27W LED on the front

[103Alex1]

OK here's what's rigged up might be easier to see.

The master FET switch off the battery opens the circuit and closes it so I just use that to turn the light on and off.

The only contacts I have that aren't insulated are the BUSbar pins battery side of the DC-DC converter and the soldered wire contacts on the DC-DC converter itself (+ve / -ve IN pair and +ve / -ve OUT pair)

Perhaps best to just put the multimeter pins on either :

+ve in / -ve in

or

+ve out / -ve out on the DC-DC converter ?

So my guess is - assuming that current the light side of the DC-DC will be >200mA so use 10A range on multimeter, put pins on DC-DC out contacts and then open the switch ?

 

[103Alex1]

You measure voltage in paralell, current in series:


Ohm's Law Series-Parallel Circuits Calculation | Electrical Engineering | Learn Electrical Engineering for Beginners

Beyond me for this time of night (maybe after a lot of studying - when not on cocodamols, Mike lol). I kind of think more in terms of "put the pins on the contacts before opening the circuit when you measure current" if that's what's meant by "connecting leads in series" ?

 

[Alan Quay]

pull the crimp off from the fuse box. switch circuit on. connect black test lead to crimp, and red to terminal on fuse box.

 

[103Alex1]

1)i am confused by the drawing, and assuming it represents 1 x 27w lamp and 1 x 36v lamp. I don't understand what the pair of scissors represents (poss switch?), but this wont get you any high/low - just on/off

Yes, the lamps need supply at different input voltages. The scissors is meant to be a handlebar switch with a power in and 3 separate power out leads (only one is shown - tho others will hook up to tail lamp and a CREE).

The switch has 3 output leads :

1 - off on low / on on high

2 - on on low / off on high

3 - on on low / on on high

So there will be other lights on different circuits for the other settings, this is just one of them. The max current supplied through the handlebar switch is 10A and I won't nearly exceed that as it's being su-pplied at 36V.

 

[103Alex1]

pull the crimp off from the fuse box. switch circuit on. connect black test lead to crimp, and red to terminal on fuse box.

I'm getting big sparks doing that on both 10A and 200mA settings. Something isn't right ! ... but the light is coming on and readings are flashing up on the multimeter ... the sparks are considerable though - worried I blow something up lol

 

[Alan Quay]

Should be ok, you have enough fuses. What current are you getting?

 

[103Alex1]

Should be ok, you have enough fuses. What current are you getting?

OK hold on I'll try again ... blinded by the flashes and couldn't see it !

EDIT :- 0.65 on the 10A setting.

That DC-DC is adjustable and I set it to 12V before soldering light contacts on. If I want to try adjusting the voltage can I measure this by putting the multimeter contacts on the out wires going to the light when that is switched on or do I need to desolder the light contacts, adjust and then reattach ?

 

[Alan Quay]

That's 26 watts then. So now, connect back up as normal, and measure volts on the output of the converter. If it was 12v, then turn up to 24v. if it was 24v turn down to 12v. then re-measure current.

!! MAKE SURE YOU PUT THE RED LEAD BACK IN THE RIGHT HAND SOCKET, AND TURN DIAL TO VOLTS BEFORE MEASURING VOLTS !!

 

[Alan Quay]

... do I need to desolder the light contacts, adjust and then reattach ?

No, you can simply 'dab' meter probes across the output of the DC-DC converter while its all powered up to measure voltage.

 

[103Alex1]

OK. Done.

Volts turned up to 23.9V

Current measured is 0.6A

Not a busting lot in it but seems less current drawn at the battery so maybe less efficiency loss in the DC-DC converter setting it higher relative to the input voltage ?

I think there must be a buck converter in the lamp and fixed output with so little difference in current drawn at the battery - does that sound likely ?

Am I right in thinking there will be more current if measured after the DC-DC converter than if measured before it as we've done ? Just thinking about Amps ratings of those converters more than anything - also in terms of other circuits I'm going to rig up ...

