Abstract: A circuit tester having a multi-position probe is provided. The circuit tester includes a handle with a detent assembly that allows for positioning the probe at various angles for testing a device. Once a good connection is made with the device under test, an indicator such as a light is lit or a sound is emanated. The probe may be folded into a compartment within the handle once the testing is completed.

Abstract: A circuit tester having a multi-position probe is provided. The circuit tester includes a handle with a detent assembly that allows for positioning the probe at various angles for testing a device. Once a good connection is made with the device under test, an indicator such as a light is lit or a sound is emanated. The probe may be folded into a compartment within the handle once the testing is completed.

Abstract: A timing light for measuring timing of spark ignition has separate displays of engine RPM and timing advance. Another aspect of the invention provides a flashlight function which triggers the flash tube of the timing light to produce a constant bright light source for locating timing marks within an engine compartment. The flashlight function can be incorporated into a dual display digital timing light, or other timing light designs. A dedicated control on the timing light functions to place the flash tube in a continuous flashlight mode.

Abstract: A timing light for measuring timing of spark ignition has separate displays of engine RPM and timing advance. Another aspect of the invention provides a flashlight function which triggers the flash tube of the timing light to produce a constant bright light source for locating timing marks within an engine compartment. The flashlight function can be incorporated into a dual display digital timing light, or other timing light designs. A dedicated control on the timing light functions to place the flash tube in a continuous flashlight mode.

Abstract: A timing analyzer for engine diagnostic testing includes a variable sensitivity knob for testing ignition timing for both a conventional four stroke engine and a DIS four stroke engine. The timing analyzer has a pickup which is adapted to be placed around a lead from a spark plug in the engine. During spark plug firing, a current spike appears in the spark plug lead. The timing analyzer is adapted to be triggered when a current spike above a selected threshold level is detected. When the timing analyzer is triggered, a pulse of light is produced from the nose cone of the analyzer. During engine operation, the spark plugs are continuously being fired, which creates a strobe light effect from the analyzer. The timing analyzer is aimed at timing marks on the engine block, and at a single mark on the rotating flywheel, which permit the engine to be properly timed.

Abstract: An ignition adapter for DIS four stroke engines provides conventional voltage waveforms for a diagnostic oscilloscope. Spark plug leads from a DIS four stroke engine are grouped together depending on their respective firing polarity. A first signal pickup is placed around the spark plug leads from the spark plugs of one signal polarity, for example a positive signal polarity, and a second signal pickup is placed around the spark plug leads from the spark plugs of opposite polarity, for example a negative signal polarity. A trigger pickup is placed around the #1 cylinder spark plug lead. The voltage waveforms received in the signal pickups are applied to the ignition adapter, summed and displayed on the oscilloscope as a conventional voltage waveform. The polarity of the waveform can be reversed using a polarity switch. The waveform received in the trigger pickup is applied to the ignition adapter and compared to a reference voltage.

Abstract: An electronic meter for testing engine parameters includes a slide switch and related circuitry for detecting, scaling and displaying the correct value of engine speed for both a conventional four stroke engine and a DIS four stroke engine, as well as for a two stroke engine. The electronic meter has a pickup which is adapted to be placed around a lead from a spark plug in the engine. The electronic meter is adapted to be triggered when a current spike in the spark plug lead is above a selected threshold value. When the electronic meter is triggered, a voltage pulse is stored in an integrating circuit in the meter. The electronic meter scales the voltage across the integrating circuit, measures the scaled voltage, and displays the value on the meter. The slide switch and associated circuitry for the electronic meter are adapted to vary the threshold level for the trigger, as well as appropirately reduce the output voltage of the integrating circuit, depending on the type of engine being tested.