ТЛ-4М - восстановление чувствительности измерительного механизма, намагничивание постоянным током

Channel support: 4100 1111 8764 9602 (transfer to YuMoney). In this video, we'll use a simple method and available tools to restore the magnetization of the TL-4M tester's measuring mechanism magnet. The TL-4M is a combination amateur radio instrument, an autometer with a transistor parameter measurement function. The instrument has a measuring mechanism with an external magnet, which loses its magnetization over time. This increases the tester's error, causing it to underestimate readings and exceed its specifications. Using a 15,000 μF capacitor rated at 80 V and a B5-31 power supply to charge this capacitor to 90 V, we restore the magnet's strength with a powerful current pulse, discharging the capacitor through the winding wound on the measuring mechanism's magnet. The winding contains 20-25 turns of wire with a diameter of approximately 0.3 mm. To prevent arcing, connect sections of thick wire with a cross-section of 1.5 mm² to one end of the winding and one terminal of the capacitor. We determine the polarity of the winding connection before applying a pulse by applying a small voltage and noting the direction of the arrow shift. To supply a 100 µA current to the coil, I used a P33 resistor box instead of variable resistors. Equipment and materials used in the video: TL-4M measuring mechanism - patient; V7-22A voltmeter; B5-31 power supply (off-camera); B5-44 power supply (off-camera); P33 resistor box (off-camera); 15,000 µF 80 V capacitor; Single-core insulated wire, approximately 2 meters long.