AC/DC Headlamp switch needed

[stinkwheel]

Not sure if this will be possible.

I'm looking for a neat, ideally one-piece headlamp switch for a bike with an AC/DC lighting system.

The side and tail lights are DC from the battery. The main headlight is direct single-phase AC from the alternator with an AC regulator.

So, there is an AC and DC input.

In the "side" position, the DC is connected to the side and tail lights.

In the "ON" position, the DC is connected to the tail light only. The AC is connected to an AC regulator and to the dip switch.

The Dip switch then toggles the AC output to either Headlamp or full beam.

The output to the AC regulator has to come off after the "on" switch but before the "dip" switch, if it was beyond the dip switch, both filaments would come on at the same time but it can't be powered up unless the headlamps are on.

Just to make it more difficult, I'd rather it didn't have an indicator switch but this isn't a deal breaker. Again, I'd rather the sidelights went off when the headlight goes on but again, not a deal breaker.

Wow, complicated huh?

Visual representation below.

https://www.bikechatforums.com/download.php?id=102891

https://www.bikechatforums.com/download.php?id=102890
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Meatybeaty]

Would this adapt, cheap and cheerful Chinese
https://www.ebay.co.uk/itm/7-8-22mm-LED-Motorcycle-Handlebar-Mount-Switch-Headlight-Hazard-Brake-ON-OFF/174052980962

[stinkwheel]

[Easy-X]

Does it need to look good? If yes then your choices are minimal. If "standard" Chinese copies aren't a problem then there's plenty of this sort of thing:

https://i.ebayimg.com/images/g/ogwAAOSw3w9c4mSt/s-l500.jpg

Order a few different ones and either they work or maybe possible to dismantle and rejig the wiring.
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Robby]

Have you considered upgrading the wiring to 1980 spec and junking the AC stuff?

[jaffa90]

Plenty of copies,
https://www.cometarestauraciones.com/producto.cgi?num=3253
Any good at Spanish?

[Easy-X]

[stinkwheel]

[Nobby the Bastard]

[steve the grease]

Stuff like old honda Xl250's had AC headlight too, switchgear 100% reliable too, but probably not cheap?

[stinkwheel]

[Nobby the Bastard]

How about making the sidelights AC as well and do away with the DC side of the light switch?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[WD Forte]

It's counterproductive IMO
It sounds like you're trying to maintain an old inefficient system wasting limited power which will give
dubious lighting at best.
Nowadays simple circuitry and leds will allow you to use that power more efficiently
and get a better, more reliable, light output.
____________________
bikers smell of wee

[stinkwheel]

[Easy-X]

The minimum I'd expect on a "modern" bike might be:

Ignition off: no lights
Ignition on, engine off: sidelights + tail light from DC/battery (but with no separate switch, "always on")
Ignition on, engine on: switchable headlight + hi/lo beam, brake light - both from AC

For simplicity I'd consider running all the lighting bar the headlight from the DC - the brake light only being active occasionally.

IMO trying to shut off the sidelights when the headlight is active is a) a lot of bother and b) counterproductive: what happens if you stall? Headlight goes out and you have no sidelights until you switch the headlight off!

For minimalism you could have a multi position ignition switch (off, on, on+lights) and just a hi/lo toggle on the handlebars.
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

I'm an idiot!

The solution is relays. Two of them. The side light/tail light can be wired in standard fashion. The usual DC headlight outputs can be used to trigger a SPNO relay which is switching the AC. That feeds the AC regulator and a second, changeover relay. The changeover normally feeds the headlight and feeds high beam when switched by the high beam supply (can even use an LED high beam tell-tale then).

Also reduces the load on the switch because the main bulk of the lighting current is going through a relay. Less and thicker wiring between the alternator and the lights and no weedy little contacts. It will probably also get rid of the momentary period of darkenss when going from Hi to lo beam.

So I can use pretty much any standard switch, just need to find one that looks good! Ideally one with all the lights and the horn control on one cluster but no flashers.

Might go C90 again because the choke lever is perfectly capable of working the decompressor.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

One relay.

One switch position does dc side.
Other position does dc side and relay that powers ac side.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Nobby the Bastard]

One relay. The second relay (dip/mwin) will light up the bulb on the off side whether or not the first is fired.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[stinkwheel]

Needs two so it can feed the AC regulator regardless of dip/beam position. That feed would come off the output of the SPNO before it feeds into the changeover.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

Don't blame me when you can't turn off the light....
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[stinkwheel]

[Nobby the Bastard]

'to AC reg' is bypassing 'AC in'

It would be easier if you have the diped and main on a seperate switch like a modern bike.

Edit: your diagram is ignoring the connectons made at earlier positions on the switch, yes 2 relay works.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Nobby the Bastard]

On turns on side, and Hi turns on and side on as well
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[stinkwheel]

[stinkwheel]

Wrong relays. 2x DPST would do it.

https://www.bikechatforums.com/download.php?id=102896

A C90 light switch has separate outputs for the tail/instrument lights and the side lights as well as the main and dip.

I also attached an original wiring diagram for the bike. I didn't before because it doesn't show you the switch outputs anyway. I checked them with a meter and the connection to the AC regulator from the switch is via the dip switch. It's always connected to either the main or dip output (but never both together).

The OEM switch works but it's shite quality and has indicators too.

Yes, seperate switches would be easier but one of the things I'm trying to do is make room for a decent valve lifter lever as well as the light switches, choke lever, throttle assembly, clutch lever and brake lever. I'm running out of space and ditching a switch cluster would make that space.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.