A programmable resistor is designed to emulate the use of resistive sensors and variable resistors in systems when testing devices such as engine controllers.
Resistor chain used in a typical programmable resistor
Pickering's programmable resistors in their simplest form consist of a basic chain of resistance values switched in or out of the circuit with reed relays, electro-mechanical relays, or solid-state switches. We also offer multi-channel programmable resistors with very fine value adjustment and high accuracy, including programmable resistive bridges for strain gauge simulation.
Two-channel precision programmable resistor with calibration facility
Applications for Programmable Resistors
Programmable resistors have many applications in electronic test, verification and simulation systems:
- Strain Gauge Simulation
- Used in mechanical systems to measure the tension or compression of structural components. Simulation requires extremely fine setting resolution with high accuracy and temperature stability.
- Used in mechanical systems to measure the tension or compression of structural components. Simulation requires extremely fine setting resolution with high accuracy and temperature stability.
- Temperature Sensor Simulation
- Simulation of resistance-based temperature sensors such as positive or negative temperature coefficient thermistors.
- Resistance Temperature Detectors (RTDs) can be wire-wound or thin film. Both PT100 and PT1000 types can be simulated, requiring fine setting resolution.
- Pressure Sensor Simulation
- For the simulation of pressure senders in mechanical systems or barometric pressure sensors in applications such as altimeters in the aerospace industry.
- For the simulation of pressure senders in mechanical systems or barometric pressure sensors in applications such as altimeters in the aerospace industry.
- Select on Test Resistance
- A programmable resistor can be used in a test environment where a component's value is optimized at the production test stage.
- A programmable resistor can be used in a test environment where a component's value is optimized at the production test stage.
- Load Resistor
- Where a circuit under test requires the connection of an external load.
- Where a circuit under test requires the connection of an external load.
- Position Sensor Simulation
- Rotary or linear position sensors in mechanical systems usually take the form of potentiometers and are used in applications such as throttle position senders in automotive systems.
- Rotary or linear position sensors in mechanical systems usually take the form of potentiometers and are used in applications such as throttle position senders in automotive systems.
- Switch Simulation
- Can be used to simulate the contacts of a worn or contaminated switch for automotive ECU (Engine Control Unit) testing.
- Can be used to simulate the contacts of a worn or contaminated switch for automotive ECU (Engine Control Unit) testing.
- Fault Insertion
- Can be used for injecting fault conditions when testing the fault tolerance of aircraft or automotive control systems.
- Can be used for injecting fault conditions when testing the fault tolerance of aircraft or automotive control systems.
Selecting a Programmable Resistor
Pickering offers a variety of PXI programmable resistor modules and PCI programmable resistor cards for use in medical, automotive and aerospace applications. We offer different features for use in different applications; these include:
- Platform
- Solutions in both the PXI and PCI formats
- Ethernet control of any of our PXI modules when installed in our LXI Chassis
- Number of Channels
- Between 1 and 18 channels
- Between 1 and 18 channels
- Range
- Many resistance ranges are available with values from a short circuit to millions of Ohms
- Modules and cards are available with a narrow setting range and very fine resolution for simulating sensors and strain gauges
- Resolution
- Resistance setting resolutions are available from 10Ω to 2mΩ for a wide range of applications
- Resistance setting resolutions are available from 10Ω to 2mΩ for a wide range of applications
- Power Handling
- Generally 100mW for precision programmable resistors and up to 1W for standard programmable resistors
- We also offer a PXI programmable load module with up to 15W power handling (model 40-292)
- Minimum Resistance Value
- The lower the minimum resistance value required, the greater the errors caused by relay contact resistance and copper trace losses.
- Generally, modules and cards with a low minimum resistance do not have as wide a range of resistance values as those with higher minimum resistances.
- Accuracy
- High accuracy requires careful design to ensure low loss paths, management of thermoelectric EMF and the use of higher stability resistors
- High accuracy requires careful design to ensure low loss paths, management of thermoelectric EMF and the use of higher stability resistors
- Calibration Port
- A calibration port allows the user to check the resistor channel without disconnecting the front panel connector. It can be used to connect any of the resistor channels to a DMM to perform an accurate four-terminal measurement.
- A calibration port allows the user to check the resistor channel without disconnecting the front panel connector. It can be used to connect any of the resistor channels to a DMM to perform an accurate four-terminal measurement.
- Custom Programmable Resistors
- If the desired accuracy, precision, range, number of channels, power handling, etc., is not available, we can often configure custom builds or even design a new version of a PXI/PCI model.
We carry over 130 PXI modules and over 120 PCI cards featuring:
- Up to 18 channels in a single PXI/PCI slot
- Resistance ranges from 1Ω to 22MΩ
- Resolutions down to 2mΩ with accuracies down to 0.03%
- PXI modules can be supported in our LXI Chassis
- Supported by a full range of connector and cabling solutions
Learn more about programmable resistors on our Knowledgebase or by downloading our free whitepaper, "Understanding Programmable Resistors for Sensor Simulation in Test."
