Lighting coil issue, help me please

[bogan]

wait a sec, this is not an electric start batteryas i first thort is it? and is this a complete different wiring set from the ignition stuff?

[Starky307]

wait a sec, this is not an electric start batteryas i first thort is it? and is this a complete different wiring set from the ignition stuff?

Complete system I have built from bike specific parts.

My bike is a MX bike that I brought a stator and reg/rec for.

It had no wiring diagram for the reg/rec so I made my own wanting to have an automatic headlight/tailight.

[Starky307]

That description is infeasible. You have an error somewhere.

Uh huh.

I think either the diagram you have drawn is not what you actually have, or else you have a fault in the circuit. Give all the connections the yank test and see if they fail.

You are on the right track though. What you have drawn should work.

Steve

B-A represents the voltage that is up and above that of the battery when the bike runs. If the bike is idling the bat = 12.5 and B to A = 0 when the bike is half rev or greater the battery voltage is 13.2 (+/- 0.3) and B to A = 1.3 or slightly more.

I have tried and tested all connections again.

The wiring diagram i have provided is exactly as it is wired on the bike, me and my Father have checked it again and again.

[CookMySock]

B-A represents the voltage that is up and above that of the battery when the bike runs. If the bike is idling the bat = 12.5 and B to A = 0 when the bike is half rev or greater the battery voltage is 13.2 (+/- 0.3) and B to A = 1.3 or slightly more.

Impossible! The only way that can happen, is if the battery, diode, and relay coil is wired in series. The measurements you show, and the way the circuit is behaving, all lead to an error in the relay wiring. Your diagram shows it wired in parallel, which is correct. You have something wired incorrectly.

The wiring diagram i have provided is exactly as it is wired on the bike, me and my Father have checked it again and again.

If it were me, I would pull it all off and start again. Wire up the rectifier/regulator and the diode to the battery, and test that its working. Leave the headlight circuit completely disconnected for now. Add the relay coil and don't do anything else until this is working.

With the diode there, does it not occur to you that you can simply attach the wire to the headlight between the rectifier/regulator and the diode? No relay is required.

Steve

[bogan]

Impossible! The only way that can happen, is if the battery, diode, and relay coil is wired in series. The measurements you show, and the way the circuit is behaving, all lead to an error in the relay wiring. Your diagram shows it wired in parallel, which is correct. You have something wired incorrectly.

I think hes got a half ac waveform coming out of the rectifier, which is probably doing funny things with the relays coil inductance.

Why dont you just get rid of the battery, add a cap across the rectifier and connect the headlight to that? no need for relays etc, the headlight will only go when ur riding.

[CookMySock]

I think hes got a half ac waveform coming out of the rectifier, which is probably doing funny things with the relays coil inductance.

I assumed a full-wave rectifier. Yeah, maybe.

Why dont you just get rid of the battery, add a cap across the rectifier and connect the headlight to that? no need for relays etc, the headlight will only go when ur riding.

What he has drawn should be working though.

Steve

[Starky307]

I think hes got a half ac waveform coming out of the rectifier, which is probably doing funny things with the relays coil inductance.

Why dont you just get rid of the battery, add a cap across the rectifier and connect the headlight to that? no need for relays etc, the headlight will only go when ur riding.

I would love to do this but I don't know what size capacitor to use, any ideas how to size it up?

[Starky307]

Impossible! The only way that can happen, is if the battery, diode, and relay coil is wired in series. The measurements you show, and the way the circuit is behaving, all lead to an error in the relay wiring. Your diagram shows it wired in parallel, which is correct. You have something wired incorrectly.



If it were me, I would pull it all off and start again. Wire up the rectifier/regulator and the diode to the battery, and test that its working. Leave the headlight circuit completely disconnected for now. Add the relay coil and don't do anything else until this is working.

With the diode there, does it not occur to you that you can simply attach the wire to the headlight between the rectifier/regulator and the diode? No relay is required.

Steve

I've pulled it apart twice so I'm onto my third try now.

I'm sure I tried putting the lights in between the reg/rec and the diode but nothing happened.

I'll try that tomorrow.

It must be a half wave rectifier as that would be the reason for needing either a capacitor or a battery to make up the short fall and keep the lights bright.

