Showing posts with label using. Show all posts
Showing posts with label using. Show all posts
Monday, January 26, 2015
Boomer Audio Power Amplifier Using LM4906
The well-known LM386 is an excellent choice for many designs requiring a small audio power amplifier (1-watt) in a single chip. However, the LM386 requires quite a few external parts including some electrolytic capacitors, which unfortunately add volume and cost to the circuit.
National Semiconductor recently introduced its Boomer® audio integrated circuits which were designed specifically to provide high quality audio while requiring a minimum amount of external components (in surface mount packaging only). The LM4906 is capable of delivering 1 watt of continuous average power to an 8-ohm load with less than 1% distortion (THD+N) from a +5 V power supply. The chip happily works with an external PSRR (Power Supply Rejection Ratio) bypass capacitor of just 1 µF minimum.
National Semiconductor recently introduced its Boomer® audio integrated circuits which were designed specifically to provide high quality audio while requiring a minimum amount of external components (in surface mount packaging only). The LM4906 is capable of delivering 1 watt of continuous average power to an 8-ohm load with less than 1% distortion (THD+N) from a +5 V power supply. The chip happily works with an external PSRR (Power Supply Rejection Ratio) bypass capacitor of just 1 µF minimum.
In addition, no output coupling capacitors or bootstrap capacitors are required which makes the LM4906 ideally suited for cellphone and other low voltage portable applications. The LM4906 features a low-power consumption shutdown mode (the part is enabled by pulling the SD pin high).
Additionally, an internal thermal shutdown protection mechanism is provided. The LM4906 also has an internal selectable gain of either 6 dB or 12 dB. A bridge amplifier design has a few distinct advantages over the single-ended configuration, as it provides differential drive to the load, thus doubling output swing for a specified supply voltage. Four times the output power is possible as compared to a single-ended amplifier under the same conditions (particularly when considering the low supply voltage of 5 to 6 volts).
Additionally, an internal thermal shutdown protection mechanism is provided. The LM4906 also has an internal selectable gain of either 6 dB or 12 dB. A bridge amplifier design has a few distinct advantages over the single-ended configuration, as it provides differential drive to the load, thus doubling output swing for a specified supply voltage. Four times the output power is possible as compared to a single-ended amplifier under the same conditions (particularly when considering the low supply voltage of 5 to 6 volts).
Boomer Audio Power Amplifier Circuit Diagram:
When pushed for output power, the small SMD case has to be assisted in keeping a cool head. By adding copper foil, the thermal resistance of the application can be reduced from the free air value, resulting in higher PDMAX values without thermal shutdown protection circuitry being activated. Additional copper foil can be added to any of the leads connected to the LM4906. It is especially effective when connected to VDD, GND, and the output pins. A bridge configuration, such as the one used in LM4906, also creates a second advantage over single-ended amplifiers. Since the differential outputs, Vo1 and Vo2, are biased at half-supply, no net DC voltage exists across the load.
This eliminates the need for an output coupling capacitor which is required in a single supply, single-ended amplifier configuration. Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low frequencies without severe attenuation. But in many cases the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 100 Hz to 150 Hz. Thus, using a large input capacitor may not increase actual system performance. Also, by minimizing the capacitor size based on necessary low frequency response, turn-on pops can be minimized.
Tuesday, November 18, 2014
Melody Generator using M66T
Components List:
C = 1uF
R = 4.7KW
Q = 2SC9013
About IC M66T series:
The M66T series is a CMOS LSI designed melody generator IC for use in telephones and toys application. It has an on-chip ROM programmed for musical performance. Produced by CMOS technology, the device results in very low power consumption. And with built-in RC oscillator, a compact melody module can be constructed with only a few additional components.
