Signal Converters in Hydraulics

Complex hydraulic systems require highly developed regulation or control. This is the only way to ensure that the system is always operated at peak performance. To achieve this, a central processing unit and comprehensive sensor technology are required. Together, both ensure that the hydraulic system operates within its defined parameters, is operated with minimal wear, and consistently delivers the desired performance. The transmission of signals is carried out by the signal converters.

Signal Converters – From Physical to Electrical Values

The following measured values are important in hydraulic systems:

• Pressure
• Volume flow
• Temperature
• Particle density
• Cavitation warnings (noise)

The two primary values in hydraulic systems are volume flow and pressure. These determine the force of the actuators and their movement speed. Pressure is also an important indicator of possible leaks. If it drops quickly or suddenly, for example, a major leak can be assumed. Sensor-based monitoring of pressure is important for the operational safety of hydraulic systems.

The temperature of the hydraulic medium can reach critical limits. When the hydraulic oil begins to boil, gas bubbles form. These are compressible—unlike the liquid oil. This compressibility leads to disruptions throughout the entire hydraulic system. Monitoring the temperature is therefore an important value in highly developed hydraulic systems.

Particle density and noise generation are monitored less frequently. However, they provide information about the “cleanliness” of the hydraulic medium and its internal wear. For simple systems, it is sufficient to replace the filters and hydraulic oil within the specified intervals. For critical systems, however, additional monitoring is an important contribution to operational safety.

Monitoring Values in Connection with a Signal Converter

The monitoring of these physical values is performed by sensors. These convert the measured quantities into electrical impulses. In some cases, this requires immersing the sensors in the volume flow. With certain designs, external mounting is also possible. This makes it easier to replace them.

Signal Converters – From Measurement Signal to Control Signal

The multitude of different measured quantities can make sensor-based monitoring of a hydraulic system challenging. The control and regulation units available today are very demanding regarding the quality of incoming information. Therefore, it may be necessary to amplify or attenuate the sensor-captured values. This is the task of signal converters. They receive the incoming signal current and convert it into a constant voltage that can be interpreted by the control units. How this control current must be configured is specified by the manufacturer of the processing unit. This makes it possible to use a variety of different sensors from various manufacturers. This gives designers more creative freedom and purchasers more options for the economic design of a hydraulic system.