A transmission system (90, 100, 110, 120, 130, 140) for transmission of signals through a non-contact interface, said transmission system comprising: - a transformer inductively coupling a first circuit to a second circuit through the non-contact interface, wherein - the second circuit comprises a first transmitter circuit having a first digital transmitter (TRAN2) arranged to provide a first digital input signal via a first resistor to a first winding of the transformer, whereby one or more voltage pulses are formed in said first winding, wherein the one or more voltage pulses take a positive or negative form based on if the first digital input signal has a positive or negative edge, and wherein - the first circuit comprises a first receiver circuit having a first comparator (COMP1) arranged to receive one or more induced voltage pulses from a second winding of said transformer, induced by the one or more voltage pulses in the first winding, and to provide a first digital output signal reflecting said first digital input signal based on said one or more induced voltage pulses, wherein said transmission system is a bi-directional transmission system (130; 140), and wherein - the first circuit comprises a second transmitter circuit having a second digital transmitter (TRAN1) arranged to provide a second digital input signal via a second resistor to the second winding of the transformer, whereby one or more voltage pulses are formed in the second winding, wherein said one or more voltage pulses take a positive or negative form based on if said second digital input signal has a positive or negative edge, and wherein - the second circuit comprises a second receiver circuit having a second comparator (COMP2) arranged to receive one or more induced voltage pulses from the first winding of said transformer, induced by said one or more voltage pulses in the second winding, and to provide a second digital output signal reflecting said second digital input signal based on said one or more induced voltage pulses, characterized in that the first (TRAN2) and/or second (TRAN1) digital transmitter comprises tri-state logic to enable the first and/or second digital transmitter to assume a high impedance state when not transmitting signals and wherein the first and/or second digital transmitter comprise a transmit enable input (TX2EN, TX1EN) for disabling the high impedance state when transmitting digital signals. - a transformer inductively coupling a first circuit to a second circuit through the non-contact interface, wherein - the second circuit comprises a first transmitter circuit having a first digital transmitter (TRAN2) arranged to provide a first digital input signal via a first resistor to a first winding of the transformer, whereby one or more voltage pulses are formed in said first winding, wherein the one or more voltage pulses take a positive or negative form based on if the first digital input signal has a positive or negative edge, and wherein - the first circuit comprises a first receiver circuit having a first comparator (COMP1) arranged to receive one or more induced voltage pulses from a second winding of said transformer, induced by the one or more voltage pulses in the first winding, and to provide a first digital output signal reflecting said first digital input signal based on said one or more induced voltage pulses, wherein said transmission system is a bi-directional transmission system (130; 140), and wherein - the first circuit comprises a second transmitter circuit having a second digital transmitter (TRAN1) arranged to provide a second digital input signal via a second resistor to the second winding of the transformer, whereby one or more voltage pulses are formed in the second winding, wherein said one or more voltage pulses take a positive or negative form based on if said second digital input signal has a positive or negative edge, and wherein - the second circuit comprises a second receiver circuit having a second comparator (COMP2) arranged to receive one or more induced voltage pulses from the first winding of said transformer, induced by said one or more voltage pulses in the second winding, and to provide a second digital output signal reflecting said second digital input signal based on said one or more induced voltage pulses,