Switch bounce tester

Claim 1

A mechanical electric switch contact bounce tester circuit comprising: means for actuating the switch to be tested so as to generate signals indicative of switch bounce; a first comparator circuit having a first input adapted to be coupled to the signals from the switch to be tested and a second input of a first adjustable threshold voltage level, said comparator generating a signal each time the switch bounces; an integrating operational amplifier having one input coupled to the output of said first comparator circuit through a resistor and to one plate of a capacitor and a second input coupled to a fixed potential, said capacitor having its other plate coupled to the amplifier output, the output of said amplifier being proportional to the cumulative noncontact bounce time of said switch; a second comparator circuit having a first input coupled to the output of said operational amplifier and a second input coupled to a second adjustable threshold voltage, said second comparator generating a signal each time the cumulative output exceeds a certain value; a differentiating circuit coupled in the output of said second comparator; an electronic switch having a control terminal coupled to the output of said differentiating circuit and an electric indicator in circuit with said electronic switch; and a clock circuit coupled to a switch periodically paralleling said integrating operational amplifier to periodically short same and discharging the cumulative output whereby the cumulative noncontact bounce of the switch contacts of a switch under test will activate said indicator whenever the time aCcumulation of noncontact bounce within the period established by said clock circuit exceeds a predetermined time to produce a voltage summation by said operational amplifier sufficient to exceed said second adjustable threshold voltage level.