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Related Manuals for H2W technologies LPAM-1
Summary of Contents for H2W technologies LPAM-1
- Page 1 Linear Power Amplifier Module User's Guide Version 2.0...
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Page 2: Table Of Contents
Table of Contents Table of Contents Technical Specifications..................7 Absolute Maximum Ratings..............7 Amplifier Specifications................7 Amplifier Board Layout..................9 Pinouts........................11 User Connection Header................11 Amplifier Mode Select................13 Voltage / Current Selection Header..........13 Power Supply Monitor Enable..............14 Integrator Reset Enable.................15 Amplifier Configuration Block..............15 Voltage Mode Gain Setting ............16 Current Mode Configuration ...........18 Power Supply...................23 Load Connection..................25... - Page 3 Table of Contents Connecting Multiple Units..............41 Appendix A......................45 Dimensions....................45...
- Page 4 List of Figures Table of Figures Figure 1. Layout of the amplifier board and the various features........9 Figure 2. amplifier mode selection jumper..............13 Figure 3. Power supply monitor jumper location............14 Figure 4. Integrator reset jumper detail................15 Figure 5. Amplifier configuration block details............16 Figure 6.
- Page 5 List of Tables List of Tables Table 1. User Connection Header signal names and pinout........12 Table 2. Details of the various configuration options...........17 Table 3. Recommend values for the forward gain in current mode......18 Table 4. Factory configuration of the integration components........18 Table 5.
- Page 6 Linear Power Amplifier Module LPAM-1 Key Features • Linear - Designed for low noise operation • High Output Current: 7A Continuous output 9A Peak output • Wide Power Supply Range: 27 Volts to 60 Volts • Wide Bandwidth: >10kHz in current mode >10kHz in voltage mode...
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Page 8: Technical Specifications
Technical Specifications Technical Specifications Absolute Maximum Ratings Parameter Value Units Supply Voltage Output Current Continuous Peak Input (command) Voltage supply voltage = 27 V +/- 10 supply voltage = 48 V +/- 20 Operating Temperature °C (ambient temperature, natural convection cooling) Power de-rating occurs beyond this temperature. - Page 9 Amplifier Specifications Parameter typical Units Disable input signal high TTL level, 5V low TTL level, 0V Amplifier Fault output TTL compatible, with 200 ohm resistor inline (current limited to 25 mA) Current Sense output (buffered) Current Limit Output reference voltage 0.5 V / A Offset Adjust Adjusts output to zero for zero...
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Page 10: Amplifier Board Layout
Amplifier Board Layout Amplifier Board Layout This section of the manual describes the general layout of the board, and the location of key features. Refer to this diagram when making connections and when locating functions on the board. Voltage / Current Ground Lug Select Integrator Reset... -
Page 12: Pinouts
Pinouts Pinouts This section explains the various connections that can be made to the amplifier module. Note that all connections should be securely made with the proper connectors. Improper connections may result in poor performance, or may possibly damage the amplifier and other connected equipment. -
Page 13: Table 1. User Connection Header Signal Names And Pinout
User Connection Header Pin Number Signal Comments Available for signal conditioning circuitry, 10mA max. Ground connection. Available for signal conditioning circuitry, 10mA max. REF - Command signal negative or ground reference. REF + Command signal positive or signal. Current Limit Output of current limit setting. -
Page 14: Amplifier Mode Select
Amplifier Mode Select Amplifier Mode Select Voltage / Current Selection Header The amplifier is designed to function either as a voltage amplifier or a current amplifier. Selection of what mode the amplifier operates in is by way of a jumper. Placing jumper J1 in the 1-2 position selects voltage mode. -
Page 15: Power Supply Monitor Enable
Amplifier Mode Select amplifier uses a built in current feedback loop to continuously change the voltage applied to the load so the commanded current is always applied to the load. The maximum continuous current available is 7A. Consult the section titled, “Amplifier Configuration Block” for details on matching the amplifier to your load. -
Page 16: Integrator Reset Enable
Integrator Reset Enable Integrator Reset Enable Along with the power supply monitoring feature of this amplifier, an integrator reset feature is provided. Jumper SW EN enables / disables resetting of the integrator of the amplifier. With this jumper in the 1-2 position, the integrator used for the current feedback loop is cleared or reset to zero when the amplifier is first powered up, or when the amplifier is disabled. -
Page 17: Voltage Mode Gain Setting
Amplifier Configuration Block A B C D E F G H Figure 5. Amplifier configuration block details. Voltage Mode Gain Setting In voltage mode, the total gain of the amplifier is determined by the components A, C, and D in the configuration block. From the description in Table 2 and the schematic diagram in Figure 6, the total gain can be calculated as the product of G , where G is the final... -
Page 18: Figure 6. Schematic Representation Of The Amplifier
Amplifier Configuration Block Row Part Name Function Default Value This resistor with D sets the first gain stage of the amplifier. The resulting gain is G = D/A. Current loop feedback gain resistor. Sets the gain in voltage mode for the amplifier. The resulting gain for this stage is G = C/1k. -
Page 19: Current Mode Configuration
Current Mode Configuration In order to set the gain of the amplifier, you need to select components D and A. These set the forward gain such that the amplifier delivers G Amps/V. The equation for the forward gain of the amplifier is Table 3 shows recommended values G –... - Page 20 Do You Want an Integrator? First you need to determine whether you want integration or not. The capacitor E will introduce an integrator in the feedback loop in order to assure zero steady state error in current independent of load resistance and back EMF. The disadvantage of using an integrator in the current loop is the following: if you are using an actuator driving a load with very little friction, the slightest offset in the input may cause a runaway in the motor unless you are operating a stable closed loop externally.
