Controller Light Output - Uses?

01wellsd

Pedelecer
Apr 30, 2020
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You spell even worse that you calculate! In one short sentence, two spelling errors!!! (resisor needs to disipate) DUUUUHHHHH!
Also, you apparently did not look at the web page I posted, as it states clearly that a 1 Watt LED needs only 3.6 volts! Industry standard.
I used 4 volts to keep it simple for you!
Obviously, not simple enough.
Try a re-think and a re-calculation!
If you need help, I can post the simple calculation for you, if you do not wish to look at the web page!
Look at this web page:-
That makes it REALLY easy for you!
Many people, myself included, type quickly and mistakes do happen.
With the amount of useful information that VFR pumps out to this forum I'm not surprised that there are sometimes spelling or grammatical errors.
I think that bringing that into this thread is quite childish and unnecessary.

Also, I don't know VFR at all, but what if he has dyslexia?
Would be really big of you to insult him from behind your keyboard then wouldn't it?
 
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Bikes4two

Esteemed Pedelecer
Feb 21, 2020
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'----------On a related subject, the Japanese designers at Panasonic have an interesting way of wasting energy in voltage reduced bicycle lighting. Their 26 volt mid drive unit has a lighting takeoff fed by a high frequency voltage chopper to produce AC with a very uneven mark-space ratio to simulate a 6 volt supply over time from the 26 volt Li-ion. Useless for fast reacting LEDs of course, in bicycle designs it feeds tungsten filament 6 volt bulbs, their slow reaction time evening out the chopped current into a smooth flow by resistance wastage as heat. Clearly they weren't considering efficiency in combining the resistance method with electronic complexity!
.
I'd be interested to read that article but from the way you describe the action of that device, it sounds like a switched mode power supply aka buck converter. These devices don't 'waste' voltage, they alter the voltage.

The buck converter will in itself use some level of power - whether that is less or more than a simple dropping resistor requires some bench testing.

And of course using a buck converter takes you into the realms of finding a location for it and any connectors, containers, waterproofing etc but does offer a more stable voltage for the lights as the bike battery discahrges say from 42v to 30v. As a very rough estimate, if the dropping resistor is sized to 'drop 5/6th of the battery terminal voltage, then the voltage available to the light will vary from 1/6th of 42v to 1/6th of 30v which is 7v and 5v respectively,which for LED lights may not even be noticeable.

As a retired electronics person, I favour the more 'correct' buck converter approach, but the practical man in me is edging towards the dropping resistor(almost :confused:) . I can fully understand why some folks just opt for clip-on lighting. More stealable but no additional cables and independant of the ebike battery (thinking flat battery scenario here).

The little beastly below at around £4 uk pricing, could likely be found a home inside some light fittings.

37291
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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I'd be interested to read that article but from the way you describe the action of that device, it sounds like a switched mode power supply aka buck converter. These devices don't 'waste' voltage, they alter the voltage.

The buck converter will in itself use some level of power - whether that is less or more than a simple dropping resistor requires some bench testing.

And of course using a buck converter takes you into the realms of finding a location for it and any connectors, containers, waterproofing etc but does offer a more stable voltage for the lights as the bike battery discahrges say from 42v to 30v. As a very rough estimate, if the dropping resistor is sized to 'drop 5/6th of the battery terminal voltage, then the voltage available to the light will vary from 1/6th of 42v to 1/6th of 30v which is 7v and 5v respectively,which for LED lights may not even be noticeable.

As a retired electronics person, I favour the more 'correct' buck converter approach, but the practical man in me is edging towards the dropping resistor(almost :confused:) . I can fully understand why some folks just opt for clip-on lighting. More stealable but no additional cables and independant of the ebike battery (thinking flat battery scenario here).

The little beastly below at around £4 uk pricing, could likely be found a home inside some light fittings.

