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View Full Version : Hall Effect or Proximity Sensor, What's best?



NickP
09-13-2018, 04:04 PM
Might be a simple answer for some, but I just can't wrap my head around this. As I understand, a hall effect unit works on a magnetic signal applied in the proper location and polarity to either open the switch or close the switch and a proximity works much the same but is activated with a piece if iron or steel and depending upon the sensor opens or closes the switch.

I want to know if I can replace a currently used double throw double pole rocker/toggle switch with one of the above.

Thanks in advance.

55 Rescue Dog
09-14-2018, 05:33 AM
What is the switch for? And the current?

chevynut
09-14-2018, 05:58 AM
A Hall Effect sensor can be a proximity sensor and requires a magnetic field to be passed by it. There are lots of technologies used for proximity sensing. Without knowing the application or intended operation it's hard to give an answer.

Also, any sensor is just going to output a signal that then needs to be used to drive something else, like a relay. If you need a DPDT switch, the sensor alone can't provide that function unless it's built into a larger assembly.

NickP
09-14-2018, 06:10 AM
What is the switch for? And the current?

RD, it's 12V. The present switch (toggle) opens a fuel door on a vehicle but they are so archaic looking. The Hall Effect intrigued me due mostly in part of their size and ease to hide externally, much like the present day vehicles do.

NickP
09-14-2018, 06:43 AM
The application is a hidden fuel door (tail light). all 12 V DC. Currently, activation is by toggle switch. through a bank of relays and micro switches that control polarity specific to direction of the door. Nothing groundbreaking by any stretch, just wanted to see if I can modernize it.

55 Rescue Dog
09-14-2018, 06:51 AM
Maybe just get a better looking latching on/off pushbutton switch. Many options for buttons, including LED lighted. A prox switch or anything similar might get a little more involved.

chevynut
09-14-2018, 11:56 AM
You could maybe set it up so the filler opened up when the bezel was touched while the driver was close to the filler with one of those keyless start fobs. Not sure how they work but new cars have keyless and "buttonless" door handles. My DIL's Toyota 4Runner has them.

https://www.yourmechanic.com/article/how-touch-activated-car-door-locks-work

https://www.hella.com/techworld/uk/Technical/Car-electronics-and-electrics/Keyless-Go-3195/

https://www.ididitinc.com/i-25049820-id-touch-keyless-start-ignition-system.html

chevynut
09-14-2018, 12:26 PM
https://dangerousthings.com/shop/xem-access-controller/

55 Rescue Dog
09-14-2018, 02:43 PM
A capacitance proximity sensor can detect a finger, or liquid.

Rick_L
09-14-2018, 03:03 PM
For ignition triggering, a Hall effect sensor is 3 wire - power, ground, and signal. A "magnetic pickup" is 2 wire. The motion produces the power needed. No expert on this stuff, but seems to me that a sensor with external power might work more consistently for slow speed or touch applications, and be less dependent on precision. But I'm no expert on this stuff.

55 Rescue Dog
09-14-2018, 04:37 PM
Pictures of your current setup and what you want it to do, or function like would be good to know?

NickP
09-14-2018, 06:25 PM
https://dangerousthings.com/shop/xem-access-controller/

LOL, that's what Stephen King's Mr. Mercedes used to get into a car.

55 Tony
09-15-2018, 03:10 PM
A hall effect is more common, I believe they are still used in keyboards. Either one would without a doubt need some electronic circuitry to boost the signal. The output of either won't be strong enough to trigger the smallest relay. Also you will still need to move either a small magnet or piece of ferrous metal to make it work, or you are buying it as a package and will look like any other switch you can buy. The only reason they are used is because of their reliability. Think of a distributor, the points do last long, but still they have a definite lifespan. Not so with the hall or proximity sensor. They can last indefinitely. (not so if you have a MSD LOL) Anyway, I think I'd look for some type of fancy switch(es).

55 Rescue Dog
09-15-2018, 03:48 PM
If someone could market a 12 volt PLC (programmable logic controller) for automobiles, that would be great. An idea I've had for years. I'm sure it could be easily done, and then you could use electronic switching for inputs, and have built in programmable relay outputs. Wireless switches are another possibility. It would be fun to just program turn signal flashing, and sequence anything with just a lap top.