This tiny circuit is a simple way to make a fading led without having to program chips or writing code. Just a few simple components and youre ready to fade all. Timer as an Amplifier. Conventional methods of audio amplification use high power circuits to drive a loudspeaker for areas like an auditorium or any other hall. However for applications involving use of small loudspeakers for low range requirements, we can meet the requirements by constructing a low power amplifier with a low output current such as 2. A. In this article we are describing the principle, design and operation of a low power audio amplifier using 5. Timer. The 5. 55 Timer generates a carrier signal which is modulated by the amplified audio signal to produce a modulated signal. This signal is used to drive a small loudspeaker. Low Power Audio Amplifier Circuit Principle Here this circuit is based on the principle of audio amplification using operational amplifier and pulse width modulation using 5. Timer. The audio signal is amplified using low noise high input operational amplifier TL0. Timer. 5. 55 Timer is used as an astable multivibrator producing an oscillating signal. This signal is modulated by the audio signal such that the width of the output pulse varies with respect to the voltage at the control pin the audio signal, causing pulse width modulation. Timer as an Amplifier Circuit Diagram Circuit Diagram of a Low Power Audio Amplifier using 5. Timer Electronics Hub. Circuit Design of Low Power Audio Amplifier Here the circuit designing is a simple process involving just two steps designing the preamplifier section and designing the astable multivibrator section. Here we are using a low noise JFET input operational amplifier TL0. Vs. A voltage divider network is designed using two resistors each of 4. K, so that a voltage of 6. V is applied to the non inverting terminal of the OPAMP. Assuming our required gain to be around 2. VV or 2. 7. 2d. The 555 timer datasheet specifies that 555 IC is a highly stable device for generating accurate time delays or oscillation. Additional terminals are provid. Timer Circuit Design Software' title='555 Timer Circuit Design Software' />B and the value of one of the feedback resistors to be around 1. K, we calculate the value of another resistor to be around 2. K. Since output impedance is low for this amplifier, we use a resistor of about 1. K at the output to connect it to the control pin of the 5. Timer. Next step in the design process involves designing the 5. In normal circuit connection for 5. Timer Circuit Design Software' title='555 Timer Circuit Design Software' />Timer as astable multivibrator, we use two resistors for both charging and discharging of the capacitor. However to provide faster discharge rate, we use here a diode 1. N4. 00. 7 instead of the resistor. Here our required output frequency is around 1. KHz and assuming the value of capacitor to be around 1. F, we can calculate the value of threshold resistor to be around 1. K Forward resistance of 1. N4. 00. 7 is around 1. Ohms. Related Post 1. Subwoofer Amplifier Circuit. Low Power Audio Amplifier using 5. Timer Circuit Simulation Once the circuit is designed, the next step involves circuit simulation. Here we follow a series of steps to simulate the circuit using Multisim software. The microphone simulation model is selected from the Lab. View instruments under Simulate menu. Required parameters are set accordingly The time of recording and sampling rate. The designed circuit is build using the software and the microphone is connected as input to the circuit. A loudspeaker model is selected from the Lab. View instruments under Simulate menu and connected as output to the circuit. The interactive simulation setting is accomplished by setting the end time equal to or more than the time of recording. As long as the circuit simulation takes place, the Play button of the loudspeaker is grayed out and once the simulation ends, the button is enabled. How 5. 55 Timer as an Amplifier Circuit Works The circuit operation is divided into two segments the pre amplifying electric signal amplification operation and the pulse width modulation operation. The amplifying operation is performed by the low noise operational amplifier TL0. The input audio signal is sensed using the microphone and converted to a low voltage electric signal. This low voltage AC signal is fed to the non inverting terminal of the OPAMP through an electrolyte capacitor of 1u. F, which blocks the DC current of the audio signal. This signal is amplified using the operational amplifier with a gain depending upon the values of feedback resistors. Here the OPAMP works in linear mode so as to make the voltage at non inverting terminal equal to the output voltage using the feedback network. This amplified signal is then fed to the control pin of the 5. Timer through the capacitor to remove the DC component and the resistor. Here the 5. 55 Timer works in the astable mode with the frequency of output signal determined by the combination of resistors R1 and C1. However since here we are applying the control voltage, the width of the output pulse varies depending upon the control voltage. The carrier output signal produced by the 5. Timer is modulated by the audio voltage and the resultant modulated signal is used to the drive the loudspeaker. Here the loudspeaker does not responds to the high frequency signal, but rather to the DC value of the modulated signal and thus the audio signal appears amplified. Timer as an Amplifier Circuit Applications This application can be used to develop low power music systems used in vehicles. It can be used in classrooms with limited areas. Limitations of Audio Amplifier Circuit This circuit is suitable only for low power loudspeakers. Timer doesnt produce 5. This circuit is theoretical and may require changes in hardware implementation. IC Wikipedia. The 5. IC is an integrated circuit chip used in a variety of timer, pulse generation, and oscillator applications. The 5. 55 can be used to provide time delays, as an oscillator, and as a flip flop element. Derivatives provide two 5. Introduced in 1. 97. Signetics,4 the 5. It is now made by many companies in the original bipolar and in low power CMOS. How To Install A Drainage System Around The House there. As of 2. 00. 