Abstract: A digital time dependent relay is constructed for long time-lags and converts an incoming current signal into a binary number (n). The relay comprises one or more binarily controlled frequency multipliers, such as a Binary Rate Multiplier, or Decade Rate Multiplier, the control signal of which consists of the binary number and an input frequency which is determined by an adjustable oscillator and occurs when the incoming input signal exceeds a predetermined level. The output frequency of the multiplier is supplied to a binary counter which delivers an output signal when its contents reach a predetermined value. By a series-connection of two or more multipliers, an output frequency is achieved which is proportional to a second or higher power of the binary number and thus to the same power of the incoming current signal. The desired time-lag is determined by the frequency of the oscillator, by the control signal to the multiplier, and by the predetermined value of the counter.

Abstract: A system for transmitting signals between stationary and movable portions of a machine without utilizing any direct electrical contacts. An alternating supply source for the system is provided on the stationary portion and is connected to a stationary coupling member of an inductive coupling. A movable coupling member of the inductive coupling is arranged on the movable portion of the machine. A pulse generator connected to the movable coupling member receives its alternating supply voltage through the inductive coupling and generates a pulse during each period of the supply. A temperature dependent resistor controls the pulse generating device so that the phase portion of the pulse in relation to the zero passage of the supply voltage is dependent on the sensed temperature. The pulses are fed back through the inductive coupling to a measuring device arranged on the stationary portion of the machine.