Products for USB Sensing and Control
Products for USB Sensing and Control

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## Switchable Voltage Divider

ID: 1134_0
This product will not be produced again, and will be discontinued once it runs out of stock. It's possible that exceptions could be made for high-volume customers. Contact sales@phidgets.com to discuss options. For measuring platinum RTDs, you should consider using the TMP1200 instead.

This adapter lets you interface with all sorts of non-Phidgets resistance sensors, just select the resistance you want.

## $15.00 Quantity Available: 219 Qty Price 5$14.25
10 $13.50 25$12.00
50 $10.50 100$9.75

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.

#### Comes packaged with

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 #### Interface Boards and Hubs 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. Product Voltage Inputs Image Part Number Price Number of Voltage Inputs Voltage Input Resolution 1010_0$80.00 8 10 bit
1011_0 $50.00 2 10 bit 1018_2B$80.00 8 10 bit
1019_1B $110.00 8 10 bit 1203_2B$70.00 8 10 bit
DAQ1000_0 $20.00 8 12 bit HUB0000_0$30.00 6 (Shared) * 16 bit
SBC3003_0 $120.00 6 (Shared) * 16 bit #### Phidget Cables 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. Product Physical Properties Image Part Number Price Cable Length 3002_0$2.00 600 mm
3003_0 $1.50 100 mm 3004_0$3.00 3.5 m
3034_0 $1.50 150 mm 3038_0$2.25 1.2 m
3039_0 $2.75 1.8 m CBL4104_0$1.75 300 mm
CBL4105_0 $2.00 900 mm CBL4106_0$2.50 1.5 m

## Getting Started

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:

1. Connect the 1134 to the HUB0000 with the Phidget cable.
2. Connect a variable resistance sensor to the terminal block on the 1134.
3. Select an appropriate measurement range for your application by toggling the desired DIP switch. We are toggling the 27.4K switch. When the switch is down, the associated measuring resistor is selected. It is possible to have more than one switch toggled and have the resistors in parallel.
4. Connect the HUB0000 to your computer with the USB cable.

Now that you have everything together, let's start using the 1134!

## Using the 1134

### Phidget Control Panel

In order to demonstrate the functionality of the 1134, we will connect it to the HUB0000, 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:

### First Look

After plugging in the 1134 into the HUB0000, and the HUB0000 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:

• Serial number: allows you to differentiate between similar Phidgets.
• Channel: allows you to differentiate between similar objects on a Phidget.
• Version number: corresponds to the firmware version your Phidget is running. If your Phidget is listed in red, your firmware is out of date. Update the firmware by double-clicking the entry.

The Phidget Control Panel can also be used to test your device. Double-clicking on an object will open an example.

### Voltage Ratio Input

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:

• Modify the change trigger and/or data interval value by dragging the sliders. For more information on these settings, see the data interval/change trigger page.
• Select the 1134 from the Sensor Type drop-down menu. The Sensor Value will now return a value between 0 and 1.

## Technical Details

### General

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.

### Formulas

The Formula to translate voltage ratio from this sensor into resistance is:

${\displaystyle {\text{Resistance (Ohms)}}=R_{eq}\times {\frac {1}{{\text{VoltageRatio}}-0.001}}}$

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 HUB0000 (or compatible product).

### Configuring the Voltage Divider

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.

### Variable resistance sensors

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 IMAGES Bend Sensors FLX-01 n/a

### Phidget Cable

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.

## What to do Next

• Programming Languages - Find your preferred programming language here and learn how to write your own code with Phidgets!
• Phidget Programming Basics - Once you have set up Phidgets to work with your programming environment, we recommend you read our page on to learn the fundamentals of programming with Phidgets.

This device doesn't have an API of its own. It is controlled by opening a VoltageRatioInput channel on the Phidget that it's connected to. For a list of compatible Phidgets with VoltageRatio Inputs, see the Connection & Compatibility tab.

You can find details for the VoltageRatioInput API on the API tab for the Phidget that this sensor connects to.

#### Product History

Date Board Revision Device Version Comment
March 2010 0 N/A Product Release

#### Product Specifications

Sensor Properties
Sensor Type Resistance
Controlled By VoltageRatio Input
Sensor Output Type Ratiometric
Resistance Min 172 Ω
Resistance Max 1 MΩ
Electrical Properties
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
1121_0 $7.00 1 kΩ 21 kΩ 1134_0$15.00 172 Ω 1 MΩ