Hitchcocks Forum

old ts 185 , 2 sets of coils ,both are earthed , so only 2 x (unconnected) wires emerging, no 1 runs thru a simple diode* and trickle charges a small battery for stop light and horn. it is only a trickle

* simple diode is just that , just a single diode.

No 2 coil (higher power,,,,,,,joke?) runs thru a 6v AC regulator , and feeds h/lamp. (25w!!!!!!!)

what would happen:

change light switch to a 2 pole on/off , contacts 1 turn on light fed from battery

contacts 2 , to join output of AC regulated (6v) thru a simple rectifier to the battery

the h/light dims a lot (now) and rizes with increase of revs however connecting to the battery would create a steady light.

tech question:

regulating 6v AC to DC would give an increase in voltage (x 1.16 I thought I read?) this would supply maybe 7v to the battery , which would be ok?

If I can solve the rectifyers , can anyone see any problems ?

I take it that you want to change the bike from AC to DC. It can be done. Let's face it, you could buy BSA D7 Bantams in AC or DC flavor, so it has to be possible. However, without a full wiring diagram of your bike, it's a bit tricky trying to suggest a starting point. Another problem is that the two AC coils you have appear to have different outputs. The Lighting coil appears to be 30W (25W for the headlamp. 5W for the tail lamp). I've no idea of the rating of the other coil. I reckon it's 18W, but that's a guess. It sounds like you want to chuck everything into the battery and then run the lights from that. It's easy enough to add a diode from the lighting coil and run it to the battery, but this circuit needs to be switched (or you'll fry the battery). As said, I'd need a wiring diagram to figure out the circuit.

thanks barry , yup you have got it ,I have a wiring diagram , the AC regulator is a single wire device that "dumps excess to deck),, like a zenner , I will ditch it. The light switch is easy to fabricate (2 pole on/off) the original charging diode was damaged , its no more than a single IN400? , however I have used a MUR820 (8 amp)

or would you keep the ac regulator (to stop runaway) and then rectify it?

Hi Alan, it sounds like it will work, I think you would need to either get a 6v rec/reg or install the A/C reg after the new rectifier so that you convert it back to D/C before you can regulate it, but I'm not sure if the A/C reg would work on D/C but probably not. I'm also not into 6 volt availabillity because out here it is virtually non existant

Alan,
Another thing I keep an eye on a Honda Monkey bike forum and they have kits to convert them from 6 volt to 12 volt, not sure if this would help at all.

cheers norm , the coils are grounded to earth at one end , so a 4 wire reg/rect cannot be used ,

here is a sketch of the charging circit http://i39.tinypic.com/dcuan9.jpg the rectification is just an overgrown diode

Hi Alan, I'm wondering if you ran the wire from each coil to a the input wires on a rec/reg the other rec/reg wires to each side of the battery. That is pretty much how the Bullet system works, 6 coils in the stator giving you 2 sets of 3 charging coils

hi norm , sorry late getting back to you. the coils are not a set of 6 , like a brit/indian bike , they are 2 x small coils inside the magnet flywheel , think early bsa bantam / lambretta etc they are about 2in long and about 3/4 in square , with a bolt hole either end to bolt them down , lifting and joining (insulating) the earth wires would do as you say , but they are different capacities and impedence

Hi Alan, I know the coils you are talking about but it is the same with the Bullet using the 4 wire stator, one set of coils has a greater output than the other, depending on which way you wire it up. Are you able to get an A/C output reading from each coil?

yes norm , but only between the engine casing and a single coil wire , the bullet is totally insulated from ground with 2 wires per coil , this bike is earthed on one end of each coil , therefore you cannot use a 4 wire reg/rect