Specifications

RTS 2nd Generation SERVO AMPLIFIER

PVD 3487 GB 03/2004

FIG 2

In some cases, gain limitation is due to resonance: the

motor starts to whistle or vibrate at high frequencies (>

100 Hz). A -1 filter must be included at a frequency 3 to 4

times lower than the oscillation so the gain can be

increased by the same ratio. This can be done by

connecting a C103 capacitor in parallel with the R101

proportional gain resistor, and increasing the capacitor

until the whistling stops (usually several tens of nF) and

then continuing to increase gain while monitoring

overshoot and torque ripple. The C103 10 nF capacitor is

ready fitted as standard in parallel with the R101 gain

resistor.

FIG 3

When the gain is set, the C101 integration capacitor must

be reduced to produce 15 - 20% overshoot (still for small

speed increments).

100 à 300 Hz

Temps

Dépassement 20 %

Vitesse

FIG 3 : a, b, c - graphs obtained with

decreasing C101 values

FIG. 2 : a, b, c, - graphs obtained with

increasing C103 values

100 - 300 Hz

Time

Speed

20% overshoot

Time