DE20109031U1 - Integrated bicycle electronics with direction indicator and automatic lighting - Google Patents

Description

Description

Integrated bicycle electronics with direction indicator and automatic lighting

The current electrical equipment of a typical bicycle is completely inadequate. The side dynamo that is generally used is fundamentally unreliable. When the road is wet, snowy or dirty, this dynamo slips. It can then no longer provide sufficient power.

The consequences of this unreliable power supply are often catastrophic. At night, you will see many cyclists riding without lights. Other road users are not able to see these cyclists until it is too late and accidents may occur. Attempts to indicate an intention to change direction using hand signals are difficult for following road users to see at night. The cyclist's uncertainty and poor visibility increase the risk of accidents. A flashing indicator similar to that used on motorcycles would be very helpful here.

A modernization of the bicycle's electrical systems in line with current technical possibilities is therefore urgently required. The following requirements must be met by a modern electrical equipment on a bicycle:

1. Constant operational readiness, even when stationary, e.g. at traffic lights

2. Minimal energy consumption

3. Largely maintenance-free

4. Low weight

The electrical system presented here meets these requirements.

-1-

The basis of a modern electrical system on a bicycle is a hub dynamo. Examples include the hub dynamos from Shimano and SON. The hub dynamo in the front hub of the bicycle rotates continuously while the bike is being driven. However, the rider only needs to use significant energy when power is drawn from it. The figures given here refer to a driving speed of 20 km/h. The idle loss is around 0.6 watts. This corresponds to less than 1% of the power required by the rider. An additional power of 5 W is only required when the dynamo is producing electrical power. Headwinds, poor road surfaces or incorrect tire pressure require significantly more additional power from the rider. The electrical efficiency of these dynamos is around 70%.

A modern bicycle must have electrical power available at all times, even when stationary. Therefore, a NiMH battery with a nominal voltage of 6 volts is recharged as required using the hub dynamo, controlled by the window discriminator. The block diagram of the entire system is shown in Figure 1. The individual components are shown in detail in my patent DE 100 00 734 Cl. The attached photos show the actual design.

In a central unit (ZE) built into the headlight of the bike, there is an electronic window discriminator (FD) with a rectifier that automatically recharges the battery (AK). The clock generators (TR), (TL), a brightness sensor with switch (AS) and the other switches. Since the battery is always ready for use, a direction indicator similar to that on motorcycles can easily be integrated as stated. This is operated with a thumb switch (BS) on the handlebars.

-2-

This is a crucial innovation in the system described here. According to the road traffic regulations, cyclists must indicate or signal every change of direction by hand signals. This necessarily causes a change in the center of gravity of the rider-bike system. Instability of the system is the inevitable result of this method. Letting go of the handlebars leads to further destabilization and uncertainty for the rider. Small obstacles on the road that are rolled over or that the rider tries to avoid can even lead to a fall. At night, signaling a change of direction by hand signals may not be recognized in time by the following road user. This increases the risk of an accident.

The indicator device used here is clearly visible at least 50 m during the day and up to 200 m at night. The key innovation is the use of yellow (= 590 nm) LEDs as indicators (front, rear, front, rear), which are very efficient. At a voltage of 6 V, a current of only about 100 mA flows in the LED indicator. In comparison to a standard bulb indicator with 12 W (some motorcycles use up to 21 W), this means a power ratio of 0.6 W: 12 W = 1: 20. This means that only 5% of the energy previously required is used to achieve the same effect.

The weight of a prototype of this new bicycle electrics with 4 bunkers (without dynamo) is less than 500 g.

The battery is discharged during flashing and at night when the lights are switched on. Its voltage is therefore constantly monitored electronically by the window discriminator in the central unit. If the voltage drops below 5.7 V, the

-3-

Dynamo switched on to charge the battery until it has reached a voltage of 6.5 V again. The connection to the dynamo is then automatically interrupted until the voltage has dropped back to 5.7 V, etc. In order to recharge the energy taken from the battery during a flashing process, around 10% of the pure flashing time used is required as operating time for the dynamo. Since turning left is generally more dangerous, the flashing frequency should be higher than when turning right. An integrated sound generator indicates the flashing frequency acoustically. This means that the status of the bunkers can be recognized not only from the position of the thumb switch (BS). The lighting system (LI) contains, in accordance with the state of the art, a halogen lamp with 2.4 W output and a rear light with integrated LED, which take on the parking light function. The driver can decide whether the lighting is switched on automatically or manually at dusk.

To ensure reliability, the components are wired using a two-wire system. The electrical cables should be routed in the bicycle frame or in an appropriate cable duct.

The service life of the electronics built into the headlight and the LED indicators is almost unlimited.

The entire bicycle headlight is shown in Figure 2. The battery (AK) and the electronics (EL) form the central unit (ZE).

The system described here fulfills requirements 1 to 4 above.

List of reference symbols

AK: Battery-5 cells AA NiMH ZE: Central unit - in the headlight

DY: Hub dynamo LI: Lighting - headlight + tail light

FD: Window discriminator AS: Automatic switch depending on brightness

TL: Clock generator+tone generator, left BS: Indicator switch on the handlebar

TR: Clock + tone generator, right LS: Light switch on the headlight

VL ₅ HL: LED indicator left HS: Main switch on the headlight

VR ₅ HR: LED bunker right

to picture 2

AK: Battery

EL: Electronics

SC: Headlights

ZE: Central unit

Claims (1)

Integrated bicycle electrics with direction indicator and automatic lighting, characterized in that it contains: 1. 1.1 a bicycle headlight ( Figure 2) containing: - a 6 V NiMH battery made of 5 AA cells (AK) - a control electronics ( Figure 1) with: a) Window discriminator (FD), which switches a dynamo (DY) on or off to charge the battery depending on the voltage. b) Two clock generators (TR, TL) that control direction indicators (VL, HL, VR, HR) with adjustable flashing frequency and acoustic signal generator. c) Brightness-dependent switch (AS) for switching the lighting system (LI) on or off, main switch (HS) and light switch (LS). - 1.2 2 × 2 LED direction indicators attached to the handlebars or luggage rack close to the rear light. - 1.3 Indicator switch (BS) on the handlebar.