The 1134 - Switchable Voltage Divider is an adjustable resistor used to create a voltage divider with a variable resistance sensor. The 1134's resistance can be tuned to be close to the resistive sensor by flipping the dip switches on the board. The individual resistance values available (in Ohms) are 249, 820, 2.61K, 8.45K, 27.4K, 91K, 300K and 1M. It is possible to have multiple switches flipped which puts the corresponding resistors in parallel.
The 1134 Provides an interface to non-Phidgets variable resistance sensors such as: Force Sensing Resistors (FSR), light sensors, thermistors (heat sensors), and bend sensors.
|Controlled By||VoltageRatio Input|
|Sensor Output Type||Ratiometric|
|Resistance Min||172 Ω|
|Resistance Max||1 MΩ|
|Current Consumption Max||30 mA|
|Supply Voltage Min||3 V DC|
|Supply Voltage Max||5.3 V DC|
|Optimal Measurement Resistance Min (@172Ω)||17.2 Ω|
|Optimal Measurement Resistance Max (@172Ω)||1.7 kΩ|
|Optimal Measurement Resistance Min (@1MΩ)||100 kΩ|
|Optimal Measurement Resistance Max (@1MΩ)||10 MΩ|
|Load Resistance Max||50 MΩ|
|Load Resistance Resolution||1 %|
|Recommended Wire Size||16 - 26 AWG|
|Operating Temperature Min||-40 °C|
|Operating Temperature Max||105 °C|
|Date||Board Revision||Device Version||Comment|
|March 2010||0||N/A||Product Release|
Welcome to the 1134 user guide! In order to get started, make sure you have the following hardware on hand:
Next, you will need to connect the pieces:
Now that you have everything together, let's start using the 1134!
In order to demonstrate the functionality of the 1134, we will connect it to the 1018, and then run an example using the Phidget Control Panel on a Windows machine.
The Phidget Control Panel is available for use on both macOS and Windows machines. If you would like to follow along, first take a look at the getting started guide for your operating system:
Linux users can follow the getting started with Linux guide and continue reading here for more information about the 1134.
After plugging in the 1134 into the 1018, and the 1018 into your computer, open the Phidget Control Panel. You will see something like this:
The Phidget Control Panel will list all connected Phidgets and associated objects, as well as the following information:
The Phidget Control Panel can also be used to test your device. Double-clicking on an object will open an example.
Double-click on a Voltage Ratio Input object in order to run the example:
General information about the selected object will be displayed at the top of the window. You can also experiment with the following functionality:
The 1134 is a voltage divider with switches. The switches can be used to control which resistors are used in the voltage divider. From left to right, the resistance values (in Ohms) are 249, 820, 2.61K,8.45K, 27.4K, 91K, 300K and 1M. It is possible to have multiple switches flipped, putting the corresponding resistors in parallel.
The Formula to translate voltage from this sensor into resistance is:
Where Req is the equivalent resistance of the switches that are flipped on in Ohms. The Switchable Voltage Divider has an internal buffer on the output. This allows the output to be read without distortion caused by the device reading the measurement, such as the 1018 (or compatible product).
To optimize the 1134 to meet your needs, you have to adjust the switchable resistance to match the characteristics of your chosen variable resistor. First, adjust the resistance for no stimuli on your sensor, then apply maximum stimuli and make sure that the voltage stays within a range that gives you an acceptable resolution. The formula is most accurate at a voltage of 2.5V, with an error of 0.4%. At 0.5V and 4.5V, the error increases to approximately 1.1% and at 0.25V and 4.75V, it increases to 2.1%. As a general rule, if the voltage is over 4.5V, a lower resistance should be switched in. If the voltage is below 0.5V, a higher switch should be toggled. Continue adjusting the switches until you find an acceptable range.
Warning: It is possible for the 1134 to apply up to 5V to the variable resistor. If the resistor cannot handle this voltage, it can be damaged. The 1134 is a very simple way of measuring resistance. When interfacing to sensors with small resistances (like 100Ω RTDs, for instance), large currents can flow - up to 30mA. This level of current may cause substantial heating in the variable resistor, distorting the measurement or even possibly permanently damaging it.
Here are some interesting variable resistance sensors that could be used with the 1134.
|Manufacturer||Sensor Type||Example||Digikey Search|
|CUI Inc.||Force Sensors||IESP-12||force sensor|
|U.S. Sensor||Thermistors||615-1037-ND||thermistor radial|
The Phidget Cable is a 3-pin, 0.100 inch pitch locking connector. Pictured here is a plug with the connections labelled. The connectors are commonly available - refer to the Analog Input Primer for manufacturer part numbers.
This adapter can be used to interface one Interlink FSR. Here's a complete list of all the different varieties we sell:
|Product||Sensor Properties||Physical Properties|
|Image||Part Number||Price||Force Min||Force Max||Sensing Area|
|3103_0||$6.50||1 N||20 N||19.6 mm²|
|3104_0||$7.50||1 N||20 N||126.7 mm²|
|3105_0||$10.00||1 N||20 N||14.5 cm²|
This sensor can be read by any Phidget with an Analog Input or VINT Hub port. It will connect to either one using the included Phidget cable. VINT Hub ports can behave just like Analog Inputs, but have the added flexibility of being able to be used as digital inputs, digital outputs, or ports to communicate with VINT devices. For more information about VINT, see the VINT Primer.
|Image||Part Number||Price||Number of Voltage Inputs||Voltage Input Resolution|
|HUB0000_0||$30.00||6 (Shared)||* 16 bit|
|SBC3003_0||$120.00||6 (Shared)||* 16 bit|
This sensor comes with its own Phidget cable to connect it to an InterfaceKit or Hub, but if you need extras we have a full list down below. You can solder multiple cables together in order to make even longer Phidget cables, but you should be aware of the effects of having long wires in your system.