3update, it was estimated that 1 billion units were manufactured every year. The 5. Historyedit. Die of the first 5. The IC was designed in 1. Hans R. Camenzind under contract to Signetics later acquired by Philips Semiconductors, and now NXP. In 1. Camenzind joined PR Mallorys Laboratory for Physical Science in Burlington, Massachusetts. He designed a pulse width modulation PWM amplifier for audio applications,8 but it was not successful in the market because there was no power transistor included. He became interested in tuners such as a gyrator and a phase locked loop PLL. He was hired by Signetics to develop a PLL IC in 1. He designed an oscillator for PLLs such that the frequency did not depend on the power supply voltage or temperature. However, Signetics laid off half of its employees, and the development was frozen due to a recession. Camenzind proposed the development of a universal circuit based on the oscillator for PLLs, and asked that he would develop it alone, borrowing their equipment instead of having his pay cut in half. Other engineers argued the product could be built from existing parts, but the marketing manager bought the idea. Among 5xx numbers that were assigned for analogue ICs, the special number 5. Camenzind also taught circuit design at Northeastern University in the morning, and went to the same university at night to get a masters degree in Business Administration. The first design was reviewed in the summer of 1. There was no problem, so it proceeded to layout design. A few days later, he got the idea of using a direct resistance instead of a constant current source, and found that it worked. The change decreased the required 9 pins to 8, so the IC could be fit in an 8 pin package instead of a 1. This design passed the second design review, and the prototype was completed in October 1. Its 9 pin copy had been already released by another company founded by an engineer who attended the first review and retired from Signetics, but they withdrew it soon after the 5. The 5. 55 timer was manufactured by 1. Part nameeditIt has been falsely hypothesized that the 5. Hans Camenzind has stated that the part number was arbitrary,5 thus its just a coincidence they matched. The NE and SE letters of the original parts numbers NE5. SE5. 55 were temperature designations for analog chips from Signetics, where NE was commercial temperature family and SE was military temperature family. Depending on the manufacturer, the standard 5. DIP 8. 1. 2 Variants available include the 5. DIP 1. 4 combining two complete 5. DIP 1. 6 combining four reduced functionality timers on one chip. The NE5. C to 7. 0 C, and the SE5. C to 1. 25 C. These were available in both high reliability metal can T package and inexpensive epoxy plastic V package packages. Thus the full part numbers were NE5. V, NE5. 55. T, SE5. V, and SE5. 55. T. Low power CMOS versions of the 5. Intersil ICM7. 55. Texas Instruments LMC5. TLC5. 55, TLC5. 51. CMOS timers use significantly less power than bipolar timers, also CMOS timers cause less supply noise than bipolar version when the output switches states. The ICM7. 55. 5 datasheet claims that it usually doesnt require a control capacitor and in many cases does not require a decoupling capacitor across the power supply pins. For good design practices, a decoupling capacitor should be included, however, because noise produced by the timer or variation in power supply voltage might interfere with other parts of a circuit or influence its threshold voltages. Internal schematiceditThe internal block diagram and schematic of the 5. Green Between the positive supply voltage VCC and the ground GND is a voltage divider consisting of three identical resistors, which create two reference voltages at  13 VCC and  23 VCC. The latter is connected to the Control Voltage pin. All three resistors have the same resistance, 5 k for bipolar timers, 4. CMOS timers. It is a false myth that the 5. IC got its name from these three 5 k resistors. Yellow The comparator negative input is connected to the higher reference voltage divider of  23 VCC and Control pin, and comparator positive input is connected to the Threshold pin. Orange The comparator positive input is connected to the lower reference voltage divider of  13 VCC, and comparator negative input is connected to the Trigger pin. Purple An SR flip flop stores the state of the timer and is controlled by the two comparators. The Reset pin overrides the other two inputs, thus the flip flop and therefore the entire timer can be reset at any time. Pink The output of the flip flop is followed by an output stage with push pull P. P. output drivers that can load the Output pin with up to 2. A varies by device. Cyan Also, the output of the flip flop turns on a transistor that connects the Discharge pin to ground. CMOS version. The typical pinout of the 5. IC packages are as follows 211. Pin5. 56 PinPin name. Pin purpose21. 7GNDGround supply ground reference voltage zero volts. TRIGTrigger when this input falls below  12 of CTRL voltage typically  13. VCC, CTRL being  23. VCC by default if CTRL is left open, the OUT pin goes high and a timing interval starts. More simply, as long as the trigger is kept at low voltage, OUT will be high. Output of the timer totally depends upon the amplitude of the external trigger voltage applied to this pin. OUTOutput the push pull P. P. output is driven to GND or approximately 1. V below VCC. Note CMOS timer parts can drive output up to VCC rail. Signetics recommends a 1 n. Fdecoupling capacitor be connected at the output pin in circuits that connect to digital logic inputs, which may help minimize 5. RESETReset a timing interval may be reset by driving this input to GND, but the timing does not begin again until RESET rises above approximately 0. Overrides TRIG, which overrides THR. CTRLControl or Control Voltage or CV provides control access to the internal voltage divider by default is  23. VCC. By applying a voltage to the Control Voltage input one can alter the timing characteristics of the device. In most applications, this pin is not used, thus it is recommended to connect a low noise 1. Fdecoupling capacitor film or C0. G ceramic between Control pin and Ground pin to filter noise on the higher reference voltage. The control pin input can be used to build an astable multivibrator with a frequency modulated output. THRThreshold when the voltage at THR threshold is greater than that at CTRL  23. VCC if CTRL is open the timing OUT high interval ends. DISDischarge open collector output, which may discharge a capacitor between intervals. In phase with output. VCCPositive supply the guaranteed voltage range of bipolar parts are typically 4. Note CMOS timer parts have a lower minimum voltage rating. It is recommended that a 1. Fdecoupling capacitor be connected as close as possible to this pin,2 and optionally a 1. F reservoir capacitor depending on the load connected to the output pin.