APPARATUS AND METHOD FOR TRANSMITTING AUXILIARY SIGNALS ON EXISTING VEHICLE WIRING

• US 3,872,424 A
• Filed: 10/12/1973
• Issued: 03/18/1975
• Est. Priority Date: 10/12/1973
• Status: Expired due to Term

• Current Assignee: Robert S. Enabnit
• Original Assignee: Robert S. Enabnit
• Inventors: Enabnit, Robert S.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/406,076
• Time in Patent Office: 522 Days
• Field of Search: 340/52R,52F,53,181,182,21R,58 180/103
• US Class Current: 340/442
• CPC Class Codes: B60Q 11/00 Arrangement of monitoring devices for devices provided for in groups B60Q1/00 - B60Q9/00
• CPC Class Codes: B60Q 11/007 the lighting devices indicating change of drive direction
• CPC Class Codes: G07C 5/0825 using optical means

Abstract

In a vehicle electrical system including a plurality of electrical circuits, short duration power pulses of insufficient average energy to light vehicle lamps are transmitted via wiring for one of the existing circuits to an accumulating circuit that provides a continual source voltage for a remote conditionmonitoring circuit. A gating circuit couples the pulses transmitted via the first existing circuit to a second one of the existing circuits in response to the output of the remote condition-monitoring circuit for return to a condition-warning indicator. The return pulses are detected and a signal fed to the warning indicator that is indicative of the presence or absence of pulses. The presence of pulses provides a '"'"''"'"''"'"''"'"'conditionnormal'"'"''"'"''"'"''"'"' indication whereas the absence of pulses initiates a '"'"''"'"''"'"''"'"'condition-abnormal'"'"''"'"''"'"''"'"' or warning indication.

Claims

1. In combination with a vehicle electrical system including a plurality of n individual circuits, apparatus to effect power and information communication between a remote condition monitoring circuit and a warning indicator using the circuit wiring for the n individual circuits comprising:

a. a pulse generator coupled to a first of the n individual circuits to provide short duration voltage pulses of insufficient average power to affect normal circuit operation;

b. circuit means coupling the remote condition monitoring circuit to the first of the n circuits to accumulate the pulses and provide a continual source of DC power to the monitoring circuit;

c. a gating circuit intercoupling the remote monitoring circuit, the first of the n circuits, and a second of the n circuits, to gate pulses from the first of the n circuits to the second of the n circuits in response to the output of the remote monitoring circuit; and

d. circuit means coupling the warning indicator to the second of the n circuits to detect the presence of pulses and provide an input signal to the warning indicator indicative of the monitored condition as reflected in the presence or absence of pulses.

2. The apparatus according to claim 1, wherein the first of the n circuits is a vehicle brake-signal circuit and the second of the n circuits is a vehicle turn-signal circuit.

3. The apparatus according to claim 1, wherein the first of the n circuits is a vehicle light circuit and the second of the n circuits is a vehicle turn-signal circuit.

4. The apparatus according to claim 1, wherein the circuit means coupling the remote condition monitoring circuit to the first of the n circuits comprises a series diode and storage capacitor, said capacitor charging rapidly during forward conduction of the diode in the presence of a pulse and the low inverse-conduction of the diode preventing charge dissipation back into the circuit such that a constant voltage is sustained across the capacitor during the pulse interval.

5. The apparatus according to claim 1, wherein the gating circuit comprises:

a. a transistor driver having base, emitter, and collector electrodes, the base connected to the output of the condition monitoring circuit, the emitter connected to vehicle ground through a resitance, and the collector connected to the first of n circuits; and

b. an output transistor having base, emitter, and collector electrodes, the base connected to the emitter of the driver transistor, the emitter connected to the second of n circuit, and the collector connected to the first of n circuit;

said driver transistor switched into conduction by an appropriate voltage from the condition monitoring circuit such that the output transistor is switched into conduction by the voltage appearing across the emitter resistor of the transistor Driver and pulses are gated to the second of n circuit.

6. The apparatus according to claim 5, wherein a normal monitored condition maintains the gating circuit conductive while an abnormal monitored condition switches the gating circuit to its non-conductive state such that pulses are no longer gated to the second of n circuit.

7. The apparatus according to claim 6, wherein a plurality of monitoring circuits are provided each having a transistor driver associated therewith, said transistor drivers connected in series such that a drop in base voltage at any one driver due to an abnormal condition occurrence sensed by its respective condition monitoring circuit renders all of said drivers non-conductive.

