Speedo Pulse generator?

[fredvv44]

Is there a pulse generator that will fit a Cal2 gearbox? On my Morgan 3 wheel replica I've been using a Hall Effect sensor to send pulses from the brake rotor gaps and they burn out for some reason. Some last for several thousand miles and some only last for two blocks. I've put shielding around the send wire and a capacitor across the send wire to ground to catch voltage spikes which helped. Any suggestions on that would be appreciated also.
Thanks,
Fred V

[jacksonracingcomau]

Acewell make the perfect one. It is short cable driving hall effect pick up, wires to speedo.
Guzzi use generic thread size at gearbox, same as yamaha and bmw, sender cable is called s7, I think
Worked faultlessly on mine for about ten years.
On my sb I use their wheel sender, magnet on disc, pick up behind caliper, that works perfectly too

[John A]

You can use a tach cable (shorter) out of the transmission to the pulse generator with some creative fittings to hook it up.  I don’t remember how I did it but it’s all industry standard parts once you get into it, so that should give you the option of just about any generator

[Kiwi_Roy]

I used a reed switch for my VII Sport/Speedhut they are rated in billions of operations and dirt cheap.
All you need to do is mount a magnet on a brass bolt filed square to fit the old cable hole, no bearings required.
I can't find a picture but the sensor ended up about the size of a 35mm film can and used the nut off an old cable as the mounting thread.
To protect the reedswitch I have it on the outside of an aluminium can away from the spinning magnet.
Orient the switch so the magnetic field passes through the reed from end to end to suck the contacts closed, it would have worked better above the spinning magnet, just experiment.
Anyone with a lathe could make a nice sensor from aluminum or plastic rod to screw straight on the gearbox.
A word of caution about reed switches, don't bend the leads holding onto the glass envelope or it will crack, grasp the wire with needle nose pliers next to envelope to take all the stress off the glass.

You must be doing something wrong with the Hall Effect switch, they are almost bullet proof, can you post a diagram?

[John Croucher]

I have been using a Sigma brand bicycle reed switch for over 20,000 miles.  Put a couple of magnets in the brake rotor and calibrated the speedo based on the number of pulses per revolution. 

[fredvv44]

Here is my wiring for my pulse sensor, and the schematic of the sensor.





This is the device I'm using.
https://www.alliedelec.com/product/zf-electronics/gs100701/70207638/?mkwid=qSC0cYd2&pcrid=30980760979&gclid=CjwKEAjw96aqBRDNhM6MtJfE-wYSJADiMfgggYzYH6L3s33VEULwEO-1QJXSCoCEvBUdD0YobwDGxBoC2I7w_wcB

I hope you can make some sense out of this. I have added a capacitor from the tan/brown to ground in an attempt to catch any voltage spikes. Doing this started making the thing work.
Thanks for your help,
Fred V

[rjamesohio]

This is a great thread with some awesome contributions!

FWIW - I've tried some Hall Effect sensors and you have to be careful with the diameter as it is a very tight fit coming out of the gearbox due to the proximity of the airbox, at least on 2003 Guzzis and I suspect others.

The smaller home-brewed solutions here look much cheaper, smaller and better.

I also like using a sensor rather than GPS because the GPS takes so long so synch.

My .02 after playing with these things for far too long.

Rocket

[Kiwi_Roy]

Here is my wiring for my pulse sensor, and the schematic of the sensor.





This is the device I'm using.
https://www.alliedelec.com/product/zf-electronics/gs100701/70207638/?mkwid=qSC0cYd2&pcrid=30980760979&gclid=CjwKEAjw96aqBRDNhM6MtJfE-wYSJADiMfgggYzYH6L3s33VEULwEO-1QJXSCoCEvBUdD0YobwDGxBoC2I7w_wcB

I hope you can make some sense out of this. I have added a capacitor from the tan/brown to ground in an attempt to catch any voltage spikes. Doing this started making the thing work.
Thanks for your help,
Fred V

That looks pretty normal for a Hall Effect circuit, the only thing I wonder if you are getting some sort of a spike coming in on the VCC wire, You could add a 1K resistor in series and an electrolytic capacitor from VCC to Ground

[Kiwi_Roy]

Looking back at your original post you say you have a capacitor between Send and ground
I don't see a wire marked Send, are you referring to wire 4?, that would be wrong, a capacitor can supply a large current even though the duration is very short think of it like a battery with a low impedance output.
A capacitor across 1 to ground is OK, perhaps 10 microfarad with a 1 K resistor in between +12 and 1 to filter out any sharp spikes from a relay coil or other inductive device.
The pull-up resistor could be 1K (12 mA at 12 Volt), well within the 25 mA switching current spec.
Perhaps add another 1K resistor between wire 4 and the speedo input just so there's no possibility of overloading the output, if you read the speedo input spec it's probable quite high like over 1 Meg ohm

[fredvv44]

Thanks Roy. The "send" wire would be Black #4 so my comment was incorrect.
The capacitor is between tan/brown#1 (12V) and blue#3 ground. That would match what you suggest.

"with a 1 K resistor in between +12 and 1 to filter out any sharp spikes"
#1 is the +12. I have a resistor between #1 and #4 (+12 and sensor output) as called for. I am using a Classic Instrument brand speedometer.

It seems to me  that I'm getting a spike from somewhere but when the sensor blows I can't relate it to any action. I do have relays for turn signals, headlights, horn and starter.