- Page 21 Kp = 1 ( B = 1 K) R Load Gain 0.8333 0.7143 0.6250 0.5556 0.5000 Note that the gain depends on the load resistance and will not be consistent throughout the operating temperature range of the load since the load resistance increases as the load resistance gets warm.
- Page 22 Parameter Value Units R Load 4 Ohms L Load 0.0001 Henry with the following components for the compensation network: Component Purpose Value Units Integration gain capacitor 2.20E-008 Farads Loop gain resistor 1000 Ohms You can tune these values to optimize performance. A MATLAB and a Simulink model are available that will simulate the system where you can adjust these parameters online.
- Page 23 If there is too much overshoot due to integration reduce the integral gain by increasing • the capacitance of E. You may need to increase the loop gain using B to dampen the response after selecting • Also note that the higher the inductance the more proportional loop gain you will require and the less integral loop gain you will require.
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Page 24: Figure 7. Simulink Diagram Showing The User Adjustable Values
Lload = .1e-3; Rload = 4; % tune these in the Simulink diagram or here Comp_E = 22e-9; %integration capacitor - increase to reduce integral gain standard 0.05 micro Comp_B = 1e3; %feedback gain resistor - variable - increase to increase loop gain Then run the file again to see if the response as you would like it. -
Page 25: Power Supply
the small signal MATLAB model. This simulation is more realistic than the MATLAB model. For slow systems ( system with large inductance, > .01 Henry) you will need to slow the signal generator frequency in order to observe the steady state response of the system. Note that both these simulations give you a starting point for the tuning values and you may still need to adjust these on the actual system. -
Page 26: Load Connection
Pin 1 Signal Positive (+) Negative (-) Figure 8. Power connection details. Load Connection The load is connected to the amplifier at this connector. Note that the each of the pins is duplicated within this connector for additional current handling capability. User connections should make use of all the pins for optimal current handling ability. -
Page 27: Gnd Lug
Load Connection Pin 1 Signal Load (-) Load (-) Load (+) Load (+) Figure 9. Load connection details. GND Lug The GND lug is provided for convenience where several amplifiers are connected together (multiple channel application) and a common ground reference is needed. This is the only ground that should be treated as common between the input/output signals and the amplifier itself. -
Page 28: Offset Adjustment
Offset Adjustment Figure 10. GND connection. Offset Adjustment A potentiometer is provided to allow setting the output voltage / current of the amplifier to zero for zero commanded input. Turning the potentiometer to the right (clockwise) increases the offset, making the value more positive. Offset Adjust Figure 11. - Page 29 Offset Adjustment one was placed there. Current Limit Adjustment Current limiting allows the user to set a maximum (peak) current that the amplifier will provide to the load. The amplifier will provide current up the set current limit. Continuous currents of 7 Amps are possible, while peak currents may reach 9 Amps. The current limit is adjusted by means of a multi-turn potentiometer .
