Tomos electrical: a55 regulator and charging circuit

I'm working on this bike, i've got a single tapped (non electric start) 12v 80w tomos stator, hooked up to the 4 pin reg/rec out of a late model 2008 ish revival.

tomoscdi12vdc.jpg

Based on this Regulator :

https://myronsmopeds.com/wp-content/uploads/2008/04/Tomos-Wiring-2008-11+-Revival-TS-100dpi.jpg

I breadboarded this last night using alligator clips and everything was hunky-dory, i had good light (looked to be regulating) on the LED headlight, and when i switched it backwards no light (polarity correct) so i sat down and made a super nice, tucked and wrapped wiring harness.

When i went to start it up the headlight was flickering, the tail lights were too bright, and after a couple seconds of runnign it blew the tail and brake light and now the LED headlight is just flashing.

I think i might have put too much draw on the Rectifier side of the unit, like maybe it can't handle full bore current into the center tapped 'dc' input? maybe it cant handle 12 or 6v x whatever current blows bulbs on the DC out? Maybe the reg/rec is fine and i'm a dummy?

Anyone mess with these? does this make sense? I was hoping using a known good r/r made in italy not china this thing would just fire up and work perfecto but maybe i'm using it wrong.

I'm having a really hard time finding any pure DC reg/rec units that aren't made for a floated ground. The only ones i find are this same center tapped coil style which makes me think maybe there is a reason and they can't handle the current on the 'battery' side. Maybe i should just take the 'floated ground' and ground one of the ac sides and send it? (edited)

Re: Help needed: tomos electrical nerds

Totally normal JBOT /

You need to make yourself a choke to reduce the spikes.

Sneak into your wife's sewing room and grab a plastic bobbin and wrap the wire around it as much as you can and then rent a couple small zip ties to hold it all together.

The way it works is as the voltage Spike hits the winding with parallel wire some of the voltage i Spike will bleed through the insulation and jump onto the parallel wire making the spike longer and with less of a peak.

This will make it easier for your voltage regulator is if the peak is too erratic the voltage regulator spins its time just turning off and by the time it turns on it tries to turn off again and sometimes will actually make the spike worse

Re: Help needed: tomos electrical nerds

Totally normal JBOT /

I was looking over your wiring diagram I don't see a rectifier in there before the regulator.

So I would run both wires to a rectifier and between the rectifier and the regulator I would make a couple of small chokes you can actually do like an infinity wrap and have them go to each other the ground and the positive like interlocking chain links of donuts.

This will smooth out the spikes and help your regulator do its job.

Chances are you burned out that regulator because it was receiving an ac voltage

Re: Help needed: tomos electrical nerds

Alright, so a few things. First, if you're breadboarding up a unit, you are introducing a whole bunch of stray capacitance that won't be in your wiring harness. When using LED lights, you may need to add a little output capacitance (20 uF or so) for stability. I'm not sure if this is necessary with this particular unit, but it is a thing I have run into before with other rec/reg units and LED lights. A battery would also work.

You're using the 230844 unit, yeah? The labeling on this unit is super dumb. Reading the wiring diagram I get:

AC: Coil input

GND: frame "ground"

DC: Coil input

+B: DC output

I haven't been able to find any specs on the DC output power rating.

You shouldn't leave the yellow wire floating; it needs to complete the input circuit. Connect it to frame "ground" as that is the reference for your lighting coils.

Re: Help needed: tomos electrical nerds

I'm surprised to see a recommendation for chokes; they are typically only useful in the 10s of MHz and above frequency rage.

Re: Help needed: tomos electrical nerds

Yeah a capacitor is probably better for this application than a choke

Re: Help needed: tomos electrical nerds

🇮🇹💦 Of the Loin /

What is going on with this setup? How is DC and AC coming out of the same coil on the magneto?

I'm pretty sure I'm not reading the diagram wrong.

