Which is which?
The LED Brake lights for 1 more car.
Can you tell which side has LEDs inside?
The answer is the left side. The right side has bulbs inside. They almost look
the same but there are differences in power consumptions and the delay to
light on/off.
The left side.
The right side.
This is another experiment to use LEDs instead of conventional bulbs.
I decided to use LEDs for every car around me since the life is far longer and
the power consumption is much less. You also can expect almost no
maintenance too. Initially, I used LEDs only for the left side to make a
comparison.
The LED unit I used this time was a direct replacement type of a home made
unit similar to what I used for the Honda Life. The location of each LED
chips are optimized to get the best reflections and I have to assemble the
unit after doing some experiments. Prior to the assembling, I needed to find
the best position and the direction of chips. The best position is sometimes
3cm away from the socket and sometimes it was only 5mm or less. That is
the reason why the chips are located away from each other at the photo
shown below.
Setting LEDs only for the left, I got two problems. The right side (bulbs) started
to turn on a bit slower and it looked the light was moving from left to right.
LEDs have no delay to radiate the light energy when the DC is applied but
bulbs need time to heat up the filament and this causes a delay. When
releasing the pedal, vice versa. The left side (LEDs) turns off quicker than
the right side. The right side remains to shine for a few hundred milli seconds
more. It looked strange and I quickly used LEDs for both sides.
Another problem I encountered was the brake warning light in the cluster
turned on informing me that something was wrong with the bulbs. The car
had a warning circuit and it worked because the current was not within the
range. As I checked the circuit , there was a current sensing comparator.
The best idea might be to change the range of the current but it needs
some extra efforts and temporarily I stopped the function lifting a resistor
that indirectly drives the indicator shown below.
As I analyze the warning circuit, the current is sensed by the voltage at both
ends of the resistors indicated by an arrow. Increasing the resistance would
be a solution but I would be trying it in the future. As long as there would be
no break down of the LED lights, the warning circuit would not be needed and
I set the priority low. The only thing I worry about is the connection issue. I twice
had the connection problem of brake lights with German cars. Both of them
were caused by a galvanic corrosion. Although I have changed the bulb the
problem no light was not fixed because both problems were caused at the
connector having a extremely big resistance. Those brake light units were
supplied by Bosch and I realized that they were not familiar to the galvanic
corrosion issues at that time. Toyota cars seldom have this type of problem
and the Celsior would be all right and the priority could be set low, I think
through my past experience.
