Monday, August 27, 2012

Basic LM35 temperature sensor circuit

 This is basic of workmaship LM35 temperatur sensor, whish is taken from the LM35 spending and boosted again by the amplifier op-amp. High output if the sensor is received by ic LM35 high temperature . You can use the output as driver relay, fan , or other. And if yo want to see modifications LM35 temperature sensor see .

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Tuesday, August 14, 2012

150W Car Power Amplifier Circuit Diagram

150W Car Power Amplifier Circuit Diagram150W Car Power Amplifier Circuit Diagram

When the amplifier is installed ashamed in the suitcase, we shall allegation a changeabout works stop. The LA47536 possesses a activity bend by in it pin4. This anguish crave a babyish astriction aloft to 2V in alpha up the amplifier. Transistor Q1 and Q2 makes the activity of walking stop for distance. Aback the authoritarian activates the larboard indicator, either afire the ashamed fires or columnist on the ballast , lamps rear bake alive Q2 who he akin bogus to drive Q1 who applies a astriction > 2V on it pin4. Overview

LA47536 Four-Channel 45 W BTL Car Audio Adeptness Amplifier

The LA47536 is a 4-channel BTL adeptness amplifier IC developed for use in car audio systems. The accomplishment date features

- A accurate adulatory analysis that uses V-PNP transistors on the aeriform accessory and NPN transistors on the low accessory to board aeriform adeptness and superb audio quality.

- The LA47536 includes about all the functions adapted for car audio use, including a standby switch, a muting function, and ceremony advocacy circuit. It additionally provides a self-diagnosis activity (output annual detection). (Sanyo)

Functional Description

1. Standby Changeabout Activity (pin 4)

The pin 4 alpha voltage is set to be 2 VBE. Aback Vst is 2.0V or higher, the amplifier will be on, and aback Vst, is 0.7V or lower, the amplifier will be off. Note that pin 4 requires an operating accustomed of at diminutive 40uA.

2. Muting Function

The IC is set to the aeriform accessory by ambient pin 22 to the amphitheatre potential. In this state, the audio accomplishment is muted. The time affiliated with which the muting activity operates is set by an conflicting RC circuit, and this time affiliated influences the pop blubbering that occurs aback the amplifier is affronted on or off.

The muting on and off times due to the recommended conflicting basal belief (R=10k, C=3.3uF) are as follows.

Muting on time: 50ms

Muting off time: 20ms

3. Self-Diagnosis Activity (Speaker aficionado prevention)

During constant accessory operation, the LA47536 detects, internally, whether or not an abnormal amplifier accomplishment annual has occurred, and outputs this arresting from pin 25. Applications can ahead advocate aficionado and added problems by accepting the adjustment microcontroller ascertain this pin 25 accomplishment arresting and advantage either the standby accessory or the adeptness supply. (An abnormal accomplishment annual may be acquired by, for example, accredit capacitor arising current.) The pin 25 arresting is affronted off by ambient pin 1 to the amphitheatre potential.

4. Oscillator Stability

In some cases, base oscillations may be induced by the PCB layout. This accent can be abandoned by abacus the accoutrement listed below. Note that the optimal capacitor bulk allegation be complete by testing in the complete army accessory in the end product. Connect a capacitor and resistor (0.1uF and 2.2) in alternation amidst ceremony accomplishment pin and ground.

5. Audio Affection (Low band)

The affluence characteristics in the low frequencies can be bigger by accurate the capacitance of the accredit capacitors variable. The recommended capacitance is 2.2uF and smaller.

6. Advocacy Circuits

Do not amphitheatre the outputs with the STBY voltage at about 1.4V. Also, do not changeabout the IC off in the aground accessory with a time affiliated provided for the STBY voltage.

7. Pop Noise

Although the LA47536 includes an pop blubbering blockage circuit, pop blubbering can be arrangement akin added by appliance the muting activity as well. Activate the muting activity at the above time as adeptness is applied. Then, afterwards the accomplishment DC abeyant has stabilized, changeabout off the muting function. Aback arbor the amplifier off, ancient changeabout on the muting activity and afresh changeabout off the adeptness supply. These two methods are able at aspersing pop noise.
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Wednesday, August 8, 2012

500mW PLL FM Transmitter 88 108MHz

500mW PLL FM Transmitter 88-108MHz

This PLL transmitter is controlled and the frequency is very stable and can be programmed digitally. Transmitter will work 88-108 MHz and output power up to 500mW. With a small change can set the frequency of 50-150 MHz. The output power is often set to several watts with transistors. So therefore I decided to build a simple transmitter with great performances. The frequency of this transmitter can easily be changed by software and space / compress air coil. This transmitter is the oscillator colpitts. Oscillator is a VCO (voltage controlled oscillator) which is set by the PLL circuit and PIC micro controller. This oscillator is called the Colpitts oscillator and voltage controlled to achieve the FM (frequency modulation) and PLL control.
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12 volt DC Power Supply from USB port

Using this circuit we can convert 5V DC from the computer USB port to 12V DC and a circuit like this will find a lot of application in USB powered systems. The heart of this circuit is IC LT1618 which is a constant current, constant voltage boost converter. The IC has a wide input voltage range of 1.8 to 18V DC and output voltage can be up to 35V DC.
In the circuit resistors R1, R2 sets the output voltage. Pin number 9 is the shutdown pin, less than 0.3V to this pin will shut down the IC. Pin number four is the current sense adjust pin. The current sense voltage can be reduced by applying a DC voltage to this pin. If this adjustment is not needed connect this pin to ground and you can omit components R3, R5 and Q1.

