Build a Portable GSM900 Cellular Phone Jammer Circuit Diagram

Portable GSM900 Cellular Phone Jammer Circuit Diagram Emits a carrier that sweeps the 925-960 MHz cellular tower transmitter band (handset receive band)

 GSM900 Cellular Phone Jammer Circuit Diagram

[Continue reading...]

Build a Low voltage regulators Circuit Diagram

These Low voltage regulators Circuit Diagram short-circuit protected regulators give 6, 7, and 9 V from an automobile battery supply of 13 V nominal; however, they will function just as well if connected to a smoothed dc output from a transformer/rectifier circuit. Two types are shown for both positive and negative ground systems. The power transistors can be mounted on the heatsink without a mica insulating spacer thus allowing for greater cooling efficiency. Both circuits are protected against overload or short-circuits. The current cannot exceed 330 mA.

Under normal operating conditions the voltage across R2 does not rise above the 500 mV necessary to turn Q2 on and the circuit behaves as if there was only Q1 present. If excessive current is drawn, Q2 turns on and cuts off Ql, protecting the regulating transistor. The table gives the values of Rl for different zener voltages.

 Low voltage regulators Circuit Diagram

[Continue reading...]

5 band graphic equalizer using a single IC

This circuit uses a single chip, IC BA3812L for realizing a 5 band graphic equalizer for use in hi-fi audio systems.The BA3812L is a five-point graphic equalizer that has all the required functions integrated onto one IC. The IC is comprised of the five tone control circuits and input and output buffer amplifiers. The BA3812L features low distortion, low noise, and wide dynamic range, and is an ideal choice for Hi-Fi stereo applica-tions. It also has a wide operating voltage range (3.5V to 16V), which means that it can be adapted for use with most types of stereo equipment.

[Continue reading...]

Let’s to build a mini organ keyboard circuit using UM3511

The previous
day my son said ” A friend has a mini organ. Casio SA-76 44 Key Mini
Keyboard, Orange It is Good quality but expensive.
My son would have
the same. But I said, as we are the Electronic inventor, to try to
create their own. We are proud and cheaper too.
You might like this
mini organ keyboard circuit certainly. Because in addition to the
simple, the price is not expensive, effective really worthwhile.
You may consider the main features of the circuit, as follows.
1. Can works with DC voltage in rang 3-12 Volt by low current consumption.
2. There are the music playback up to 15 keys, or a note from G3-G5.
3. Can be programmed to play. Repeat for up to 47 notes.
4. Can act as a music source by up to 15 songs.(Simple carbohydrates. Press any key. To select the desired song.)
How circuit works
In the heart of the circuit is the UM3511
-IC is designed to act this purpose

-Internal IC consists of a lot. We do not need to explain the
operation of the circuit Internal this IC. Our job only assembly
equipment used in the first the circuit to be completed.


-From circuit in figure 1 will see that we can connect a output of
pin 5 on the UM3511-IC to drive a transistor output to emit loud sound
out to the speakers directly.
-For the variable resistor-VR1 act as
determine a frequency of the oscillator circuit. When we created
successfully. Should be adjusted to the correct value. When adjusted,
you may use the normal resistor instead.
-The switch-S1 as an
option act the work of circuit that music will be played by the
application of the factory, or will play music as we have played own.
From pushing keyboard as by various notes.
For a list of songs that can be programmed from the factory. Which will play out as We have push switch as follows.
G3 Hush little baby
A3 Twinkle Little Star
C4 Dream of Home and Mother
D4 Christmas Carol
E4 Are You Sleeping
F4 The Famer in the Dell
G4 In a Persian Market
A4 Mary Had a Little Lamp
B4 Long Long Ago
C5 Santa Lucia
D5 Little Brown Jug
E5 Butterfly
F5 The Train is Running Fast
G5 Close Encounters of the Third Kind
How to build and setting
Suppose that you want to play Santa Lucia, it may be done as follows.
1. Hit the switch S1 to the program.
2. Press the C5 keyboard switch.
Only this time, it will play the music you want to finish it, it will stop automatically.

For convenience we have on the power supply is designed for the 5 volt
dc regulator circuit. To be applied to the input voltage from 6 volt to
24 volt. It also allows the voltage to be smooth, no hum at play.

Figure 2 the pcb layout of a mini organ keyboard circuit using UM3511
All components except the transformer and speaker. We can assemble onto the PCB. As shown in Figure 2.

For keyboard switch because we want you to get a feel for the playing.
As the organ of the fact that selling in the shop. We chose to use a
computer key switches.

[Continue reading...]

Short Circuit Protection With A MOSFET

If you have an application in which a MOSFET is already used to switch a load, it is relatively easy to add short-circuit or overload protection. Here we make use of the internal resistance RDS(ON), which produces a voltage drop that depends on the amount of current flowing through the MOSFET. The voltage across the internal resistance can be sensed using simple comparator or even a transistor, which switches on at a voltage of around 0.5V. You can thus avoid the use of a sense resistor (shunt), which usually produces an undesirable extra voltage drop. The comparator can be monitored by a microcontroller. In case of an overload, the software can initiate suitable countermeasures (PWM regulation, alarm, emergency stop etc.). It is also conceivable to connect the comparator output directly to the gate of the MOSFET, in order to immediately cut off the transistor in case of a short circuit.

[Continue reading...]

Auto Sound Systems One Piece at a Time

Those who are in the market for auto sound systems are probably well aware of the many decisions that need to be made throughout the process. Gone are the days when you went in, pointed to a box and walked out with all the pieces, parts, and components you would ever need for a really kickin sound. The truth of the matter is that there are many pieces and parts that work together in order to create the ultimate sound system and everyone seems to have different requirements, styles, tastes, and budgets to work with.

Because of this, many manufacturers of auto sound systems have wised up to the fact that some people will buy the components they need to create the sound system of their dreams piece by piece as budgets allow. This is actually a very intelligent way for customers on a budget to buy the sound system they are hoping to some day have. As a result you will find that speakers, amplifiers, sub woofers, and the actual stereo are often sold separately and at very reasonable prices.

Most of us hate living within limited budgets but understand that often in life it is a necessary evil. Living on a budget is not such a terrible thing really. If we had everything we wanted, what on earth would there be to look forward to? At least that is what I keep telling myself. I, however, seem to be the queen of budget living and bargain hunting. I love little more in life than finding a great deal on an item Ive had my eye on for quite a while and hate little more than finding it cheaper once Ive purchased it. As such, I tend to invest a great deal of time researching any major purchase before taking the plunge. A good auto sound system by this I mean good quality, minimal features is going to run (total package and installation) at least $1,000 with many costing a good deal more than that.

That doesnt mean you need to have a thousand bucks lying around the house in order to begin building your auto sound system. You can buy a decent set of speakers for around $200-$260 if you desire. You can find sets at lower prices, but this is the price for a fairly decent set of speakers that should serve you well. Keep in mind that you could very easily spend a lot more than this on speakers if you arent careful. Living on a budget means you have to make some sacrifices along the way in order to have the things you want in life. Buy the speakers and have them installed (if you can do it or your know someone who can, this will save a lot of time and money).

Once you have the first component, whichever one that may be (that choice is entirely up to you and largely dependent on your personal tastes and which need replacing worse in the vehicle you own) you can begin saving towards the next. You should also consider asking friends and family (who would like to know what to get you for the holidays) to help you reach your smaller goals along the way. Most people are glad to help with specific items if they know what those items are. The point is that this isnt an all or nothing proposition. Take small steps towards your prize and you will find that you are constantly getting one step closer.

[Continue reading...]