Elmo ISP manual Amplifier adjustment and diagnostics, Balance adjustment, Current limit adjustment

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8.Amplifier adjustment and diagnostics

Important remarks:

A. If all the previous steps were accomplished you may now turn on the power and continue with the following adjustments. You may omit the step for current mode or velocity mode according to your application.

B. In some applications, especially those where the motor electrical parameters (total inductance and resistance in the armature circuit) are much smaller or larger than normally encountered, the current loop response should be optimized before proceeding with the following steps - See Appendix A.

8.1Balance adjustment

If the motor is rotating with the command signal at zero voltage, a balance adjustment will be necessary. Turn the balance trimmer (T5) as required until the motor stops. As a rule, have the command signal connected and set to zero when balancing the amplifier. This way, any offset in the command signal will be canceled.

8.2Current limit adjustment

The amplifiers' current limits can be adjusted without the need for loading. Disconnect motor leads and connect a voltmeter between the Current Command Monitor (terminal H-15,R-18a,E-J1/7) and the circuit common. Apply maximum input voltage to one of the inputs to cause an error at the error amplifier (input gain trimmer should be fully CW). In order to adjust the continuous limit - turn T3 (Ip) fully CCW to disable Ip, then use T2 (Ic) to adjust the continuous limit by monitoring the meter readout. Full CW rotation of T2 will result in rated current limit. After adjusting the continuous limit, turn T3 up to the desired peak level.

The current monitor range is up to 7.5V and its scale depends on the amplifier rated continuous current (Ic) and is given by:

ISP - Rev 6/95