Automotive test apparatus for coupling to the ignition system of automotive internal combustion engines
First Claim
1. Test apparatus for coupling to the ignition system of internal combustion engines havingcoupling means (10, 11, 12) adapted to be coupled to the ignition system of an internal combustion engine, and a pulse-shaping circuit connected to the output of the coupling means and providing an output signal having a predetermined relation to the ignition pulses regardless of additional spurious pulses being applied to the coupling means, said circuit comprisinga semiconductor switch (22, 35) providing said output signal upon change of state thereof;
- and a charge storage circuit (26,
34) connected to the coupling means (10, 11,
12) and to the semiconductor switch (22,
35), said charge storage circuit having a short loading time and a re-loading or discharge time which is long with respect to said loading time to rapidly transfer a pulse applied thereto to the switch and cause rapid change of state of said switch while slowly unloading the pulse stored therein and prevent further change of state of operation of said switch during said unloading or discharge time.
0 Assignments
0 Petitions
Accused Products
Abstract
To prevent transfer of stray pulses from the ignition system to test apparatus, a pulse-shaping circuit is connected between the output of the ignition system and the test apparatus itself which includes a semiconductor switch providing an output signal to the test apparatus upon change of state thereof, and a charge storage circuit connected to the coupling element of the test system to the ignition system and to the semiconductor switch, the charge storage circuit having a short loading time and a re-loading or discharge time which is long with respect to the loading time thereof to rapidly transfer pulses to the switch and cause rapid change of state thereof while slowly unloading the charge and prevent further change of state of the switch during the unloading time, and thus suppress and eliminate stray pulses.
16 Citations
10 Claims
-
1. Test apparatus for coupling to the ignition system of internal combustion engines having
coupling means (10, 11, 12) adapted to be coupled to the ignition system of an internal combustion engine, and a pulse-shaping circuit connected to the output of the coupling means and providing an output signal having a predetermined relation to the ignition pulses regardless of additional spurious pulses being applied to the coupling means, said circuit comprising a semiconductor switch (22, 35) providing said output signal upon change of state thereof; and a charge storage circuit (26,
34) connected to the coupling means (10, 11,
12) and to the semiconductor switch (22,
35), said charge storage circuit having a short loading time and a re-loading or discharge time which is long with respect to said loading time to rapidly transfer a pulse applied thereto to the switch and cause rapid change of state of said switch while slowly unloading the pulse stored therein and prevent further change of state of operation of said switch during said unloading or discharge time.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
Specification