This invention relates to a device for avoiding battery drain in a motor vehicle.
In a motor vehicle the direct current load , such as, the turn signal lamp, brake lamp, beeper, horn, service indicator lamps, among others, are always connected to the battery of the vehicle. When the engine is off, these loads, supplied by the battery, cause the battery to be drained; and this leads to electric start problem in the vehicle.
Take the example of the brake lamp, which is one of the direct current loads. As a safety requirement the driver of the vehicle usually applies the brake while starting the vehicle with electric starting mechanism. The braking system of the vehicle is provided with a brake or stop lamp which glows whenever the brakes are applied. The brake lamp, whenever it is on, consumes about 21 W which is supplied by the battery when the engine is off and the vehicle started by the electric starting mechanism, with the driver applying the brakes as a safety precaution. This results in battery drain
Even when the engine is on and the brake lamp glows on application of the brakes, the power to the lamp might still be furnished by the battery when the magneto/alternator produces an output voltage lower than the battery voltage. The foregoing conditions which are frequently met with in practice lead to battery drain leading to various difficult situations, notably, those associated with the electric start of the engine.
This invention therefore proposes a device for avoiding the above mentioned drawbacks and avoiding, or at least minimizing, battery drain in a motor vehicle.
The device for avoiding battery drain in a motor vehicle, according to this invention, comprises a magneto/alternator connected to a regulator-rectifier; AC load of the vehicle connected to the said regulator-rectifier; a battery, a brake lamp and DC load of the vehicle, the DC load being connected to the said regulator-rectifier, said device being characterized in that the brake lamp is directly connected to the said regulator-rectifier and further characterized in that the input end of a diode is connected to the regulator-rectifier with its output end connected to the battery, said DC load being connected to
2

the battery, such that while the battery is enabled to supply power to the DC load and to receive power from the regulator-rectifier through the diode for charging purposes , the said battery is selectively disabled from supplying power to the brake lamp either directly or through the diode.
This invention will now be described with reference to the accompanying drawings
which illustrate, in
Fig. 1 the known circuitry of the battery
And
Fig. 2 the circuitry of one of possible embodiments of this invention, by way of example,
and not by way of limitaion.
Referring to Fig. 1 it will be seen that the magneto/alternator G of the vehicle is connected to the DC load (DCL), the AC load (ACL), as well as to the battery B of the vehicle, through a regulator-rectifier RR. The battery B is also connected to the DC load so much so that when the magneto/alternator is off, the battery supplies the DC load of the vehicle, including the brake lamp, when the driver applies the brakes (with the engine off) for safety reasons, while using the electric start mechanism.
Referring to Fig. 2 it will, be seen that the magneto/alternator and regulator-rectifier of the vehicle is connected to the DC load (DCL), the AC load (ACL), as well as to the battery B of the vehicle through a diode D such that as the magneto/alternator G is now enabled, as always, with the engine running, to supply power through the diode D to the battery for charging it; and the battery is now selectively enabled to supply power to the DC load, but not to the brake lamp, since the diode D selectively obstructs the flow of current from the battery to the brake lamp. In other words, with the engine off, while the battery is enabled to supply power to the DC load of the vehicle, the brake lamp alone, selectively, will not receive power from the battery, even when the driver applies the brake during starting of the engine, thus avoiding battery drain.

The term "diode"in this specification and Claims means and includes not only the "diode" as normally meant and understood but also other devices performing the same or similar function when incorporated in the device proposed herein, in the manner described and illustrated as aforesaid.
From the foregoing it will be observed that this invention is cost saving, economical in performance, capable of being readily incoiporated in the vehicle replacing the known circuitry device and highly beneficial to motor vehicle users and owners It will be appreciated that various other embodiments of the device proposed herein are possible without departing from the scope and ambit of this invention.

We Claim:
1. A device for avoiding battery drain in a motor vehicle, comprising a
magneto/alternator connected to a regulator-rectifier; AC load of the vehicle connected to the said regulator-rectifier; a battery, a brake lamp and DC load of the vehicle, the DC load being connected to the said regulator-rectifier, said device being characterized in that the brake lamp is directly connected to the said regulator-rectifier and further characterized in that the input end of a diode is connected to the regulator-rectifier with its output end connected to the battery, said DC load being also connected to the battery, such that while the battery is enabled to supply power to the DC load and to receive power from the regulator-rectifier through the diode for charging purposes, the said battery is always selectively disabled from supplying power to the brake lamp either directly or through the diode.