Overview — the auxiliary tier of the new-energy power-conversion family

The Youlai new-energy power-conversion family covers four roles on a modern electric commercial vehicle, layered by power scale:

  • Heavy-duty tier — EBX-2314 HV-DCDC controller (36 kW HV→24 V) · EBX-2514 HV-DCAC inverter (30 kW HV→220 VAC VTL)
  • Mid-duty tier — EBX-2512 integrated 6 kW HV-DCDC
  • 24V→12V main tier — EBX-2407 dual-battery equaliser (24V→12V step-down + cell balancing, 100A / 30A SKUs)
  • Auxiliary tier — the EBX-2515, this product — an isolated 12 V supply for an independent 12 V sub-system

The auxiliary tier solves a problem that the main 24V→12V tier does not address: galvanic isolation. The EBX-2407 dual-battery equaliser is a high-current non-isolated step-down that supplies the main 12 V auxiliary bus shared with the rest of the vehicle — cabin radio, dash-cam, telematics, lighting, USB charging. Any 12 V load that draws from the EBX-2407 output shares the same ground reference as the vehicle 24 V system; any common-mode noise on the 24 V system propagates straight onto the 12 V supply. For most 12 V loads that is fine. But for sensitive sub-systems — an independent 12 V data-acquisition cluster doing high-resolution analog measurement, a precision instrument that needs a clean ground reference, an independent 12 V CAN node that needs to be floated against the main vehicle network, a process-control sub-system in an industrial deployment — the shared-ground arrangement injects measurable noise into the measurement loop.

The EBX-2515 inserts a 1000 VDC galvanic isolation barrier between the input side and the output side. The primary side connects to the 24 V auxiliary bus (or the 12 V or 30 V variants across the 9-36 V input window); the secondary side delivers a clean regulated 12 V / 15 A that has its own ground reference, isolated from the input ground by the 1000 V barrier. Common-mode noise on the input ground does not reach the secondary side; the secondary side can be floated against the rest of the vehicle electrical system for sensitive measurement work; the input side can suffer a transient ground fault without dragging the secondary side down with it.

Engineering details

1000 VDC primary-to-secondary galvanic isolation

The 1000 VDC isolation barrier is the headline feature. The barrier is achieved through a transformer-coupled topology: the input-side switching stage drives a high-frequency transformer (operating at the 100 kHz switching frequency), the secondary side rectifies and regulates the output, and the only coupling between primary and secondary is the magnetic-flux path through the transformer core. There is no electrical conductor that crosses the barrier — even on a worst-case primary-side fault, the secondary side stays isolated.

Wide 9-36 VDC input window

The wide input window covers three nominal supply voltages with one SKU:

  • 12 V class (Vin around 12 V) — light commercial vehicles, passenger-car derivatives, agricultural machinery; conversion efficiency 83.3 % typical at this corner
  • 24 V class (Vin around 24 V) — the typical commercial-vehicle operating point; conversion efficiency 91.5 % typical, very close to the module's peak efficiency
  • 30 V class (Vin around 30 V) — the upper end of the 24 V class working window when the alternator / DCDC is in top-of-charge state; conversion efficiency 91.9 % typical, the module's highest-efficiency operating point

Across the rated input window the peak efficiency reaches 92.2 %. The wide input window also gives the OEM the freedom to use the same SKU across multiple platform programmes — one inventory line, one approval cycle, one supplier qualification effort.

Built-in protection envelope

The protection state machine covers all four classes of failure mode on a DCDC module:

  • Under-voltage — the input side reaching the under-voltage threshold disables the switching stage to avoid running the regulator in an indeterminate state; the module auto-recovers when the input returns to the working window
  • Over-current — the output current is clamped at the 17 A limit; sustained over-current trips the output
  • Output short-circuit — an output-side short triggers the protection state machine within microseconds; the module attempts a hiccup-mode restart at a low duty cycle, and auto-recovers when the short is cleared
  • Over-temperature — internal body temperature reaching 110 °C trips the output; auto-recovery on cool-down to a safe threshold

Die-cast aluminium + organic-silica-gel potting + IP67

The mechanical construction is built for rugged deployment. The die-cast aluminium-alloy housing gives the module a metal-grade structural envelope and the primary thermal-shed path (heat is conducted from the internal PCBA through the potting compound to the aluminium walls and then to ambient via natural convection over the fin surface). The organic-silica-gel potting bonds the PCBA to the housing for both thermal conduction (fast natural-convection heat-shed without needing external cooling) and mechanical-shock damping (the potting damps the resonance modes of the PCBA against the long-vibration commercial-vehicle profile). IP67 ingress rating — dust-tight and water-tight to 1 m / 30 min immersion, suitable for under-dash, chassis-side or industrial-cabinet placement.

