F4901 1.1a 24v Schematic Jun 2026
is a surface-mount , specifically identified in design documentation as POLYSW-1D1A24V-GP-U . Model Designation: Manufacturer Part Series: PolySwitch Secondary ID: 69.50007.A41 2. Technical Specifications
+24V DC Input │ ▼ ┌──────────────┐ │ F4901 Fuse │ (1.1A, 24V Resettable/Standard) └──────┬───────┘ │ ├──────────────┐ │ │ ▼ ▼ ┌──────────┐ ┌──────────┐ │ TVS │ │ Bypass │ │ Diode │ │ Cap. │ └────┬─────┘ └────┬─────┘ │ │ ▼ ▼ ───────┴──────────────┴─────── GND │ ▼ To Downstream Circuit (Load < 1.1A) Schematic Node Breakdown:
The designation typically refers to a specialized circuit protection footprint—most commonly an surface-mount (SMD) resettable PTC fuse or a dedicated fast-acting fuse block rated for 1.1 Amperes at a maximum operating voltage of 24 Volts DC.
The F4901 is composed of a non-conductive polymer matrix filled with carbon black particles. At normal operating currents, these particles form dense conductive chains, allowing current to pass with minimal resistance (often only a few milliohms, designated as Rmincap R sub m i n end-sub R1maxcap R sub 1 m a x end-sub When a short circuit or overcurrent condition occurs: I2Rcap I squared cap R
Check the operational temperature inside the enclosure. If the ambient air is very hot, a 1.1A PPTC fuse will trip at much lower currents. You may need to add a soft-start circuit to manage inrush current. 3. F4901 is Physically Scorched or Discolored f4901 1.1a 24v schematic
Based on cross-referencing databases and common Chinese power supply topologies, the F4901 is highly likely a or a DC-DC buck converter with the following characteristics:
Severe ambient thermal issues or high inrush currents from large downstream capacitors.
If you have confirmed that the fuse is blown, here are your next steps:
Without a specific datasheet or more detailed description of what "F4901 1.1A 24V" refers to, providing an exact schematic is not feasible. Electronic part numbers can vary significantly between manufacturers, and without the correct datasheet, any attempt to describe or draw a schematic would be speculative. is a surface-mount , specifically identified in design
Look for generic "24V 1A Buck Converter" modules on LCSC or Mouser – they will almost perfectly match the F4901 pinout described in this article.
When a laptop like the Acer Aspire 5560G experiences a "black screen" but still powers on, technicians often check the F4901 fuse for continuity. If this fuse is blown, it breaks the circuit for the screen's backlight.
28V to 48V DC Output: 24V DC @ 1.1A Efficiency: ~88%
PLC (Programmable Logic Controller) I/O digital input/output protection blocks. If the ambient air is very hot, a 1
The fuse trips below the 1.1A threshold. This is usually caused by high ambient temperatures inside the enclosure. PPTC fuses must be derated if operating environments exceed 25°C.
[Source] -> [F4901] -> [TVS Diode to GND] -> [Load] 3. Footprint and Mounting
current (2.2A), the F4901 cannot generate enough internal heat to trip effectively. To help narrow down your design, tell me:
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