- Classic Plus and Minus DC Power Supply - produces both a positive 15v and a negative 15v from a 20vac wall adapter.
- AC to DC Boost Converter with PFC - Implementation of a AC to DC Boost Converter with power factor correction.
- Classic Linear 5v Supply Using 6.3vac Transformer - Circuit consists of an iron core transformer, a bridge rectifier, a filter capacitor and a voltage regulator.
- AC-to-DC converter circuit utilizing IGBTs - AC-to-DC converter furnishing a regulated DC-output voltage from an AC-input supply voltage
- Non-isolated Off-line AC to DC Power Supply - Efficient circuit can provide up to 100ma of a regulated 5 volts from an AC power.
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Showing posts with label to. Show all posts
Thursday, December 11, 2014
Wednesday, November 12, 2014
The illustration provides below schemes 8V-60V to 12V Converter Circuit Diagram. It uses LT3433, an automatic step up and step down switching regulator IC with 4V to 60V input voltage which can be useful in automotive electronics using various wide input voltage range.
According to the LT3433 datasheet, this Automatic Step-Up and Step-Down Conversion device is a 200kHz fixed frequency current mode switching regulator using a single inductor which can be applied in applications such as wall adapter powered systems and battery power voltage buffering.
Read completely about Step Up/Step Down DC to DC Converter Circuit Diagram using LT3433 here in pdf archive (source: linear.com)
Read MoreSunday, October 26, 2014
Relays are often used as electrically controlled switches. Unlike transistors, their switch contacts are electrically isolated from the control input. On the other hand, the power dissipation in a relay coil may be unattractive for battery-operated applications. Adding an analogue switch lowers the dissipation, allowing the relay to operate at a lower voltage. The circuit diagram shows the principle. Power consumed by the relay coil equals V2/RCOIL. The circuit lowers this dissipation (after actuation) by applying less than the normal operating voltage of 5 V. Note that the voltage required to turn a relay on (pickup voltage)is usually greater than that to keep it on (dropout voltage).
In this respect the relay shown has specifications of 3.5 and 1.5 V respectively, yet the circuit allows it to operate from an intermediate supply voltage of 2.5 V. Table 1 compares the relay’s power dissipation with fixed operating voltages across it, and with the circuit shown here in place. The power savings are significant. When SW1 is closed, current flows through the relay coil, and C1 and C2 begin to charge. The relay remains inactive because the supply voltage is less than its pickup voltage. The RC time constants are such that C1 charges almost completely before the voltage across C2 reaches the logic threshold of the analogue switch inside the MAX4624 IC.
When C2 reaches that threshold, the on-chip switch connects C1 in series with the 2.5 V supply and the relay coil. This action causes the relay to be turned on because its coil voltage is then raised to 5 V, i.e., twice the supply voltage. As C1 discharges through the coil, the coil voltage drops back to 2.5 V minus the drop across D1. However, the relay remains on because the resultant voltage is still above the dropout level (1.5 V). Component values for this circuit depend on the relay characteristics and the supply voltage. The value of R1, which protects the analogue switch from the initial current surge through C1, should be sufficiently small to allow C1 to charge rapidly, but large enough to prevent the surge current from exceeding the specified peak current for the analogue switch.
The switch’s peak current (U1) is 400 mA, and the peak surge current is IPEAK = (VIN – VD1) / R1 + RON) where RON is the on-resistance of the analogue switch (typically 1.2 Ω). The value of C1 will depend on the relay characteristics and on the difference between VIN and the pickup voltage. Relays that need more turn-on time requires larger values for C1. The values for R2 and C2 are selected to allow C1 to charge almost completely before C2’s voltage reaches the logic threshold of the analogue switch. In this case, the time constant R2C2 is about seven times C1(R1 + RON). Larger time constants increase the delay between switch closure and relay activation. The switches in the MAX4624 are described as ‘guaranteed break before make’. The opposite function, ‘make-before break’ is available from the MAX4625. The full datasheets of these interesting ICs may be found at http://pdfserv.maxim-ic.com/arpdf/MAX4624-MAX4625.pdf
Read More
In this respect the relay shown has specifications of 3.5 and 1.5 V respectively, yet the circuit allows it to operate from an intermediate supply voltage of 2.5 V. Table 1 compares the relay’s power dissipation with fixed operating voltages across it, and with the circuit shown here in place. The power savings are significant. When SW1 is closed, current flows through the relay coil, and C1 and C2 begin to charge. The relay remains inactive because the supply voltage is less than its pickup voltage. The RC time constants are such that C1 charges almost completely before the voltage across C2 reaches the logic threshold of the analogue switch inside the MAX4624 IC.
