# Hall Effect Sensor



## fltenwheeler (Aug 28, 2010)

I have been looking at TIM (Transistor Ignition Module) and I have been able to find a lot of information. But when it comes to *Hall Effect Sensor* the only thing I can find is on the HAL506UL. I have not been able to find a suppler and started looking for other units. So far I have come up with the following.

ALLEGRO MICROSYSTEMS - A1120LUA-T

and

HONEYWELL S&C - SS441R

Has anyone tried ether of these or have other options?

Thanks

Tim


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## stevehuckss396 (Aug 28, 2010)

I have used the honeywell to make plugs go snap. They work fine.


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## JackG (Aug 28, 2010)

Take a look at Parallax. They sell a Melexis 90217 Hall-Effect Sensor for use with their micro processor. I used one to build an rpm readout for my Sherline lathe & mill.

http://www.parallax.com/Store/Senso...pageindex/3/Level/a/ProductID/90/Default.aspx


Jack


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## jpeter (Aug 28, 2010)

I've had pretty good luck using a gb14c40L IGB ignition driver, insulated gate bipolar transistor, for a driver, hooked up pretty much like the datasheet recommends. I think I leave off the diode acrossed the coil. I use a resistor coil from a 12 volt automobile ignition. I switch the igbt with a hall effect switch, points will work too. Regardng hall sensors, there's generally two types, switch and latch. You need a switch. They're a dollar or so from digikey. Buy a bunch cause you're gonna burn out a few getting the bugs worked out. Some things to watch is to be sure to get a hall effect sensor capable of handling high ambient temperatures. At first I didn't think about heat causing problems but with hall effect sensors heat matters. I use 125c ones. Higher temp ones get quite pricy and I don't seem to need them. Also, to help prevent emi from blowing out the hall sensor add a 20K 1watt resister in the HV lead from the coil. Use 1 watt cause its physically large enough to keep the spark from jumping from one end to the other. I control dwell with a shutter. Lots of web sites suggest placing a south pole magnet in a disk on the crank or cam but they don't account for adjusting the dwell. Use a steel disk with about a 22 degree slot running between the magnet and hall sensor, on the cam of course. A shutter on the crank reqires wider slot. That gets the dwell in the ball park. If the hall sensor is in a distributor I add some low wattage, for small size, zener diodes directly to the hall sensor to protect it from emi. TIM seems easy but its not. Its the best way though for a small engine. Points add a lot of drag and too mounting the cap is always an ugly problem. I get most of my parts from digikey.
On a hit'n miss its pretty easy too to add a second hall effect sensor parallel to the first to the valve pushrod, use a shutter here too, to keep the unit from firing during the coasting period. That'll extend battery life a lot.
Good luck.


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## gbritnell (Aug 28, 2010)

I found the HAL 506-UA-A-U-B sensor at this supplier. They are extremely sensitive and work great.
http://www.semiconductorstore.com/index.asp?
gbritnell


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## jpeter (Aug 29, 2010)

That hall sensor looks better than what I use. I notice it can stand 150c degrees. That would be even better than my 125 degree suggestion. Its cheaper too.


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## fltenwheeler (Aug 29, 2010)

Hi

ALLEGRO MICROSYSTEMS - A1120LUA-T, HONEYWELL S&C - SS441R, and MICRONAS - HAL506UA-A have following basic parameters.

Unipolar Switching (South Pole, Logic Low) 
High Sensitivity (35 Gauss)
Operating voltage (3 to 24 volts DC)
Operating temperatures (up to 150°C)
Switching time (1.5 to 2 &#956;s)

Can someone please double check the above?

Thanks

Tim


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## jpeter (Aug 29, 2010)

Without ever having tried one I'd say the specs are perfect for what you need. Looks like the perfect unit. The price, at $0.75 each, is good too. The tricky part though is protecting it from EMI and so is finding a transistor and circuit to switch. You'll need too to spend some design time getting the dwell right. I learned early on the diameter of the cam, disk holding the magnet, plays a big role in determining the dwell. On multi cylinder engines switching becomes more of a problem cuz on a small cam the magnets interfear with each other, such as in my v8 (.500 dia cam). Larger disks often are out of scale and shorten the dwell too, or maybe lengthen it. I have to think about that. Good luck. When you get it work'n you'll be proud as a peacock.


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## Kermit (Aug 29, 2010)

I've attached some pics to show another way of adjusting the dwell/

The round magnet is the active/activating magnet. The square magnet is set to oppose the field of the activating magnet. Once you have gotten the proper cam postion timing, this method can be used to 'fine tune' the on/off time of the hall effect sensor. 

