Solid HT white wire data

[duivendyk]

Buck pucks can certainly be useful,they put out a programmable current,but if you had multiple LED loads with different current requirements you would need one for each I would think.Of course if you had a number of similar devices,that is with similar current requirements you could string them in series from one until you run out of voltage.I'm not sure if it can put out a higher output voltage than the supply voltage.It's not exactly cheap either around $20 I think.Is there anyone who has had experience using one ?

 

[etacovda]

if you're talking about the AMM - it blew the fuse + looks like its killed a resistor in series with it. I'll try replacing the fuse and see how it get on, accidentally switched it to reading current directly across the battery terminals... doh! resistor is a wierd one as well, 0.85 ohms if i am reading the stripes correctly - but i am not getting continuity across it with a resistance reading from another meter, so i think its nuked.

 

[impression]

just a quick question, i've heard of people running lights straight off the white wire, just a bulb.

is it possible to run LED type lights/bubs straight off the white wire ?

 

[duivendyk]

No, not safely, the white wire puts out short ac pulses,-15-20V negative and + 6-8 V positive,LED's usually cannot stand more than few Volt negative, due to zener breakdown,so a series diode(cathode,band to WW,anode (pos) to LED) would be needed to get rid of the positive part of the pulse.The LED would need to have its anode at ground and the diode to the cathode (neg).
They also start drawing lots of current with increase in voltage above a threshold voltage, typically 3-4 V.(when they start to light up).Without limiting the current with a series resistor, they would burn up at higher voltages.I don't know really how they would fare with short high voltage pulses. You can string a number of them in series to handle higher inputs,lets say 4 or so (of the same kind).Sticking a sizable cap,500mF or higher to ground after the series diode and putting a series dropping resistor between it and the LED'(s) would reduce the peak current and the 'flicker' effect at low speed.LED's happen to turn off in a fraction of a microsecond.A big storage cap would provide a steadier dc voltage and reduce this.The size of the resistor would depend on the type,number&current rating of the LED's,start out with 500 Ohm or so and measure current.The anode (pos) of the LED's would have to at ground,(Ammeter between resistor and input (neg) of LED's).Have you lost your appetite for charging batteries?

 

[impression]

duivendyk I just want a simple diagram where i can wire up a circuit to charge my battery and then run 'whatever' from the battery

it took my about 10 mins to understand the wall of text you posted, i can only take in so much at a time without pictures to help sorry about that, i know its hard to explain things.

my last post, i was just curious about the led's vs bulb difference.

 

[duivendyk]

OK I'll try, you mean the 3.6 V battery in your torch or what, a 6 or 12V battery?.

 

[impression]

i think 12v battery will be best as from there i can use auto parts without having to step down or up any voltages from the battery

 

[MurraySabrePlus]

LOL

 

[duivendyk]

Hi Imp,do you understand that you cannot run an LED directly from 12V batteries,they individually run at 3-4 V typically,so you either have to stack up a number of them in series, say 3 for instance which would get you up to 10.5 V (3x3.5),leaving voltage room for a series current stabilizing resistor,or you have to use a voltage to current convertor interface device like the 'Buck Puck' which is designed to provide a fixed but controllable current.
As I have tried to explain to you before, LED's like to be driven from a constant current, source.If you run them from a voltage source like a battery it should be have a particular voltage and a stable one suitable for the LED in question.If you had an LED for 3.5V for instance and jacked up the voltage to 4.5V or higher, the current (and the light output) would go way up and you would probably destroy it.If you had let's say the 3 LED combination (of identical devices) you could run it from a 12V battery and use a series dropping resistor to set the current with.
There may be LED tail or headlights around that can be run directly from 12V.Look into what is around in A.Delve into Forum archives,Sir Jakesus is in the know, I am not an expert on what devices are around.I can give you the info &schematics to build your 12V battery charger,I will provide for the simplest overcharge prevention (an LED indicator ) that would tell you to, either stop charging or turn your lights on,the more sophisticated ones are simply too complicated for you to successfully put together I'm afraid,but you have to think things through on the output side,I can't be of much help there.

 

[impression]

Sounds good, I shall buy new lights that run directly off the 12volt battery