Passion in Electronics
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.
In case you wan to build an small amplifier for your small speaker, here’s a 3W per channel amplifier for you. Take note that this can only operate up to 5.5V. You can’t use USB to power this circuit as USB can only provide up to 2.5W power. If you will use 8 ohms speaker, it can only provide up to 1.4W of power.
Minimum value of Ri is 18k. Minimum speaker impedance is 4 ohms.
If you love listening to a music with super loud bass, then here’s a circuit that can help you boost the bass. There are many ways to boost the bass and I will be sharing some of the most simple ways. And of course the simulation result, if it works on the simulation then it will also work on the actual.
The circuit
The circuit is very simple and only needs few components.
There are many tone control designs out there. Let’s take a look at those and analyze each circuit. If you are planning on designing a tone control circuit for your guitar effects, it is not actually that not hard to do. You only need to understand the basics. Please note that these are only passive type tone control meaning you will loose some signal strength when you use this circuit. To compensate for the attenuation caused by this circuit, you will need to add an amplifier circuit with a gain of at least 2.
I have been mixing church sound system for quite a while now and I have encountered so many problems and solved most of them. On this article I will share tips to make your sound system sound best.
Most church sound system most challenge is the very tight budget. Very tight budget leads to very cheap sound system and leads to poor quality. Taking into account that most church sound techs are not knowledgeable enough for the job which leads to less optimal sound quality the system can deliver.
On this tips, I will assume that you already know how to operate a mixer and the whole sound system and you already have a sound system in place. I will create a separate post on Mixer 101 and choosing a right sound equipment.
So what to do after you have set up and turned on your system? Set the volume of the amplifier to 50% or less. This is to have maximum signal to noise ratio on the line. Setting the volume of the amplifier close to 100% will led to lower signal level and that level may close to the noise level. Take note also that when you set the volume of the amplifier to very low, the tendency is for you to crank up the volume of the mixer and may lead to signal distortions. Set the main volume of the mixer to unity gain(0dB) or just below the maximum. Adjust this when necessary on sound check.
Avoiding Feeback
One way to avoid feedback is to properly hold the mic(above picture). Holding it on the diaphragm(head) will introduce feedback at some conditions. It is like increasing the sensitivity of the mic so it introduces feedback. More information on this Article link here.
–More to come…
Here’s a simple amplifier that I used for my speaker project. The IC operates at 5V. Note that although it runs on 5V, it can’t be powered via USB because USB can only deliver 2.5W. Ri minimum value is 18k which will give you 24dB voltage gain. The voltage gain is computed by equation : 20 log(2*(142k/Ri))
Solar Energy industry has been growing so fast and you can now buy a solar panel or solar powered gadgets almost anywhere. I have been looking to design a solar power system for my home but I can’t find time or I can’t find the best solution to do it. Recently I have been ask to design a high power flashlight for a bike and when I am looking for a charger IC, I stumbled on this one and luckily it is also perfect for solar power applications.
About The IC
The Charger is from Linear Technology’s LTC4015 – Multichemistry Buck Battery Charger Controller with Digital Telemetry System. It has a I2C communication port that can be use to monitor voltages, current, temperatures and battery health. You can also set the charging current and voltage via I2C. You can also use it as a standalone charging IC and wont require any programming. But it is best to use this feature, this will save you space and parts count because you wont be needing an additional current sensors for your application to monitor battery and input current.
Application Circuit
Sample Program
You can download the sample program for arduino and other platform below.
Downloads:
LT4015 Datasheet
LT4015 Sample Program
Crossover circuit is used to split audio frequencies into 2 or 3 part. There are 2 kinds of crossovers, active and passive. Passive crossovers is use to connect woofer, midrange and tweeter speakers to one source. It basically splits the frequency into 3, bass frequencies to woofer, mid frequencies to midrange speaker and high frequencies to tweeter. Active crossovers is used to split signal going to the amplifier. The benefit of using active crossover is that you have more controls, you can tweak levels and frequencies. The main disadvantage is the cost, aside from the crossover itself is expensive, it will also require multiple amplifier.
Continue reading “Active Crossover Design”