Plz explain what comes out of the stator, If it truly is center tapped, that likely means the "reg/rec" is probably little more than a zener diode and a capacitor and it's designed to send pulsed DC to a SLA battery

Re: Help needed: tomos electrical nerds

haha yeah, a choke isn't going to make much difference, also i'm the one that does the sewing in my family thank you very much.

I'm using a really high end LED headlight unit that has lots of nice capacitors and shit, but i've also got supercapacitors i bought for a project, i was thinking about hooking them up just to keep the lights on but it might be good to have it in just to keep things happy. This is like a really fancy headlight so i'm assuming the 'flashing' is just it responding to some weird frequency shit.

when i had it breadboarded i didn't ground the case of the reg/rec, so that was another thing i was thinking about?

so, should i tie the yellow to the ground or should i tie the yellow to the input tap? I got into a different scooter reg/rec similar to this (designed for a center tap coil) and i remember having to fuck with that, i think i ended up with both of the inputs coming off a single tap coil. I don't know enough about the inner workings on this thing to know whether it makes any difference for 'yellow' (i'm assuming higher voltage AC in .... more turns) vs 'white' which i'm assuming is the lower voltage AC in being fewer turns?

i have a tomos battery stator on another bike i could actually measure the coil resistances of yellow/silver vs redwhite/white and see.

Re: Help needed: tomos electrical nerds

yeah maitland, if its not clear from my previous post, its a double tapped coil with a yellow and red/white output, similar to the way a lot of scooters are set up, the headlight coil typically has the higher output so the 'DC' stage of the reg isn't just sitting there getting melted with your big halogen headlight.

i'm running a lower draw LED but its still 25W max power rated, so without a battery on the back side of that 'red' dc+out, i might have chooched it.

Re: Help needed: tomos electrical nerds

> 🇮🇹💦 Of the Loin Wrote:

> -------------------------------------------------------

> What is going on with this setup? How is DC and AC coming out of the

> same coil on the magneto?

>

> I'm pretty sure I'm not reading the diagram wrong.

>

> Plz explain what comes out of the stator, If it truly is center tapped,

> that likely means the "reg/rec" is probably little more than a zener

> diode and a capacitor and it's designed to send pulsed DC to a SLA

> battery

It isn't. See my post about how the rec/reg on the diagram is labeled super dumbly. You have to trace the signals to figure out what is going on.

Re: Help needed: tomos electrical nerds

> Graham Motzing Wrote:

> -------------------------------------------------------

>

> when i had it breadboarded i didn't ground the case of the reg/rec, so

> that was another thing i was thinking about?

Yeah, the rec/reg case seems to be the DC reference "ground" per the wiring diagram (note how the turn signal bulbs return to "ground").

> so, should i tie the yellow to the ground or should i tie the yellow to

> the input tap?

To "ground." You need to complete the circuit so that your lighting coil has a way to pass current to the rec/reg, and per your diagram, that coil is "ground" referenced.

> I got into a different scooter reg/rec similar to this

> (designed for a center tap coil) and i remember having to fuck with

> that, i think i ended up with both of the inputs coming off a single tap

> coil. I don't know enough about the inner workings on this thing to

> know whether it makes any difference for 'yellow' (i'm assuming higher

> voltage AC in .... more turns) vs 'white' which i'm assuming is the

> lower voltage AC in being fewer turns?

If both inputs are the same voltage, there will be no power delivered to the rec/reg.

> i have a tomos battery stator on another bike i could actually measure

> the coil resistances of yellow/silver vs redwhite/white and see.

It's always a good idea to check your coils!

Re: Help needed: tomos electrical nerds

It is possible that the rec/reg works in some super weird non-obvious way; one would have to check each pin on a working setup with an oscilloscope to know for sure.

I am assuming that the center tap (yellow) to last coil output (red/white) is its input, since the latter only connects to the rec/reg, and there's no reason to have a coil there if it is just to feed back DC into the stator.

The center tap to frame voltage is, I assume, regulated at the rec/reg, and goes onto power a bunch of stuff including the tail light, dash lights, etc.

The DC output is clearly frame referenced, and comes out of the +B pin (pink wire from rec/reg).

