Abstract:
A method and an apparatus for monitoring and supervising the lubricant content of elevator ropes in an elevator, which includes at least a hoisting machine provided with a drive motor, the hoisting machine including at least a traction sheave, around which one or more elevator ropes are fitted side-by-side, which ropes move under the effect of friction along with the rotational movement of the traction sheave and at the same time move the elevator car. The lubricant content is monitored and supervised by the aid of a magnetic measuring device disposed in the immediate proximity of the traction sheave and the elevator ropes by collecting in the measuring device the metal dust detaching in connection with wear of the traction sheave and of the elevator ropes during operation of the elevator and by letting the metal dust switch on an alarm about a lubricant content of the elevator ropes that is too low.
Abstract:
A control unit of controlling a direct-current load (M1), said control unit comprising a DC/DC bridge (B1) provided with controllable semiconductor switches (UT, UB, VT, VB, WT, WB) and having two bridge sections (B11, B12), one (B12) of which conducts direct current while the other one (B11) is controlled via PWM to regulate the current magnitude. The bridge section controlled via PWM consists of two bridge arms (B111, B112), and the semiconductor switches (UT, UB, VT, VB) in these bridge arms are turned on alternately.
Abstract:
A control unit of controlling a direct-current load (M1), said control unit comprising a DC/DC bridge (B1) provided with controllable semiconductor switches (UT, UB, VT, VB, WT, WB) and having two bridge sections (B11, B12), one (B12) of which conducts direct current while the other one (B11) is controlled via PWM to regulate the current magnitude. The bridge section controlled via PWM consists of two bridge arms (B111, B112), and the semiconductor switches (UT, UB, VT, VB) in these bridge arms are turned on alternately.
Abstract:
A control unit of controlling a direct-current load (M1), said control unit comprising a DC/DC bridge (B1) provided with controllable semiconductor switches (UT, UB, VT, VB, WT, WB) and having two bridge sections (B11, B12), one (B12) of which conducts direct current while the other one (B11) is controlled via PWM to regulate the current magnitude. The bridge section controlled via PWM consists of two bridge arms (B111, B112), and the semiconductor switches (UT, UB, VT, VB) in these bridge arms are turned on alternately.
Abstract:
A control unit of controlling a direct-current load (M1), said control unit comprising a DC/DC bridge (B1) provided with controllable semiconductor switches (UT, UB, VT, VB, WT, WB) and having two bridge sections (B11, B12), one (B12) of which conducts direct current while the other one (B11) is controlled via PWM to regulate the current magnitude. The bridge section controlled via PWM consists of two bridge arms (B111, B112), and the semiconductor switches (UT, UB, VT, VB) in these bridge arms are turned on alternately.