Patent ID: 6567255
Filing Date: 2003-05-20
Classification: F16K

Abstract:
An electromagnetic actuator comprising a control circuit, a combinational circuit, and a power section having at least one final control element, wherein the power section is operative with a magnetic coil suitable for activation of hydraulic valve upon connection of the magnetic coil via electrical lines to an output of the power section, said at least one final control element being connected electrically in series between a source of operating voltage (UB) and said output of the power section; the combinational circuit passes on an output signal of the control circuit to the power section only when, in addition to the output signal of the control circuit, the combinational circuit is fed a release signal; and, upon connection of the magnetic coil to the power section, the power section effects a current flow from an operating voltage via said at least one final control element and the magnetic coil to a reference potential to correspond to the output signal of the control circuit passed on by the combinational circuit, wherein the voltage (uo) of that line (5) which is supplied with the operating voltage (UB) via said at least one final control element (7; 7â€²) upon activation of the power section (3; 3â€²) is fed to an evaluation circuit (9; 9â€²), and the evaluation circuit (9; 9â€²) has a threshold switch (10) which converts the voltage (ua) fed to it into a switching signal (US), the threshold voltage (Ua0) of the threshold switch (10) being slightly greater than the reference potential (âŠ¥).