Hall effect woes!

[jgedde]

I don't have problem with playing nice and I understand that we are all trying to help.
What pinches me is when your giving wrong information to someone just to look smart.
Not having the circuit diagram or parts number any parts replacement
suggestion can make things worst .
And nobody on earth can guess what circuit he's using

Luc, He did give his circuit diagram. It's in his original post... And, bipolar, non-latching, hall sensors are "you've seen one, you've seen them all". My suggestions were for general filtering, bypassing, and transient protection. If you'd draw out my recommendations, you'd see that it is not wrong... A series resistor, and a bypass capacitor along with a zener in parallel with the hall sensor to clamp transients that still get through.

I use hall sensors here at work on a daily basis. After 15 years of working with them, I know that they're generally robust, but do fail under certain conditions and I'm well versed in what they are. Want to see the inside of a failed sensor? Look here...

Let's see what he comes back with. I think there's a good chance my sugegstions will work.

John

 

[jgedde]

Hi,
I have finally managed to get my Kerzel H&M running but am now plagued with Hall effect failures.
I have used a few circuits but the latest was posted in an earlier thread here which I cannot track back to. The circuit is attached.
This circuit works fine but I have yet to run more than a few minutes before the Hall effect goes T*ts up and dies. I have put protection diode and capacitor as recommended elsewhere but no luck. Any ideas?

By the way Creast, what hall sensor are you using? Can you give us the part number? If not, verify you have the correct pin out. Generally they are as follows:
pin 1: Power
pin 2: Ground
pin 3: Out

I can't help but wonder if you have output and power pins reversed... The hall will actually sort of work that way, but it shorts out the power supply through itself every time it turns on...

John

 

[canadianhorsepower]

Luc, He did give his circuit diagram. It's in his original post... And, bipolar, non-latching, hall sensors are "you've seen one, you've seen them all". My suggestions were for general filtering, bypassing, and transient protection. If you'd draw out my recommendations, you'd see that it is not wrong... A series resistor, and a bypass capacitor along with a zener in parallel with the hall sensor to clamp transients that still get through.

I use hall sensors here at work on a daily basis. After 15 years of working with them, I know that they're generally robust, but do fail under certain conditions and I'm well versed in what they are. Want to see the inside of a failed sensor? Look here...

Let's see what he comes back with. I think there's a good chance my sugegstions will work.

John

I've been working with hall sensor for many year. It's the most common sensor we put in Robots. Designing robot is a part of my hobby, I teach robotic engineering as a job.
As far as the diagram is concern their is a partial one, no voltage applied to the sensor is specified or what kind of sensor he's using check the picture I've attached . After you've seen one sensor you've seen them all as far as operation is concern yes, but not as far as specs.

 

[Noitoen]

That's what I meant in post #2. There is no supply to the hall device but then again, maybe the drawing was incorrectly posted with a mistake.

 

[canadianhorsepower]

That's what I meant in post #2. There is no supply to the hall device but then again, maybe the drawing was incorrectly posted with a mistake.

I saw that to that's why I ask for the drawing if this is it a simple fixe
but if something is missing we just can't guess what it is

 

[jgedde]

Although the circuit shows no direct supply on the diagram, I am supplying 12v to the Hall device which the spec says it should be ok with. The supply however is the same as that to the coil so maybe thats a problem?

Luc,

Remember he said this? (see above) His hall is running from 12V despite what the schematic shows...

John

 

[canadianhorsepower]

Luc,

Remember he said this? (see above) His hall is running from 12V despite what the schematic shows...

John

back to square one
no specs nobody knows the value and
numbers assume are useless

 

[creast]

Hi Guys,
The circuit was published here on another thread and I have yet to find the original thread again so I can quote who published it.
Although the device shows no supply to the hall I thought it obvious to connect the supply to + and - rails the device is connected to.
The device I am using is Allegro A1102 and running at 12V from a battery.
I have implemented the mods suggested by John and so far its holding out but I have added extra safety by earthing to my PSU unit.
As I need to do some work on the engine I will make a test rig for long term testing the circuit and then without a real earth since I want to run battery only.
I will keep you posted.
Many thanks
Rich

back to square one
no specs nobody knows the value and
numbers assume are useless

 

[steam58]

i would like to build a circuit for my upshur that uses a hall effect. can you post the circuit that you got that will work
thanks
jay

 

[creast]

Hi again,
I located where I saw the circuit.
http://www.homemodelenginemachinist.com/f26/ignition-circuit-help-19673/index2.html
John, I am surprised you didn't remember since you did comment on it to member DSage.
You said not to connect the common HT to the collector. So should it go to the +ve ??
Cheers
Rich

 

[jgedde]

Creast, No need to rewire the coil it should be OK the way it is. dsage's circuit is just fine.

My circuit is well on it's way to being completed and I expect to have test results on Monday along with any circuit revisions that were necessary to:
1) Ensure robust operation despite component tolerances.
2) Safety of the hall sensor.
3) A good strong spark whikle maintaining a long battery life.

