gegyx wrote:Maximus leoIf you've been the designer and experimenter for over a year, you have the necessary perspective to say that your system is reliable. So it's a real progress.
On one of your links, it seemed to me that we were inspired by your idea, with subsidies ... What mattered to you was security, and that's all your credit.
It's been a while since I curse the builders. How can we not put in series on the bicycles, a fixed system of lighting, with leds, rechargeable and powerful, with the modern technology?
Instead, we have self-contained, battery-powered casings that fall out of fear and are often forgotten. This enrages me, because legislation in this area, for reliable and non-removable lighting, would provide greatly increased security. While in fact, with these nutty systems, bicycles run with absent or deficient lighting most of the time. When politicians talk mostly about safety, they should think about these basic things, which would preserve the future of many people, especially children ...
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I did not understand your last schematic:
2 rectifier bridges by generator
The 12v lamp 6 w is the stop light?
The surge limiter only controls T1 which controls this lamp. Interest? Swing the overload in the stop light?
Why T2 and T3? While leds and series resistor, it works as well, and that would use a resistor + 2 transistors + 4 diodes in less?
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For the red leds, put less, half flashing, would be more conspicuous, and more economical. No ?
Another point could be improved, it is the mediocre efficiency (20%) of these standard "dynamos". But it is also true that you have implemented a reliable system with standard parts accessible to all for a lower price.
I confirm that it is completely viable insofar as the lighting uses not too many LEDs (4 at the back and 8 at the front), it lights up a little better than a conventional system and it doesn 'is not necessary to recharge. The dynamos used are not adapted indeed but they are found everywhere and not expensive. Special dynamos are needed, capable of supplying greater current and integrated into the brake system.
For the electronic circuit, I have been criticized on several occasions for not having put an overcharge protection circuit for the batteries. So I installed one on the Ni-MH battery system, it comes from an old Li-Ion battery circuit where it is essential because there is a risk of destruction of the batteries in the event of overcharging. This control circuit is only active when the dynamos are in operation, the LM393 comparator compares a fraction of its supply voltage (almost identical to that of the batteries but it is not that of the batteries) with a reference obtained by a 1N4148 diode (this reference voltage is not perfect but sufficient). If the supply voltage exceeds a certain threshold (adjustable by the potentiometer) the output of the comparator switches and the Darlington transistor goes to saturated state and lights a 12 V lamp which absorbs the charging current and therefore protects the batteries. There are many other possibilities of protection circuits but this one works well and it does not use the energy of the batteries.
The transistors T2 and T3 and the 4 diodes are two constant current generators (well, pretty much!). The role of this circuit: allow almost constant lighting and protect the LEDs.
- The circuit fixes an operating current for the LEDs around 18 mA as long as the battery voltage is greater than 8 ~ 9 volts.
- In case of failure of the batteries, the dynamos will flow directly into the LEDs but the current will be limited and the LEDs will not suffer.
Without this circuit, the lighting varies with the voltage of the batteries and with the braking, it is not very sensitive certainly especially if the level of charge is high but there is another drawback: in case of failure of the batteries the dynamos then flow directly in the leds without any control, the voltage can rise and the diodes can be destroyed and these are the most expensive elements.
The system remains experimental but it has proven itself. There are other circuits in development: there is one that operates under pulses, the LEDs are powered by high but very short current pulses, the retinal persistence means that we obtain powerful lighting with ridiculous consumption. , a few tens of milliwatts. Another circuit under study, a circuit that uses only one battery. The problem with the batteries connected in series and the numerous successive recharges is that the difference between their voltages tends to increase, we have batteries at 1,15 V and others at 1,35 V. A solution is to use a single battery and a switching power supply (capable of working under 1 volt!) providing a constant voltage for the LEDs.
Fiare flashing red rear LEDs is not a problem and I have nothing against it but it is not legal in France.