Electel Blogspot

I had previously shown how to drive N-channel MOSFETs in low-side configuration. You can find the tutorial here: http://electel.blogspot.com/2016/12/low-side-mosfet-drive-circuits-and_23.html I’ve been requested to write a tutorial/article regarding high-side MOSFET drive. So, here I’ll talk about N-channel MOSFET high-side drive. Let’s first look at the common low side configuration.  Fig. 1 - N-channel MOSFET configured as low-side switch Now let’s look at a MOSFET configured as a high-side switch. Fig. 2 - N-channel MOSFET configured as high-side switch You can quite easily see the difference between the high-side configuration and the low-side configuration. In the low-side configuration, the load is connected between the drain and +V, while the source is connected to ground. Thus, the gate drive is referenced to ground. So by applying a voltage of >7V (for Power MOSFETs) or >4V (for Logic Level MOSFETs), the MOSFET can be fully turned on. Now let’s talk about the high-si...

On different forums, I often find people asking for help in calculating the required turns for a ferrite transformer they are going to use in offline SMPS half-bridge converter s . The half-bridge topology is very popular for offline converters in the power range 100W to 500W, sometimes goin g up to even 1000W. In an offline SMPS half-bridge converter, the line voltage is rectified and filtered and is then converted to high frequency with 2 MOSFETs – one in high-side configuration and the other in low-side configuration. This high frequency high voltage AC is fed to the ferrite transformer to step down the voltage to low voltage high frequency AC which is then rectified to DC and filtered to provide clean DC output. A vital thing to remember is that in a half-bridge converter, the 2 MOSFETs work along with 2 capacitors to create the high voltage high frequency AC. The configuration of the capacitors, MOSFETs and transformer causes the transformer to be supplied half the voltage of the...

LEDs (lights) , interfaced with 8051 microcontroller, can be used to display binary numbers or on/off states while Seven Segment Displays (SSD) can display digits but that's not enough. What if you wanted to display a proper message consisting of numbers, letters, characters, symbols e.t.c.? That's where LCD Screens jump in. LCDs make it convenient to display anything to the user. It may sound tricky to interface an LCD with a microcontroller but trust me or not, it's simpler than it looks and this short tutorial will make sure that you get the hold of it. READ MORE

I had previously shown how to generate sinusoidal pulse width modulation (SPWM) signals using the ECCP module in a PIC for generating a sine wave output for use in DC-AC inverter. I have had requests from people asking how to generate the same SPWM signals with other microcontrollers that don't have the ECCP module, such as the super popular PIC16F877A. And so I had written another article where I showed how to generate sine wave using SPWM with the CCP module of a PIC. This concept, as I had mentioned in that tutorial, can be extended to use for any microcontroller that has a PWM module. And so, I’ve decided to demonstrate how to generate sine wave using SPWM with an Atmel AVR microcontroller. The microcontroller I’ve chosen is the ATMEGA16. However, the concept can be used on any AVR that has a PWM module. The output sine wave is to have a frequency of 50Hz. I have chosen to use a switching frequency of 16kHz for SPWM. So, here I talk about how to generate sine wave using sinusoi...

Automatic Voltage Stabilizer with PIC16F873A Download links for the article:  Google docs (go to the link, click File in the PDF window, then click Download): https://docs.google.com/file/d/0B4SoPFPRNziHb3VrX3JhWko3d1E/edit Scribd link: http://www.scribd.com/doc/207498741/Automatic-Voltage-Stabilizer-with-PIC16F873A 4shared download link: http://www.4shared.com/office/ktU0k9dqba/Voltage_Stabilizer.html You can download all the files related to the voltage stabilizer: Google docs (go to the link, click File in the PDF window, then click Download): Code: https://drive.google.com/file/d/0B4SoPFPRNziHbWtkVUc1VUM1REU/edit?usp=sharing HEX: https://drive.google.com/file/d/0B4SoPFPRNziHSVJ1a0t2STNDd3M/edit?usp=sharing PCB: https://drive.google.com/file/d/0B4SoPFPRNziHdkE0SzI4SDQ5V3M/edit?usp=sharing PCB images: https://drive.google.com/file/d/0B4SoPFPRNziHNEtSQlVtX2x4VWc/edit?usp=sharing https://drive.google.com/file/d/0B4SoPFPRNziHQXl2eWtydmh3WkU/edit?usp=sharing https://drive.google.c...