- Pin 1 (O/P) Melody Output
- Pin 2 (Vdd) Positive Power Supply
- Pin 3 (Vss) Negative Power Supply
The following are the M66T series and the song generated by its series:
- M66T-01L : Jingle Bells + Santa Claus Is Coming To Town + We Wish You A Merry Christmas
- M66T-05L : Home Sweet Home
- M66T-09L : Wedding March (Mendelssohn)
- M66T-19L : For Alice
- M66T-68L : It Is A Small World
Sunday, November 16, 2014
32 768 KHz Oscillator using Watch Crystal
a 32.768 KHz square wave from a common watch crystal. The output can be fed to a 15 stage binary counter to obtain a 1 second square wave. The circuit on the left using the 4069 inverter is recommended over the transistor circuit and produces a better waveform. The single transistor circuit produces more of a ramping waveform but the output swings the full supply voltage range so it will easily drive the input to a CMOS binary counter.
Sunday, November 2, 2014
14W CLASS A AMPLIFIER USING 2N3055 ELECTRONIC DIAGRAM
14W CLASS A AMPLIFIER USING 2N3055 ELECTRONIC DIAGRAM
Why Class A ? Because , when biased to class A, the transistors are always turned on, always ready to respond instantaneously to an input signal. Class B and Class AB output stages require a microsecond or more to turn on. The Class A operation permits cleaner operation under the high-current slewing conditions that occur when transient audio signal are fed difficult loads. His amplifier is basically simple, as can be seen from the block diagram.
METAL DETECTOR USING BEAT FREQUENCY OSCILLATOR ELECTRONIC DIAGRAM
METAL DETECTOR USING BEAT FREQUENCY OSCILLATOR ELECTRONIC DIAGRAM
The NAND gates use CMOS 4011 chip, a low power component that is suitable for this battery-operated circuit. You can see that this chip is supplied by a 5V voltage coming from an LM7805L regulator. You might wonder what the purpose of this regulation is, since the power supply come from a 9V battery and the CMOS gates can handle the voltage of 3-15 Volt. The main purpose of the regulator is to keep a constant voltage source for the reference oscillator frequency stability, since the frequency is affected by the power supply voltage variation as the battery voltage drops in the long time of usage.
This circuit uses parts as follows :
- U1: CD4011
- U2: LM389
- U3: 78L05
- R1: 2.2k 5%
- P2: 4.7k lin.
- R3: 330k 5%
- R4: 270k 5%
- R5: 1k 5%
- C1: 390pF (NPO)
- C2,C3,C4: 10nF
- C5: 10uF 16v electrolytic
- C6,C8: 220 uF 16v electrolytic
- C7: 100uf 16v electrolytic
- C9: 100nF ceramic
- P1: 4.7k log
- L1: 22cm in diameter with 14 turns AWG 26
- K1: SPDT toggle switch
- J1= Headphone jack 1/4 or 1/8 inch
- Other parts: 9v battery connector, speaker or headphones
Monday, October 13, 2014
Latest IC Power Supply Schematic using DC DC Converter
This is an IC power supply schematic to provide +15V to all of the IC chips using two Lambda DC/DC converters. One 24V/15V DC/DC converter, Lambda PM10-24D15, will be used to provide +15V to the UC3825BN PWM IC, the IR2110 gate driver IC’s, and the ISO124 isolation IC.
Saturday, October 4, 2014
Simple Preamp Mic using IC LM358
This circuit is a simple audio microphone preamp based on a single IC LM358. The circuit is very simple, cheap and easy to build.
Note:
- variable resistor of R5 to adjust the gain of op-amplifier IC LM358.
- The LM358 has two op-amp module, you may build stereo audio pre-amplifier using single LM358.
Component list of simple preamp mic circuit:
R1, R3, R4 : 10K
R2 : 1K
R5 : 100K-1M Potensiometer
C1 : 0.1uF
C2 : 4.7uF/16V
IC1 : LM358 dual op-amplifier
Mic : Electret Microphone
Thursday, September 25, 2014
Simple Light Activated Switch Using IC555
This circuit activates a relay upon detecting the absence of light on an LDR (light dependent resistor).
