Passion in Electronics
I have featured several articles on solar power charging circuits, now I am actually making one for my home use. I am currently on works to develop this system, although I know the theories behind it, I still learned a lot in this process. This system will be used for cellphone charging and a small light.
If you are a electronic hobbyist and at the same time a guitarist, this project is for you. I have seen many circuits of guitar preamp online but none of them gives you the PCB design and circuit simulations. I already made a version of this project years ago and it works. I also have included simulation files together with the eagle PCB files for you to download if you want to build this project. Take note that the capacitor sizes are not yet taken into account. You will need to edit some few capacitors like the C10 which will be bigger than it is on the board.
There is actually a board that you can attach to arduino for measuring current but if you don’t need a very accurate measurement, you can use this very simple circuit. Usually a low resistance resistor is connected in series to the load. The voltage of the resistor is measured and divided to its resistance, the result will be current.
This circuit can actually deliver up to 70W at 4 ohms at 10% THD at 14.4V power supply which is very suitable for car audio applications. Make 4 of this amplifier and you will have a powerful 280W audio system for your car which will be very loud. Continue reading “70W Car Amplifier Project”
If ever you want to build your own guitar amplifier, here’s the first thing you need to build. This is because guitar preamp are not usually sold as a kit unlike amplifiers. Guitar preamp are actually simple and usually consist of 2 stage, first – gain stage which amplifies the signal coming from the guitar and second – the filter stage which boost or cut frequencies that is determined by the user. Some preamp also includes effects such as distortion and reverb as the most common.
Since electricity is one of our basic needs and it doesn’t come for free. In fact it increases every year. Meanwhile sun power is free for all so why not use it? Here is a very simple way to charge your battery using solar power.
Why need a charging circuit?
Solar cells and batteries comes in different voltage and current capacity. You need to match these ratings for safety and reliability reasons. Connecting a higher voltage solar panel to a battery might over charge the battery and may cause it to explode. It is best to limit the voltage and current output of the solar panel to avoid this from happening.
Many years ago, it is not easy to build a powerful audio amplifier. You will need big power transistors with massive heavy heatsinks plus a heavy transformer too. It will also require a lot of efforts to build it, from drilling the heatsinks and connecting those wires. It is a very tiring task. Today a 200W amplifier can be as small as your mobile phone. Thanks to the evolution of Class D audio amplifiers. Smaller and more efficient amplifiers are now possible.
Often times we used a simple toggle switch to switch between audio source. This is the easiest and simpliest method. But this simple circuit creates some clicking or boom sound when switching audio sources specially when the 2 audio source are operating. Here’s a simple and effective circuit to switch between audio sources gently. It gently decrease the volume of the audio source previously selected and while slowly increasing the volume of the selected audio source.
Building a bluetooth speaker nowadays won’t require so much technical knowledge. You just need to know how and where to connect wires. You can now buy a bluetooth receiver with a built in amplifier online and make your own audio system for your car for cheaper price.
WHY DIY(Do it Yourself)?
Some cheap car amplifiers on the market is not honest on their advertised power, these are very common to cheap and not so known brands. By doing it yourself, aside from getting cheaper, you can also be sure that your amplifier has the right power you need.
Last time I have featured an active Di box circuit. Here is a more simple circuit that only uses 1 JFET instead of an OPAMP.
This circuit is so simple that you can actually build it without PCB. You can also just use a universal board on this one. I actually copied this circuit from an acoustic guitar. haha! sure it works and I also have simulated it.