When C2 reaches that threshold, the on-chip switch connects C1 in series with the 2.5 V supply and the relay coil. This action causes the relay to be turned on because its coil voltage is then raised to 5 V, i.e., twice the supply voltage. As C1 discharges through the coil, the coil voltage drops back to 2.5 V minus the drop across D1. However, the relay remains on because the resultant voltage is still above the dropout level (1.5 V). Component values for this circuit depend on the relay characteristics and the supply voltage. The value of R1, which protects the analogue switch from the initial current surge through C1, should be sufficiently small to allow C1 to charge rapidly, but large enough to prevent the surge current from exceeding the specified peak current for the analogue switch.
The switch’s peak current (U1) is 400 mA, and the peak surge current is IPEAK = (VIN – VD1) / R1 + RON) where RON is the on-resistance of the analogue switch (typically 1.2 Ω). The value of C1 will depend on the relay characteristics and on the difference between VIN and the pickup voltage. Relays that need more turn-on time requires larger values for C1. The values for R2 and C2 are selected to allow C1 to charge almost completely before C2’s voltage reaches the logic threshold of the analogue switch. In this case, the time constant R2C2 is about seven times C1(R1 + RON). Larger time constants increase the delay between switch closure and relay activation. The switches in the MAX4624 are described as ‘guaranteed break before make’. The opposite function, ‘make-before break’ is available from the MAX4625. The full datasheets of these interesting ICs may be found at http://pdfserv.maxim-ic.com/arpdf/MAX4624-MAX4625.pdf
Friday, October 24, 2014
This inverter circuit can provide up to 800mA of 12V power from a 6V supply. For example, you could run 12V car accessories in a 6V (British?) car. The circuit is simple, about 75% efficient and quite useful. By changing just a few components, you can also modify it for different voltages.
Part List:
R1, R4 2.2K 1/4W Resistor
R2, R3 4.7K 1/4W Resistor
R5 1K 1/4W Resistor
R6 1.5K 1/4W Resistor
R7 33K 1/4W Resistor
R8 10K 1/4W Resistor
C1,C2 0.1uF Ceramic Disc Capacitor
C3 470uF 25V Electrolytic Capcitor
D1 1N914 Diode
D2 1N4004 Diode
D3 12V 400mW Zener Diode
Q1, Q2, Q4 BC547 NPN Transistor
Q3 BD679 NPN Transistor
L1 See Notes
MISC Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board Read More
Part List:
R1, R4 2.2K 1/4W Resistor
R2, R3 4.7K 1/4W Resistor
R5 1K 1/4W Resistor
R6 1.5K 1/4W Resistor
R7 33K 1/4W Resistor
R8 10K 1/4W Resistor
C1,C2 0.1uF Ceramic Disc Capacitor
C3 470uF 25V Electrolytic Capcitor
D1 1N914 Diode
D2 1N4004 Diode
D3 12V 400mW Zener Diode
Q1, Q2, Q4 BC547 NPN Transistor
Q3 BD679 NPN Transistor
L1 See Notes
MISC Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board Read More
Thursday, October 23, 2014
5.1 channel amplifier consists of 6 amplifiers 1 channel mono, which has certain specifications on each canals. Has 6 channel surround sound amplifier that consists of Front Left ,Center,Front Right ,Rear Left (Left Surround),Rear Right (Right Surround) , and LFE (Subwoofer).For clarity I give a simple illustration of the layout and the circuit for these speakers.
| 5.1 Speaker Setup |
Accoustic Field Generator
Acoustic Field Generator is generating acoustic sound with surround effects are adjustable with a standard Dolby Surround, able to produce surround sound is good enough but not too much need of funds. Technological developments as if not only focused on one area alone but on all fronts. The development of technologies that exist today one of them is in the field of audio. With more advanced audio technology today not only as mere entertainment but has become a hobby, hobby is not cheap of course. Many audio enthusiasts trying to make music sound that sounded to be very hard to make music sound as live, the addition of the amplifier, woofer or special speakers that cost is not cheap.