It is particularly well suited to control outside lighting as used for driveways and garage entrances: Contrary to its normal use as an astable or monostable multivibrator, the Type 555 IC in this circuit functions as a comparator. To explain this rather I unusual application, it is necessarily to note that the operation of a 555 is normally as ( follows: the output goes high 1 upon receipt of a trigger (start) pulse on input pin 2. This pulse is a voltage whose level is lower than of the supply voltage. The output goes low again when the voltage at the second input, pin 6, has briefly exceeded of the supply level.
In the present design, the second input is not used, but the output of the chip can none the less revert to the low state, since pin 6 is connected direct to the positive supply rail. This setup is accounted for by the accompanying Table, taken from the 555’s data sheets. In principle, the supply voltage for the circuit must equal the coil voltage of the relay. Do not / t apply more than 16 M however as this may damage the 555. The current consumption of the circuit is 4mA, exclusive of the relay at a supply level of 12 V Components R2 and C1 ensure a delay of about l0s before the relay is energized, so that the circuit is rendered insensitive to rapid changes in the light intensity Basically the circuit has no hysteresis effect. However, when the supply is not regulated, the actuation of the relay y will lower the supply level somewhat. This lowers the internal threshold of the IC, since the trigger point is defined as of the supply level (pin 2).
Therefore, the hysteresis of the circuit can be dimensioned as required by fitting a resistor in series with the supply. It is also possible to tit a resistor between pins 5 and 7 of { the 555, as shown in the circuit diagram. The amount of hysteresis is inversely proportional to l the value of the resistor, and 100K is a reasonable starting point for experiments. The sensitivity of the trigger circuit can be controlled if R1 is replaced with a 1M potentiometer or preset.
It is particularly well suited to control outside lighting as used for driveways and garage entrances: Contrary to its normal use as an astable or monostable multivibrator, the Type 555 IC in this circuit functions as a comparator. To explain this rather I unusual application, it is necessarily to note that the operation of a 555 is normally as ( follows: the output goes high 1 upon receipt of a trigger (start) pulse on input pin 2. This pulse is a voltage whose level is lower than of the supply voltage. The output goes low again when the voltage at the second input, pin 6, has briefly exceeded of the supply level.
In the present design, the second input is not used, but the output of the chip can none the less revert to the low state, since pin 6 is connected direct to the positive supply rail. This setup is accounted for by the accompanying Table, taken from the 555’s data sheets. In principle, the supply voltage for the circuit must equal the coil voltage of the relay. Do not / t apply more than 16 M however as this may damage the 555. The current consumption of the circuit is 4mA, exclusive of the relay at a supply level of 12 V Components R2 and C1 ensure a delay of about l0s before the relay is energized, so that the circuit is rendered insensitive to rapid changes in the light intensity Basically the circuit has no hysteresis effect. However, when the supply is not regulated, the actuation of the relay y will lower the supply level somewhat. This lowers the internal threshold of the IC, since the trigger point is defined as of the supply level (pin 2).
Therefore, the hysteresis of the circuit can be dimensioned as required by fitting a resistor in series with the supply. It is also possible to tit a resistor between pins 5 and 7 of { the 555, as shown in the circuit diagram. The amount of hysteresis is inversely proportional to l the value of the resistor, and 100K is a reasonable starting point for experiments. The sensitivity of the trigger circuit can be controlled if R1 is replaced with a 1M potentiometer or preset.
Schmitt Trigger Using IC 555
Several circuits exist for using NE 555 as a Schmitt trigger.The circuits are s0 arranged that when the voltage exceeds aset value, say V1, the output of NE 555 becomes high. When the voltage falls below, say V2, the output becomes low. Almost all such circuits use the internal hysteresis pro- vided by ·the three 5k resistors. Though such circuits are simple to design, the Schmitt trigger action of such circuits puts a limitation on the designer. In such circuits, for exam- ple, the difference between Vl ( the upper trip point) and V2 {the lower trip point) is fixed at l/ 3 Vcc by the internal potential divider, and this difference cannot be varied. The circuit shown in Fig. 1 avoids this limitation.
lt enables the use of an NE555 as a general-purpose Schmitt trigger with externally adjustable characteristics. Rl and R2 form a potential divider of Vcc and apply a voltage V1 = R1/R1+R2 * Vcc to terminal 6. Similarly, a voltage V2 = R3/R3+R4 * Vcc is applied to terminal 2. The input voltage Vi is applied to terminal 5 (negative . terminal of threshold comparator).
