Electronic help

Quoting del <[email hidden]>:

Quoted message said:

I now have a DLumotec Oval and Seculite Plus. The dynamo I have, which
will eventually be replaced subject to funding, is a Union bottle job
(circa 1990). Can both these LED lights be run together without either
one burning out? Or should I use the old filament headlight as well?

The normal Oval is a filament bulb, not an LED. It should have a 2.4W bulb
if it is to be used with the Seculite and a 3W bulb if not.

Quoted message said:

Connect the lights in series or parallel, with or without the filament
h/light?

Headlight/taillight pairs go in parallel. If you were going to run a
second headlight that would go in series with a switch to short it out at
low speeds but that arrangement isn't viable with a bottle dynamo. Leave
the old headlight off.

Quoted message said:

The packaging suggests that the overvoltage protection is limited,
especially in the Seculite, for the time that they will run on their
own should the other blow it's diode or break a wire or some other
fault. Would getting a voltage regulator (zener diode?) help?

No point. If your headlight blows a bulb, you know about it (providing you
develop the habit of always turning the light off when you stop. Why? You
can ride in the day with the light left on and not notice - and then you
can blow the front bulb and not notice - but you can't ride in the dark
and not notice the light has been left off) - you can stop immediately and
replace it with a spare. If you don't have a spare, you can't ride legally
anyway. Therefore, you're unlikely to blow up the Seculite unexpectedly.

In the unlikely event that the taillight fails - or the more likely event
that the wiring to it goes - you'll tend to notice the headlight suddenly
becomes unusually bright, and even if you don't, the worst that happens is
that you blow up an inexpensive bulb.
--
David Damerell <[email hidden]> flcl?
Today is Second Brieday, September.

del said:

I now have a DLumotec Oval and Seculite Plus. The dynamo I have, which
will eventually be replaced subject to funding, is a Union bottle job
(circa 1990). Can both these LED lights be run together without either
one burning out? Or should I use the old filament headlight as well?

If your old dynamo generates 3W at a nominal 6 Volts (and its the 0.5A of
current that matters, not the number of volts), then it is producing the
same as a standard B&M bottle model, and any other dynamo which meets the
long established German standard.

If not, and its producing too much current as the speed rises, then you have
problems.
(I had a Sanyo bottom bracket dynamo which used to produce too much current,
so fitted with a 1W rear bulb to prevent bulbs popping whenever I got to
18mph).

Quoted message said:

Connect the lights in series or parallel, with or without the filament
h/light? I used to run front and rear filament bulbs in series before
so that I'd know when the rear had burned out.

The new lights are 2.4W (front) and 0.6W (rear).
Connected in parallel that means a 3W load, matching the theoretical
generator power, which is how the makers recommend connection.

( if you connect the two in series, you'll put all of the 0.5A through the
rear lamp, which will blow quickly as its designed to take 0.1A. There is
also a chance you blow the front as well).

Quoted message said:

The packaging suggests that the overvoltage protection is limited,
especially in the Seculite, for the time that they will run on their
own should the other blow it's diode or break a wire or some other
fault. Would getting a voltage regulator (zener diode?) help?

Not sure it would help, as (AFAIK) they use a zener for protection already
:-).

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

In article <[email hidden]>

Nigel Cliffe said:

del said:

I now have a DLumotec Oval and Seculite Plus. The dynamo I have, which
will eventually be replaced subject to funding, is a Union bottle job
(circa 1990). Can both these LED lights be run together without either
one burning out? Or should I use the old filament headlight as well?

If your old dynamo generates 3W at a nominal 6 Volts (and its the 0.5A of
current that matters, not the number of volts), then it is producing the
same as a standard B&M bottle model, and any other dynamo which meets the
long established German standard.

If not, and its producing too much current as the speed rises, then you have
problems.
(I had a Sanyo bottom bracket dynamo which used to produce too much current,
so fitted with a 1W rear bulb to prevent bulbs popping whenever I got to
18mph).

But less light at lower speed - Sanyo fitted a voltage regulator to the
later model, or you can buy a voltage regulator to add to any dynamo,
which permits full brightness at lower speeds but prevents over-voltage
at higher speeds.

Quoted message said:

Quoted message said:

Connect the lights in series or parallel, with or without the filament
h/light? I used to run front and rear filament bulbs in series before
so that I'd know when the rear had burned out.

The new lights are 2.4W (front) and 0.6W (rear).
Connected in parallel that means a 3W load, matching the theoretical
generator power, which is how the makers recommend connection.

( if you connect the two in series, you'll put all of the 0.5A through the
rear lamp, which will blow quickly as its designed to take 0.1A. There is
also a chance you blow the front as well).

But if you connect them in series some of the voltage will drop across
one lamp and some across the other, so neither sees the full 6V and the
total current will be lower (and neither lamp will operate at its design
output).

"David Damerell" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In the unlikely event that the taillight fails - or the more likely event
that the wiring to it goes - you'll tend to notice the headlight suddenly
becomes unusually bright, and even if you don't, the worst that happens is
that you blow up an inexpensive bulb.

4 quid and I can't get them locally :-(

cheers,
clive