John

 

[creast]

Hi John
I did all the safety measures you suggested including the 100 ohm to the capacitor and the circuit seems to behave ok.
I am rigging it to a motor to keep triggering for some hours whilst I do work on the engine.
Look forward to the results of your circuit.
Cheers
Rich

Creast, No need to rewire the coil it should be OK the way it is. dsage's circuit is just fine except for guarding the hall from the discharge of the 4.7uF cap.

I would just add a resistor in series with the output lead to protect the hall from the discharge current when the hall turns on if you haven't already done so. That sucker can hold enough energy to fry the hall if you don't limit the current. 100 to 400 ohms should be fine.

My circuit is well on it's way to being completed and I expect to have test results on Monday along with any circuit revisions that were necessary to:
1) Ensure robust operation despite component tolerances.
2) Safety of the hall sensor.
3) A good strong spark whikle maintaining a long battery life.

John

 

[jgedde]

Hi John
I did all the safety measures you suggested including the 100 ohm to the capacitor and the circuit seems to behave ok.
I am rigging it to a motor to keep triggering for some hours whilst I do work on the engine.
Look forward to the results of your circuit.
Cheers
Rich

Rich, I'm glad to hear it all worked out so far. Keep us posted on your life test.

Cheers,
John

 

[dsage]

Sorry I wasn't aware of this thread or I would have chimed in earlier to defend (as it were) my circuit. But it seems John (jgedde) has done a good job since his circuit is almost the same. Albeit he chose to add a bit more protection ( no harm done with a few extra parts). I haven't found any of it necessary. Read on...

The only thing I wish is that people would link to the original post and not take things like the schematic out of context and paste it without the original comments on it. I think it was properly linked a couple of posts back but if not here it is (I hope I have it right myself)
http://www.homemodelenginemachinist.com/f26/ignition-circuit-help-19673/index2.html

POST #17

You will note that #6 in the list states that the hall sensor CAN but need not be supplied from the same supply as the coil.

LUC there IS a supply stated for the Hall sensor and you in fact circled it a few posts back it's +VE just like the rest of the stuff connected to the same point on the left side.
I guess to be more clear (and conventional) there COULD have been another line marked +VE up at the top shown feeding the whole left side but it would be somewhat redundant since the hall sensor is connected there already and it's marked clearly +VE which is somewhat standard notation for a logic power supply (well, for me anyway).

As for the Hall sensor, I suppose a part number would have been useful but most of the ones folks use are pretty much the same. There is very little current requirement for the sensor so I can't imagine one that wouldn't work. Read on....

The coil supply is marked separately as +12v ignition supply. On purpose to show that it need not be the same as +VE.

The circuit was designed so you can drive it from any logic circuit not just a hall sensor. You could substitute any 5v logic device even a microprocessor output to the driver input. Of course +Ve would be the supply used for that circuit. In the case of a micro +Ve would be 5v.
*** I did state in the original post that the only important thing is to be sure the grounds (negatives) of the two supplies are connected together.

I also have a version with the front end driven by a 555 timer to create a "buzz" coil" multi-spark ignition. I have the ignition coil and the 555 running from the same 12v battery as well READ ON...

I find in a lot of cases problems are self-inflicted. A lot of folks don't follow proper grounding procedures interconnecting the various pieces so it's not a problem with the circuit per se but an interconnecting wiring issue.
I think Steve touched on it when he said when he grounded something properly he had no more problems.
This is just something you learn after 38 years experience (like me). You can't really put it in a schematic.

Addition of extra components to cure whatever problems one experiences in their particular situation are certainly allowed but don't be afraid to look at the wiring to see if the problems are being caused by other issues. I admit finding these things is a bit of a black art. One that I don't even understand most times. But attention to grounding detail is important.

The suggestion of resistor and capacitor on the +VE to the Hall sensor (a filter of you wish) if you are going to use a common supply for the logic and ignition is a good suggestion. Although you have the biggest filter in the world right there in front of you connected to exactly the same place. It's called the battery. Having said that the battery does have some impedance so it may not pass spikes well. So go ahead and use the resistor/capacitor filter or what ever makes you happy.
Sorry if you blow a Hall sensor figuring out that you may need that. I never did.

More important is that you have a good short heavy ground lead from the battery negative to the engine block and ground everything to the same point. No long wires.

Re the high voltage circuit:
Coils only have three leads so the negative of the coil is connected to one side of the HV side of the "transformer". As shown the connection is inside the coil.
Someone stated that with the circuit drawn the way I have it that HV current path is made through parasitic capacitance or some such crap. To that I say draw the WHOLE circuit including the battery. You will see that the HV current comes from the HV lead, jumps the spark plug gap to ground. The HV current flows through the (very low resistance) battery back to +12v where it is connected to the primary side of the ignition coil. It then it flows through the low resistance primary winding to the junction I've shown inside the coil to the HV side to complete the HV path. (just the way it's done for as long as the kettering ignition has been around). The various low resistances along the way have no effect. In fact they can enhance the spark.

