摘要 |
The circuit controls a regulating valve associated with the hydraulic cylinder (6) for the lower clamp element (3). The actual press within the hydraulic cylinder (6) is monitored by a press sensor providing an electrical signal compared with a reference signal to provide the control signal for the regulating valve. The difference signal obtained by comparing the actual press signal and the reference signal is fed via a limiting circuit to an integrator together with the differential of the actual press signal, actual press signal, provided by a differentiator with an associated switch preventing its operation when the difference signal is below a given threshold value.
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