8. The apparatus according to claim 1, wherein the circuit means coupling the warning indicator to the second of n circuit comprises an RC circuit connected through a series diode such that the presence of pulses in the second of n circuit charges the capacitor through the diode and the absence of pulses discharges the capacitor through the resistor.

9. In combination with a vehicle electrical system including a source of DC power, a brake-signal circuit, a turn-signal circuit, a tire pressure monitoring circuit, and a condition warning indicator, apparatus to effect communicating power signals to and information signals from the monitoring circuit to the warning indicator using the existing brake and turn-signal circuits comprising:

A. a pulse generator connected in the brake circuit to provide short duration voltage pulses, said pulses having insufficient average power to affect normal operation of the existing circuits;

B. first circuit means coupling the tire pressure monitoring circuit to the brake circuit to accumulate the pulses and provide a continual source of power to the monitoring circuit;

C. gating circuit means intercoupling the pressure monitor, brake, and turn-signal circuits to gate pulses from the brake circuit to the turn-signal circuit in response to the output of the pressure monitoring circuit; and

D. second circuit means coupling the warning indicator to the turn-signal circuit and responsive to the presence and absence of pulses to provide a signal input to the warning indicator representative of the monitored condition as reflected in presence or absence of pulses.

10. The apparatus of claim 9, wherein normal tire pressure affects the pressure monitoring circuit in a manner to effect gating of the pulses from the brake circuit to the turn-signal circuit while an abnormal pressure effects switching of the gating circuit to a non-conductive state such that pulses are not gated to the turn-signal circuit.

11. The apparatus of claim 9, wherein the second circuit means is an RC circuit coupled through a series diode such that the capacitor is charged in the pulse duration and discharged across the circuit resistor in the absence of a pulse, said warning indicator providing a safe indication as long as the capacitor is periodically charged by the presence of pulses but switched to an unsafe warning indication when the capacitor completely discharges due to the absence of pulses.

12. The apparatus of claim 11, wherein a plurality of pressure monitoring circuits are provided to monitor the pressure condition of a plurality of vehicle tires, said monitoring circuits receiving power from the first circuit means and the gating circuit comprises:

a. an equal plurality of transistor drivers having base, emitter, and collector electrodes, each of said drivers coupled and responsive to a respective monitoring circuit, the plurality of drivers connected in series such that the conductive state of one affects the conductive state of the rest and the first of said series connected transistors has its emitter connected to vehicle ground through a resistance while the last of said series transistors has its collector connected to the brake circuit; and

b. an output transistor having baSe, emitter, and collector electrodes, the base connected to the emitter of said bottom transistor driver, the collector connected to brake circuit, and the emitter connected to the turn-signal circuit, said output transistor responsive to the emitter voltage of the bottom transistor driver as determined by the conductive state of the series drivers such that switching into non-conduction effectively blocks pulse gating from the brake circuit to the turn-signal circuit.

13. The apparatus of claim 12, wherein the vehicle electrical system includes right and left turn-signal circuits and the monitoring circuits are split into right and left tire pressure monitoring circuits with gating circuits associated therewith such that pulses are gated from the brake circuit to the right turn-signal circuit in response to the right tire pressure monitoring circuits while pulses are gated to the left turn-signal circuit in response to the left tire pressure monitoring circuits and a second circuit means is associated with each right and left turn-signal circuit to provide input signals to the warning indicator representative of the pressure conditions existing on either right or left sides of the vehicle.

14. In a vehicle electrical system of n existing circuits, the method of communicating power to and information signals from a remote condition monitoring circuit to a warning indicator using the existing n circuits comprising the steps of:

A. generating pulses of insufficient average power to affect the normal operation of the existing n circuits;

B. transmitting the pulses on a first of the n circuits to the remote condition monitoring circuit;

C. accumulating the pulses at the condition monitoring circuit to provide a continual source of power to the circuit;

D. gating the pulses from the first of the n circuits to a second of the n circuits in response to the condition monitored by the monitoring circuit; and

E. utilizing the gated pulses on the second of the n circuits to provide a voltage signal to the warning indicator indicative of the monitored condition.

15. The method of claim 14, wherein the first of the n circuits is a vehicle brake-signal circuit and the second of the n circuits is a vehicle turn-signal circuit and the pulses are gated only in response to a normal monitored condition, the pulses being blocked for an abnormal condition occurrence with a resultant warning signal being developed in the warning indicator due to the absence of pulses in the turn-signal circuit.

16. The method of claim 14, wherein the condition monitored is a vehicle tire pressure and the pulses are maintained when the tire pressure is normal while an abnormal drop in pressure is reflected in the absence of pulses.