Still, 0.6A for a lamp that powerful is pretty blooming great. Thanks a lot for talking me through this btw ... really to get some real readings

 

[Alan Quay]

So it looks like the light unit has a buck converter inside it. At 24v the cable from your DC-DC converter will need to carry just over 1A, and if you run it at 12v, just over 2A. I would run it at 24v in that case.

On second thoughts, run it at 22v. That will give you a little bit of room for drift should it occur.

 

[103Alex1]

Brilliant stuff. Think I'll test the other one too and see what that's taking supplied at 36V and update that thread.

The DC-DC converter is rated for 3A but I'd rather stay well below if possible - less heat I guess and as it's not an external housing box that is my main objective, to keep everything as efficient and cool as I can.

Scimitar .... you might not be successful in rigging up a dimmer switch to this light if it has an internal buck converter. Looks like it's a fixed-output device despite the possible indications to the contrary on the product listing. However you could rig the lights up to a hi/low system that turns them on/off with a lever-pull switch or rocker switch rather than using a dimmer. Or even angle 2 down and have 2 facing ahead, and use an off/low/high switch to bring the dipped 2 on low and all 4 on high.

That switch I got is really nice and very compact. Very flexible output options too for a secondary lighting system. Just wish it hadn't cost as much as one of the effin lights !

 

[Scimitar]

Scimitar .... you might not be successful in rigging up a dimmer switch to this light if it has an internal buck converter. Looks like it's a fixed-output device despite the possible indications to the contrary on the product listing. However you could rig the lights up to a hi/low system that turns them on/off with a lever-pull switch or rocker switch rather than using a dimmer. Or even angle 2 down and have 2 facing ahead, and use an off/low/high switch to bring the dipped 2 on low and all 4 on high.

My application for them is initially on the Suzuki, which has a marginal alternator, so I'll be wiring one each in parallel with hi/lo on the headlamp circuit and replacing the main headlamp bulb with a (fairly useless) H4 LED, just to keep something in there.
When funds and time permit, I'll be doubling them up, as the alternator/charging system can cope happily with a pair of 27Watters plus 8W headlamp plus the normal tail-lamps (which will be LEDs).
For the next time, I'm really tempted by the 48W version of this - but the price is still a bit high ($80 pair), so I'll wait for them to come down.

 

[Scimitar]

Scimitar .... you might not be successful in rigging up a dimmer switch to this light if it has an internal buck converter. Looks like it's a fixed-output device despite the possible indications to the contrary on the product listing. However you could rig the lights up to a hi/low system that turns them on/off with a lever-pull switch or rocker switch rather than using a dimmer. Or even angle 2 down and have 2 facing ahead, and use an off/low/high switch to bring the dipped 2 on low and all 4 on high.

My application for them is initially on the Suzuki, which has a marginal alternator, so I'll be wiring one each in parallel with hi/lo on the headlamp circuit and replacing the main headlamp bulb with a (fairly useless) H4 LED, just to keep something in there.
When funds and time permit, I'll be doubling them up, as the alternator/charging system can cope happily with a pair of 27Watters plus 8W headlamp plus the normal tail-lamps (which will be LEDs).
For the next time, I'm really tempted by the 48W version of this - but the price is still a bit high ($80 pair), so I'll wait for them to come down.

 

[103Alex1]

Another step forward prepping this for wiring up (and the other light that's going on my "HIGH" light setting). I've fitted a Delphi waterproof connector so this large light can be plugged in when bolt-mounted on the front of the bike, without having to open up my triangle box - which would be a pain and likely to result in the light staying in the cupboard more than it should.

When the 27W light isn't fitted I've followed GeeBee's suggestion and adapted a male connector housing by filling in the pin slots with automotive silicone. The connector will stay cable-tied most likely to the underside of the stem head and the 'blanking plug' will keep the connection waterproof when the light isn't mounted on the bike :

2 bullet connectors are fitted on the ends of the light wires that'll be inside my box, for coupling to the power supply. The bullet connectors are easy to insert when the box is built and I can always remove them and hardwire the lights onto the power supply 'Y-connection ... but it might not be a bad thing to have them able to be disconnected from the power supply lead so I'll see how it goes. Stitch in time & all that.

