Remote control circuit

Claim 1

Remote control circuit, especially infrared remote control circuit, for controlling a plurality of functions of a device, for example a toy vehicle or diapositive slide projector, comprising a transmitter (1) that can be switched on and off, which comprises a pulse generator and components (R3 to R6; R9 to R12) which determine a number of different pulse interval durations with unchanged pulse duration, this number corresponding to the number of the functions (A1 to A4) to be controlled, each of which components can be switched on by a switch (S1 to S4), and comprising a receiver (figure 2) which evaluates the pulse interval duration, the transmitter as multivibrator being constructed of two transistors (T1, T2), wherein the collector of the first transistor is connected to the base of the second transistor, the collector of which is connected via an RC-element (C2, R2) to the base of the first transistor (T1), and the components (R3 to R6; R9 to R12) which determine the pulse interval durations are connected to the base of the first transistor (T1), characterized in that the transmitter (1) is composed of complementary transistors (T1, T2) and that the transmitting component (D1) is connected to the collector of the second transistor (T2), each of the switches (S1 to S4) switching on and off the transmitter (1 ), that the receiver (figure 2) comprises an RC charging circuit (R7, C3), the capacitor (C3) of which charges during the pulse interval via its resistor (R7) and is discharged upon receipt of a transmission pulse, so that a sawtooth voltage (figure 3b, 4b) is produced, the periods of which correspond to the received pulse intervals (figure 3a, 4a) and the amplitude of which consequently corresponds to the pulse interval duration, and that behind the RC charging circuit (R7, C3) a filter stage (R8, C4) is connected, which forms a voltage level from the amplitudes of the sawtooth voltage, and that after the filter stage (R8, C4) a voltage level evaluator stage (JC) is connected, which controls one of the functions when the occurring voltage level corresponds to a voltage level from a number of voltage levels which corresponds to the number of the components which determine the pulse intervals.