Teledyne 4060 manual Electrometer-Amplifier PCB

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Series 4060

Maintenance

 

 

 

the thyristor gating circuit is continuously delivering gate current from pin 4 of A1, thus maintaining constant full wave AC power to the heater.

When the temperature reaches the selected control point, pin 13 voltage is about the same as pin 9 voltage, and proportional control takes over. The rate at which thyristor (triac) Q1 conducts and allows power to be delivered to the heater is determined by the combination of components R2 & R3, R4, C3, R5, and the thermistor resistance at the control temperature. Consequently, the balance point of the bridge formed by this combination of components can be altered by the selection of R3, causing the circuit to seek a temperature at which the thermistor resistance balances the bridge.

Because IC A1 triggers the thyristor at zero-voltage points in the supply voltage cycle, transient load current surges and radio frequency interference (RFI) are substantially reduced. In addition, use of the zero- voltage-switch reduces the rate of change of on-state current (di/dt) in the thyristor.

5.5.3Electrometer-Amplifier PCB

Schematic No. B79159

Assembly Dwg. No. B79153A

The ions formed in the process of burning hydrogen in the presence of hydrocarbon components of the sample gas cause an electrical conduction between two electrodes in the combustion chamber (or detector cell) that is amplified by a high sensitivity and high input impedance electrometer-amplifier circuit. The electrical output of the electrometer-amplifier is directly proportional to the quantity of flame ionizable hydrocarbons present.

The electrometer amplifier PC board is located on the side of sample module, interconnected to the electronics circuitry by means of a single 8 pins cable, so that the ease of replacement of a board is maintained.

The high input impedance requires a shield, or cover, which is removable for access, as well as a shielded input conductor. Interconnection with the collector is made by a coaxial cable.

Although the cable and fittings are intended for coaxial service, the cable is actually being used as a shielded single-conductor connection. The collector cable plugs into a coaxial connector on the electrometer amplifier PC board, which is located at the side of the sample module.

Teledyne Analytical Instruments

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Contents Series Teledyne Analytical Instruments SeriesTeledyne Analytical Instruments Iii Safety MessagesSeries Combustible GAS Usage Additional Safety InformationSeries Teledyne Analytical Instruments Vii Procedure for Removal of Internal Inaccessible Shock HazardsViii Table of Contents Operation Maintenance & Troubleshooting Appendix B AppendixTeledyne Analytical Instruments Xiii List of FiguresList of Tables Introduction Main Features of the AnalyzerSeries Introduction Analyzer Description Principle of OperationIntroduction Series Model 4060 Front Panel Interface Applications Introduction Operational TheoryModes of Operation Series Operational TheoryOperational Theory Series Analyzer SubsystemsSample System Gas Flow Control System Internal Temperature ControllersFlame Ionization Detection Cell Fuel and Blanket Air SystemsTypical Piping Diagram for the Model Detection Cell Flame Ionization Cell Electrometer-AmplifierFlame Guard Circuit Anode Power SupplyFlame Ignition Circuit Series Installation InstallationUnpacking the Analyzer Mounting the AnalyzerElectrical Power Connections Installation SeriesUser Connections Electronic ConnectionsModel 4060 Rear Panel with Optional Gas Manifold Equipment Interface Connector Pin Arrangement Pin Function Threshold Alarm System Alarm Remote Calibration Connections Range ID Relay Connections 2.10 RS-232 Port Pin out of 50 pin D-Sub ConnectorGas Connections Commands via RS-232 InputGas Connections Less than 0.5 PPM Placing the System in Operation Equipment OperationSeries Operation Activating the Support Gases Preliminary Power-Off Check ListOperation Series 1 Air Flame IgnitionCarrier Gas Span GasAnalyzer Operation Sample PumpVerification of the Flame Guard Circuit Ignition and/or Flame Guard Circuit FailureSeries Operation Style Conventions Default ParametersEnter Navigation and Data EntryMenu Structure EscapeMain Menus Span ALT-SPAN System Self-Diagnostic TestModel Screen Alarms Function AL-1 Defeated AL-1 High AL-1 NON-FAILSAFE AL-1 NON-LATCHING Operation Series Range Function Analog Output AdjustmentLinearization Setting up an AUTO-CALChanging Stream Autocal Password Password Protection Group SetupTiming Entering a Password Enter NEW Password Screen Logging Out Repeat Password Entry ScreenStandby Series Operation Operation Series Teledyne Analytical Instruments Series Maintenance Maintenance & TroubleshootingMeasuring Circuit Electrical Checks Maintenance SeriesAnode Voltage Check Electronic Stability Printed Circuit Board ReplacementCollector Cable Temperature Control Electronic CheckIgnition and/or Flame Guard Circuit Checks Sampling System Printed Circuit Board Descriptions Flame Guard and Anode Power Supply PCBProportional Temperature Controller PCB Electrometer-Amplifier PCB Maintenance Series Appendix Specifications and Initial SettingsSeries Appendix Appendix Series Recommended Spare Parts ListAnalytical Instruments PC Board Assemblies Drawing ListAppendix Series Teledyne Analytical Instruments Appendix B B1 Addendum and Testing Results