OLA2 Open Loop Amplifier. Installation and Operating Manual Release May 2013

Transcription

1 OLA2 Open Loop Amplifier Installation and Operating Manual Release May

2 OLA2 - SAFETY INSTRUCTIONS Read this page carefully before installation and use of the instrument, and follow all instructions in section 4 of Installation Procedures for safe installation of this product. INTRODUCTION The following clauses contain information, cautions and warnings that must be followed to ensure safe operation and to retain the instrument in a safe condition. WARNINGS Any removal from the structure or removal of parts, except those to which access is permitted, is likely to expose live parts and accessible terminals, which can be dangerous to life. Any adjustment, maintenance or repair, of the opened instrument under voltage, shall be performed only by a qualified person who is aware of the hazard involved. The instrument shall be disconnected from all voltage sources before it is opened (for service method). Components, which are important for the safety of the instrument, may only be renewed by components obtained through Akribis service organization. Before switching on, ensure that the instrument has been installed in accordance with the Installation Instructions. Maximum DC supply must be according to the types described in the operating manual. 2

3 Introduction This manual is intended for the use of the design engineer who is implementing the OLA2 servo amplifier into his machine. It covers the various aspects of the implementation process from basic understanding of the product concept and features, through a detailed explanation of the user accessible functions, down to mounting guide lines and requirements from peripheral devices. Chapter 2, Servo Amplifier Description, includes a description of the various features of the OLA2, a list of all the pins and their functions and a block diagram of the product. Chapter 3, Operation of the Servo Control, describes all the user accessible functions and gives the design engineer the guide line as for how to design the peripheral circuits. Chapter 4, Wiring Instructions, covers the requirements from peripheral equipment like motors, cables, the power supply in order to achieve successful operation of the OLA2. 3

4 2. Servo Amplifier Description This amplifier for voice coil motors incorporates Digital ICs and hybridized power stage. This design enables very high thermal conductivity, high current carrying capacity, The control section is implemented by dedicated ICs that contribute to its performance Standard features 3A Continuous and up to 6A Peak Current Capability without Heat Sink Adjustable continuous and peak current limits adjustments Adjustable fix interval applied peak current duration Operational Parameters Operating Supply (Min) (V) 12 Operating Supply (Max) (V) 40 Continuous Output Current (A) 3 Peak Current (200ms) (A) 6 Ordering Part Number OLA2-24V Fault protection Short between the outputs or between each output and the Power Return. Over temperature ( > 165 deg celius ) 4

5 Block diagram of the OLA2 2.3 Connector Pins Description Control Connections Table A : Control connections Pin Function Remarks ER Amplifier Enable Input Return EN Amplifier Enable Input Set active high to servo on amplifier DR Motor Direction Input Return DI Motor Direction Input Controls the forward or reverse direction of motor Power connections Table B: Power connections Pin Function Remarks VP Positive Power Input PR Power Input Return M1 Motor Power Output 1 M2 Motor Power Output 2 5

6 3. Operation of the Open Loop Amplifier This section attempts to describe as accurately as possible the operation of the Open Loop Amplifier (OLA2). Most of the description will be referring to the Timing Diagram as shown below. Upon initial power on, with the EN inputs pins is set to Active High, the motor ( In this case, Voice Coil ) would move in whatever direction the DI inputs is set at. Assuming that the DI is Active Low, M1 would send a PWM waveform out. A small ramp up to the set VH ( Holding Torque Value ) ( See Motor Current timing chart A). Note that the DT (Peak current application time ) is NOT activated. As the Direction of the voice coil is changed, through the DI inputs. ( See Timing Diagrams B ). A DT is applied. This DT would switch the ramping current momentary for a fixed period of time that is set by the DT value. This particular feature is to allow instantaneous peak current ( based on the VP values ) to flow in the voice coil. ( Prolong period of high current flowing in the voice coil would damage it ) Before, it switches again to the VH values. This would repeat for every DI change in state. Please see the section on the setting of the VH, VP and DT values. 6

7 3.1 DT, VH, VP setting procedure DT Procedure 1. To increase the acceleration force, we can adjust the red DIP switch at the site of OLA2. 2. The DT time changes the applied Acceleration Force ( This changes the peak force by apply a longer Vp ). 3. There are 5 positions on the DIP switch. Each position represents 1 bit. For standard model, each ON position represents 1ms ( 1 bit timing ). For example, DIP SWITCH Value BINARY PATTERN = 1 BINARY PATTERN = 3 BINARY PATTERN = 7 BINARY PATTERN = If we try switch on 1,2 and 3, then DT = ( 1 bit timing => 1 ) + ( Binary Pattern Value of => 7 ) = 8 ms, which is the peak current running time. Vp and Vh setting procedure 7

8 1. Turn the VH potential meter at OLA2 drive in clockwise direction as per attached photo. More number of turn we apply, the holding torque will increase more. 2. Turn the VP potential meter at OLA2 drive in clockwise direction as per attached photo. More number of turn we apply, the acceleration force will increase more. 3.3 RMS Current Measurement Basically, the OLA2 uses 2 sections. Applied peak current and Holding current. Peak current is applied time that is base on DT setting. Set this section as T1. Check the VP against the chart to obtain the corresponding current. The rest of the cycle is the holding current. Apply the same method as of VP. Use multi-meter with current measurement capability to get the RMS current. Ensure that the operating current is NOT beyond the motor design continuous or the OLA2 maximum operating current. Consult Akribis Technical personnel if you are unsure. 4. Wiring Instructions Digital Input Interfaces 8

9 Type of Input Input current Optically isolated Vin - 6.1V Iin = * Iin = 2.4 Vin = 12V High-Level Input Voltage 12V < Vin < 30 V, 24V typical 4.1 DC Power Supply DC power supply can be at the voltage in the range defined within the technical specifications. The supply source must comply with the safety aspects of the relevant requirements in accordance with the most recent version of the standard EN60950 or equivalent Low Voltage Directive Standard, all according to the applicable over voltage Category. The power source must have enough current rating to match the motor and OLA2 peak current capacity. 5. Appendix A: Mechanical Drawing 9