 195: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 17 ...
Page 196: ...3700 Portable Samplers Appendix A Replacement Parts Lists A 18 ...
Page 200: ...3700 Portable Samplers Appendix B Accessories B 4 ...
Page 210: ...3700 Portable Samplers Appendix C General Safety Procedures C 10 ...
Page 224: ...3700 Portable Samplers Appendix E Calculating Flow Increment Between Samples E 4 ...
Page 234: ...3700 Portable Samplers Appendix G Material Safety Data Sheets G 8 ...
Page 238: ......
Page 240: ......
Page 242: ......