The UTP3305-II is the precision-grade refresh of UNI-T's UTP3305 platform — the same 335W three-channel linear topology, with a four-digit LED display reading 10 mV / 1 mA, tighter regulation specs and a temperature-controlled cooling fan.
Two adjustable channels deliver 0–32V at 0–5A; a third channel provides a fixed 5V at 3A for logic-level power. Knobs, banana jacks, OVP/OCP via current-limit protection, and a front panel that doesn't require a manual to operate.
Linear regulation keeps output ripple under 1mVrms with no switching artifacts, no EMI signature competing with the circuit you're actually trying to characterize. CH1 and CH2 combine in series (up to 64V) or parallel (up to 10A). Load regulation tightens to CV <0.01% + 3 mV — visible improvement when the load steps and the rail has to hold steady.
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Three Channels, 335W Total — CH1 and CH2: 0–32V / 0–5A adjustable. CH3: fixed 5V / 3A for logic-level power.
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Four-Digit LED Display, 10 mV / 1 mA Resolution — Per-channel voltage and current readouts that read down to 10 mV and 1 mA — fine enough to actually see what the load is doing.
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Tighter Regulation — Load regulation CV <0.01% + 3 mV / CC <0.2% + 3 mA. Tracking accuracy ±(0.1% of reading + 30 mV).
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Linear Topology, ≤1 mVrms Ripple — Clean DC output with no switching frequency, no harmonic spurs.
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Auto CV/CC Crossover — Automatic transition between constant-voltage and constant-current operation when the load steps, with current limit protection.
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Series and Parallel Modes — Combine CH1+CH2 for up to 64V series or 10A parallel — front-panel selectable, no external wiring.
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Temperature-Controlled Cooling Fan — Fan speed scales with internal temperature. Quiet at light loads, full airflow when the supply is working hard.
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Output ON/OFF Control — Front-panel master output button keeps you in command of when current actually leaves the supply.
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Knob-and-Button Operation — No firmware to update, no PC software to install, no LAN port to configure. Front-panel only — designed to behave the same way on day one and year five.
The UTP3305-II keeps the operational simplicity of the UTP3305 — knobs, banana jacks, output ON/OFF — and tightens the parts that matter when your circuit actually responds to the supply. Resolution improves from 100 mV to 10 mV; current resolution drops from 10 mA to 1 mA. Load regulation moves from CV ≤1×10⁻⁴ + 3 mV to CV <0.01% + 3 mV (functionally identical) but with the added programming-accuracy spec ±(0.1% of reading + 30 mV) that the original UTP3305 doesn't publish.
The temperature-controlled cooling fan is a quality-of-life upgrade that matters in classrooms and small-team R&D rooms: the supply is genuinely quiet at moderate loads, and only spins up when you're actually running it hard. The four-digit LED display replaces the original three-digit dual display — same operational language, finer readout.
Applications
Teaching Labs & Trade Schools
Per-station cost that lets a 20-bench classroom stay inside budget, with the precision display students actually need to see what's happening on the rail. Quiet fan operation makes a 30-station lab livable.
Analog Bench Development
10 mV / 1 mA resolution shows the small effects that 100 mV / 10 mA hides — supply load lines, sensor bias drift, op-amp quiescent current. Dual 0–32V / 5A adjustable channels with tight load regulation power op-amp ±supplies, audio amplifiers, and balanced analog stages.
Service & Repair
Reliable bench supply for board-level service work with the resolution to set rails accurately and the current capability to drive higher-power loads. CV/CC auto crossover handles unknown loads safely.
Mixed-Signal Prototyping
Two adjustable rails with master-slave-style behavior in tracking, plus a fixed 5V CH3 for logic, covers most prototyping needs in a single instrument. Linear output stays clean across the full range.