The sound effects are living seems to now is something that most do not have to exist in every good audio devices. This effect is basically a surround effect that can lead to sound as though coming from different directions and his voice can still be heard clearly. Currently Compo-tape tape that has been a lot of these facilities surround sound but not good enough when heard from a considerable distance because of the effects surroundnya missing. This is because the distance is too far listener and speaker, speaker layout is not quite right, or the effect of unfavorable surround.
Surround effects are nice and can be heard with a good surround system is a system that is in movie theaters and to make it not a bit prangkat needed funds. However, if satisfaction remains the number one then the fund is not a major problem. To find a middle ground between price and quality surround effects it was attempted to make the Acoustic Field Generator that can produce surround sound is good enough but not too much need of funds. Acoustic Field Generator is capable of generating acoustic sound with surround effects are adjustable with a standard Dolby Surround.
Accoustic Field Generator Construction
Basically an Acoustic Field Generator built from op-amp circuit and filters. Op-amps are usually used as a voltage amplifier in the Acoustic Field Generator is more widely used as active filters. The filter in the tool is very instrumental in creating an acoustic sound that is really clear, but in practice, almost all the filters, do not miss the precision of the signal with a specific frequency. An op-amp is good for this application is the op-amp which has a wide bandwidth, rise time, slew rate and fast setting timenya. In addition to op-amp and active filter, theres more important parts of the power supply. This is the part that is instrumental in creating excellence acoustic sound because of the bad power supply which is the only producer of noise, which will enter into a voice signal path so that should clear acoustic sound into an acoustic sound with the addition of reverberation (noise). The power supply used is the twin power supply + / - 18 volts DC. Part Acoustic Field Generators
Before we start doing this project, it helps us know in advance about the function of each speaker.
Front Channel
Channel Front is a forward channel input signal LR. LR signal is passed to an amplifier with gain = 1 so that this signal is passed without change / to filter the input signal LR. Front Left and Front Right, is a public speaker that we encountered in stereo amplifier, consisting of a woofer and tweeter. Woofers generally produce low tone sound with a frequency range ranging from 80Hz - 250Hz, while the tweeter produces a high tone with a frequency range between 15kHz - 20kHz. For projects that we will create, its good we use a good quality woofer, with a size of 10 inches and a type piezoelectric tweeter for each speaker fronts.
Channel Front is a forward channel input signal LR. LR signal is passed to an amplifier with gain = 1 so that this signal is passed without change / to filter the input signal LR. Front Left and Front Right, is a public speaker that we encountered in stereo amplifier, consisting of a woofer and tweeter. Woofers generally produce low tone sound with a frequency range ranging from 80Hz - 250Hz, while the tweeter produces a high tone with a frequency range between 15kHz - 20kHz. For projects that we will create, its good we use a good quality woofer, with a size of 10 inches and a type piezoelectric tweeter for each speaker fronts.
| Front Channel 5.1 Amplifier |
Center Channel
Center, the fullrange speakers, which produce sound with a frequency range between 80Hz - 10Khz. Output from the center speaker is a summation of left and right signal (left + right = center). In a movie or song Dolby Surround format, commonly used center for dialogue / vocal or speech of the actor / artist of a film and to produce a sound that moves ahead of us.
| Center Channel 5.1 Amplifier |
Rear Channel with Surround System
In this section is the core of this hard perangakat. These sections produce surround effects. To produce the surround effect is required special IC MN3005 / 8 and MN3101. Both these ICs will delay the incoming signal in several phases, so that the signal output from this phase will be left with a signal phase of the signal lain.Pada this section L and R are deducted (LR) and then passed in the buffer, filter LPF, delay line, filter LPF (7KHz) and the last is a splitter between the signals R and L. Circuit which causes the surround effect is 75KHz LPF circuit that produces its output fed to the Right Rear 75KHz LPF amplifier input while it diparalel with the Left Rear amplifier input so as to produce two signals L and R which is basically a LR signal a phase lag with the original signal phase.
