zener diode help

twhitehousescat

polymaff wrote: »

Is this too simple?


If the intent is to have the headlight on if and only if the alternator is running (post #6), either:


1. Connect an similar rectifier arrangement with inputs in parallel with the alternator rectifier's inputs, and with its output connected to the headlight, or,


2. Break the feed from the alternator rectifier to all of the other circuitry, insert a schottky diode in the break, cathode toward the other circuitry then connect a similar schottky diode, anode to the anode of the first schottky diode and cathode to the headlight.


NB This is assuming circuitry as in post #18

NO NO NO , as I tried to point out , both those sketches (post 18) are totally wrong , post 19 shows the actual pic from MY book , MY bike https://forums.moneysavingexpert.com/showpost.php?p=75419021&postcount=19

polymaff

polymaff wrote: »

Is this too simple?


If the intent is to have the headlight on if and only if the alternator is running (post #6), either:


1. Connect an similar rectifier arrangement with inputs in parallel with the alternator rectifier's inputs, and with its output connected to the headlight, or,


2. Break the feed from the alternator rectifier to all of the other circuitry, insert a schottky diode in the break, cathode toward the other circuitry then connect a similar schottky diode, anode to the anode of the first schottky diode and cathode to the headlight.


NB This is assuming circuitry as in post #18

twhitehousescat wrote: »

NO NO NO , as I tried to point out , both those sketches (post 18) are totally wrong , post 19 shows the actual pic from MY book , MY bike https://forums.moneysavingexpert.com/showpost.php?p=75419021&postcount=19

Can't see a lot of difference - why wouldn't my suggestions - particularly #1 - be just as applicable?

techquest

The fact that you have an alternator means that you have plenty of voltage/current about. I would just like to see for myself that we are all talking off of the same page as far as the wiring on the bike goes. So sorry to ask twhitehousecats, what bike is it actually?

twhitehousescat

polymaff wrote: »

Can't see a lot of difference - why wouldn't my suggestions be just as applicable?

1. Connect an similar rectifier arrangement with inputs in parallel with the alternator rectifier's inputs, and with its output connected to the headlight,

umm no thank you , I have ridden bikes that have had h/light powered only from coils on geni , basicly the lights go out at tickover

2. Break the feed from the alternator rectifier to all of the other circuitry,

is that reg /rect , the red wire that carries upto 120w at 12v and run direct to the battery that is the only circuit the reg/rect uses

twhitehousescat

techquest wrote: »

The fact that you have an alternator means that you have plenty of voltage/current about. I would just like to see for myself that we are all talking off of the same page as far as the wiring on the bike goes. So sorry to ask twhitehousecats, what bike is it actually?

the bike is a slightly modified suzuki gn125

this is an older diagram ,




the bike has been modified and now uses a much smaller battery , the wiring now differs a lot from that pic , that dates back to about 1983

polymaff

twhitehousescat wrote: »

the idea us that the h/light will not be on when engine is not running

twhitehousescat wrote: »

umm no thank you , I have ridden bikes that have had h/light powered only from coils on geni , basicly the lights go out at tickover

Can you expand these two into a single rigorous specification? Just what is to be the light's state in engine run, engine idle and engine off and the respective states of any switches that currently affect the light?


You'll only get a competent solution from a competent spec.

twhitehousescat

when a bike runs its lights directly from the alternator , they have 2 sets of coils , when the bike comes to a junction the lights dim badly at tickover and often blow bulbs if over revved , ie missed a gear change

the later bikes that are fuel injection , ie light on all day are wired presumably thru the fuel injection ecu to only light when engine running


Can you expand these two into a single rigorous specification? Just what is to be the light's state in engine run, engine idle and engine off and the respective states of any switches that currently affect the light?


ignition in on position , light switch in on position , NO light until the engine is running , light to work even at tickover , ability o turn light on/off at will with engine running , using switch already fitted, the light is to be left in its state of wiring , which already used a relay to get full power

that

Another idea

if you place a small neon lamp alongside a spark plug cable it glows (pulses).

Get a small neon, put along a spark plug cable, attach a photo resistor so it looks at the neon and wrap it up. When the photo resistor detects a light pulse it will delay a relay from turning on for say 10 seconds (adjust your own time).

https://www.ebay.co.uk/itm/Light-Detect-sensor-12V-photoresistor-relay-module-with-timmer-light-control-MO/152238888895

as that light pulses and the engine revs, will the circuit keep switching off and on? Will a capacitor store enough charge to stop this??

twhitehousescat

umm , that idea sounds (and will look) tacky as in muckin tacky

"Estimated between Mon. 18 Mar. and Fri. 26 Apr."


get me pension before then

techquest

twhitehousescat wrote: »

the bike is a slightly modified suzuki gn125

this is an older diagram ,

the bike has been modified and now uses a much smaller battery , the wiring now differs a lot from that pic , that dates back to about 1983



Thanks for the info, lol had to use my poor excuse for Spanish to find my way around it. So 3 phase alternator 12v output. Is the alternator the original? Sorry but exactly what is your intended use of the light and did you ever give the bulb size?