An attachment for automatic light switching on a vehicle that has as existing equipment the following:
- (a) a battery with one polarity connected to said vehicle metal chassis defined as ground potential and the other polarity defined as high potential,
- (b) basic lights comprising a set of head lights electrically connected preferably in parallel and a set of park lights electrically connected preferably in parallel;
- (c) an enabling system, also called the ignition system, for the user of said vehicle to enable or disable the mechanical powering means of said vehicle which, when enabled, would move said whole vehicle a predetermined way when a predetermined electromechanical action is met;
- (d) a path energizing said set of head lights when closed, a path energizing said set of park lights when closed, and a path energizing said ignition system when closed, each of said paths being connected in series with said battery;
- (e) a light switch having a plurality of electrical terminals thereon and three positions operating in conventional manners:
- an OFF position that by itself would interrupt both the closed path that energizes said sets of head lights and the closed path that energizes said sets of park lights, a PARK position that by itself would close the path that energizes said set of park lights, and a HEAD position that by itself would close both the path that energizes said set of head lights and the path that energizes said set of park lights;
- and
- (f) an ignition switch having a plurality of electrical terminals thereon, a STOP mode that would interrupt the enabling electrical connections of said ignition system, and a RUN mode that would close said enabling electrical connections;
- said attachment for automatic light switching comprising, in combination:
- (a) a control block including a suitable number of electrical pins, having each practically infinite internal electrical resistance, assigned by programming as sensing input means to gather at predetermined intervals of time the logical states of devices electrically connected thereto;
- a suitable number of electrical pins assigned by programming as controlled output means to actuate, when energized, other devices electrically connected thereto;
- and logical processing means including memory means preprogrammed to decide when to energize and when to de-energize said controlled output means according to the combinations and sequences of the logical states of devices electrically connected to said sensing input means;
- (b) controlled switch means having a predetermined number of pairs of contact terminals and electrically connected to and actuatable by said controlled output means for changing the electrical resistance through each of all said pairs of contact terminals of said controlled switch means from a practically infinite value to a practically zero value, and vice versa;
- (c) powering means using preferably said battery to energize said control block and eventually to energize said controlled switch means on actuation from said control block;
- (d) a light switch transducer means for providing on demand from said control block, the logical state of at least one of said three positions of said light switch, said light switch transducer means including electrical transducer means providing two logical states out of the energizing and de-energizing of each particular one of a predetermined number of closed paths electrically interruptible by a particular one of said three positions of said light switch, said electrical transducer means being made by electrically connecting each of the two electrical terminals of a sensing resistor of predetermined electrical resistance to each of the two electrical contact terminals of the particular pair of contact terminals of said controlled switch means which is electrically connected in series with said particular one of a predetermined number of closed paths electrically interruptible by a particular one of said three positions of said light switch and then sensing with an electrical connection to said sensing input means of said control block, the change in voltage, with respect to said ground potential, at a predetermined one of said two electrical terminals of said sensing resistor;
- said change in voltage being caused by the closing and interrupting of said particular one of said three positions of said light switch and said change in voltage being sensed only when the resistance through said particular pair of contact terminals of said controlled switch means is made into a practically infinite value;
- (e) an ignition switch transducer means for providing the logical state, presence or absence, of the STOP mode of said ignition switch;
- (f) electrical wire insert means, each interrupting and creating each of pairs of insulated electrical terminals in series in each of a predetermined number of closed paths of said basic lights, anywhere on each of said closed paths of said basic lights;
- (g) electrical wire interrupting means connected to a predetermined number of said pairs of insulated electrical terminals of said insert means as well as to a predetermined number of said pairs of contact terminals of said controlled switch means to allow each pair of contact terminals of said controlled switch means to be inserted in series with each of said predetermined number of energizing closed paths of said basic lights at convenient locations, said convenient locations being predetermined for said vehicle, and not restricted electrically to a single definite location with respect to said battery, said light switch, and said basic lights;
- and
- (h) electrical wire signaling means connected to said transducer means of said light and ignition switches as well as to said sensing input means to provide to said logical processing means the combinations and sequences of the logical states of said light and ignition switches, said transducer means of said light and ignition switches being predetermined to be the most convenient on said vehicle.