Servoamps with differential inputs and a high degree of common mode rejection are immune to differences in ground voltages

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Other Materials from the Main Document

• Article «Avoiding some common servo system problems»
• Figure 1. This circuit uses a servoamp drive that can make motions or operation erratic by exposing the servoamp to common-mode voltage interference, V_CM
• Figure 2. Servoamps with differential inputs and a high degree of common mode rejection are immune to differences in ground voltages
• Figure 3. If the servoamps lead are longer than 16 in., a decoupling capacitor is still often needed at the servoamp even if there is a large capacitor in the power supply
• Figure 4. To eliminate crosstalk between amps, use individual pairs of wire from the power amp to each amp (upper schematic) rather than using a dc bus common to all amps (lower schematic)
• Figure 5. In this setup, the servo becomes a regenerative brake, converting kinetic energy into electricity. The electricity is sent through the servo to the dc bus where it charges a capacitor