Also, the input voltage V1 is divided into half (by the internal 5k resistors) and is applied to the positive terminal of the trigger comparator. When the input voltage exceeds twice the value of V2, the trigger comparator output becomes high and the output of NE555 becomes high. After exceeding twice the value of V2, if the input voltage reduces, no change in the timer output occurs until the input voltage goes below VI. When the input goes below V1, the threshold comparator output goes high and the timer output goes low. Thus the NE555 acts as a Schmitt trigger with adjustable hysteresis points of 2 XSV2 and Vl. ’ .
Care should be taken to keep 2xV2 larger than Vl, as is expected from any Schmitt trigger. If this is not satisfied, the timer will not behave as a Schmitt trigger but will operate as a simple comparator (with 2xV2 as the comparison voltage). Another important point is that the internal impedance of the input voltage should be very low, so that the voltage at negative input of the threshold comparator is now significantly modified by the internal potential dividing resistors
(connected to Vcc and earth).
A typical circuit is given in Fig. 2 along with input and
output waveforms.
Read More..
lt enables the use of an NE555 as a general-purpose Schmitt trigger with externally adjustable characteristics. Rl and R2 form a potential divider of Vcc and apply a voltage V1 = R1/R1+R2 * Vcc to terminal 6. Similarly, a voltage V2 = R3/R3+R4 * Vcc is applied to terminal 2. The input voltage Vi is applied to terminal 5 (negative . terminal of threshold comparator).
Also, the input voltage V1 is divided into half (by the internal 5k resistors) and is applied to the positive terminal of the trigger comparator. When the input voltage exceeds twice the value of V2, the trigger comparator output becomes high and the output of NE555 becomes high. After exceeding twice the value of V2, if the input voltage reduces, no change in the timer output occurs until the input voltage goes below VI. When the input goes below V1, the threshold comparator output goes high and the timer output goes low. Thus the NE555 acts as a Schmitt trigger with adjustable hysteresis points of 2 XSV2 and Vl. ’ .
Care should be taken to keep 2xV2 larger than Vl, as is expected from any Schmitt trigger. If this is not satisfied, the timer will not behave as a Schmitt trigger but will operate as a simple comparator (with 2xV2 as the comparison voltage). Another important point is that the internal impedance of the input voltage should be very low, so that the voltage at negative input of the threshold comparator is now significantly modified by the internal potential dividing resistors
A typical circuit is given in Fig. 2 along with input and
output waveforms.
Simple Capacitive Switch Circuit Using IC 555
Take a square wave signal with a given frequency and integrate it. This gives a stable continuous average voltage.
By changing the existing frequency of the signal the average integrated value remains the same but, at the instant when the frequency is changed, a positive or negative voltage peak will appear due to the momentary change in the average waveform of the signal. This is the principle upon which our switch is based. The 555 or 7555 timers will oscillate in a stable manner. However, if we add an external capacitive sensor it becomes possible to vary the oscillation frequency. ln this circuit the square wave is integrated by the triple RC network, while IC2, used as a comparator (with a variable reference value), uses the changes in the integrated voltage to alternately make and break the relay.
Thus when you e move close to C the relay makes; if you remain stationary the relay breaks. It may seem a blt basic but it is a valid idea and it is worth l looking at it in greater detail. To obtain better results you could take the signal after integration and differentiate between negative pulses (the frequency decreases as the value of C increases: when the sensor is approached) and positive pulses (the frequency increases again if the sensor is no longer affected) and compare them. Without this l refinement the size of the sensitive plate must be such that the frequency of oscillation be at least several kHz. Failing this the operation of the circuit would often be disrupted by false detections. Coarse and fine adjustment is provided, using P1 and P2, to reduce the risk of incorrect switching. Note: The numbers in parentheses are the pins if an LM3l1 is used in place of the CA3130
By changing the existing frequency of the signal the average integrated value remains the same but, at the instant when the frequency is changed, a positive or negative voltage peak will appear due to the momentary change in the average waveform of the signal. This is the principle upon which our switch is based. The 555 or 7555 timers will oscillate in a stable manner. However, if we add an external capacitive sensor it becomes possible to vary the oscillation frequency. ln this circuit the square wave is integrated by the triple RC network, while IC2, used as a comparator (with a variable reference value), uses the changes in the integrated voltage to alternately make and break the relay.