Rear Left and Rear Right, also known as surround speakers. This speaker is generally a semi-midrange speaker (usually used on television or Mini Compo), commonly called satellite speakers. In a movie surround speakers are used to generate the audible sound of distant voices or sounds that move from the back of our approach. In a music surround speakers produce sound backing vocals and generally sounds like guitars, violins and trumpets sounded clear here.
| Rear Channel 5.1 Amplifier |
Subwoofer Channel
Part of this subwoofer is the summation of inputs L and R inputs to a summing amplifier. The output of the summing amplifier is passed to a class 2A LPF which will only pass signals with frequency rendah.Subwoofer, sometimes referred to as LFE (Low Frequency Effect). For these speakers using a subwoofer speaker. Speaker woofer speaker subwoofer is designed specifically to be able to respond to sound with a very low frequency, ranging from 15Hz - 120Hz. For low tone effect can be produced by either (without any harmonic frequency), then the acoustic box / box speakers are also designed specifically with a variety of methods (there are no visible speaker / inside the box, there are that use insulation / labyrinth, etc. ), so that the speaker is capable of compressing the air effectively, so that will feel the effect.
| Subwoofer Channel 5.1 Amplifier |
| Wiring Diagram Home Theater Amplifier / 5.1 Amplifier |
Friday, October 17, 2014
There are monitors which only have three BNC inputs and which use composite synchronization (‘sync on green’). This circuit has been designed with these types of monitor in mind. As can be seen, the circuit has been kept very simple, but it still gives a reasonable performance. The principle of operation is very straightforward. The RGB signals from the VGA connector are fed to three BNC connectors via AC-coupling capacitors. These have been added to stop any direct current from entering the VGA card. A pull-up resistor on the green output provides a DC offset, while a transistor (a BS170 MOSFET) can switch this output to ground. It is possible to get synchronisation problems when the display is extremely bright, with a maximum green component.
In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.
This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity.
LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.
Resistors: R1,R2,R3 = 470Ω
R4 = 100Ω
R5 = 3kΩ3
Capacitors:
C1,C3,C5 = 47µF 25V radial
C2,C4,C6,C7,C10 = 100nF ceramic
C8 = 4µF7 63V radial
C9 = 100µF 25V radial
Semiconductors:
D1 = LED, high-efficiency
D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05
Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω .
Sunday, October 5, 2014
This inverter will sufficiently power any of your 115VAC (or 220VAC)small appliances। T1 choice of amperage is yours to make, but if you can salvage a heavy-duty unit from somewhere, use it. The least expensive method to get a larger transformer would be to remove the old 2000v primary and then re-wind an old microwave transformer. Most of these transformers are rated 1KW or better. Your local TV or Electronics repair shop may have one or dig one up from the dumpster. Just in case you dont know, micro-wave transformers can keep their charge (via the connected electronics) for a long time, so be careful!R1 and R2 are 10 ohm, wire-wound, and at least 5 watts. Wattage/cooling should be increased accordingly if you decide to beef up the output. For D1 and D2 you can use any power diode like the 1N4002 to 1N4005.If you live in Europe, Australia, or any other country with a 220VAC system, the only different is the transformer. This particular circuit can be constructed to handle up to 1 KiloWatt (1000 watt). If there is enough interest, I can modify this circuit to include a crow-bar circuit, battery backup, or more output in watts, or everything.The power output is determined by transformer T1, and power transistors Q1 & Q2. Assume a transformer of about 15A and the chosen transistors of 2N3055 (15A) type, the inverter can supply about 300 watts with the parts shown. If you are good with electronics all you have to do is replace the 2N3055s and T1 accordingly for more output. It is imperative to mount Q1 and Q2 on large coolribs. If you intend to beef everything up with a couple kilowatts a standard (5") cooling fan will also be required. If this is the case, the 2N3771 power transistor is a good choice at 30Amps. NTEs replacement, NTE181, is an improved version of the 2N3771 and carries 90volts instead of the 40 volts and can dissipate 200W instead of 2N3771s 150W.It is mandatory to include at least one suitable fuse and enclose this project in the correct casing. To be really safe you may want to include a primary and secundary fuse for your own protection. You are dealing with 120VAC or 220VAC at respectible amperage so be careful. The powercord also needs to be secured to prevent accidents.The 68uF Tantalum capacitors were chosen for their endurance. Normal electrolytic capacitors would overheat and explode. Somesort of cooling fan inside the project case may be a good choice, I myself use a ball-bearing cpu-fan from an old computer. New they dont cost that much either, about 3 bucks or so.
Since T1, and Q1/Q2 are NOT part of the PCB, these few parts can easily be used on a piece of Vero or experimenters board. Radio Shack and Tandy have these boards also available at a very reasonable price. The receptacle(s) on T1s output will be part of the case (obviously). I Just a small note about the 12 Volt battery, this circuit and others similar can draw huge amounts of current and will drain your battery in hurry so dont let your battery go dead! Thats why a wind/solar power combination would be an excellent future addition. For those interested in a PCB, I have included one below with a layout. As soon as I get my digital camera I will include pictures of the finished project. Read More
Thursday, October 2, 2014
Philips have developed the Type TDA1514 AF amplifier chip, which is remarkable for its l excellent specifications, ruggedness and output power.
