zener diode help

coffeehound

is this just for daylight running? Wouldn’t want something this flakey for nighttime running. To stop it dropping out at junctions you’d need to know the generator output at tickover and calculate for that. Might be worth asking on the motoring board where the guys understand this stuff

Heedtheadvice

I must be tired as wrote a long reply sith lots of concerns over tbe design.....and then lost my post!


Some ably summed up by coffeehound!


Suggest much more design thought before proceeding. I cannot see how your guy's design, as presented would work!!

DoaM

You could fit an electrolytic capacitor in parallel with the zener diode to help smooth the DC voltage.

twhitehousescat

Heedtheadvice wrote: »

I must be tired as wrote a long reply sith lots of concerns over tbe design.....and then lost my post!


Some ably summed up by coffeehound!


Suggest much more design thought before proceeding. I cannot see how your guy's design, as presented would work!!

there are no other points on the running engine that would give a supply , YES there is in excess of 12v ac at a very low tickover

flakey? modern designs of the engine use a tap from the ECU , however mine is carb

triumphs and many others use a feed from the oil light , light out enegises relay , no oil light on mine

what i suspect a few readers have not noted is that a bike alternator (permanent magnet) is wired somewhat different to a car alternator

twhitehousescat

DoaM wrote: »

You could fit an electrolytic capacitor in parallel with the zener diode to help smooth the DC voltage.

thanks , that was a thought , however it would leave light active / ign off until it was exhausted , as posted above , there IS 12v ac (plus) at tickover

twhitehousescat

thanks , both of your pics differ to the simple system used on this bike

the bike uses 3 sets of coils , each coil has a lead , then 3 inputs to the reg /rect , and 2 out (+ and earth )

this is probably the easiest pic to describe it , the output (+) is connected to the battery , I like the guy that made the suggestion to me am simply going to tap into one of the yellow wires

the picture says regulator , but it is actually a combination regulator/rectifier

that

my pics have three sets of coils too.

the actual circuit is powered by the battery, not the alternator. There are three rotor coils, and one stator coils which supplies the power. To limit, or control the power to the battery the voltage across the statator is varied so that you get a regulated output from the generator.

I change a picture on the last link above too

How many watts is this light (because a alternator and generator can only generate so much). Cant you just put a switch on it like the other lights, or do you want to incorporate it into a current lighting switch?

twhitehousescat

ok , your systems differ to the one that is used on my bike , my pic is ACTUALLY from my book , my system has a combo reg/rect and no warning light

I think for other people that might want to comment , MY circit is the one we want to go off

as stated at post one or shortly after , I wish to tap off from one wire coming from the coils , this coil will be giving 12-35? v AC , and wish to build a simple circuit , that will allow a small 12v DC relay to be tripped when it senses ac voltage

twhitehousescat

that wrote: »

my pics have three sets of coils too.

the actual circuit is powered by the battery, not the alternator. There are three rotor coils, and one stator coils which supplies the power. To limit, or control the power to the battery the voltage across the statator is varied so that you get a regulated output from the generator.

I change a picture on the last link above too

How many watts is this light (because a alternator and generator can only generate so much). Cant you just put a switch on it like the other lights, or do you want to incorporate it into a current lighting switch?

I wish to trigger a 12v DC relay that will take power from the battery and feed my h/light switch , the only "currant" is what is needed for the RELAY COIL to trip

the battery on this bike is very small (4ah) , no, a bigger one cannot be fitted , the headlight will run all day and night with the engine running , BUT if the h/light is left on by accident then there is not enough cranking power for the starter

so a simple solution is needed

that

So when the bike is not running you want the light out? I am assuming the ignition will be off? OK, how about putting a relay across the ignition switch so that soon as the key is remove the relay trips? You then do not need the fag packet circuit either then

https://www.ebay.co.uk/itm/Micro-Relay-4-PIN-12v-20a-Diode-Normally-Open-Mini-20-amp-CAR-VAN-MARINE-MRY3/122534235358


there is a picture above which does not show for me, not sure if it is there or not
https://imgur.com/a/H5Mfqfg