Thus when you e move close to C the relay makes; if you remain stationary the relay breaks. It may seem a blt basic but it is a valid idea and it is worth l looking at it in greater detail. To obtain better results you could take the signal after integration and differentiate between negative pulses (the frequency decreases as the value of C increases: when the sensor is approached) and positive pulses (the frequency increases again if the sensor is no longer affected) and compare them. Without this l refinement the size of the sensitive plate must be such that the frequency of oscillation be at least several kHz. Failing this the operation of the circuit would often be disrupted by false detections. Coarse and fine adjustment is provided, using P1 and P2, to reduce the risk of incorrect switching. Note: The numbers in parentheses are the pins if an LM3l1 is used in place of the CA3130
Simple Flasher Circuit Using Unijunction Transistor
This circuit will operate reliably from noisy or fluctuating power supplies and unlike many multivibrator circuits is inherently self-starting when power is applied.
In this flasher circuit unijunction transistor G1 is used as a relaxation oscillator supplying a continuous train of pulses to the gates of the SCRs. Assume that SCR2 has been triggered into conduction and that lamp 2 is energized. The next trigger pulse from O1 triggers SCR1, this discharges C2 and the resultant commutation pulse turns off SCR2. The resistor R2 in the anode of SCR1 is of a value high enough to prevent SCR1 from latching on. SCR2 is re-triggered by the next triggering pulse from O1. Using the component values shown, the flash rate of this circuit is adjustable by R2 from 35 to 150 flashes a minute.
In this flasher circuit unijunction transistor G1 is used as a relaxation oscillator supplying a continuous train of pulses to the gates of the SCRs. Assume that SCR2 has been triggered into conduction and that lamp 2 is energized. The next trigger pulse from O1 triggers SCR1, this discharges C2 and the resultant commutation pulse turns off SCR2. The resistor R2 in the anode of SCR1 is of a value high enough to prevent SCR1 from latching on. SCR2 is re-triggered by the next triggering pulse from O1. Using the component values shown, the flash rate of this circuit is adjustable by R2 from 35 to 150 flashes a minute.
Wednesday, September 24, 2014
Simple Variable Voltage Current Power Supply Circuit Using a Single FET
- For many applications the requirements are not that stringent and a simple, discretely constructed regulator as described here will suffice.
- The current limiting components can then be left out.
- With values as shown, the output I voltage is 12V and the output current is limited to 0.5 A. For applications not requiring current limiting the circuit can supply up to 1 A.
- The relation between input voltage, load resistance and regulated output voltage is shown in table 1.
- This table can therefore be used to determine whether the regulation for a particular application is sufficient. The ’heart’ of the regulator, high power low-frequency transistor T1, l must be fitted onto an adequate heatsink. FET T3 operates as a current source with an output 3, maximum of 11 . . . 18 mA: this it limits the base current of T1, of course, but the alternative would have been a very low value resistor; ‘ or this would have resulted in large!
- The cost of high grade, regulated power supplies has dropped with the advent of modern lCs.
Tuesday, September 23, 2014
3 Channel Audio Mixer using LM3900 circuit and explanation
This audio mixer schematic uses an LM3900 IC but is not a professional audio dj mixer. The IC houses four integrated Norton amplifiers. The advantage of using the four op amps is that they only need a single power supply. Since this amplifier circuit is current controlled, the DC bias is dependent on the feedback coupling. The schematic diagram shows inverting AC-Norton amplifiers. The DC output must be set at 50 percent of the power supply. In this case, a maximum output can be achieved without distortion (also called symmetrical limitation through overdrive).