View attachment 37291
The lights we mentioned earlier have built in buck converters specific to the lights as a ready-made solution. They're cheap, efficient and reliable - win win!
 

flecc

Member
Oct 25, 2006
52,799
30,374
I'd be interested to read that article but from the way you describe the action of that device, it sounds like a switched mode power supply aka buck converter. These devices don't 'waste' voltage, they alter the voltage.
There wasn't an article, Panasonic release no tech details on their pedelec designs, it comes from physical checking by a couple of us. It was quite a recent design and if they'd used a switched mode supply could have utilised LED lighting instead of wasting current in filament bulbs. However they didn't have to find space for a converter, the chopping was as I described and carried out in the all function circuit board with no voltage conversion.

For lighting it was crude but it worked after a fashion, though nothing like as adequate as LED lighting.
.
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
1,672
921
This output from the controller is very useful. I don't use it for driving lights, but for powering a very loud horn and also as a feed for my voltmeter.

These horns are cheap, but loud enough to get you taken seriously by cars and run up to 60V.

12V versions are available, but they use far higher current.

37292
 
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Nealh

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Nealh

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I'd be interested to read that article but from the way you describe the action of that device, it sounds like a switched mode power supply aka buck converter. These devices don't 'waste' voltage, they alter the voltage.

The buck converter will in itself use some level of power - whether that is less or more than a simple dropping resistor requires some bench testing.

And of course using a buck converter takes you into the realms of finding a location for it and any connectors, containers, waterproofing etc but does offer a more stable voltage for the lights as the bike battery discahrges say from 42v to 30v. As a very rough estimate, if the dropping resistor is sized to 'drop 5/6th of the battery terminal voltage, then the voltage available to the light will vary from 1/6th of 42v to 1/6th of 30v which is 7v and 5v respectively,which for LED lights may not even be noticeable.

As a retired electronics person, I favour the more 'correct' buck converter approach, but the practical man in me is edging towards the dropping resistor(almost O NO) . I can fully understand why some folks just opt for clip-on lighting. More stealable but no additional cables and independant of the ebike battery (thinking flat battery scenario here).

The little beastly below at around £4 uk pricing, could likely be found a home inside some light fittings.

View attachment 37291
No need for one as the lights for wiring already have an integrated one inside hence the 6v - 60v usage range.

Just noticed vfr also mentioned this in #24, I hadn't read his reply until I browsed the rest if the thread.
 

jimriley

Esteemed Pedelecer
Jun 17, 2020
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384
This output from the controller is very useful. I don't use it for driving lights, but for powering a very loud horn and also as a feed for my voltmeter.

These horns are cheap, but loud enough to get you taken seriously by cars and run up to 60V.

12V versions are available, but they use far higher current.

View attachment 37292
I'm sure I came across a front led up to 60v with horn and switch on my net meanderings.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
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I don't need internet calculators, like you because I understand how it works, so I can do it in my head. They used to call it mental arithmetic. Of course you can only do that if you have the understanding and the mental capacity to multiply by 6.

That's right. the resistor will be fine when it dries out; however, your expensive light won't fare so well when it gets the entire battery voltage across it - should make a nice pop and maybe a bit of fizz too.

BTW, you control LEDs by current, not by voltage. That's why you need driver circuits for them.
You apparently do not understand how high wattage ceramic resistors work either. They are sealed, and can be safely used in many environments!
Another negative!
Thats like saying that a ceramic tea cup would leak tea!!!
A standard carbon resistor might be affected, but not a metal or ceramic....Some heating elements for small heaters, can even be built with such resistors.....though I haven't seen that in the last 40 years myself!

Here are images of resistors that are sealed and totally unaffected by a drop or two of water.....just as I said.
 

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Nealh

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I'm sure I came across a front led up to 60v with horn and switch on my net meanderings.
I have a STVZO one off AliExpress with the integrated horn, they need a Wuxing handlebar switch to operate for on/off and horn. The ones without horn don't need the handlebar switch as they have one on the rear of the light.
 

