Wiring in a spot - full AC loom

[dansuper]

Hi all,

I have a Lucas sealed beam spot that I want to wire in using my current elec. set up. Not sure of the wattage of spot.

I'm running full AC with the BGM 120 watt stator and AC/DC regulator/rectifier.

I'd like to keep things pretty simple - ideally, to mount it in line with the headlamp and just isolate it with an on/off toggle. My knowledge of electrics is s**t, but I am assuming it is better or safer to use a relay... or something?

Cheers,

Dan.

[Minority]

Don't think you can get 12v AC relays?

[coaster]

Don't think you can get 12v AC relays?

Even if you could (you can't), there isn't enough power to operate a spot (assuming you want it to be useful) at the same time as the headlight using either the SIL or the BGM stator. If you want to operate a spot in order to improve your lighting, the way to do it is to convert your stator to DC by making a simple mod to it and then using a Wassel single phase rectifier/regulator to convert the stator out put to DC. You then a battery from a house alarm (cheap off ebay) wired in parallel to the feed from the Wassel unit and change the rear lamp to an LED type. The spot could then be wired to operate from the high beam feed via a relay and an isolating switch. It is important to remember though, that the stator still won't generate enough power to operate the headlamp AND the spot light. However, you will be charging the battery when the spot isn't in use and the stored charge will supplement the stator feed to give sufficient power to operate them both but only for brief periods. In practice, this works quite well as you generally don't stay on full beam for very long in any journey. I have 2 35 watt spots on my Jet and a 7.2 Amp per hour battery has held up easily on cross country journeys of an hour or so. In theory, it SHOULD last for around 4 hours (55/60 H4 headlight+ 2 x 35 watt spots = 130 watts = 10.8amps). If you use the spot a lot, the electrics might not re-charge the battery quickly enough for your usage so topping it up from a mains charger from time to time might be necessary.

Do a search on here for Wassel DC conversion and you should find the excellent wiring diagram posted by Byron

[dansuper]

Thanks Coaster - I've been avoiding the reality of the DC conversion for a while now. Will bite the bullet and do it!

[camel]

just charge a sealed alarm battery from your BGM regulator dc output and just wire in the spot for that...keep all your other lights ac...

[Donnie]

It is important to remember though, that the stator still won't generate enough power to operate the headlamp AND the spot light.

Hang on a minute, as Im thinking about this for over the winter as I currently run an ac setup but powering a battery to use the front spotlight.

Will a wassel conversion actually improve the lighting overall? I mean if you take the spots etc out of the equation completely.

What's the difference in the front headlight only between a normal AC system and a 12v DC Wassel converted system?

[coaster]

It's a misconception that the DC system has more power, in fact it produces slightly less due to losses in the rectification process . The benefit of going full DC (providing a battery is fitted) is that the battery will even out the supply to the lights so they remain bright even at low speeds. The supply to the main light as well as brake lights and indicators (if fitted) is also maintained if the engine cuts out which is a major safety benefit in my book. Led rear lamps also work better with DC supplies.

The other option of having AC lights and a small rectifier to charge the battery would only do if you didn't intend to use the spot very often as it will only give a trickle charge at best.

The best way of improving the headlight in my view is going for an H4 headlight conversion an fitting a 55/60 watt Xenon lamp.

[coaster]

A better way to explain the DC advantage:
If the mains water pressure in a house is low, the bath is fed from a holding tank in the loft. Water slowly fills the tank so that when you need to run a bath, it is delivered at a far greater pressure. Depending on the size of the tank you might get one or two baths before the tank is empty. You will then have to wait until the tank has sufficient water in it before the bath ca be used again. AC is like only ever being able to fill the bath slowly.

[Donnie]

Good stuff, I was a bit unsure if going full dc would be better lighting if you took the battery out of the equation.

I've decided to make a start going through my current system given i have a battery running of a regulator on a trickle charge for the rear brake light, horn and a spotlight but really want a better front headlight too (main reason originally for fitting a spot)

The spots great for short runs but after 45 mins it's notically dim, so only really a stop gap measure to be honest.

[soulsurfer]

Good stuff, I was a bit unsure if going full dc would be better lighting if you took the battery out of the equation.

I've decided to make a start going through my current system given i have a battery running of a regulator on a trickle charge for the rear brake light, horn and a spotlight but really want a better front headlight too (main reason originally for fitting a spot)

The spots great for short runs but after 45 mins it's notically dim, so only really a stop gap measure to be honest.

Without battery, there is still an improvement in lighting, I guess it's more stable or something, but mine was noticeably brighter on tick over too.