Teledyne 402REU - Hydrocarbon analyzer - Manual (Page 47)

Total Hydrocarbon Analyzer Maintenance and Troubleshooting
5-13 Teledyne Analytical Instruments
12, -24 VDC (non-regulated) at pin 4, regulated +15 VDC at pin 15, and
regulated -15 VDC at pin 1.
The circuit board can be easily tested (by verifying the voltages while
in operation) as follows:
Regulated \15 volts:
1. Connect the negative voltmeter lead to the common (pin 2) and
the positive lead to pin 15 of the card connector. The measured
voltage should be 15±0.5 volt. Refer to Figure 5-1.
2. Then connect the positive DVM lead to pin 1 of the card
connector. Measured voltage should be -15±0.5 volt.
Non-regulated \24 volts:
1. With the negative lead of the DMM still connected to pin 2
(ground), connect the positive lead to pin 12, and verify 24
volts (nominal).
2. Then connect the positive lead to pin 4 and verify -24 volts
(nominal).
Input Voltage 40-50 VAC:
Using a voltmeter set to measure at least 50 VAC, test the voltage
between the circuit card pins 8 and 10; voltage should measure ca. 30-
50Vrms. Voltage from either pin 8 or pin 10 to ground should measure half
the voltage found across pins 8 and 10.
5.5.3 Proportional Temperature Controller Printed
Circuit Board
Schematic No. B-30974
Assembly Dwg. No. B-30868
The temperature of the chamber to be controlled is regulated by a
thermistor-directed electronic circuit. The thermistor and heating element
are located in the chamber, and the balance of the circuit components are
mounted on the temperature controller printed circuit board, which plugs
into a connector on the motherboard.
The control temperature is determined by the value of resistor R3 on
the temperature controller printed circuit board, selected (at the time of