By mechanizing this opposing magnets movement in and out based on RPM's you can create a method of advancing/retarding spark timing. A magnetic governor device-if you will.

Kermit


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## jpeter (Aug 29, 2010)

That's an interesting approach to setting up a sensor. I'm gonna have to study that some. They make a sensor too called a gear sensor. It contains the magnet so all you need is a cam, i think that'd be called a reluctor; maybe not. 
Hey, check out my v8. The distributor od is 1 inch. The cap is delrin and the wires are test lead wire from RadioShack. Its my own design electronics using the chip mentioned earlier.
[ame]http://www.youtube.com/watch?v=fojWVfJbZ0s[/ame]


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## doubletop (Aug 30, 2010)

Courtesy of RadioSpares http://www.rs-components.com/index.html

http://docs-asia.origin.electrocomponents.com/webdocs/002e/0900766b8002e123.pdf

http://docs-asia.origin.electrocomponents.com/webdocs/0d88/0900766b80d8805b.pdf

Pete


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## Kermit (Aug 30, 2010)

http://archives.sensorsmag.com/articles/0397/mar_mag/index.htm

Some simple arrangements of Hall Effect sensors and their applications.


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## kcmillin (Apr 7, 2011)

Sorry for bringing up an old topic.

I am having trouble with the hall sensors burning out after only a tiny bit of use. I would like to troubleshoot the problem, but I need more hall sensors.

I have been using the $8 hall sensors and connectors from S&S. I would like to use the same size, as that is what fits my distributer. 

The numbers on the sensor say "04E" but I can't find this number anywhere.

I have looked through the links listed above, but there is too much to look through to get what I want. Plus alot of nonsense I don't understand.

I found this but I know that I can get them cheaper.
http://www.model-engine-plans.com/partskits/ignitionsystems/sensorsmagnets.htm


So, can anybody post a hyperlink *DIRECTLY* to a hall sensor?? I don't know how to choose, I just want what I have, and what works. 



Thanks 

Kel


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## Metal Butcher (Apr 7, 2011)

Hi Kel, Here's two links.

http://www.mouser.com/Search/ProductDetail.aspx?R=SS441Rvirtualkey67810000virtualkey785-SS441R

http://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=6213

I used the Micronas HAL506UA-A, the Honeywell SS441R Is comparable and good too.

-MB


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## kcmillin (Apr 7, 2011)

Thanks a lot MB

Kel


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## Swede (Apr 8, 2011)

I certainly tried desperately for many months to use hall sensing in my radial engine, but in the end, gave it up. The hall chips kept blowing from the high-voltage weirdness that is part of a spark ignition.  

My flaw was (I believe) in the location of my chip, which was inside the distributor, at the base. I think a much better option is to have the chip mounted a bit more remotely, such as a camshaft takeoff, or maybe an extension of the distributor shaft opposite the distributor itself. So if something like that is desired, some kits or plans may need to be modified before hand. Don't wait until the project is done, thinking you can replace points or cams with a hall system in the traditional location...


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## jpeter (Apr 8, 2011)

Add zener diodes where ever possible for spike suppression
Make sure your choice of hall sensor can take the heat.


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## kcmillin (Apr 8, 2011)

jpeter  said:
			
		

> Add zener diodes where ever possible for spike suppression
> Make sure your choice of hall sensor can take the heat.



Where exactly would one put these diodes? On the hall sensor wires? If so, which ones?

Kel


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## Metal Butcher (Apr 8, 2011)

kcmillin  said:
			
		

> Where exactly would one put these diodes? On the hall sensor wires? If so, which ones?
> 
> Kel



Jim, are the diodes something you add to a home built ignition system?

Hi Kel. If your having sensor failures, they are most likely caused by high voltage (used to spark the plug) seeking out ground, and going to the sensors face or its ground lead. The solution is to fully insulate the sensor and its leads, and to make sure you have the engine properly grounded all the way back to the ignition coil. Over voltage protection is built into the sensor, as shown in 'features' on the link below.

http://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=6213#details.

-MB


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## Metal Butcher (Apr 8, 2011)

Kel, I want to add one more piece of info to help solve the sensor failure puzzle. If your ground is interrupted or poor at the coil, it will eventually (or instantly) 'blow' the hall sensor.

The best way to eliminate this potential ground connection fault as the source of the problem, is to solder on small strips of copper (lugs) to the wires that go to the coil, drill small holes at their ends and attach them to the (+/-) lugs on the coil with small nuts and bolts. 

-MB


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## kcmillin (Apr 8, 2011)

Thanks again MB. I have insulated the sensor using the heat shrink technique of yours. I am going to look more into your solution for securing the wires to the coil better.

Kel


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