Piezo Valves - Hartridge CRi-PC Operating And Servicing Manual

CRi-PC Operating and Servicing Manual
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Figure 3.2 Solenoid Injector Drive Signal
3.2.2

Piezo Valves

These use the inherent properties of piezo crystals (that they deflect with applied voltage) to
activate the valve. There is a positive current pulse (I) to switch the valve on, and a negative
current pulse to switch the valve off. The overall pulse width (T) is the time between the
positive and negative current pulses.
Figure 3.3 Piezo Injector Drive Signal
Siemens were the first manufacturer to introduce piezo injectors, the main advantage over
solenoid valves being that piezo valves have a much faster response time.
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HL037 (EN), Issue 13, AT714, 05/14