So, this brings up another point. If you have a CRAPPY battery with high resistance, and not a nice Gel Cell made with proper connections (mentioned briefly above) spikes created by the HV current through the battery are more likely to develop across it causing problems with other things connected to the battery i.e. the driver circuit. So go ahead and add the filter.

Like I said I can't allow for everyone's self-inflicted problems. Add whatever components you need to to make it work for you.

I have no intention of sounding "snippy" here. Upon re-reading it comes across that way. Sorry for that. Just trying to clarify a few things

Sorry for such a long post.

Now let the arguments begin. :fan:

Sage

 

[dsage]

Based on what I've already posted maybe the drawing below will make things more clear with regards to the +VE connection. As mentioned in my previous post +VE can be, but does not need to be, the same 12V connected to the ignition coil side of the circuit. Just be sure the grounds (negatives) of both supplies are connected together (to the same point with short stout leads). if you choose to use separate supplies.

Any other components you find necessary to add to correct your local particular issues are optional and up to the individual builder. I find the circuit works fine like it is. Maybe I'm lucky. I'd be happy to analyze at any concerns others can identify.


Sage

 

[canadianhorsepower]

LUC there IS a supply stated for the Hall sensor and you in fact circled it a few posts back it's +VE just like the rest of the stuff connected to the same point on the left side.
I guess to be more clear (and conventional) there COULD have been another line marked +VE up at the top shown feeding the whole left side but it would be somewhat redundant since the hall sensor is connected there already and it's marked clearly +VE which is somewhat standard notation for a logic power supply (well, for me anyway).

SAGE it's funny how you can explain thing. In the first quote your giving a lecture about VE was well indicated and that We should all have known this

The circuit was designed so you can drive it from any logic circuit not just a hall sensor. You could substitute any 5v logic device even a microprocessor output to the driver input. Of course +Ve would be the supply used for that circuit. In the case of a micro +Ve would be 5v

then a few line after the next quote, your explaining that VE+ could have been different then the 12 volts so this only shows that I was wright in asking what he had as VE+.

If someone is asking for help we must assume that he's lacking knowledge or experience to fully succeed. There for asking precise question about the circuit only makes more precise diagnosing suggestion




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[Mosey]

I am lacking in knowledge and following along in the hopes of learning how these systems work. I would appreciate it if you would refrain from sarcasm and less than polite personal criticism of those who offer their knowledge for the rest of us. I admire and respect those folks who share their knowledge, and don't need to make themselves look wise by criticizing others.
Thank you.
Mosey

 

[dsage]

LUC:
Yeah - except that all of what you have written gets back to my very first point right a the top. Which I guess you didn't read.

People need to RTFM which was left behind when the circuit was clipped from the other thread. (RTFM for those that don't know means Read the F'n manual)
It was all explained in the other thread linked to and if people would not extract a schematic without all of the attached information AND READ IT !!! they would have seen the notes about it being able to be driven by any sort of circuit not just a hall sensor. That other circuit would include the +VE of that circuit.
I even pointed that out AGAIN in my post here so in my my mind I've explained it now 3 or 4 times. If people don't care to read and absorb the info and ask questions if they don't understand (back where the circuit was - not here) there isn't much I can do.

If I were to simply draw the circuit with +12v on the left side then the whole uniqueness of the circuit would be lost. I purposely used a logic level version of the IGBT so it could be driven this way. That little tid-bit of information was left behind as well but was explained back where the circuit came from. People have even substituted a regular bi-polar darlington transistor in it's place which defeats my purpose. But I didn't say anything.

I know I write too much and people don't like to read so I guess it's all on my head. I spend a lot of time trying to explain things so people can understand but they have to read. Certainly it's difficult to explain things to people with no background in electronics but I do my best.

I'll go away now and keep my circuits to myself.

Sorry Mosey. Your post got in before mine since I spent so much time editing this (like I usually do to get it right). I agree with you but sometimes....

Sage

 

[canadianhorsepower]

[QUOTELUC:
Yeah - except that all of what you have written gets back to my very first point right a the top. Which I guess you didn't read.
]
Well your guess is wrong cause I read it. Btw I'm not the one needing help here I teach that stuff. But being a teacher in that field
I know that all questions should ask to diagnose something. I can't assume what someone else did with a circuit if I'm not asking.
Now if your mad at someone because they use or modify your circuit don't jump on MY head for it. I was simply trying to help

 

[jixxerbill]

So will there ever be a circuit posted on this site that will work AND everyone will agree upon ?? I'm seriously just asking.. Everytime this type of thread gets started it just turns into a "that wont work do it this way" thread.. I can appreciate everyone's take on doing things and I know there are several ways to skin a cat.. But with the electronic knowledge on here it seems everyone could agree on a circuit.. Maybe everyone post thier version of the PERFECT circuit and then put them together and come up with the holy grail of ic circuits.. Thanks..Bill