Hall transistors

[Antman]

Wow, GB is that little V Twin yours? What’s the classy looking casing made of? What’s under it, timing? … transmission? Wait til you see my antigrav prime mover. I’m still making toolholders.

If I was in a good electronic workshop with books of chip spec sheets, no prob. I’m at least 12 years away. What you might use is some rotating part that interrupts light instead of, I assume, a rotating magnet. Then a light source and sensor either side. You get 1 piece, U-shape examples. You’d need a spec book of standard opto elctronics devices to decide what you want and could use, and their specs, what wire goes where etc. Your opto device wants a power supply, milliamps, only, and will output a signal that hopefully excites the coil through the same amplifier as the hall device. Also, if you ever see something that needs a zener diode, find an alternative.

Ant

 

[Blogwitch]

George,

I think I have shown it before recently.

It is the little leads coming out of the back of the hall that causes all the problems. As soon as I had them soldered, tiny silicone sleeves were fitted and superglued into place to stop any chance of a short.

After I had the circuit working, I always potted the hall into a small ali block with epoxy, and had a Futaba plugged fly lead coming from it. That made them almost bomb proof forever.


Bogs

 

[gbritnell]

Thanks Bogs,
The short was my fault. I had a bad joint in the battery/coil box. I contacted Allen Howell about the new Halls that I received. He said the bigger ones must have been old stock. I was just wondering if anyone knew where to get them. I can use the new ones but I will have to shim the opening where they mount.
George

 

[Blogwitch]

Supposedly George, you can get the non polarity ones, so it would pick up the magnet no matter which way around the magnet was mounted.

I did a bit of digging a few years ago, and from what I could gather, was that they sensed on the end of the hall rather than on the flat face. If that was the case, it would make them much easier to mount, you could in fact pot them into a bit of thin tube, much easier to hold.

Having made some of these units, I can clearly see how easily it could have been shorted.

I used to run mine on a small 6volt SLA, and even though they gave over 7 volts fully charged, I never had any trouble with that.

Bogs

 

[solver]

You can also use a small reed switch to substitute a hall. You will be surprised on the speed that you can get on a small reed.

I followed a thread at madmodder, where one member was testing reed switch on his engine at http://madmodder.net/index.php?topic=2456.60

According to that, mechanical factors prevented him to use it for a long term.

 

[TarheelTom]

Since the mid '80s, nearly all automotive ignition systems use a Hall effect sensor to detect the crankshaft position. Seem to work well, and never need to be adjusted. Most failures (that I'm familiar with) seem to be an overheating problem melting the insulation on the wiring between the sensor and the ignition computer.

Slightly off topic, but there is a current thread on another forum about using Hall effect sensors for home switches and limit switches on mills and lathes.

Tom