I need a device that flags voltage drop to $value

wuzamarine

I am trying give more umph/pep/current to a DC motor using super capacitors and one possible solution is to toggle charge to the sups as an energy harvesting technique by monitor a circuit main with a hall effect sensor, for when voltage drops to a given point (about 250mA). In a perfect world where I am emperor, this $value will be adjustable but not required for this prototyping.

Upon depletion to said point/value, device will switch/toggle mains.

over 7 years ago

0 wuzamarine over 7 years ago

Prodigy 250 points

What TI product would be the ideal solution?

0 Rick Duncan over 7 years ago in reply to wuzamarine

TI__Guru** 114905 points

Hi wuzamarine,

Our experts have been contacted and should reply soon.

Other options could be the current sense amplifiers: www.ti.com/.../current-sense-amplifiers-overview.page

0 wuzamarine over 7 years ago in reply to Rick Duncan

Prodigy 250 points

I think you might of hit the nail on the head, especially if low/high side refers to detection of low voltage www.ti.com/.../ina209
Still reading

0 RE over 7 years ago in reply to wuzamarine

TI__Mastermind 20985 points

wuzamarine, welcome to the forum. A Hall effect sensor isn't going to be the right device for measuring voltage. They fundamentally measure magnetic fields (which are generated by current or permanent magnets). I also recommend looking into shunt resistors.

Best regards,
RE

0 wuzamarine over 7 years ago in reply to wuzamarine

Prodigy 250 points

hmmm. it requires a 3.3v charge to do its job. more power. It would be nice if there was a mosfet level solution.

0 wuzamarine over 7 years ago in reply to RE

Prodigy 250 points

I see how shunt would work if I was looking for voltage 'increases', but not decreases
en.wikipedia.org/.../Shunt_(electrical)
But yes, I need an inverse shunt resistor.

0 RE over 7 years ago in reply to wuzamarine

TI__Mastermind 20985 points

If you have an MCU that can read the analog measurement from its ADC, it could handle the voltage increase or decrease any way that your firmware decides. Or as another idea, a comparator device can convert an analog voltage to a digital 0 or 1 once the input crosses the reference threshold. Also, take a look at instrumentation amplifiers. Good luck!

Best regards,
RE

0 wuzamarine over 7 years ago in reply to RE

Prodigy 250 points

RE said:
If you have an MCU that can read the analog measurement from its ADC, it could handle the voltage increase or decrease any way that your firmware decides. Or as another idea, a comparator device can convert an analog voltage to a digital 0 or 1 once the input crosses the reference threshold. Also, take a look at instrumentation amplifiers. Good luck!

Best regards,
RE

I do have a msp-430fr5994 that I just slapped the training wheels on and just took Blink.c for my first spin around the block.

I am realizing this gizmo has many features that might be of use as this project takes off and is the correct platform to be on. But on this project, the MCU is about step #6 and I'm still on step #2 and really hoping to avoid plugging in a 3 or 5v power supply for something that should be transistor level logic.

I still have a little ways to go before I'm productive on this Launchpad, but getting there.

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I need a device that flags voltage drop to $value