CÓMO FUNCIONA UN GALVANÓMETRO ¡LO DESMONTAMOS!

Summary

This video explores the functionality and repair of a 1960s moving coil galvanometer, a versatile instrument for measuring both direct and alternating current, as well as voltage. The presenter demonstrates the various scales for measuring electrical properties and the simplicity of the device's design, which includes copper coils, resistors, and a rectifier diode for alternating current. It also covers the repair process, showing how to fix the galvanometer by soldering copper wires and replacing parts. The video concludes with a demonstration of the device's operation, highlighting its reliability despite its age.

Takeaways

• 😀 The video demonstrates the cleaning and repair of a 1960s moving coil galvanometer, which can measure both direct current (DC) and alternating current (AC).
• 😀 The galvanometer has six connection terminals and a selector switch for either DC or AC measurements.
• 😀 The color-coded terminals (white for DC, red for AC) help users easily identify the correct settings for different measurements.
• 😀 The galvanometer's needle can be adjusted to zero using a small control dial to ensure accurate readings.
• 😀 Various scales are available for measuring DC and AC current and voltage, with different ranges for each type of measurement.
• 😀 The video shows how to measure the voltage of a 1.5V battery, demonstrating that the instrument functions well and provides accurate results.
• 😀 The galvanometer can also be used to measure current, as demonstrated by measuring the current drawn by a 6V bulb, with the appropriate scale selected for the measurement.
• 😀 AC voltage measurements are shown using a transformer connected to a battery charger, with safety precautions taken, such as ensuring the circuit is turned off while making connections.
• 😀 The importance of measuring current in series (for ammeter readings) and voltage in parallel (for voltmeter readings) is highlighted.
• 😀 The inner workings of the galvanometer are explained, including the moving coil mechanism and its interaction with a magnetic field to detect electrical current.
• 😀 The video concludes with a demonstration of how to reassemble the galvanometer after cleaning and repairs, ensuring it is functional and properly adjusted for future use.

Q & A

What type of instrument is being discussed in the video?

The instrument discussed is a moving coil galvanometer from the 1960s, which is used to measure electrical quantities like current and voltage in both direct current (DC) and alternating current (AC) circuits.

How can you switch between measuring DC and AC with the instrument?

You can switch between DC and AC by using the selector switch on the instrument, labeled 'CC' for direct current (DC) and 'CA' for alternating current (AC).

What are the different scales available on the galvanometer for measuring current and voltage?

The galvanometer offers various scales for measuring both current and voltage. For DC, the scales include up to 2 milliamps, 20 milliamps, and 1 amp. For voltage, the scales include up to 10V and 100V. For AC, the scales include up to 1.5 amps, 15V, and 150V.

What is the purpose of the small dial or knob on the instrument?

The small dial is used to adjust the needle of the galvanometer to zero. It allows the user to fine-tune the reading, ensuring that the needle is properly calibrated before taking a measurement.

How does the instrument measure voltage in a circuit?

To measure voltage, the instrument is connected in parallel with the component whose voltage is being measured. The measurement of voltage can be done in both DC and AC circuits, using the appropriate scale for each type of current.

What is the process for measuring current using this instrument?

To measure current, the instrument must be connected in series with the component whose current is being measured. The galvanometer measures the current as it flows through the circuit.

What adjustments are necessary when measuring AC voltage or current?

When measuring AC, the selector switch must be set to 'CA' for alternating current. For voltage, a rectifier (diode) is used to convert AC to DC, allowing the galvanometer to measure the AC quantities effectively.

What is the significance of the resistors and diodes used in the galvanometer?

The resistors are used to calibrate the instrument for different measurements, either in series or parallel. The diode is crucial for rectifying the alternating current (AC) into direct current (DC), allowing the galvanometer to measure AC as well.

How does the galvanometer needle function when current flows through the coil?

When current flows through the coil inside the galvanometer, it creates a magnetic field, causing the coil to rotate. This rotation moves the needle, indicating the magnitude of the electrical measurement being taken.

What are the challenges of using this instrument in a home setup?

One significant challenge of using this instrument in a home setup is the danger of working with AC current. Proper safety precautions must be taken, and users should be cautious while handling live electrical circuits, especially when measuring AC voltage or current.