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What if sensor output is 0-10 Vdc?

wiki.ubnt.com/MFi-Custom_Sensors#ColliHigh_Illuminometer
This example shows values for the the divider circuit for a 5 volt output sensor.
I want to hook a sensor that has a 0-10Vdc output.

Found this neat little calculator www.raltron.com/cust/tools/voltage_divider.asp

That tells me if I use a 64K resistor on the input A+ and a 16K resistor between G and P the 10 volts should be seen as 2 volts to the mport.
Hopefully that keeps the smoke from releasing!!
Walks in, tells it like it is, walks out , milks a cow
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Re: What if sensor output is 0-10 Vdc?

Um, sure, but this 'calculation' doesn't need
an online tool; it's completely obvious.

It's just the ratio of the voltage dropped
through each resistor. For 10V/2V, simplify
to 5/1; one resistor is 4/5 of the voltage
drop, the other is 1/5 of the drop.

You could use almost any resistor pair you
like, for example 32K and 8K would be fine,
or 8K and 2K.

Let's say the sensor has a 20V output. That's
20V/2V or 10/1. One resistor is 9/10 of the
total, the other is 1/10. So a 90K and 10K resistor,
or 45K and 5K or 9K and 1K--your choice. Dave

> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
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Re: What if sensor output is 0-10 Vdc?

Umm, Dave...

don't forget...the overall resistance of the resistor network needs to be high enough that you don't excessively load the output of the sensor, but not so high as to introduce noise into the ADC. Some judicious filtering often helps.

Remember those good, ol' analog days? I did a heck of a lot of home automation from scratch in the early 80's using National Semiconductor 8-bit ADC0804's and various things scattered around the house (thermistors, etc.). Connected it all to the parallel port of my Ohio Scientific C1P and let it turn stuff on and off based on time and temperature.

Stinkin' Rayburn digital thermostat you can buy for $20 does all that and more now...
SuperUser
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Re: What if sensor output is 0-10 Vdc?

Completely true, Vance--but beyond the
ability of that 'calculator' to account for.

One thing nice about modern chip ADCs
is their high input impedance, or in other
terms, low loading. This means that a
high-impedance sample is fine--and a
high-resistance divider is best. Dave

> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
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Re: What if sensor output is 0-10 Vdc?

Don't forget I milk cows for a living and play with electronics part time for cigarette money and the fun of learning.
Walks in, tells it like it is, walks out , milks a cow
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Re: What if sensor output is 0-10 Vdc?

Just watch out for that middle teat!
Those cows don't want that milked. Dave

> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com