Mechanical drawing — top + side views

EBX-2515 mechanical engineering drawing — top view with four corner mounting holes (Ø6.3 mm) and finned heat-shed surface, side view with low-profile body height
EBX-2515 mechanical engineering drawing — 79 (W) × 101 (D) × 39 (H) mm body envelope (69.5 mm internal width / 48.5 mm internal depth / 26 mm mounting-hole edge clearance). Four Ø6.3 mm mounting holes on the corner flanges accept M-class mounting bolts for direct chassis-side fastening. Side view (lower section) shows the low-profile 39 mm body height with the recessed multi-conductor pigtail exit on the side face.

Output electrical characteristics reference

EBX-2515 output electrical characteristics reference table — full output spec including voltage / current / power / efficiency / ripple / switching frequency / soft-start / over-temperature / working temperature
EBX-2515 / VT-DD241215S output electrical characteristics reference — output voltage min 11.7 / typical 12.0 / max 12.3 VDC, output current typical 15 A (max 16 A peak, not for sustained use), output power typical 180 W (max 190.4 W peak, not for sustained use), output current limit 17 A, conversion efficiency typical 83.3 % @ 12 V / 91.5 % @ 24 V / 91.9 % @ 30 V (peak 92.2 % across the rated window, min 78.2 %), output ripple at 20 MHz bandwidth 1760 mVp-p @ 12 V / 1600 mVp-p @ 24 V / 1360 mVp-p @ 30 V (max 2480 mVp-p), switching frequency 100 kHz, soft-start time 20 ms, internal over-temperature trip 110 °C, working ambient −40 ~ +85 °C.

Input efficiency reference

EBX-2515 input voltage / no-load current / output voltage / output current / efficiency reference table
EBX-2515 input-side reference — typical input voltage points 12 / 24 / 30 VDC (full range 9-36 V), absolute maximum 36 V, no-load input current typical 105 mA at Vin = 12 V / 41 mA at Vin = 24 V / 31 mA at Vin = 30 V (note the inverse-with-Vin relationship, characteristic of an efficient switching topology); full-load efficiency 83.3 % at Vin = 12 V / 91.5 % at Vin = 24 V / 91.9 % at Vin = 30 V.

Headline feature list

EBX-2515 headline feature list — wide input, 180W output, 92.2% efficiency, 105mA no-load, 1000 Vdc isolation, 4-class protection, organic-silica-gel potting, die-cast aluminium, IP67, −40~+85°C
EBX-2515 OEM-side headline feature summary: wide 9-36 VDC input · 12 V / 180 W output · up to 92.2 % conversion efficiency · typical 105 mA no-load current · 1000 VDC primary-to-secondary isolation · full protection envelope (under-voltage, over-current, output short-circuit, over-temperature) · organic-silica-gel potting process · die-cast aluminium housing for fast natural-convection cooling · IP67 ingress · −40 to +85 °C working ambient.

Comparison with the related Youlai 12 V supply modules

ModelInputOutputIsolationFunctionTypical use
EBX-25159-36 VDC (wide)12 V / 15 A / 180 W1000 VDC galvanicIsolated step-down for an independent 12 V sub-systemSensitive sensor / DAQ / industrial sub-system
EBX-240716-32 VDC (24V series-stack)12 V / 100A or 30A SKUNon-isolatedMain 24V→12V supply + dual-battery cell balancingMain 12 V auxiliary bus on a 24 V vehicle

The EBX-2515 is the right choice when an independent 12 V sub-system on a 24 V vehicle (or any deployment that needs an isolated 12 V rail from a wide-input DC source) needs a clean isolated supply with up to 180 W of regulated output, decoupled by 1000 V from the main vehicle electrical ground. For the high-current non-isolated main 24V→12V supply (with built-in dual-battery balancing) for the whole vehicle 12 V auxiliary bus, look at EBX-2407.

Manufacturing & testing

Built under IATF 16949 with APQP project planning and a PPAP package available for OEM programmes. Every unit is end-of-line functional-tested before packaging — the input voltage range across the 9-36 VDC envelope at the three reference operating points (12 V / 24 V / 30 V), the 12 V output voltage regulation across the input window (11.7 - 12.3 V envelope), the 15 A continuous output capability, the conversion efficiency measurement at each reference operating point, the 1000 VDC primary-to-secondary isolation withstand check, the output current limit at 17 A, the over-temperature trip at the 110 °C threshold, the output short-circuit hiccup-mode recovery, and the IP67 ingress baseline are all checked.

How to ask

The EBX-2515 belongs to the Smart Control Modules family. To request the harness drawing, the pigtail conductor length / colour-code / termination option, the OEM-side custom-output-voltage variant (12 V is standard, custom voltages negotiable on the VT-DD24xxxxS family), the mounting-bracket option or a PPAP package, please use the contact page with your target vehicle / industrial programme, expected annual volume and key technical requirements (input voltage class, output current need, isolation requirement, ambient-temperature window, mounting orientation, EMC profile, IP rating). Drawings welcome.