Led Wiring

[Biggles]

Can I wire 3 x 12v LED in series and run 36v through them like I could with filament lights?

[Michael Wooding]

The simple answer is yes

 

Mike

[alan_fincher]

Not convinced!

 

These are complex devices with a lot of electronicson board to turn nominal 12v into much lower volts needed by actual device.

 

Probably okay,but wouldn't guarantee it.

[smileypete]

Should be OK if they're all the same, but no guarantees.

 

cheers, Pete.

~smpt~

[nicknorman]

I think if they are the type that can run at up to say 30v, ie have switch mode regulation circuits, there are likely to be problems such as strobing.

 

If they are the type that are designated only 12v, they are likely to have no regulation, or analogue regulation. These should be OK in series.

 

If they are the former type (switch mode regulation) there is nothing to be lost, and probably lots to be gained, by wiring them in parallel provided they are rated up to the max voltage (in your case 36v). If they are not rated up to the max voltage, but you find problems with them in series, you might be able to resolve it by adding largish capacitors across each light so as to smooth the current pulses from the switch mode regulation.

 

But anyway, there is unlikely to be any damage so suck it and see!

[Nickhlx]

If they consume the same current, and each drop approx 12 volts, then 36 Volts across 3 in series will be OK.

 

The problem that may arise is that the regulator circuits may behave unpredictably if they have higher or lower volts applied across each and therefore take differing currents, which in series will have knock on effects to the others and the whole setup may oscillate trying to find "equilibrium" and self destruct in the process

 

One way to find out though .... !!!

 

How is the 36 volts obtained, and is it "regulated", or simply the max volts that might be obtained, worse case, on a 24 volt system equalisation charge ?

 

Nick

[Biggles]

36v? Sorry should have explained, its for the front light on my electric bike (36v) I begrudge keep paying over a fiver for a 36v filament bulb which seem to only last a short while. Not sure if its vibration or what, but they blow very quickly.

 

So my thoughts were observing polarity of the 12v LED's would work the same as filament bulbs.

 

I am only looking to use Linky these.

 

Ta

[smileypete]

They should be fine.

 

What's less likely to work is the MR16 type LED lamps which these days often have a constant current regulator inside.

 

With the latter it might be interesting to try out with cheapo ones, but for a guaranteed result it's best to use a buck regulator, which can be had for buttons off Ebay these days anyway.

 

cheers, Pete.

~smpt~

[nicknorman]

Yes they should be fine because it says they have series resistors. Not terribly efficient but then you have a big battery on the bike!

[trackman]

Now there's an issue! I sympathise with the OP. I have a similar problem on unpowered pushbikes with hub dynamos fitted.

These are nominally 6V systems. Again, the halogen headlights bulbs cost a fiver or so and don't last long.

I'd love to fit LED units but can't find any suitable ones despite some research on line.

Ironically the systems came with LED rear lights as standard, but the ones with front LEDs too cost about 50% more to buy new than those we have! That's to say over £300! For a dynamo and 2 lights!

[ditchcrawler]

Can I wire 3 x 12v LED in series and run 36v through them like I could with filament lights?

I tried this with 2 early 12 volt ones on 24 volts and it worked fine, however when I replaced them with higher powered LED clusters, the first were only I think 7, they worked at first but didn't last long. I think the early ones were just 7 LEDs in series so upping it to 14 and doubling the voltage was OK. The larger clusters were a bit more complex and the individual LEDs rapidly gave up the ghost.