WheezyRider

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Apr 20, 2020
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I have a STVZO one off AliExpress with the integrated horn, they need a Wuxing handlebar switch to operate for on/off and horn. The ones without horn don't need the handlebar switch as they have one on the rear of the light.
Yes, forgot to mention I use a Wuxing handlebar switch for the horn. I've got one with the horn on its own and another with an integrated light switch.
 

Nealh

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Yes, forgot to mention I use a Wuxing handlebar switch for the horn. I've got one with the horn on its own and another with an integrated light switch.
The light output form the 100lux models are very good and for town night riding is superb.
 

WheezyRider

Esteemed Pedelecer
Apr 20, 2020
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You apparently do not understand how high wattage ceramic resistors work either. They are sealed, and can be safely used in many environments!
Another negative!
Thats like saying that a ceramic tea cup would leak tea!!!
A standard carbon resistor might be affected, but not a metal or ceramic....Some heating elements for small heaters, can even be built with such resistors.....though I haven't seen that in the last 40 years myself!

Here are images of resistors that are sealed and totally unaffected by a drop or two of water.....just as I said.
I think what vfr was getting at is that when it gets wet, if the leads are not well insulated you could get a conducting path along the outside of the resistor.

However, my biggest concern is the amount of heat generated in a small space. It must get quite hot and I wouldn't like to touch it, or brush against it by accident.

Dropping resistors are ok for small indicator LEDs, but for high power lighting LEDs it's not a great solution, when 6 to 60V input bike lights are so readily available at low cost.

BTW Andy, do you think you could find a way of posting that is not so confrontational? Everyone has their own views and opinions, but for a forum to work properly, people need to express their opinions in a way that is not aggressive, confrontational or trying to score points off of others.

We want to encourage as many people as possible to get into e-bikes and if they go on a forum where people are tearing chunks out of each other, it is completely counter productive. Many people (especially women) will be put off posting if they see this kind of behaviour for fear that their posts will be torn apart by others.

There are ways of stating your points without upsetting others. I don't always get it right, but I do my best to try to accommodate the views of others and agree to disagree, rather than cause a pointless escalation.
 

Nealh

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Andy's is like Cloughie, where both parties sit down and dsicuss something then at the end he decides he is right any way. No matter what others say.
Most on the forum post out of experience /knowledge but Andy tends I think to read a lot of nonsense on the web then cuts and pastes links on here for which I have no time for.
 
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jimriley

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Andy's is like Cloughie, where both parties sit down and dsicuss something then at the end he decides he is right any way. No matter what others say.
Most on the forum post out of experience /knowledge but Andy tends I think to read a lot of nonsense on the web then cuts and pastes links on here for which I have no time for.
I reckon its not hard to get the measure of posters when joining a new forum, who knows what, who to pay attention to, who to take with a pinch of salt.
 

Nealh

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I reckon its not hard to get the measure of posters when joining a new forum, who knows what, who to pay attention to, who to take with a pinch of salt.
Some times a pinch of salt is know where near enough.
 
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Bikes4two

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Feb 21, 2020
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I reckon its not hard to get the measure of posters when joining a new forum, who knows what, who to pay attention to, who to take with a pinch of salt.
True enough - I've not been on this forum long and already I am able to sort the wheat from the chaff (or maybe the salt from the vinegar?).

Anyway, back to the original posting - obviously most just use the 'light output' from the controller for ...... lighting:D. So guess what, I think I'll follow the wise and do the same.

AliExpress seems the most likely source (and I've scoured the site a number of times - but you get crossed eyes after a while) but I am a little cautious about which choice of light to go for in that I know that many of the cheap Cree LED lights have a very untidy beam pattern that can be disconcerning/annoying for other road users (and I know this is less of an issue for off-road use).

So if anyone can either give a recommendation or pointer (with links please) to a front light with a decent beam pattern, I'd be very grateful (and I'll not be going for the Busch and Muller type either - I'm a pensioner after all :cool: ).

Getting a decent front light is the first goal and then a good rear red light that will fit snugly on the pannier rack also.

Thanks in advance