Electronics FAQ – Your Multilingual Guide to Electronics

  Are BLDC Motors AC or DC | Brushless DC Motor Working, Difference Between Brushed and Brushless DC Motor, Advantages and Applications Are BLDC motors AC or DC? Learn about brushless DC motor working, differences, advantages, and uses of BLDC, AC, and DC motors. Are BLDC motors AC or DC? A BLDC motor runs on DC voltage. We also find BLDC motors in Ceiling fans and washing machines that run on AC, but in that case, AC is first converted to DC by an SMPS or switch-mode Power Supply.  Why BLDC Motor run exclusively on DC?  The BLDC motor brain is called an 'Electronic commutator', which is nothing but an electronic switching circuit that only runs on DC voltage .  Nowadays, we find BLDC motors in Electric Vehicles that run on a DC battery pack.  Difference between Brushed v/s Brushless DC Motor:  A BLDC motor is very similar to the DC motor, but there are some basic differences in the construction. Let's understand that.  Conventional brushed DC motor: I...

Digital Volume Control in Modern Audio Amplifiers. What is the principle of a Digital Potentiometer and its role in audio amplifiers?  We all know antic audio amplifiers use analogue potentiometers. They become noisy due to dust and require frequent cleaning. Modern amplifiers use digital volume control, though the volume control knob looks the same, the circuit for the same is entirely different. It uses fixed resistors in a voltage divider configuration and switches them electronically to control volume. This is done in digital volume control. Digital volume control module:  Modern audio amplifiers no longer use an analogue potentiometer to control volume. How does volume control work in Audio Amps? The volume control knob of an audio amplifier is essentially a voltage divider. Voltage Divider principle:  The output of the pre-amp is scaled and given to the power amp. And this scaling is done by analogue potentiometer by turning the volume control knob of the amp. Digit...

  How to Wire 2-Way Switches to Control One Light Fixture | 2-Way Switch Wiring Diagram, Steps, and Connection Guide What is a two-way switch? You need ‘ Two Way ’ and not ‘three way’ as wrongly mentioned in the earlier answer. The technical name of the switch is   SPDT,   i.e. ‘ S ingle   P ole   D ouble   T hrow ’ switch. Uses of a Two-Way switch:  Staircase light control:  A two-way switch is used for the staircase light control from the two different locations.  Wiring diagram of Two-Way switches:  The most popular application of this switch is ‘Staircase light control’ and ‘Bed switch’. Wiring and function are shown in the following animation. Animation of the working of a Two-Way switch: Wiring diagram of Two-Way Switches:  FAQ Set: Q1. What is a two-way switch wiring system? A two-way switch system allows a single light fixture to be controlled from two different locations using two switches. Q2. Where is a two-switch light c...

  How RC Low-Pass and High-Pass Filters Work — Simple Explanation with Examples Let me provide you with a basic understanding that will clear up any misunderstandings you may have regarding the capacitor in a high/low-pass filter. Mechanism of High/Low Pass Filter: ‘Filter’ word is a bit misleading. It doesn’t take ON/FF-type action. Filter only reduces (voltage) gain for a certain frequency compared to the whole spectrum of the frequencies of interest. A filter is basically a Voltage Divider:  The filter works on a voltage divider principle. Let me clarify. So, the output voltage reduces proportionally to the value of resistors R1 & R2. In simple words, the larger the R1 and the smaller the R2, Vout will reduce compared to Vin. Can I use the above circuit as a low-pass filter? No, because resistance doesn't change its value proportionally to the frequencies . So our goal of reducing gain for a certain band of frequencies wont be fulfilled. We need to replace R1 or R2 with...

  Purpose of Dual Power Supply in Analogue Circuit Design: Why Positive and Negative Voltages Matter Look at the following two circuits… A Push-Pull audio single-ended Amplifier:     Push-Pull Audio Amplifier with dual Power Supply: What is the difference between the two above circuits? In the second circuit, there is an absence of an output coupling capacitor. Why is a capacitor needed in the first circuit? It charges at a positive cycle and discharges at a negative cycle, generating an AC voltage across the speaker. In the second circuit, at the positive input cycle, current flows to the speaker. At a negative input cycle, current is pulled from the negative supply through the speaker, thus eliminating the output capacitor. The output coupling capacitor has a few disadvantages. It puts a limit on low-frequency response, it is bulky, and needs a high value for better low-frequency response; it may dry out, and needs a replacement after a certain period. Conclusion: ...

  Principle of Horn Loudspeakers: How Impedance-Matching Drives Efficiency & Directivity Horn speaker, horn-loaded speaker, horn loudspeaker design, how horn speakers are made, horn speaker working, horn speaker construction. Impedance Matching - principle behind a Horn Speaker: ‘Impedance matching’ for maximum power transfer. The throat ‘A’ impedance of the compression driver (speaker) is matched with the open air by the flaring portion ‘B’ (horn) for efficient sound (loudness) transfer that amplifies sound. The horn concept is not new. It is our observation that when we shout, we bring our two hands close to our mouths to form a sort of horn structure. Passive horn (speaking trumpet): A megaphone:  It is a practical example of a powered horn speaker for public announcement. Interesting fact:  Old gramophones generate sound through a pure mechanical process with the help of a big horn. FAQ Set: Q1: What is a horn speaker? A horn speaker is a type of loudspeaker that ...

 Time delay in the voltage stabiliser: purpose, benefits and explanation Some AC voltage stabilisers, especially recommended for refrigerators, have an inbuilt time delay function that delays output switching when it is turned ON or after a power failure. This post explains the real purpose of it.  The real reason is compressor lockup: Suppose the running compressor (e.g. refrigerator) is interrupted by a short-term (momentary) power outage (less than 10 seconds). In that case, the compressor locks up, the motor draws heavy current, and the compressor becomes hot. There is over-temperature protection for the compressor that trips the compressor. Powering on the delay of the voltage stabiliser solves this problem. If the running compressor is interrupted by a short-term power outage, the power-on delay does not power the compressor until the time delay is complete. This gives sufficient relief time for the compressor to come out of the vapour lock stage. FAQ: Time Delay in Volt...

  How Sound Waves Are Converted into Electrical Signals Using various methods of Microphones, Transducers, and Sensors — Working Principle, Process, and Examples A sound wave is converted to an electrical signal by several methods, such as… Sound Waves to Electric Signal: Change in the Resistance method.  Carbon microphone. Change in Capacitance method.  Condenser microphone: