Product manual

8
1129_0_Product_Manual - November 5, 2009 2:13 PM
Technical Information
TheTouchSensorchangesvaluefrom0to1000whenitistouched.Morespecically,thissensorisactuallya
capacitive change sensor. When the capacitance changes the sensor reports a thousand. If the sensor remains at
1000 for longer than 60 seconds, it will recalibrate back down to zero, regardless if the sensor is still being touched.
This recalibration can also be done manually by unplugging and plugging the sensor back into the Interface kit.
On the bottom side of the Touch Sensor there is a small exposed metallic pad. A soldered connection can be made
to the pad to increase the size and dimensions of the touchable area, such as attaching the sensor to a metallic
object or some wire. Once the sensor is recalibrated, the sensor’s value will increase to 1000 if the attached object
is touched anywhere.
Although there is an exposed metallic pad on the bottom of the board, the pad does not have to be touched directly
to activate the sensor - touching anywhere on the board will activate the sensor. The sensor can work as a close
proximity sensor, sensing objects at a distance of up to 1/2” from the board in all directions without direct contact.
The Touch sensor will also work through a thickness of up to 1/2” of glass, plastic, or paper.
Other Interfacing Alternatives
If you want maximum accuracy, you can use the RawSensorValue property from the PhidgetInterfaceKit. To adjust a
formula, substitute (SensorValue) with (RawSensorValue / 4.095)
If the sensor is being interfaced to your own Analog to Digital Converter and not a Phidget device, our formulas can
bemodiedbyreplacing(SensorValue)with(Vin*200).Itisimportanttoconsiderthevoltagereferenceandinput
voltage range of your ADC for full accuracy and range.
Analog Input Cable Connectors
Each Analog Input uses a 3-pin, 0.100 inch pitch locking connector.
Pictured here is a plug with the connections labeled. The connectors
are commonly available - refer to the Table below for manufacturer part
numbers.
Cable Connectors
Manufacturer Part Number Description
Molex 50-57-9403 3 Position Cable Connector
Molex 16-02-0102 Wire Crimp Insert for Cable Connector
Molex 70543-0002 3 Position Vertical PCB Connector
Molex 70553-0002 3 Position Right-Angle PCB Connector (Gold)
Molex 70553-0037 3 Position Right-Angle PCB Connector (Tin)
Molex 15-91-2035 3 Position Right-Angle PCB Connector - Surface Mount
Note: Most of the above components can be bought at www.digikey.com