Friday, October 31, 2014

By Using transistror Create a 12v battery charger

A very simple 12v battery charger circuit can be designed using a TIP3055 power transistor to limit the current to the battery by turning off when the battery voltage reaches approx 14v or if the current rises above 2 amp.
This battery charger electronic circuit is very simple and require few external electronic parts . Signal to turn off the TIP3055 transistor comes from two other transistors , the BC557 and BC 547. Firstly, the circuit turns on fully via the BD139 and TIP3055. The BC557 and BC 547 do not come into operation at the moment.
As the battery voltage rises, the voltage divider made up of the 1k8 and 39k creates a 0.65v between base and emitter of the BC557 and it starts to turn on at approx 14v.
The input voltage required by this charger electronic circuit project must be around 15 volts DC.
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Versatile DC DC Converter Circuit Diagram

Here is a versatile power coupler that connects a device to 5V-19V DC generated from AC mains by a power adaptor. Power adaptors come in different voltage outputs like 5V (for mobile phones), 12V (for external hard drives) and 19V (for laptops). Sometimes the power adaptor may have a voltage rating higher than the required voltage. With the converter circuit given here, the adaptor can be used to power any device at a lower voltage. 

For instance, by using a 19V laptop adaptor, you can power a TTL circuit at 5V. There can also be other instances when one needs a 3V or 6V supply. All these and many other intermediate voltages are easily possible with this versatile converter circuit when used together with any off-hand power adaptor.

Versatile DC-DC Converter Circuit diagram :

Versatile
Versatile DC-DC Converter Circuit diagram

Fig. 1 shows the circuit of the DC-DC converter. Smooth reduction in the voltage is achieved using the LM317 regulator IC. The complete unit can fit inside a piece of a glue stick tube.
Adjusting variable resistor VR1 gives the desired output voltage. The output voltage is read using a 0-100µA ammeter, whose series resistance R* is chosen such that the maximum desired voltage could be covered. For instance, if full-scale deflection (FSD) current of the meter is 100 µA and you need an output voltage of up to 15V, then R* = 15/0.0001 = 150 kΩ. The desired value of R* is obtained by using 150-kilo-ohm preset VR2. 

Use of a variable resistor which also has an on/off switch like the one in old radios is recommended. It will cut off the coupler from the input power supply without having to accomodate an additional switch. Also, use a heat-sink with LM317 to handle the desired amount of power.

Proposed-assembly

Assemble the circuit on a small general-purpose PCB and enclose in a suitable case. Fit the entire PCB inside a glue stick tube as shown in Fig. 2. Affix the female and male connectors on the opposite ends and place the ammeter in between the stick tube. You can directly read the output voltage on the ammeter after due calibration.

Note. You can use a suitable VU meter instead of 0-100µA ammeter and calibrate accordingly.

Copyright : EFY
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Thursday, October 30, 2014

Police Lights associate crystal rectifier Project

This circuit uses a 555 timer that is setup to each runn in associate Astable operative mode. This generates a nonstop output via Pin three within the type of a sq. wave. once the timers output changes to a high state this triggers the a cycle the 4017 4017 decade counter telling it to output consecutive sequent output high. The outputs of the 4017 ar connected to the LEDs turning them on and off.

Schematic
Police

Parts List

1x - NE555 Bipolar Timer
1x - 4017 Decoded Decade
6x - 1N4148 Diode
1x - 1K Resistor (1/4W)
1x - 22K Resistor (1/4W)
2x - 4.7K Resistor (1/4W)
6x - 470 Resistor (1/4W)
1x - 2.2µF Electrolytic Capacitor (16V)
2x - BC547 NPN Transistor
2x - LED (Blue)
2x - LED (Red)
1x - 9V Voltage Battery
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NE5532 Class A Power Amplifier

With the final amplifier we called. Regional Power Amp, self-control it effect on several well-notorious in the function of group of students A, Class B, Class AB and so forth. both class of the exceeding, to honor the Class A was better to the sound quality. greatest. However, class A power output to a low of 20 percent compared with a loss of power before the power consumption of regarding 5 period the power output. Therefore, the trouble of leg Although it has not paid a few audio. But anyway, despite the low-watt power, it as well provides sparkler tidy sound quality than period B and Class AB.