Re: Help needed: tomos electrical nerds

I think the yellow and white are tapped off the same coil. This is really similar to the scooter 4 wire rectifiers that use a double tapped coil to provide high power lights and lower power DC battery charging.

I will ohm out the coils when i get home to confirm.

The ground is provided on the brown wire which ties to an eyelet that is engine/frame ground, the case might ground but i've found the 4 wire scooter reg/rec often don't ground the chassis, the 2 and 3 wire reg/rec usually do.

As i'm talking through this it might make more sense that the yellow and the red/white need to both come off that same wire, but i can very easily check that.

I have also found that some of the scooter rectifiers don't regulate the DC unless they are hooked to a battery, i don't think the tomos are like that but i don't really know. I'll try putting in an SLA as well and see if that works.

hopefully i didn't fry the damn thing. I have a whole box of moto/scooter recs so i can go back to the drawing board if i have to, i just wanted this to be easy.

Re: Help needed: tomos electrical nerds

oh yeah we both posted basically the same thing at the same time, haha, thanks for talking me through it.

Re: Help needed: tomos electrical nerds

Yeah, using a battery to stabilize the output is very common on motorcycle / scooter rec/regs. It's not really that they don't regulate that voltage without the battery, it's that the circuit is unstable without the battery so it *can't* regulate its output.

And yeah, the DC output is frame referenced, so the rec/reg definitely needs a connection to the frame in order to produce it.

Re: Help needed: tomos electrical nerds

and yes, i desperately need to invest in an o-scope. those little hand held jammers you can get for like $100 on amazon... its been on my list a while but i haven't pulled the trigger.

Re: Help needed: tomos electrical nerds

Always happy to geek out about this stuff! Good luck!

Re: Help needed: tomos electrical nerds

Totally normal JBOT /

If you look at the voltage on a oscilloscope after the choke you will notice that the narrow sharp Spike drop and flatten out.

Just need to get that Spike to drop down about 20%.

Use Magwire when you make your choke.

And instead of batteries I usually find some old metalhighlid or sodium lights and yank out those big capacitors be sure you leave the little resistor in there or you will find out why it's there.

Re: Help needed: tomos electrical nerds

> Graham Motzing Wrote:

> -------------------------------------------------------

> and yes, i desperately need to invest in an o-scope. those little hand

> held jammers you can get for like $100 on amazon... its been on my list

> a while but i haven't pulled the trigger.

I picked up one of these bois and am really happy with it: https://www.tequipment.net/Rigol/DS1054Z/Digital-Oscilloscopes/

Re: Help needed: tomos electrical nerds

Just got out to the garage, couldn't wait to test.

So hooking up the yellow doesn't seem to matter.

But! I hooked up a pretty dead SLA that I had laying around (on purpose) lights came on, duh, started the bike and voltage started climbing, 11.2, 11.4, etc. Shut off bike and voltage dropped back to 11.2, so that's perfect.

Then, I remembered that I bought one of those supercap 'hybrid' batteries treats was selling a while back, never used it, of course the caps were dead, hooked up and nothing.... For a few seconds, then the voltage started rising and the lights came on!

So that's the answer, it needs a ballast, something about how the circuit in the reg is wired, so I'm gonna go dig up some supercaps that I have in my junk and make my own little lower capacitance 'battery' and hook it up. As it is, all the lights stay on for like 15 min with the hybrid cap battery

... Tail light is still on, haha

So I'll have to add a light switch which is NBD, I planned on doing a ninja mode switch anyhow, just didn't have a good one in my stash....

Re: Help needed: tomos electrical nerds

The input may well be ground referenced then; the yellow input may just be for regulating AC to the various lights its connected to.

