How do I offset an output

[Wes]

I'm playing with a 1302 linear hall effect sensor. It has an output that is about 1/2
supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or more than half of
supply.

What kind of circuit would I use to make its normal 1/2 supply voltage output equal to
zero volt? I'd need it to swing + and -.

I'd be thrilled if some one would give me the keywords to search for this circuit.

Thanks,

Wes
--
"There is only one basic human right, the right to do as you damn well
please. And with it comes the only basic human duty, the duty to take the
consequences." -- PJ O'Rourke

 

[Baron]

Wes wrote:

I'm playing with a 1302 linear hall effect sensor. It has an output
that is about 1/2 supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or
more than half of supply.

What kind of circuit would I use to make its normal 1/2 supply voltage
output equal to
zero volt? I'd need it to swing + and -.

I'd be thrilled if some one would give me the keywords to search for
this circuit.

Thanks,

Wes
--
"There is only one basic human right, the right to do as you damn
well please. And with it comes the only basic human duty, the duty to
take the consequences." -- PJ O'Rourke

Balanced supply, + gnd -

--
Best Regards:
Baron.

 

[Charles]

"Wes" <clutch@lycos.com> wrote in message
news:_ZAsl.20909$Yx2.19957@en-nntp-06.dc1.easynews.com...

I'm playing with a 1302 linear hall effect sensor. It has an output that
is about 1/2
supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or more
than half of
supply.

What kind of circuit would I use to make its normal 1/2 supply voltage
output equal to
zero volt? I'd need it to swing + and -.

I'd be thrilled if some one would give me the keywords to search for this
circuit.

An op-amp is one way to go.

You can set up a voltage divider to bias one input of the op-amp to equal
the dc offset of the sensor.

 

[Jamie]

Wes wrote:

I'm playing with a 1302 linear hall effect sensor. It has an output that is about 1/2
supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or more than half of
supply.

What kind of circuit would I use to make its normal 1/2 supply voltage output equal to
zero volt? I'd need it to swing + and -.

I'd be thrilled if some one would give me the keywords to search for this circuit.

Thanks,

Wes
--
"There is only one basic human right, the right to do as you damn well
please. And with it comes the only basic human duty, the duty to take the
consequences." -- PJ O'Rourke
If this unit has it's own power source, use a virtual ground, other

wise use a DC-DC converter with dual rail with respect to common, or
a double output and combined 2 legs to make a CT with +/- rail.

Or, use a 555 timer into a regulator of some kind to generate a (-)
voltage rail for the sensor.



http://webpages.charter.net/jamie_5"

 

[whit3rd]

On Mar 7, 1:41 pm, Wes <clu...@lycos.com> wrote:

I'm playing with a 1302 linear hall effect sensor.  It has an output that is about 1/2
supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or more than half of
supply.  

What kind of circuit would I use to make its normal 1/2 supply voltage output equal to
zero volt?

You'd use a split power supply (like, if it's running on 8V,
you'd make a +4V and a -4V pair of power sources).

You can use an operational amplifier and summing
junction, or an instrumentation amplifier, to get the
same effect.

Or, you can put a battery and potentiometer in series with the
output.

Or, wire a potentiometer to V+ and V-, tweak its output to the
zero-field value, and declare that output to be ground.
If your readout device is a multimeter, this is the easy option.

 

[Wes]

whit3rd <whit3rd@gmail.com> wrote:

On Mar 7, 1:41 pm, Wes <clu...@lycos.com> wrote:
I'm playing with a 1302 linear hall effect sensor.  It has an output that is about 1/2
supply voltage when not in a magnetic field.

Depending on polarity of magnetic field it outputs less than half or more than half of
supply.  

What kind of circuit would I use to make its normal 1/2 supply voltage output equal to
zero volt?

You'd use a split power supply (like, if it's running on 8V,
you'd make a +4V and a -4V pair of power sources).

You can use an operational amplifier and summing
junction, or an instrumentation amplifier, to get the
same effect.

Or, you can put a battery and potentiometer in series with the
output.

Or, wire a potentiometer to V+ and V-, tweak its output to the
zero-field value, and declare that output to be ground.
If your readout device is a multimeter, this is the easy option.

Thank you and the others, I'll give your last suggestion a try. I think this is what the
original respondant was trying to tell me.

Wes