NE5532 Class A Power Amplifier Circuit Diagram
Ethics of integrated amplifier class A is IC1 - NE5532 to develop indicate input through the C1 to proliferation 15-fold. The signal output from the pin 1, signal hemisphere assured through C2 to access Q1-BD139 and Q3-2N3055. is powered by dear ton, amplifiers and gesture the intensification of the no characteristic of C3 through the amplifier with the Q2-BD140 and Q4-MJ2955.

This is the beloved ton, too. after that the output signal from the helpful side of the pin E of the Q3 and the off-putting border of the pin unfashionable of the E concerning Q4 through R10 and R11, to prevent brief circuits and therefore output to the speakers. This bidding power up to 5 watts. The D1-D4 acts while a rectifier in the DC bias in favor of Q1 and Q2. And VR1 is adjusted to a constant current bias is next to masterpiece. The Q1-Q4 will be situated attached sheet cooled, Q3 and Q4, especially the thermal plate have got to be sizeable. for the reason that the circuit has high spot energy loss
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Wednesday, October 29, 2014

Simple Audio Controlled Mains Switch Circuit Diagram

To day i share a Simple Audio Controlled Mains Switch Circuit Diagram. It is often useful for audio or video equipment to be switched off automatically after there has been no input signal for a while. The function of the on-off switch in such equipment is then taken over by switch S2 in the accompanying diagram. It remains, however, possible to  switch off manually by means of Si. Automatic  switch-off occurs after there has been no input  signal for about 2 minutes: this delay makes it possible for a new record or cassette to be placed in the  relevant machine.
 
The audio input to the proposed circuit may be  taken from the output of the relevant TV set, amplifier, or whatever. The input earth is held at + 6 V  with respect to the circuit earth by potential divider  Ri-R2-R3-R4. The two 741s function as comparators: the output of ICi goes high when the in- put signal is greater than + 50 mV, whereas the out- put of IC2 goes high when the input signal  becomes more negative than -50 mV. Resistors  R6, R7, and R8 form an OR gate that drives transistor Ti. If the output of either ICi or IC2 is logic  1, Ti conducts.
 
Audio Controlled Mains Switch Circuit diagram :

 
Audio-Controlled-Mains-Switch-Circuit-Diagram
Audio Controlled Mains Switch Circuit Diagram

The 555  operates as a retrigger able monostable,  whose period is determined by Rio and Ci. The  device is triggered when its pin 2 is earthed by the  closing of S2. Its output, pin 3, then remains high  for 1 to 2 minutes, depending on the leakage cur- rent of the 555. 

The monostable resets itself as soon  as the potential across Ci exceeds a certain value.  As long as there is an input signal to the circuit, Ti conducts and Ci remains uncharged. As soon as  the audio signal ceases, Ti switches off, and Ci  charges until the potential across it is sufficient to  reset the 555. The monostable may also be reset by  closing Si, which connects pin 6 of the 555 to + 12 V.
 
Audio-Controlled-Mains-Switch


When IC3 is reset, Ci is discharged via its pin 7. Resistor Rrn serves as protection, because without it Ti could short-circuit the supply lines. When the output of IC3 goes high, T2 conducts,  the relay is energized, and the relay contacts switch on the mains voltage as appropriate. To counter the induced potential when the relay contacts close, which could damage T2, diode Di has been connected in parallel with the relay coil. 
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High Fidelity MOSFET Power Amplifier 150 W