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Page 30: Current Limit Adjustment Procedure
Current Limit Adjustment Current Limit Measured Current Limit Output (Amps) (Volts) 0.50 1.00 1.50 2.00 2.50 3.00 3.50 5.00 Table 8. Typical current limit settings Current Limit Adjust Figure 12. Current limit setting. Pin Number Function Signal (0-5V) Table 9. Current limit output pinouts. Power Amplifier Module User's Guide... -
Page 31: Status Indicator Leds
Current Limit Adjustment Procedure Adjustment of the current limit requires a few special tools: Multimeter • Small Screwdriver • To adjust the current limit, follow this procedure: 1. Connect the multimeter to the terminals shown in (connector J1). 2. Adjust the trimpot to the desired voltage for the required current setting shown in Table 8, or follow the relationship of Equation 1. -
Page 32: Amplifier Enable Inputs
External Fault Indication making the signal suitable for directly driving and external LED. Alternatively, the signal may be buffered and used as a status indicator for the connection to external control circuitry. Amplifier Enable Inputs The amplifier is provided with two inputs which must receive the proper signals before the amplifier will become enabled. -
Page 33: Command Signal
Command Signal Command Signal The input signal to the amplifier is a differential type input. This signal is called the reference signal, and is applied to the amplifier on the User Connection Header. Connections should be made at pins 4, Ref- and pin 5, Ref+. The amplifier measures the difference between the two signals present at this input and uses it as the command signal. -
Page 34: Installation
Installation Installation Installation, mounting and information on making electrical connections to the amplifier can be found in this section. Mechanical Mounting The amplifier is fitted with a series of mounting holes along two surfaces. These holes make it possible to mount the amplifier to a surface in two different configurations. Appendix A shows details of the heatsink of the amplifier. -
Page 35: Cooling Fans
Cooling Fans Cooling Fans Most applications of the power amplifier module will require the use of cooling fans, to maintain the amplifier at a safe operating temperature. The heatsink of the amplifier has holes tapped to accept #8 mounting hardware. Either two 1.25”... -
Page 36: Determining The Dissipated Power
Cooling Fans Spacer Figure 16. Mounting location of the large fan. Two fans rated for 4.5 CFM or 1 rated 9 CFM or greater should suffice for most applications. Determining the Dissipated Power Calculation of the power dissipated by the amplifier is critical to determining the amount of cooling required of the amplifier. -
Page 37: Determining The Required Airflow For Cooling
Determining the Required Airflow for Cooling Determining the Required Airflow for Cooling The power dissipated must be removed from the amplifier. This is best accomplished with the use of a fan. Calculations for the required airflow for the fan are as follows. 3.16×P 1.76×P T... -
Page 38: Electrical Connections
Determining the Required Airflow for Cooling optimal fan based on required flow rate and enclosure selection. The user should be careful to understand that the fan will need to be mounted within the manufacturer's guidelines to ensure that the specified airflow rate is achieved. Note that the above example assumes a continuous DC signal. -
Page 39: Selecting A Power Supply
Electrical Connections Description Manufacturer Supplier Shorting Jumpers 3M/ISD Digi-Key 929950-00 929950-ND Selecting a Power Supply A power supply is required to provide electrical power to the amplifier. The size, type and capacity of the power supply are highly dependent on the application. Operating Voltage The operating voltage of the power supply should be chosen to match the power requirements of the intended load. -
Page 40: Current Handling Capability
Selecting a Power Supply Current Handling Capability The power supply chosen must be able to deliver the expected power to the load, plus some additional power used by the amplifier itself. Typically, to use the amplifier at its fully rated current ability, the power supply must be capable of delivering 10A continuous, minimum. -
Page 41: Figure 17. Single Amplifier Connections
Connecting A Single Unit User Equipment Motor/ Load Required Jumper Settings Current/ Gain Selection Jumper Voltage User System Command Input Current Monitor Output Amplifier Power Supply Module Fault Indication Current Limit Setting Shutdown Inputs GND Lug User System GND Isolated Power Supply Common System GND Figure 17. -
Page 42: Connecting Multiple Units
Connecting Multiple Units Amplifier Amplifier Amplifier Module Module Module Power Supply Isolated Power Supply Common System GND Figure 18. Multiple amplifiers connected with a single power supply. Power Amplifier Module User's Guide... -
Page 43: Figure 19. Multiple Power Supplies To Drive Multiple Power Amplifiers
Connecting Multiple Units Amplifier Amplifier Module Module Common System GND Power Supply Power Supply Isolated Power Supply Isolated Power Supply Figure 19. Multiple power supplies to drive multiple power amplifiers. Power Amplifier Module User's Guide... -
Page 44: Dimensions
Appendix A Appendix A Dimensions The following pages show the mechanical drawings for the heatsink of the power amplifier module. These drawings can be used in the fabrication of the enclosure of a mounting fixture. Power Amplifier Module User's Guide... - Page 45 Dimensions Power Amplifier Module User's Guide...
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