[fredvv44]

It ends up costing me 40 bucks every time one of these blows so I might be better off to do something different as some of the other respondents have done.
It looks like the Acewell M12 Universal conversion cable will fit my tach cable and the other end will fit the gearbox fitting. I assume the 2 wires coming out of this sensor are for output to the speedometer and 12V supply.
Am I on track with this?
Fred

[Wayne Orwig]

Is it getting wet?
Is it getting cooked from heat?

If it really is a spike, Then as Roy mentioned a resistor inline as well as the cap should help. Get hold of at 10uF ceramic cap. Ceramic has a lower ESR so is better for high frequency spikes.
None of that should be needed though. Odd.

BTW, does the sensor have a built in magnet? Is it relying on random external magnetics?

[Tom H]

From a thread a few years ago, This is what was used or something like it I think to give a electronic speedo it's pulse:

https://www.ebay.com/itm/Speedometer-sender-GM-type-transimssion-16-pulse-generator-w-10-foot-harness/260778921588?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Some also added a 1 foot extension cable to move the sender to the battery area under the seat.

Hope this helps,
Tom

[fredvv44]

Thanks Wayne. My sensor has a built in magnet. It can get wet but not hot. When it blows it has always been a dry day.

Tom, I found this which I think will solve all my problems. I need to find out if it is compatible with my speedo head. It should screw right into the gearbox fitting as the description says.
https://www.dimecitycycles.com/acewell-digital-speedometer-conversion-cable-for-honda-crf-yamah-wr-ktm.html#

I'll report back what happens.
Fred

[Tom H]

That should do it. Much cleaner than the GM.

Let us know!
Tom

[fredvv44]

I have contacted Dime City Motorcycle and they are unable to tel me anything about their cable output.
Would any of you know if this is a pulse generator and what the output rate is?
Fred V

[jacksonracingcomau]

That is exactly the cable I suggested in first reply
But I use Acewell speedo so it was directly compatible
Am away on trip atm but can measure when back if you clarify output rate
If you mean signal per turn, it is one per cable rev so wheel diameter size is set as if cable was wheel
Ie one revolution of cable is same as wheel passing magnet on yours

But one thing did catch me out when first fitted, spiked like billy ho, completely erratic
I fitted resistor plugs, fixed it instantly, never used them before and know, for instance, Lucas Rita ignitions kill resistor plugs. I run points so no issues but can say, categorically, my bike needed resistance in ht to avoid spikes

[fredvv44]

That is exactly the cable I suggested in first reply
But I use Acewell speedo so it was directly compatible
Am away on trip atm but can measure when back if you clarify output rate
If you mean signal per turn, it is one per cable rev so wheel diameter size is set as if cable was wheel
Ie one revolution of cable is same as wheel passing magnet on yours

But one thing did catch me out when first fitted, spiked like billy ho, completely erratic
I fitted resistor plugs, fixed it instantly, never used them before and know, for instance, Lucas Rita ignitions kill resistor plugs. I run points so no issues but can say, categorically, my bike needed resistance in ht to avoid spikes

Thanks. That is what I anted to know. I am getting 6 pulses per wheel revolution now. I'll check with Classic Instruments to see if the speedo head will work on only one pulse.
Fred

[Wayne Orwig]

I have contacted Dime City Motorcycle and they are unable to tel me anything about their cable output.
Would any of you know if this is a pulse generator and what the output rate is?

It is two wire. So it is surely NOT hall effect. It may be a reluctance sensor. That would be difficult to adapt. Or it may be a reed switch like Kiwi Roy uses. Should be easy to adapt to.

[fredvv44]

I can't thank you all enough for your ideas. I bought a reed switch off Amazon and my wife had a stack of little round super magnets so I was in business. I called Classic Instruments who said connect the reed between ground and the signal wire to the gauge. I put a magnet on each spoke of the brake rotor so I get the same count per wheel revolution that I had with the Hall Effect sensor. It works great and is actually more stable than before.






I love learning something new.
Fred V

[Kiwi_Roy]

I'm glad it works but I'm also surprised with the magnets embedded in steel like that I would have thought very little field escapes, you could increase the field if you made an aluminium disk to move the magnets further from the steel.
The nice thing about reed switches is you can test with your Ohmmeter and get a feel for sensitivity as you slowly rotate the wheel.
----------------------------------------------------------------------------------
Reed switches are so handy, loop owners might recognize this.


Sure you can buy the original pill-box switches but where's the fun in that?
I used 1 Amp reed switches wired to LED signals and a relay for H/L beam, I have since reworked it to get the H/L switch further from the indicator and
replaced the screws with brass countersunk so I can polish it with a buffing wheel.

[fredvv44]

I just stuck the magnets to the rotor, no glue. They are rare earth magnets and are amazingly strong. In the test drive I went to 60 MPH with no issues. If they ever sling off I'll use JB Weld.

I tested the reed sw. with a  digital VOM and passing the magnet quickly the meter didn't react very well but I think that is just the reaction time of the meter.
Fred

[Kiwi_Roy]

I just stuck the magnets to the rotor, no glue. They are rare earth magnets and are amazingly strong. In the test drive I went to 60 MPH with no issues. If they ever sling off I'll use JB Weld.

I tested the reed sw. with a  digital VOM and passing the magnet quickly the meter didn't react very well but I think that is just the reaction time of the meter.
Fred

Sorry, I missed that they were just stuck on I thought you had drilled the spokes 
Yes the reed switch is extremely fast, it should be good