Re: Help needed: tomos electrical nerds

🇮🇹💦 Of the Loin /

It's likely the "battery" circuit is pulsed DC

Maybe just ditch these and get a "proper" aka not designed for a scooter, rectifier

Re: Help needed: tomos electrical nerds

> 🇮🇹💦 Of the Loin Wrote:

> -------------------------------------------------------

> It's likely the "battery" circuit is pulsed DC

>

> Maybe just ditch these and get a "proper" aka not designed for a

> scooter, rectifier

NO! NEVERRRRRRR

i love my shitty cheap reg/rec units, i've put them on lots of bikes but its always been a crap shoot. thinking back, i guess it might have been whether or not there was a battery. Sometimes ya get lucky sometimes you don't, but its funny in all the years i've been fucking with them i've never nailed down exactly what was going on.

i've got some 2.7v 10F supercaps i bought for a different project laying around, i think i'm going to do 4S (they have 5S in the 'hybrid battery' from india?) and make myself a super tiny little ballast battery i can shove in the headlight bucket, then i gotta add a light switch so the lights don't stay on for 10 minutes after i turn off the bike.

we talked a few years ago on here about a different kind of reg/rec circuit that i want to try, kind of a boost buck thing that would rectify the AC onto a DC high voltage bus with some capacitors, then some kind of pwm circuit to chop it down to 12v where it would charge another capacitor bank so you could just hook it 1-wire to a frame grounded 'half wave' system but get full wave power... i dunno if it would work but if $3 worth of supercapacitors electrical taped into a wad and stuffed into my headlight with a $8 scooter reg get me to the same place, i'm gonna stick with this.

it would just be really nice to have a plug and play '1 wire' solution for all kinds of old motorcycle stuff with janky frame grounds and weird noisy AC power.

Re: Help needed: tomos electrical nerds

whoops fucked up my math, i need to do 5S x 2.7= 13.5V, or should i do 6S. The india battery thing is 6s2p x 50F @2.7V.... i guess i should go 6S, i don't need a whole lot of capacitance but it sounds like you definitely don't want to go over the rating so 13.5 is cutting it way too close.

Re: Help needed: tomos electrical nerds

> 🇮🇹💦 Of the Loin Wrote:

> -------------------------------------------------------

> It's likely the "battery" circuit is pulsed DC

Most moped battery charging systems just use a diode; basically a half wave rectifier that just dumps into the battery. It is subtly elegant as the diode will only conduct when the input voltage is above the battery + diode drop.

> Graham Motzing Wrote:

> -------------------------------------------------------

>

> we talked a few years ago on here about a different kind of reg/rec

> circuit that i want to try, kind of a boost buck thing that would

> rectify the AC onto a DC high voltage bus with some capacitors, then

> some kind of pwm circuit to chop it down to 12v where it would charge

> another capacitor bank so you could just hook it 1-wire to a frame

> grounded 'half wave' system but get full wave power... i dunno if it

> would work but if $3 worth of supercapacitors electrical taped into a

> wad and stuffed into my headlight with a $8 scooter reg get me to the

> same place, i'm gonna stick with this.

Why go higher and then back down when you can go directly to 12V DC? Each conversion results in loss.

Re: Help needed: tomos electrical nerds

Totally normal JBOT /

If it was plug and play we wouldn't have all these long threads of confusing information on the 10,000 ways these electrical circuits can be connected to achieve almost the same results

Re: Help needed: tomos electrical nerds

🇮🇹💦 Of the Loin /

Radio shack full bridge 50A/50v rectifier is the jam

3.95 and never fails

Re: Help needed: tomos electrical nerds

> Fake Crazy Wayne Wrote:

> -------------------------------------------------------

> If it was plug and play we wouldn't have all these long threads of

> confusing information on the 10,000 ways these electrical circuits can

> be connected to achieve almost the same results

This would all be far simpler if more of us had oscilloscopes. :P

Re: Tomos electrical: a55 regulator and charging circuit

Yeah I'm gonna pull the trigger on this cool little Arduino based oscope called a Labrador, runs off an Android app and gets you some pretty awesome functionality for $30.

https://espotek.com/labrador/product/espotek-labrador-board/

I've used the cheap china handheld ones that are like 100 and they are annoying to use because you gotta use like 3 buttons to navigate all these menus, I think the phone interface is way better.

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