====================================== Servo Amplifier Description (BC-017) ====================================== The BC-017 servo amplifier circuit is designed to be attached to the BC-005 transition board. When the transition board is modified in this way, it can be used to drive up to 8 dc servo motors "directly" from an OMS VME58-8S. The servo amplifier is designed to run motors that are rated at 200mA or less maximum current. Modification of the transition board to include the servo amplifier is fairly straightforward. Once this is done, small dc motors may be attached directly to the transition board's 25-pin D connector. The +/-10V signals generated by the OMS VME58-8S will be buffered (provided with current) by amplifiers on the servo board that are configured for unity gain. The db25 connectors provide access to all of the necessary signals, and have a different pinout than the normal stepper-motor configuration. In addition, a single db9 connector is provided to bring power to the servo board. Some notes about this project, as well as pinouts: ============================== Servo Transition Board Notes 6/6/01 ============================== * Paddle board BC-003 Rev.2 MUST be used with the Servo Transition Board. * S1-S16 toggle switches must be switched down, for single-ended mode. * Encoder signals may be connected single-ended or differential, however the board is pre-configured for single-ended encoder signals. * The amplifiers are capable of driving 250mA per channel. I would recommend that motors rated under 200mA be used. This will help to prevent overheating the chips. * Rev.1: Fixed a problem that occurred when VME power is off and motor power is still on. This situation caused the motors to turn. Solved by slaving motor's +/-12V to VME +5V via a relay. ==================================== Servo Transition Board DB25 pinout ==================================== ---------------------------------------------------------- Pin Dir Function Pin Dir Function ---------------------------------------------------------- 1 14 Out +5VDC 2 15 3 Out Motor Out+ 16 4 17 5 In high limit N.C. 18 6 In low limit N.C. 19 7 In encoder A + 20 In encoder A - 8 In encoder B + 21 In encoder B - 9 In index + 22 In index - 10 In home1 (motor con.) 23 In home2 (encoder con.) 11 ground/shield 24 ground/shield 12 25 13 ---------------------------------------------------------- =================================== Servo Transition Board DB9 pinout =================================== ---------------------------------------------------------- Pin Dir Function Pin Dir Function ---------------------------------------------------------- 1 In +5VDC 6 2 In +12VDC 7 3 In -12VDC 8 4 GND 9 5 ----------------------------------------------------------