Extinguishing a dynamo standlight

[rogerzilla]

Is there any way to short the capacitor on a B&M Toplight D Plus, for railway platforms?  Or do you have to arrive 5 mins early to get it fade out?

[Cudzoziemiec]

Some models have a black push-button. On mine it's on the bottom right. It's kind of hidden, you have to look for it.

[Kim]

I don't know the Toplight D Plus (well, I've got a couple of 4DToplight Multis, which probably share the same plastic parts, but they have an obvious on/off switch for the battery side).  Electrically all you need to do is shunt (or disconnect) the standlight capacitor (easily identified by looking a bit like a coin cell battery).

I modified my Brompton stock dynamo rear light by fitting a small-value resistor (I don't remember but probably something in the region of 4.7R or so^[1]) in series with a tilt switch^[2], across the capacitor.  I positioned the tilt switch in such a way that it closes when the light is upside-down, so to extinguish the light all you need to do is perform the first stage of the fold and wait a few seconds.  This works well, as I'll usually want to stand the bike while I faff with tickets, but can also be done to good effect while riding a lift to the platform.  Crucially, it meant that I didn't have to worry about waterproofing a switch.

You could use the same approach on a non-folding bike to trigger the discharge with a reed switch and magnet.


_{[1] The resistor is a compromise between speed of discharge and how much charge you waste when the bike goes over a bump.
[2] Ball bearing type.  I decided that mercury was a bad idea around aluminium bike components.  The rattle's only noticeable in practice if you pick the folded bike up and shake it.}

[grams]

Is there any way to short the capacitor on a B&M Toplight D Plus, for railway platforms?  Or do you have to arrive 5 mins early to get it fade out?

You learn to walk quickly and obliviously and pretend you didn't hear anything. A hoody and/or headphones helps.

Or you strategically position a glove or similar.

[Cudzoziemiec]

It's the red button you can see here.

[Zed43]

You mean you are not allowed to run lights on your bike on the platforms? Why 

10x5cm of fabric with a 10cm long piece of duct tape with 2cm stickyness exposed to slap it somewhere on the frame while riding and to cover the light when you have to.

[Polar Bear]

To ensure that there is no confusion between train managers, drivers and 0latform staff as lights are also used as a signalling device on platforms.

[quixoticgeek]

To ensure that there is no confusion between train managers, drivers and 0latform staff as lights are also used as a signalling device on platforms.

Is it actually enforced?

Have never seen anyone complain about it.

J

[Cudzoziemiec]

I've known it be enforced, albeit back in the 90s. Might even have been BR at the time.

[Polar Bear]

To ensure that there is no confusion between train managers, drivers and 0latform staff as lights are also used as a signalling device on platforms.

Is it actually enforced?

Have never seen anyone complain about it.

J

Yes.  I have been an unwitting culprit myself. 

[Polar Bear]

I've known it be enforced, albeit back in the 90s. Might even have been BR at the time.

It happened to me more recently than that but I recall station staff enforcing the rules much more recently though pre covid of course.

[MikeFromLFE]

I've known it be enforced, albeit back in the 90s. Might even have been BR at the time.

My son enforced it when he was platform staff / manager - he moved upwards about 5-7 years ago.
It's certainly still in the training for his former company's platform staff. (I've just checked with him)

[drossall]

I've certainly had complaints about my Brompton.

I modified my Brompton stock dynamo rear light ... in such a way that it closes when the light is upside-down, so to extinguish the light all you need to do is perform the first stage of the fold and wait a few seconds.

Most of your posts make me wish I was as clever as you

[quixoticgeek]

I wonder if this is a UK only thing. Tho I never had issues when I used my Brompton on SER...

J

[Lightning Phil]

I’ve been asked to turn lights off on platform. When I explained it was Dynamo with no off switch. They grumbled a bit.  Put bike sideways away from platform edge whilst capacitor discharged.

[grams]

I wonder if this is a UK only thing. Tho I never had issues when I used my Brompton on SER...

You have to be noticed by the right flavour of staff: either new and keen or old and grumpy enough to care.

[Cudzoziemiec]

Presumably they also need to railway staff, either NR or TOC, rather than customer services, engineering contractors and whatever.

[jsabine]

"It's a dynamo light, it's automatic, and I can't turn it off" has discouraged station staff in the past.

By the time we've gone through more witty banter about German engineers knowing better than I do when I want my lights on, either they've turned themselves off, or my train has arrived.

[rogerzilla]

In the early days of railways, white was used for "all clear".  Imagine the confusion with other oil lamps at stations or just in lineside houses.

Other signal lighting trivia:

The "green" spectacle glass in semaphore signals is actually blue, so it looks green when lit with an oil lamp.

It wasn't possible to make a decent yellow glass for "caution" when distant signals were introduced, so the light colours were the same as a home signal in the dark (red/green).  Again, pretty confusing, as a driver could stop at the wrong signal if he was unfamiliar with the road or lost track of where he was.

[Cudzoziemiec]

Surprised no one's yet mentioned Bobbie's red petticoat.

[rogerzilla]

Surprised no one's yet mentioned Bobbie's red petticoat.

Where did Bobbie keep the red light for stopping trains at night?

[Jurek]

Fabricate a lens cap from a jar lid.
Bungee it (vb) into place.

[drossall]

Do they make long-rectangular (roughly) jar lids?

[Jurek]

Do they make long-rectangular (roughly) jar lids?

Colemans mustard powder comes in a tin with a rectangular lid.

[BFC]

Do they make long-rectangular (roughly) jar lids?

Colemans mustard powder comes in a tin with a rectangular lid.

The lid from the 454g (16oz) tin would cover most lights at 68x98mm. Could ask around local pubs and eateries rather than wait to get through that much mustard.... The 113g (4oz) tin only has a 41x62mm lid. Assuming the tin design hasn't changed since unilever moved production out of Norwich.