The circuit diagram shows that very few components are . needed to make this high- performance amplifier.
The device is housed in a 9-pin SIL POWER enclosure which has a thermal resistance of less than 1.5 K/W so that the heatsink required must have a thermal resistance of no more than 3.8 K/Wif the chip is operated at its maximum dissipation of l9 W (Ub= i-27.5 L Ta=5O °C).
The power supply to feed the chip must be capable of delivering a current of at least 3 A; the quiescent current demand of the amplifier as shown is about 60 mA.
Make sure, however, that the tracks and connections to the Sl i supply and output terminals are as short as possible, and use H double tracks where this is I necessary. In this context, it is advisable to fit decoupling 5 capacitors C3 and Ca as close as 3 possible to the chip supply pins. Resistors R2 and R3.
The supply voltage 1 should not exceed +/-27.5v. Although this project is not supported by a ready—made printed circuit board, you should not C experience too much difficulty in constructing the amplifier if it F $ is built on a piece of Veroboard.
Courtesy: Elektor Electronics
Read More
The circuit diagram shows that very few components are . needed to make this high- performance amplifier.
The device is housed in a 9-pin SIL POWER enclosure which has a thermal resistance of less than 1.5 K/W so that the heatsink required must have a thermal resistance of no more than 3.8 K/Wif the chip is operated at its maximum dissipation of l9 W (Ub= i-27.5 L Ta=5O °C).
The power supply to feed the chip must be capable of delivering a current of at least 3 A; the quiescent current demand of the amplifier as shown is about 60 mA.
Make sure, however, that the tracks and connections to the Sl i supply and output terminals are as short as possible, and use H double tracks where this is I necessary. In this context, it is advisable to fit decoupling 5 capacitors C3 and Ca as close as 3 possible to the chip supply pins. Resistors R2 and R3.
The supply voltage 1 should not exceed +/-27.5v. Although this project is not supported by a ready—made printed circuit board, you should not C experience too much difficulty in constructing the amplifier if it F $ is built on a piece of Veroboard.
Courtesy: Elektor Electronics
Wednesday, October 1, 2014
As everybody knows the voltage drop across a zener diode is dependent on the current passing th rough the diode.
Therefore, depending on the type and power of the device, there can be very noticeable deviations from the nominal zener voltage. This can be a problem, especially in circuits where a stable d.c. voltage is essential. The most logical way of solving the problem is to keep the current through the diode constant so that the zener voltage can not change. ln order that the load connected to the zener diode draws a constant current, the zener can be supplied by means of a current source. Then the current through the current source is made dependent on the zener voltage. In our adjustable zener circuit we use a zener diode with a zener voltage of 6 V. Other zener values could be used if resistors R1 . . . R4 are changed to suit another value. The maximum input voltage is mainly limited by the power which can be dissipated by T1 and T2. The d.c. input voltage must be at least as high as the sum of the zener voltages of Dl and D2.
The current source consisting of T1, R1 and D1 ensure that the current through D2 remains constant. Transistor T2, resistor R 2 and zener diode D2 in turn form a current source for zener D1 so that the current through this diode also stays constant. Diode D3 and the voltage divider, consisting of R3 and R4, ensure that this circuit can ’start’ (just as a thyristor made of transistors). As soon as the voltage is switched on a current flows through D3 causing T2 (and therefore T1) to conduct. The value of R3 must be selected such that diode D3 blocks as soon as the voltage across the zener dlode has stabilized. So care must be taken that the voltage at the anode of D3 ls less than the zener voltage of D2 plus the di0de’s own voltage drop of 0.6 V. This is defined by the formule: ; x U;
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Therefore, depending on the type and power of the device, there can be very noticeable deviations from the nominal zener voltage. This can be a problem, especially in circuits where a stable d.c. voltage is essential. The most logical way of solving the problem is to keep the current through the diode constant so that the zener voltage can not change. ln order that the load connected to the zener diode draws a constant current, the zener can be supplied by means of a current source. Then the current through the current source is made dependent on the zener voltage. In our adjustable zener circuit we use a zener diode with a zener voltage of 6 V. Other zener values could be used if resistors R1 . . . R4 are changed to suit another value. The maximum input voltage is mainly limited by the power which can be dissipated by T1 and T2. The d.c. input voltage must be at least as high as the sum of the zener voltages of Dl and D2.
