Abstract: A revolution limiter for internal combustion engines having a circuit for detecting when the engine revolutions exceed a given maximum permitted value, and a circuit for limiting the voltage on the primary winding of the coil comprising a semiconductor device which will breakdown above a given threshold voltage and a semiconductor switch connected in series between the terminal of the primary winding remote from the positive line connection and ground, the semiconductor switch being rendered conductive by the detection circuit in order to limit the voltage on the primary winding of the coil and thus prevent a spark occurring when said given limit is exceeded.