Excessive speed and theft deterrent system

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Refer now to FIG.
1 where there is disclosed a preferred embodiment of the present invention.
The output of a tachometer or any other suitable speed deteching device is coupled to the input terminal 11 of a voltage divider 13.
The voltage divider has a plurality of output terminals so that the output voltage of the tachometer can be appropriately sealed.
A switch arm 15 selectively makes contact with one of the output terminals of the voltage divider or with an off contact 17.
The switch 15 is coupled to the midpoint of resistor 19 which has its respective end terminals coupled to the inputs of a differential amplifier 21.
The differential amplifier acts as a comparator and provides an output at output terminals 23 and 25 only when the respective input signals thereto exceed a predetermined voltage.
Techniques for operating a differential amplifier as a comparator are well known in the art and therefore will not be discussed in detail herein.
The output at terminal 25 of the differential amplifier 21 is coupled to a first transistor 27 via current supply resistor 29.
Transistor 27 is of the PNP type and has its emitter terminal connected to a positive source of voltage, such as, the twelve volt supply of the vehicle battery system.
The collector of the transistor is connected to ground via a lamp 28.
The collector is also connected to an LC oscillator circuit 31.
The output of the oscillator circuit drives a transducer, such as, a speaker or horn 33, so that when transistor 27 is turned on, an audible sound is generated which warns the operator that the vehicle is approaching a predetermined speed limit.
The other output terminal 23 of the comparator 21 is coupled to a second transistor 35 which is also of the PNP type.
Transistor 35 has its emitter coupled to a positive voltage supply, such as, the twelve-volt supply of the vehicle battery system.
The collector of the transistor is connected to a lamp 37 and to the sound driver arrangement 31 via an isolation diode 39