2) Either is good. I would bridge the terminals.

I tried this - unfortunately the BUSBar 4-way pin plates are made from a material that won't allow solder to adhere to it. So guess I'll be splicing the wires !

 

[Alan Quay]

There's no easy way of saying this Alex, and no offence is intended, but I think you need to review your soldering skills an/or equipment.

 

[103Alex1]

There's no easy way of saying this Alex, and no offence is intended, but I think you need to review your soldering skills an/or equipment.

Well, I haven't had any trouble soldering anything else that doesn't involve lucar connectors or contacts. I had exactly the same problem trying to solder Halfords battery connector terminals which ended up being crimped as even the wires would not allow solder to adhere for tinning. Never had that problem with any other equipment wire. Same soldering iron same solder.

It's possible the contact plates need sanding to allow solder to adhere - an electrician friend told me some wire is like that when it's supplied for use in household electrics where all terminals are crimped or screw-terminal.

 

[Alan Quay]

A few tips:
Use flux cored solder.
Ensure iron tip is clean, and suitably sized. About 4mm chisel for this type of thing.
Clean tip while hot with wet sponge to remove slag and clinker.
Ensure parts are free from greasy stuff.
Allow iron to fully heat.
Add solder to tip to aid heat conduction.
Pre heat terminal, then get a good flow of solder onto it. A flow, not a blob.
Tin wires using same method. Again, flow, not blob.
Then, you can solder the two parts together.

All else fails, post it to me and I'll see if I can do it. You might be right, perhaps its not solder-able, but I'd be surprised.

 

[103Alex1]

A few tips:
Use flux cored solder.
Ensure iron tip is clean, and suitably sized. About 4mm chisel for this type of thing.
Clean tip while hot with wet sponge to remove slag and clinker.
Ensure parts are free from greasy stuff.
Allow iron to fully heat.
Add solder to tip to aid heat conduction.
Pre heat terminal, then get a good flow of solder onto it. A flow, not a blob.
Tin wires using same method. Again, flow, not blob.
Then, you can solder the two parts together.

All else fails, post it to me and I'll see if I can do it. You might be right, perhaps its not solder-able, but I'd be surprised.

Pretty much exactly what I was doing, Mike. Perhaps the terminal plates are aluminium or stainless steel - in which case they'd need silver solder (be cheaper just to buy another one !). I doubt it but you never know ... it doesn't say on the product spec.

Have to be careful with those 4-way plates mounted on plastic too.. if they're heated up too much and plastic isn't designed for solder contacts the housing may melt (like it does on some crimp-pin connectors if you try to solder on to the contacts when they're designed for crimp-on ones).

I'm hanging on to this BUSbar for testing various things for a bit, but when the e-bay shop re-opens after Easter I could get one sent to you direct to play around with and see if you can get the contacts to play ball with solder. I'm curious as much as anything else - as it's the 2nd time I've had the same sort of issue with a particular type of contact and solder so be good to understand the why and wherefors.

To be honest, looking at the amps which are being drawn by those lights I think I might just splice the 0v wires near the terminal in the short term and leave a bit of extra wire so they can be easily split and a connector fitted on each one for final fix. It'll be at least 10 days or more everything's ready to close up.

 

[103Alex1]

Pics, pics, pics.

This is the light run at between 22 & 24V :

You're not going to miss much with that on. It's not so intense in the near distance as a 3-CREE with wide-angle, but is much clearer in the intermediate distance. It's very hard to pick up on a camera. It's also a lot bigger, but nowhere near as 'blinding/dazzling' as a 3-CREE.

The huge bonus with this light is the ability to flick it on and off from a handlebar switch. If you're out on dark lanes and a car comes into view, you just kill it by switching down to your main bicycle lights until you've passed each other, and then flick it back on again. Tried it using the switch as a control and it's dead easy - will really work a treat and exactly what I was after.