Dynohub + LED

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one way round
and another the other way, each LED requires its own limiting resistor.
Take the forward voltage of the LED and subtract it from your average DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor

lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one way round
and another the other way, each LED requires its own limiting resistor.
Take the forward voltage of the LED and subtract it from your average DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor

lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one way round
and another the other way, each LED requires its own limiting resistor.
Take the forward voltage of the LED and subtract it from your average DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor

Trevor Wrote:
lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition an
,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figurin
now
that I definitely need a bridge rectifier and maybe some batteries a
a
kind of voltage sink. Can I just rig it up with about the righ
number
of LEDs in series to accommodate the voltages which I expect to ge
out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one wa
round
and another the other way, each LED requires its own limitin
resistor.
Take the forward voltage of the LED and subtract it from your averag
DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor
How do you know about the maiximum current unless you know the model o
the LED?
What are the specifications of the Dyno and LED(s) involved

--
daveornee

Trevor Wrote:
lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition an
,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figurin
now
that I definitely need a bridge rectifier and maybe some batteries a
a
kind of voltage sink. Can I just rig it up with about the righ
number
of LEDs in series to accommodate the voltages which I expect to ge
out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one wa
round
and another the other way, each LED requires its own limitin
resistor.
Take the forward voltage of the LED and subtract it from your averag
DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor
How do you know about the maiximum current unless you know the model o
the LED?
What are the specifications of the Dyno and LED(s) involved

--
daveornee

Trevor Wrote:
lance house wrote in message ...

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition an
,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figurin
now
that I definitely need a bridge rectifier and maybe some batteries a
a
kind of voltage sink. Can I just rig it up with about the righ
number
of LEDs in series to accommodate the voltages which I expect to ge
out
of it?

cheers
lance

LEDs burn out unless current limited, usually to a max of about 30mA
No need for a rectifier. LEDs are diodes, have one connected one wa
round
and another the other way, each LED requires its own limitin
resistor.
Take the forward voltage of the LED and subtract it from your averag
DC
voltage,(assume 6V) use Ohms law to obtain limiting resistor value.

Trevor
How do you know about the maiximum current unless you know the model o
the LED?
What are the specifications of the Dyno and LED(s) involved

--
daveornee

lance house wrote:

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

I have my Shimano Dynamo Hub hooked up to a luxeon III led but the
system is fairly complex, going through a FET rectifier (low voltage
drop), a very low voltage drop regulator which can be switched out if
necessary, a 700mA constant current regulator, as well as being mounted
in a Energiser 6v light with rechargeable batteries which charge when
the light is off. It works O.K but is overly complex when a simpler and
cheaper system might have been just as good. If anyone else is
interested in going this route I will be happy to share any
problems/solutions I encountered

lance house wrote:

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

I have my Shimano Dynamo Hub hooked up to a luxeon III led but the
system is fairly complex, going through a FET rectifier (low voltage
drop), a very low voltage drop regulator which can be switched out if
necessary, a 700mA constant current regulator, as well as being mounted
in a Energiser 6v light with rechargeable batteries which charge when
the light is off. It works O.K but is overly complex when a simpler and
cheaper system might have been just as good. If anyone else is
interested in going this route I will be happy to share any
problems/solutions I encountered

lance house wrote:

hi

has anyone tried building an LED lamp to be powered by the old
Sturmey-Archer Dynohub? I found one in fantastic condition and ,ahem,
fried one of my LED front lights on an, ah, test ride. I'm figuring now
that I definitely need a bridge rectifier and maybe some batteries as a
kind of voltage sink. Can I just rig it up with about the right number
of LEDs in series to accommodate the voltages which I expect to get out
of it?

cheers
lance

I have my Shimano Dynamo Hub hooked up to a luxeon III led but the
system is fairly complex, going through a FET rectifier (low voltage
drop), a very low voltage drop regulator which can be switched out if
necessary, a 700mA constant current regulator, as well as being mounted
in a Energiser 6v light with rechargeable batteries which charge when
the light is off. It works O.K but is overly complex when a simpler and
cheaper system might have been just as good. If anyone else is
interested in going this route I will be happy to share any
problems/solutions I encountered