connected to the inner end of the coil 46 as indicated by the connection 116 in the other fencing figure 14 the insulating sleeve 106 is eliminated and the conductive tip portion 100 is electrically connected to the outer end of the coil 46 accordingly in the fencing figure 14 only the single wire 108 is required to make an electrical connection to the coil 46 and the tip 100 considering now the circuit arrangement of the present invention shown in fig6 a low voltage supply potential indicated by the symbol v cc is provided by the batteries 120 and this supply potential is connected to the control circuit of the invention through the on off switch 122 a first tone signal which preferably has a frequency of 1 1 khz is developed by a phase shift oscillator which includes the inverting amplifiers 124 and 126 which form a part of an integrated circuit chip which is preferably of the commercial type 4069 the pin connections for this chip being shown in fig6 the output of the amplifier 126 is connected through the feedback capacitor 128 and the resistor 130 to the input of the amplifier 124 this capacitor is also connected to the resistor 132 to the input of the amplifier 126 so that a sufficient phase shift is provided to produce sustained oscillations at a frequency of 1 1 khz at the junction of the capacitor 128 and the resistor 132 a similar tone generator comprising the amplifiers 134 and 136 on the type 4069 chip the capacitor 138 and the resistors 140 and 142 is provided to generate a tone signal having preferably a frequency of 750 hz a third pulse type oscillator is provided by the amplifiers 144 and 146 on the type 4069 chip the.