provided through resistors 136 470 ohms and 138 100 ohms the output of the emitter follower circuit 116 is taken from the emitter of transistor 134 and hence the voltage developed across resistor 138 is provided to terminal 48 for an internal combustion engine having a breakerless ignition system of the type contemplated by this invention the synthesized output pulse on line 38 has an amplitude of 2 volts peak a method of testing the breakerless ignition system of fig1 by the use of the instrument shown in fig2 will now be described the method will be explained with reference to fig3 which shows the correct condition of the various l e d 39 s during different tests of the system with the instrument connected to the system in the manner described above the ignition switch 12 is turned to the off position and a load is placed on the battery 10 the load may be provided by for example turning on the vehicle 39 s lights l e d 68 will indicate whether the battery is of sufficient potential to operate the breakerless ignition system l e d 84 being on indicates that the dc voltage to coil 24 is not excessive the ignition switch 12 is then switched to on and light.