Circuit diagram of 12 volts dc power supply:

5volts to 12 volts voltage converter
Circuit Diagram-12Volts DC power supply from USB port

Notes :

  • C2 and C3 must be rated at least 15V.
  • Less than 0.3V at the shutdown pin will shutdown the IC.
  • Output voltage is governed by the following equation R1 = R2 (  (Vout /1.263V) -1).

Other Circuits Related to Power

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Saturday, August 4, 2012

Weekend Projects with Bre Pettis Make a Joule Thief

In this week’s Weekend Projects video podcast, Make Magazine’s Bre Pettis and I show you how to make a Joule Thief. The PDF file that goes with the podcast is here (450 kB PDF file).
So whatsa Joule Thief? It’s a little wisp of a circuit that allows you to drive a blue or white LED from a low voltage. Normally, if you want to light up a blue or white LED you need to provide it with 3 – 3.5 V, like from a 3 V lithium coin cell. But a 1.5 V battery like a AA cell simply will not work. But using the Joule Thief, it works like a charm. Not only does it work with a brand new battery, but it works until the battery is nearly dead– down to 0.3 V. That’s well below the point where your other toys will tell you the battery is dead, so it can steal every last joule of energy from the battery (hence the name). To learn how to make one, watch the video, which is available in a variety of formats.
The original site where we learned about the Joule thief shows you how to make a miniature version of this circuit, such that you can fit it in a tiny flashlight. However, in the video we show you how to make it big, large enough (1) to make with clumsy hands and (2) that you can see what we’re doing.
After the jump, some detailed photos of how the coil is wound in case you need more detail than in the video.


It’s a little hard to see through my fingers in the video, so here’s the detailed view of the coil and winding your own.
First, here is a selection of ferrite toroids, inductors, and transformers that are suitable for using to make a Joule Thief.
Depending on the type that you start with, you may be able to use the existing wires or need to take them off and wind it yourself.
Coil - Step 1.

To wind your own coil, start with two colors of insulated wire and a bare ferrite toroid.
Coil - Step 2.

Take the two strands of wire through the center of the toroid.

Coil - Step 3.

Keeping the two strands together, wrap them around and through the toroid again.
Coil - Step 4.

Keeping the two wires together, make a few more turns through the center.

Coil - Step 5.

Keep winding until you fit as many turns as will fit in a single layer around the toroid, typically 7-10 turns with thin insulated wire.

Coil - Step 6.

Clip the wire leads down. Note that we have two pairs of wires: one coming out the front, and one coming out the back.

Coil - Step 7.

Strip the wire ends. Take one wire from each pair of different color and attach them together.

Coil - Step 8.

Solder the cross-over pair together. This is the “common” point of the coil windings.

Weekend Projects Podcast!
In the circuit diagram for the Joule Thief, the common point of the toroid is the connection at the top of the hand-wound ferrite toroid, in the upper right of the diagram. This goes to the positive end of the battery. The other two wires from the toroid go to the resistor and to the intersection of the transistor with the LED.
One other detail that you may need to know is the symbol and pinout of the 2N3904 transistor. In the symbol, the part with the arrow is the “emitter”, the “collector” is the end above it, that also connects to the LED, and the “base” is the wire leading off to the left, between the collector and emitter. (Also remember that the end of the LED with the flat side and short lead is the end that has the flat bar in the diagram.)
An actual 2N3904 transistor looks like this.
(Well, like this if you’re hungry.)
The pins, holding it so that you can read the text on the flat side are (left to right) Emitter, Base, and Collector. I particularly like this one because it has that little EBC legend on the bottom.

So how does it work?
Pretty well, actually. (The technical discussion has been removed.)
As a side note, this is not the most efficient circuit around; its beauty is that it works with such a low voltage. So, this is a great circuit to use with a dead or dying battery, and less so for use with a brand new battery.
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Wednesday, August 1, 2012

1W Stereo Amplifier With Voltage Regulators

A simple stereo audio amplifier is built around two 7905 negative-voltage regulators (IC1 and IC2) and a few discrete components. The circuit will also work with other 79XX regulators if appropriate power supply is used. Regulator IC 7905 works as an amplifier for the voltages applied to common pin2 (Ground or GND). Also check the LM317 audio amplifier, another interesting circuit.The minimal voltage drop over the standard 7905 is around 2V and it depends on the output current. Feedback resistors in the IC set the gain of the channel internally. The amplifier is a class-A audio amplifier. The minimal applicable value of R3 for the regulator 7905 is 8.2 to 10 ohms per 5W.

7905 1 Watt Audio Amplifier Schematic

1watt 7905 stereo amplifier circuit schematic
If the required output current for LS1 is below 100 mA, the value of resistor R3 can be 33 to 51 ohms per watt. The circuit works with any load resistance (R3 in parallel with LS1 as the load) under the condition that the regulator is not overloaded with current and power dissipation. However, it is preferable to use a loudspeaker with a high resistance (8 ohms, 16 ohms or more). The amplifier works well with low-impedance headphones having a resistance of 24 to 32 ohms. The voltage difference between the ground pin of 7905 and the output pin is fixed internally.
S2 is the on/off switch. Switch S1 is for mono/stereo selection. When switch S1 is closed, the amplifier works as a two-way mono amplifier. If S1 is open, the amplifier works as a stereo amplifier. If no input signal is applied, the DC voltage on the output of the regulator 7905 should be around –5V, which depends to some extent on the value of VR1. The maximum output current of 7905 can be up to 1A and the maximum power dissipation is up to 15W. Mount the regulator IC 7905 on a heat-sink with
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