[CookMySock]

It must be a half wave rectifier as that would be the reason for needing either a capacitor or a battery to make up the short fall and keep the lights bright.

Well I don't really follow that logic.

Don't know, sorry bro. Beats me why that doesn't go.

Steve

[Starky307]

Well I don't really follow that logic.

Don't know, sorry bro. Beats me why that doesn't go.

Steve

Have a read through this link about half wave rectifiers.

I'm off to go shopping for capacitors.

[bogan]

I would love to do this but I don't know what size capacitor to use, any ideas how to size it up?

hmm, would depend on how many pole the stator is, and whether its a full wave or half wave rectifier, and rpm, safest just to go buy a big one and see how it goes. If that doesnt work i can probly work it out on monday, away from my comp atm and on dial up so cant do now

[davereid]

The circuit you have described should work perfectly without the need for a capacitor, as a relay will cheerfully pull-in on rectified AC.

Its very unlikely that your rectifier is half wave unless it is broken !

My guess is a wiring error across the coil.

If you are using a standard automotive relay, (as stupid as it seems) the coil is not always in a "standard" place.

What is the coil on one relay, may well be the contacts on another !

Your coil will have a resistance of around 70 ohms. Look for this as your starting point.

Good Luck !

[Starky307]

The circuit you have described should work perfectly without the need for a capacitor, as a relay will cheerfully pull-in on rectified AC.

Its very unlikely that your rectifier is half wave unless it is broken !

My guess is a wiring error across the coil.

If you are using a standard automotive relay, (as stupid as it seems) the coil is not always in a "standard" place.

What is the coil on one relay, may well be the contacts on another !

Your coil will have a resistance of around 70 ohms. Look for this as your starting point.

Good Luck !

No wiring errors, I can guaranty that.

There is something going on real funny like.

I undid it all again and started at the beginning, again.

Wired the output of the reg/rec straight to the battery and put the multi meter on the battery. With the bike not running it was reading 12.56vdc, with the motor running it would go up to 14.4vdc at high rpm.

This shows the reg/rec is working fine.

Next I put the diode back in between the output of the reg/rec and the battery, once again at the battery there is an increase in voltage with the motor running but there is nothing showing on the meter if I go between the negitive connection and the reg/rec positive output (before the diode).

I really need an oscilloscope to see what is happening.

P.S I tried the capacitors but I could on get 35v 2200microF and they didn't work, if i charged them on the battery they would pull the relay in for a sec or so.

In the end I've fitted the ac regulator I got as well and have the headlight running off that, for the L.E.D taillight I built my own rectifier using 4 diodes and it all goes now, no battery needed. The only problem is the lights are dim at idle, I get I'll have to live with that for now.

Thanks for all your help guys, I've blinged you all.

[davereid]

Wired the output of the reg/rec straight to the battery and put the multi meter on the battery. With the bike not running it was reading 12.56vdc, with the motor running it would go up to 14.4vdc at high rpm.

This shows the reg/rec is working fine.

Next I put the diode back in between the output of the reg/rec and the battery, once again at the battery there is an increase in voltage with the motor running but there is nothing showing on the meter if I go between the negitive connection and the reg/rec positive output (before the diode).

You are saying that

a)..you have the neg of your meter on the battery neg
b).. on the battery side of the single diode you have 12.5 to 14.5 volts depending on RPM
c).. on the other side of the diode you get no reading on you meter, and all you have moved is the positive meter lead.

Pretty clearly this is not possible, unless the meter is being mislead ! An old analog meter would be handy here, it could be that your digital meter is unable to make a good a/d conversion on the rectified AC at the regulator output.

But it still doesn't show why the relay will pull in when connected from battery neg to battery pos, yet it wont pull in when connetec from battery neg to rectifier output.

This is only possible if the point you are placing the negative of the relay is changing, or one of your negative wires is crook.

[bogan]

this is extremely perplexing. You have tried hooking up another 12v source in place of the rectifier, this makes the circuit function as you want it too right?
Therefor there has to be some sort of problem with the stator/rectifier side of things, which there shouldn't be as it is charging the battery. All i can think of is that for some reason the stator isnt generating enough current, but this seems unlikely, do you have part numbers/tech specs for the stator and rectiier components?