Remote SENSE is a four-wire connection that lets a DC power supply measure voltage at the DUT instead of only at its output terminals. Two force leads carry the load current. Two separate sense leads measure the DUT-side voltage so the regulation loop can compensate for voltage drop in the force leads.
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What Remote SENSE does
With local sensing, the supply regulates voltage near its own output terminals. Resistance in the force leads and connectors then creates a voltage difference at the load. The difference grows as output current increases.
Remote SENSE moves the measurement point to the DUT terminals. The supply compares the sensed DUT voltage with the setpoint and adjusts its output within the model’s compensation range. The sense inputs carry very little current, so their voltage drop is much smaller than the drop in the force leads.
How four-wire wiring works
| Connection | Purpose |
|---|---|
| Force positive and force negative | Carry the programmed output current from the supply to the DUT. |
| Sense positive and sense negative | Measure voltage directly at the DUT terminals. |
| DUT connection point | Defines the voltage that the feedback loop regulates. |
| Supply configuration | Enables Remote SENSE according to the exact model manual, terminals or jumpers. |
The force pair handles power. The sense pair handles measurement. Connecting the sense leads at the supply terminals defeats the purpose of measuring the DUT-side voltage.
Why cable drop changes the DUT voltage
The voltage loss in a force lead follows the current through the lead and its resistance. A low-current board may lose only a small amount, while a high-current fixture can lose enough to move the DUT outside its test tolerance. Connector contacts, terminal blocks and protection devices in the power path add to the same error.
For example, a supply set to 12V at its own terminals may deliver less than 12V at a board when the force leads carry a large current. Remote SENSE measures the board-side voltage and lets a supported supply raise its terminal output to compensate within its specified range. The actual result depends on current, cable resistance, connector quality and the model’s headroom.
Remote SENSE wiring practices
Use a separate pair for the force leads and a separate pair for the sense leads. Twisted pairs can reduce loop area and pickup. Keep the sense connections close to the DUT terminals and match +Sense to the positive load terminal and −Sense to the negative load terminal.
The permitted lead length, wire size, routing and terminal hardware depend on the power supply model. The sense path is a feedback connection, so switches, relays or other series components should only be used when the manufacturer’s wiring instructions allow them.
Correct polarity matters. A reversed sense connection can make the regulation loop respond in the wrong direction. The model manual defines the correct local/remote setting and the connection used when Remote SENSE is not enabled.
Common wiring mistakes
- Connecting +Sense and −Sense with reversed polarity.
- Connecting the sense leads at the supply terminals instead of at the DUT.
- Routing the sense pair beside a noisy high-current loop without following the instrument guidance.
- Leaving the sense terminals open when the model requires a local-sense link or defined fallback.
- Using a force cable, connector or terminal that is not rated for the load current.
The correct local/remote setting, terminal link and safe fallback condition are model-specific. The wiring diagram supplied for the exact instrument should be used when the setup is commissioned or changed.
Compensation limits and open-sense behavior
Remote SENSE has a defined compensation range. The supply needs enough output headroom to raise its terminal voltage by the force-lead drop while staying inside its voltage and power limits. Cable resistance, output current and connector resistance determine how much compensation the application needs.
Open-sense behavior is model-specific. A disconnected sense lead can produce a protection response, a local-sense fallback or an incorrect load voltage depending on the instrument design. Sense-input protection, maximum compensation, permitted lead resistance and safe fallback wiring belong to the exact model documentation.
Remote SENSE corrects the specified steady-state load-side voltage error. It does not remove force-lead heating, connector resistance or the need for correctly rated cables.
When a supply with Remote SENSE is useful
Remote SENSE is useful for high-current boards, long output leads, burn-in fixtures, automated test stations and any DUT with a tight voltage tolerance at its terminals. It is less important when the load current is low and the supply can sit close to the DUT with short leads.
For repeated tests, programmable setpoints, output enable, presets and a documented remote interface can make the setup more consistent. Remote SENSE regulates the load-side voltage; it does not by itself provide test automation.
Related programmable and high-current supplies
The Programmable DC Power Supply category is relevant when repeatable setpoints, output control or remote operation are part of the test. The High-Current Programmable DC Power Supply range is relevant when load current and force-lead drop are central to the setup.
Remote SENSE operating limits
| Specification | Why it matters |
|---|---|
| Sense terminals | S+ and S− locations, polarity and local/remote selection. |
| Compensation range | Maximum load-side drop the supply can correct. |
| Headroom | Available output voltage and power while compensating. |
| Open-sense behavior | Protection, fallback and safe wiring condition. |
| Lead limits | Permitted resistance, length, routing and wire size. |
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