Audio mixer schematic
In designing this mini audio mixer schematic you can freely choose the value of the resistor R2 (100k in the mixer schematic). Set the AC voltage amplification factor through the ration of R2/R1. To set the amplifier gain correctly, choose the value of R4=2R2 (double the value of R2).
Diagram 1.0 shows the 3-channel sound mixer circuit using three Norton-opamps. The input levels can be set by potentiometers P1 or P3. Furthermore, each input level can be trimmed with the help of trimmers pots P4 to P6 to adapt each input to the source. The resistors at the non-inverting inputs of the opamps work as DC bias and set the DC output at 50 percent of the power supply for this powered audio mixer. All three input signals are summed by the fourth opamp A4 through the resistors R3, R7 and R11. The commom volume level is cotrolled through the potentiometer P7.
You can switch an input channel on or off through the switches S1 and S3. An input channel is turned off when its switch is closed. It is also possible to replace these mechanical switches with transistor gates. By doing so, you can build an analog multiplexer circuit that can be easily expanded by several inputs.
via:http://skema-rangkaian.blogspot.com/
Wednesday, September 17, 2014
Electronic Door Minder using 555 Timer
This door minder electronic project uses an IR beam to monitor door & passage-ways or any other area. When the IR beam is broken a relay is tripped which can be used to sound a bell or alarm. This door minder electronic project is suitable for detecting customers entering a shop, cars coming up a driveway, etc.
Circuit Diagram
Electronic Door Minder using 555 Timer Transmitter Circuit Diagram
Because the IR beam is very strong distances over 25 yards can be monitored with electronic circuit . This circuit must be powered from a 12volt DC supply. The transmitter circuit consists of two square-wave oscillators, one running at approx. 250Hz and the other running at 38kHz. The 38kHz frequency acts as a carrier wave and is required by the IR receiver module on the receiver board.The oscillators are made by using two 555 timer ICs set up as astable configuration multivibrators.Another 555 timer ( IC2) is used for the 38KHz oscillator. Resistors R4 and R5 and capacitor C3 set the frequency.Diodes D1 and D3 are used to create a symmetrical output.
Circuit diagram :
Electronic Door Minder using 555 Timer Receiver Circuit Diagram
Normally the external capacitor C1 (C3) charges through resistors R1 and R2 (R4 and R5) and discharges through R2 (R5). Without the diodes this output waveform would have a longer “high” time than the “low” time. The output from the IC1 is coupled via diode D2 and resistor R3 to the trigger input of IC2. When the IC1 output is low it stops IC2 from running and IC2’s output is forced high (no IR LED current). When IC1 output is high, IC2 runs and the IR LED is pulsed at 38KHz.The receiver module consists of an IR receiver module that detects the incoming beam from the transmitter. The IR signal is used to keep a capacitor charged which in turn holds a relay operated. When the beam is broken the capacitor discharges and the relay releases.
Sunday, September 7, 2014
5V Power Supply Using LTM8021
This 5v power supply schema is designed using the LTM8021 and will provide a maximum current up to 500mA. Almost all required parts are included in the LTM8021 package. This 5v power supply schema based on the LTM8021 operate over a input voltage range between 3V and 36V .The LTM8021 supports an output voltage range of 0.8V to 5V, set by a single resistor. Only an output and bulk input capacitor are needed to finish the design.
5V Power Supply Circuit diagram
5V Power Supply Circuit diagram
Saturday, September 6, 2014
Amplifier power supply using High Current Transformer
Circuit Description
Friends ever meet a problem power supply Circuit give current not enough. I has way this out give friends try apply. Follow this circuit High Current transformer parallel circuit make you have Current tall go up very. The transformer that have many the coil , we can bring to do high Current power supply circuit well. By if the all coil has Voltage be equal. It is can bring parallel can follow this circuit is coil lead that has Voltage 24V and have Current about 1A come to parallel prevent all 2 the group have current altogether each 2A groups by have voltage at 24V be the same. This circuit then can become Dual power supply at 34V positive and -34V Negative and Ground. This circuit uses to are amplifier power supply get good. Suppose will give the electric power about 50watt. For the diode use 3A 100V sizes and use. The Stancor for filter noise signal the all well. This circuit may help to give testimony have the idea in applying work other , get please sir.