The current source consisting of T1, R1 and D1 ensure that the current through D2 remains constant. Transistor T2, resistor R 2 and zener diode D2 in turn form a current source for zener D1 so that the current through this diode also stays constant. Diode D3 and the voltage divider, consisting of R3 and R4, ensure that this circuit can ’start’ (just as a thyristor made of transistors). As soon as the voltage is switched on a current flows through D3 causing T2 (and therefore T1) to conduct. The value of R3 must be selected such that diode D3 blocks as soon as the voltage across the zener dlode has stabilized. So care must be taken that the voltage at the anode of D3 ls less than the zener voltage of D2 plus the di0de’s own voltage drop of 0.6 V. This is defined by the formule: ; x U;
Tuesday, September 16, 2014
The schema letsyou convert a serial pulse stream or sinusoidal input to a sinusoidal output at 1/32 the frequency. By varying the frequency of Vrn, you can achieve an output range ofl07:1-from about 100 kH2 to less than 0.01 H2. The output resembles that of a 5-bit d/a converter operating on paralleLdigital data. Counter IC1 generates binary codes that repeatedly scan the range from 00000 to 11111. The output amplifier adds the corresponding XOR gate outputs, Vvv or ground, weighted by the values of input resistors R1 through R4.
Pulse-train-to-sinusoid-Converter Circuit Diagram
Pulse-train-to-sinusoid-Converter Circuit Diagram
The 16 counter codes 00000 to 01111, for instance, pass unchanged to the XOR gate outputs, and cause Vom to step through the half-sinusoidal cycle for maximum amplitude to minimum amplitude. Counter output Q4 becomes high for the next 16 codes, causing the XOR gates to invert the QO through Q3 outputs. As a result, VouT steps through the remaining half cycle from minimum to maximum amplitude. The counter then rolls over and initiates the next cycle. You can change the R1 through R4 values to obtain other VouT waveforms. VDv should be at least 12 V to assure maximum-frequency operation from IC1 to IC2.
Thursday, September 11, 2014
A DC-DC converter 1.5V to 3V Circuit Diagram to reduce the voltage is easy, but the situation becomes more complicated when we have to increase the voltage. This simple scheme generates a voltage 3Vdc from 1.5 VDC, which can be a single stack. We can get good results by modifying an multivibrator using two transistors, the frequency converter is approximately 130 kHz. The inductance value can be calculated experimentally.
DC / DC converter 1.5V to 3V Circuit Diagram
Schottky diode VD1 can be replaced by any other similar characteristics.
For further stabilization of the output voltage can be placed one Zener 3V - 3.3V. This scheme can be used to feed a power LED device, a micro-controller, Arduino, etc. ..
List of Components
R1, R3: 1K
R2: 2K2
C1: 470pF
C2: 100uF / 3.3V
C3: 1000uF
L1: 470UH
VD1: 15MQ040
VT1, VT2: BC547
Tuesday, September 2, 2014
General Description:
The TDA1015 is a monolithic integrated audio amplifier circuit in a 9-lead single in-line (SIL) plastic package. The device is especially designed for portable radio and recorder applications and delivers up to 4 W in a 4 Ω load impedance. The very low applicable supply voltage of 3,6 V permits 6 V applications. 1 to 4 W audio power amplifier
Special features:
- single in-line (SIL) construction for easy mounting
- separated preamplifier and power amplifier
- high output power
- thermal protection
- high input impedance
- low current drain
- limited noise behaviour at radio frequencies
Circuit Diagram:
 |
| 1 to 4 W audio power amplifier circuit diagram |
Datasheet for TDA1015: Download
Monday, September 1, 2014
Here is the schema diagram of a effective light to frequency converter schema that can be used for variety of applications such as light intensity measurement,fun etc.
The schema is based on TLC555, the CMOS version of famous timer IC NE 555. A photo diode is used for sensing the ligt intensity.The timer IC is wired in astable mode.The leakage current of the reverse biased photo diode is proportional to the light intensity falling on it.This leakage current charges the capacitance C1.When the capacitor voltage reaches 2/3 of the supply voltage the out put (pin 3) goes low.As a result the capacitor discharges through photo diode .When the capacitor voltage reaches 1/3 the supply voltage the out put (pin 3) of IC goes high.This cycling continues and we get a frequency at pin 3 proportional to the light intensity falling on the photo diode.
