The **FRT-64-R** is an ultra-miniature, polarized SMT (Surface Mount Technology) signal relay manufactured by **NEC/TOKIN** (now part of KEMET). It is widely used in telecommunications, medical equipment, and security systems due to its small footprint and high reliability. --- ## 1. Key Technical Specifications The "FRT-64-R" designation refers to a specific configuration within the FRT series. Below are the primary electronic characteristics: | Parameter | Specification | |:---|:---| | **Contact Form** | 2 Form C (DPDT - Double Pole Double Throw) | | **Coil Voltage** | Typically 4.5V or 5V DC (Check specific prefix) | | **Max Switching Power** | 30W / 62.5VA | | **Max Switching Voltage** | 220V DC / 250V AC | | **Max Switching Current** | 1A | | **Rated Carrying Current** | 2A | | **Coil Power Consumption** | ~140mW (Standard) | | **Package Style** | SMT (Surface Mount) with "R" type lead | --- ## 2. Internal Electronic Structure ### Contact Mechanism The device uses a **twin crossbar contact** system. This design provides high contact reliability even at low signal levels (dry circuits), as it offers multiple points of contact to reduce resistance and bypass surface oxidation. ### Polarization The "FRT" series is **polarized**. It utilizes a permanent magnet in conjunction with the electromagnet. * **Benefit:** This increases sensitivity and allows for a smaller coil. * **Constraint:** You must observe the correct polarity (+/-) on the coil pins for the relay to actuate. ### Lead Shape (The "R" Suffix) In the NEC/TOKIN nomenclature, the **"R"** suffix typically denotes the lead terminal shape and packaging: * **R-bend:** This is a specific surface-mount terminal shape designed for optimal solder fillet formation on PCBs. * **Tape & Reel:** Parts ending in -R are often supplied in embossed tape packaging for automated pick-and-place machines. --- ## 3. Application Use-Cases Because of its electronic precision, the FRT-64-R is found in: 1. **Telecommunications:** Switching line signals in PABX or modems. 2. **Measurement Equipment:** Signal routing in oscilloscopes or multimeters where low thermal EMF is required. 3. **Medical Electronics:** Low-power switching in patient monitoring devices. 4. **Handheld Devices:** Its low profile (approx. 5.2mm height) makes it ideal for dense PCB layouts. --- ## 4. Typical Connection Diagram (Simple Example) When integrating the FRT-64-R, a flyback diode is essential to protect driving transistors from inductive spikes. ```python # Electronic logic representation # Pin 1: Coil (+) # Pin 8: Coil (-) # Pins 2, 3, 4: Set 1 (Common, NC, NO) # Pins 7, 6, 5: Set 2 (Common, NC, NO) [MCU_Signal] -> [Transistor_Base] -> [Relay_Coil_Pin_8] [VCC_5V] -> [Relay_Coil_Pin_1] # Note: Place a 1N4148 diode across Pin 1 and Pin 8 ```