This amplifier is designed to be as flexible as possible, with no bad habits. Indeed, it will operate stably with supply voltages as low as +/-5V (completely pointless, but interesting), all the way to the maximum supply voltage of +/-70V. The only change that is needed is to trim the MOSFET bias pot! With the full supply voltage of +/-70V (which must not be exceeded!), RMS power is around 180W into 8 ohms, or 250W into 4ohms. Short term (or "music") power is typically about 240W into 8 ohms and 380W into 4 ohms. Note that depends to a very great degree on the power supply, and a very robust supply is an absolute requirement for tThe maximum output. In general, unless you really need the maximum possible power, I suggest that you limit the supply voltage to ±56V using a 40+40V transformer. You will get around 150W into 8 ohms from this supply voltage (short-term), but you also relax the demands placed on the MOSFETs and heatsinks. It is worth noting that a MOSFET amp will always produce less power than a bipolar transistor version using the same supply voltage. Even using an auxiliary supply will make only a small difference (one reason I elected not to add the extra complexity). A bipolar design using a ±70V supply can be expected to produce something in the order of 270W into 8 ohms, and well over 500W into 4 ohms. The specified MOSFETs have a rated Vds (saturated voltage, Drain to Source) of 12V at full current, and that is simply subtracted from the DC value of the supply voltage. Using the same ±70V supply with a MOSFET amp will give less power than quoted above

ParameterMeasurementConditions
Output Power> 180W< 1% THD, 8Ω

> 275W< 1% THD, 4Ω
DC Offset< 20mVTypical
Noise< 2mV RMSUnweighted (-54dBV)
THD0.015%No load, 30V RMS output, 1kHz

0.017%8 Ohms, 30V RMS output, 1kHz

0.02%4 Ohms, 30V RMS output, 1kHz
Output Impedance< 10 mΩ1kHz, 4Ω load

< 25 mΩ10kHz, 4Ω load
Frequency Response10Hz to 50kHzAt 1W, -1.5dB
Basic Performance Figures

Low Power Version
As shown in the schematics below (figures 1 and 2), the amplifier can be made in high or low power version, and although there is a bit of vacant PCB real estate in the low power design, it is significantly cheaper to make and will be more than sufficient for most constructors. If this version is built (using only 1 pair of MOSFETs), it is essential to limit the supply voltage to +/-56V so that it can drive both 4 and 8 ohm loads without excess dissipation. With this voltage, expect about 100W continuous into 8 ohms, and around 150W into 4 ohms. Naturally, dual MOSFET pairs may be used at this voltage as well, providing much better thermal performance (and therefore cooler operation), far greater peak current capability and slightly higher power. This version may be used at any voltage from +/-25V to +/-42V.
                                                     Figure 1 - Low Power Version
 
High Power Version
The same PCB is used, but has an extra pair of MOSFETs. Since the devices are running in parallel, source resistors are used to force current sharing. Although these may be replaced by wire links, I do not recommend this. This version may be operated at a maximum supply voltage of +/-70V, and will give up to 180W RMS into 8 ohms, and 250W into 4 ohms. Short term (peak) power is around 240W into 8 ohms and 380W into 4 ohms. These figures are very much dependent on your power supply regulation, determined by the VA rating of the transformer, size of filter caps, etc.




                                                     Figure 2 - High Power Version

Although not shown, the transistors and MOSFETs are the same in this version as for the low power variant. The additional capacitors (C11 and C12) shown are to balance the gate capacitance. The P-Channel MOSFETs have significantly higher gate capacitance than their N-Channel counterparts, and the caps ensure that the two sides of the amp are roughly equal. Without these caps, the amp will almost always be unstable.

As noted above, the PCB is the same for both versions, but for Fig. 2 it is fully populated with 2 pairs of power MOSFETs. The high power version may also be used at lower supply voltages, with a slight increase in power, but considerably lower operating temperatures even at maximum output, and potentially greater reliability.

With both versions, the constructors page gives additional information, and the schematics there include an enhanced Zobel network at the output for greater stability even with the most difficult load. This is provided for on the PCB, and allows the amp to remain stable under almost any conditions.

The entire circuit has been optimised for minimum current in the Class-A driver, while still providing sufficient drive to ensure full power capability up to 25kHz. The slew rate is double that required for full power at 20kHz, at 15V/us, and while it is quite easy to increase it further, this amp already outperforms a great many other amps in this respect, and faster operation is neither required nor desirable.

