Hall Effects Sensor as Voltage Divider

Thread Starter

rft

Joined Apr 4, 2008
2
Greetings All,

I have a USB game controller that uses 10K conductive plastic pots that always need to be replaced. I wanted to replace these pots with the MAB25A Hall-Effects Sensors by Megatron; however, this sensor only have a single ended analogue output. My controller is expecting something similar to the voltage divider pot. How can I make this work?

I was even considering teaming an optical encoder with a digital pot.
Many thanks for your help and suggestions.
 

SgtWookie

Joined Jul 17, 2007
22,230
Here's the link to a datasheet that I found:
http://www.megatron.de/export/DB_MAB25A_engl.pdf

Basically, you connect it the same way as you would the potentiometer - only in this case, you need to make sure that the Vsup pin is most positive, and the GND pin is connected to the most negative. Note that they only have two supply voltages available; 5 or 24.

If your game controller is a joystick, you probably will need replacement pots with a 90° travel.

A few years ago, I used a Clarostat Hall-effect digital pot to replace a bad throttle position sensor in a Jaguar for which the original part was no longer available. It had a 90° throw, and if I recall correctly, would work from various voltages; much more like a true pot. Such a device would likely work quite well in your application. They were rather expensive though, around $38 each.
Link:
http://www.alliedelec.com/Search/SearchResults.asp?N=0&Ntk=Primary&Ntt=HRS100
(Correction - seems that it needed a 5V supply)

If these pots are to fix joysticks, you might consider using a GM-type throttle position sensor (TPS) which is a pot that has a 90° throw. You may be able to pick up a couple from a junkyard pretty cheaply.
 

Thread Starter

rft

Joined Apr 4, 2008
2
Thanks for your response; I will test tomorrow. Would you mind posting the throttle position sensor that you used for the Jaguar? At $38 each, this is a small price to pay to keep a machine running. My application is for steering using a 360deg pot. At mid range, the steering wheel is centered, towards the left is a left turn and opposite towards the right. I'm assuming a positive voltage for right, neg for left.
 

SgtWookie

Joined Jul 17, 2007
22,230
I posted a link to Allied Electric's page that has a datasheet for the HRS100 pot which I used; $38 and change. Since you are using a steering wheel, perhaps a position sensor limited to 90° travel would not be appropriate; it could make it really hard to maintain control of your simulated vehicle. I suggest you go with your original 360° pot plan instead.
 
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