Notes.
* With the given components the frequency varies from 1KHZ @ complete darkness to 24 Khz @ bright sunlight.The frequency range can be changed by using different values for C1.
* Use any general purpose photo diode for D1.
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Saturday, August 30, 2014
This High Power LEDs up to 15 Amperes Circuit Diagram employs a simple scheme that limits the current flow to the LED, you can easily modify the schema, and can change the power just replacing the value of R2. You can use a DC source of any tensions between 9V to 15V.Para powers or other LEDs just use the approximate formula:
Current (I) = 0.8/R2 where I is the current specified by the LED manufacturer. Value of I this conductor is 10A. Use R2 = 0.8/Current formula (I) to determine R2.
High Power LEDs up to 15 Amperes Circuit Diagram
Parts List
Q1 2N3055 or similar NPN transistor
R1 1W 220ohms
D1, D2 1N4001 silicon diode or rectifier
See R2 power for each LED
R2 for 1W LED 1W 2.7ohms
R2 LED to 1.5 ohms 1W 3W
5W LED R2 to 0.6 ohms or 2 x parallel 1.2-ohms/1W
Here , I will give a circuit of schemes that are used to combine 2 pieces input or stereo to 1 input mono. Why 2 inputs in to one because, if we need a stereo amplifier we want to become a stronger by combining the two input into one input, so that a higher power output. Actually without any circuit above we can combine stereo amplifier into mono, but the sound output less than the maximum , need for this additional combiner circuit.
R1______150K
R2______920R
R3______150K
R4______920R
R5______920R
U1______NE5532
For balance _: R1 / R2=R3 / R4
For balance _: R1 = R3
Gain ______: R5 / R1 = R5 / R3
Thursday, August 28, 2014
This is so useful schema diagram .This schema can out put 1.3V when we supply 5V.You can us this schema for various purposes.
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Sunday, August 24, 2014
This Ac to DC Converter Circuit Diagram includes a PMOS enhancement-mode FET input buffer amplifier, coupled to a classical absolute value schema which essentially eliminates the effect of the forward voltage drop across diodes D1 and D2.
Ac to DC Converter Circuit Diagram
Saturday, August 23, 2014
Build a Hv Power Supply With 9 To 15Vdc Input Circuit Diagram. This Hv Power Supply is The combination Hartley oscillator/step-up transformer shown in A can generate significant negative high voltage, especially if the voltage output of the transformer is multiplied by the schema in B.
Simple Hv Power Supply With 9 To 15Vdc Input Circuit Diagram
Friday, August 22, 2014
Simple 500W 12V to 220V Inverter Circuits Diagram. This is a Simple 500W 12V to 220V Inverter Circuits Diagram which produces an AC output at line frequency and voltage. 12VDC to 220V 50Hz inverter schema will power 220V or 110V appliances from 12V car battery. The schema is easy to make and is low cost. Use proper transformer.
The output (in watts) is up to you by selecting different power rating transformer and power transistor rating. If you load electronic device which require 120V AC, then use transformer with 120V in output.
Simple 500W 12V to 220V Inverter Circuits Diagram
Monday, August 18, 2014
This boost regulator is for those times when you have a 28v relay, but want to use it with a 12v source. The schema is built around the National Semiconductor LM2585, and uses the energy stored in an inductor to boost the 12 to 28v. Output voltage can be varied by adjusting the ratio of resistor values on the feedback pin.
The voltage regulator schema does it’s switching around 100 Khz, but generates no noise if SMT components are used. Output is good for about half an amp continuous, enough to power two or three large microwave relays. The board measures 1.5″x2″.
It is important to note at least these three cautions before powering up the board:
- A short-schema on the output will kill U1 and D1. Always use a 1 ohm 5w resistor, or a 2.5A fast fuse on the 12v input lead.
- Do not omit the LED (D2); It provides a visual indicator of a properly operating boost condition, but more importantly, it also provides a minimum load for the output, preventing an output “spike” which will otherwise appear when the load is disconnected abruptly.
- Keep the ratio of r2 and r3 to 22 or less to keep the output voltage within the ratings of C4 (C4 on my board is rated at 35wvdc). This ratio plus 1, multiplied times 1.25v, determines the output voltage.
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