The **MF-R010** is a Radial Leaded Multifuse (PTC Resettable Fuse) manufactured by **Bourns**. It is designed to protect electronic circuits from overcurrent conditions by increasing its resistance when a fault occurs. --- ## 1. Core Technical Specifications The following table summarizes the key electrical characteristics of the MF-R010: | Parameter | Specification | Description | | :--- | :--- | :--- | | **$I_{hold}$** | 0.10 Amps | The maximum current the device will hold without tripping. | | **$I_{trip}$** | 0.20 Amps | The minimum current at which the device will trip. | | **$V_{max}$** | 60 Volts | The maximum voltage the device can withstand without damage. | | **$I_{max}$** | 40 Amps | The maximum fault current the device can safely handle. | | **$P_d$ (Typ.)** | 0.38 Watts | Power dissipated from the device when in the tripped state. | | **$R_{min}$** | 2.50 $\Omega$ | Minimum resistance before the first trip. | | **$R_{max}$** | 4.50 $\Omega$ | Maximum resistance before the first trip. | --- ## 2. Functionality and Mechanism The MF-R010 operates based on the **Polymeric Positive Temperature Coefficient (PPTC)** principle: 1. **Normal Operation:** At room temperature and rated current, the conductive particles within the polymer form low-resistance chains, allowing current to flow easily. 2. **Fault Condition:** When an overcurrent or short circuit occurs, the temperature of the device rises (Joule heating). 3. **Tripping:** Once the temperature reaches a critical threshold, the polymer expands, breaking the conductive chains. The resistance increases exponentially, limiting the current to a safe leakage level. 4. **Resetting:** Once the fault is removed and the device cools down, the polymer contracts, the conductive paths are restored, and the fuse "resets" itself. --- ## 3. Physical Characteristics and Dimensions * **Lead Type:** Radial (Through-hole). * **Material:** Tin-plated copper leads. * **Encapsulation:** Cured, flame-retardant epoxy polymer (meeting UL 94V-0 requirements). * **Typical Dimensions:** Usually around 7.4mm in width and 11.6mm in height (refer to specific datasheet for exact tolerances). --- ## 4. Typical Applications Because of its low hold current (100mA), the MF-R010 is commonly used in: * **Telecommunications:** Protection against power cross-over. * **Industrial Controls:** Low-voltage sensor protection. * **Computer Peripherals:** USB port and keyboard/mouse protection. * **Battery Packs:** Preventing damage from external short circuits.