Original article sourse elecfree.com
Amplifier circuit diagram
Electronic Door Minder using 555 Timer
This door minder electronic project uses an IR beam to monitor door & passage-ways or any other area. When the IR beam is broken a relay is tripped which can be used to sound a bell or alarm. This door minder electronic project is suitable for detecting customers entering a shop, cars coming up a driveway, etc. Circuit Diagram ![]()
Electronic Door Minder using 555 Timer Transmitter Circuit Diagram Because the IR beam is very strong distances over 25 yards can be monitored with electronic schema . This schema must be powered from a 12volt DC supply. The transmitter schema consists of two square-wave oscillators, one running at approx. 250Hz and the other running at 38kHz. The 38kHz frequency acts as a carrier wave and is required by the IR receiver module on the receiver board.The oscillators are made by using two 555 timer ICs set up as astable configuration multivibrators.Another 555 timer ( IC2) is used for the 38KHz oscillator. Resistors R4 and R5 and capacitor C3 set the frequency.Diodes D1 and D3 are used to create a symmetrical output. Circuit diagram : ![]()
Electronic Door Minder using 555 Timer Receiver Circuit Diagram
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Normally the external capacitor C1 (C3) charges through resistors R1 and R2 (R4 and R5) and discharges through R2 (R5). Without the diodes this output waveform would have a longer “high” time than the “low” time. The output from the IC1 is coupled via diode D2 and resistor R3 to the trigger input of IC2. When the IC1 output is low it stops IC2 from running and IC2’s output is forced high (no IR LED current). When IC1 output is high, IC2 runs and the IR LED is pulsed at 38KHz.The receiver module consists of an IR receiver module that detects the incoming beam from the transmitter. The IR signal is used to keep a capacitor charged which in turn holds a relay operated. When the beam is broken the capacitor discharges and the relay releases.
Thursday, August 28, 2014
Battery Charger Circuit using Solar Cell Wiring diagram Schematic
This is a schema solar charger via USB cable emergency, it is an alternative schema that uses solar cell and LM317 to regulate and make a recharge via USB for electronic equipment that can be IPODs, cell phones, MP3, tablets, etc..
The simplicity of the schema can be noted that he does not have much appeal, but its enough to make a simple battery charge. The Solar Cell should be 12v current should be enough for loading, 10% of the batteries.
Battery Charger Circuit using Solar Cell Circuit Diagram
Wednesday, August 27, 2014
12V Step Down Dc Converter Using ADP2300 ADP2301
Using ADP2300 ADP2301 step-down dc dc regulators with integrated power MOSFET, can be designed a very simple DC DC voltage converter. Output voltage delivered by these diagram can be adjusted from 0.8 volts, up to 0.85xVin , with ±2% accuracy. The maximum output current that can be provided by ADP2300 ADP2301 regulators is up to 1.2 A load current.
12V Step-Down Dc Converter Circuit Diagram
There are two frequency options: the ADP2300 runs at 700 kHz, and the ADP2301 runs at 1.4 MHz. These options allow users to make decisions based on the trade-off between efficiency and total solution size. Current-mode control provides fast and stable line and load transient performance. Bellow you an see two design examples, which require few common electronic components.First schema will provide a 2.5V output at a maximum current of 1.2A from an input voltage of 12 volts. Second schema will provide a 5V output at a maximum current of 1.2A from an input voltage of 12 volts.
Monday, August 25, 2014
35W Power Amplifier Circuit using STK082
The following is the schematic diagram of 35W power audio amplifier. Built based on power-amp IC of STK082, this schema will give great audio output for your home audio system.
Download the STK082 datasheet
Read More..
Download the STK082 datasheet
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