    Note - There are actually two caps marked C5, and two marked C6. This is what is on the PCB overlay, and naturally was not found until it was too late. Since these caps cannot be mixed up, it will not cause a problem.

In both versions of the amp, R7 and R8 are selected to provide 5mA current through the voltage amplifier stage. You will need to change the value to use a different supply voltage ...

    R7 = R8 = Vs / 10 (k)   (Where Vs is one supply voltage only)

For example, to set the correct current for ±42V supplies ...

    R7 = R8 = 42 / 10 = 4.2k (use the next lower standard value - 3.9k)

Construction
The suggested power supply is completely conventional. Although a small amount of additional power can be obtained by using an auxiliary supply (to boost the rail voltage for the MOSFET drive stage), this is at the expense of greater complexity and more things to go wrong. The transformer for the supply should be matched to the expected power you wish to obtain from the amp. The following table shows the recommended transformer voltage and VA rating for a single channel - either use two transformers or a single unit with twice the VA rating shown for stereo.

    AC Volts    DC Volts    VA    Power (8Ω)
    20-0-20    +/-28V        100        40
    25-0-25    +/-35V        100        50
    30-0-30    +/-42           160        80
    40-0-40    +/-56V         200       150    (Recommended Supply Voltage)
    50-0-50    +/-70V         300       240

Note that all powers shown are "short term" or peak - continuous power will always be less as the supply collapses under load. Peak power levels are usually achieved (or approached) with most music because its transients are generally between 6dB and 10dB greater than the average power output. Transformer VA ratings shown are a guide only - larger or smaller units may be used, with a marginal increase or reduction of peak power. Always use at least the size shown for subwoofer use! Values in bold are preferred, and will give enough power for most systems along with optimum reliability and low operating temperature.

                                              Figure 3 - Power Supply Circuit Diagram

Figure 3 shows the power supply circuit diagram for a ±56V supply, and there is nothing new about it. As I always recommend, the bridge rectifier should be a 400V/35A chassis mount type, and should be properly chassis mounted using heatsink compound.

Filter capacitors must be rated to at least the nominal supply voltage, and preferably higher. If possible, use 105°C rated caps, and join the earthed terminals very solidly to form the star earthing point.

    Note - The fuse should be selected according to the size of the power transformer. For any toroidal transformer over 300VA, a soft start circuit is highly recommended. Use the transformer manufacturers suggested fuse - if this information is not available, ask the supplier - not me!

The DC supply must be taken from the capacitor terminals - never from the bridge rectifier. Using several small capacitors will give better performance than a single large one, and is usually cheaper as well. For example, the performance of 10 x 1,000uF capacitors is a great deal better (in all respects) than a single 10,000uF cap, at between 50% to 70% of the cost of the large unit. This lunch is not free, but it is heavily discounted
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400W Stereo Marshall Leach Amplifier

400W Stereo Audio Amplifier based on the original Marshall Leach involvement, but has made some improvements. Regarding the power supply voltage to the +-75V. VC comparing the performance of the modified Leach 700W/2R on one common board of both channels, as well as protection and control circuits for the fans. Compared to the 700W version a bit different in wiring. Because some things in the 700W version is completely tightened to perfection.

 

                                               700W version could criticize a couple of things:

1st very high gain output stage resulting in deterioration of signal noise distance. Therefore 700W version even more noisy.

2nd The absence of multipliers Ube bias current control and maintain temperature stability diagram. The 700W version of the thermal stabilization solved by a single transistor, which can sometimes cause a great loss due to power control is fast enough and has some delays. Therefore JPA400 added to this multiplier.

3rd Protection Error on board speakers, the amplifier is less comfortable and it is necessary to add this protection to the side somewhere special plate.

4th no possibility to correct the offset voltage of the amplifier output, this has a rather large weight in the differential pair of transistors and voltage level. Here this is solved by means of trimmer connected to the input Mark

5th The work points the individual stages are laid pretty low, it will also cause an increase in total harmonic distortion as well as intermodulačního distortion.



All this is in JAP400 removed. The input amplifier is Mark with adjustable offset voltage. Mark is mainly due Preamplified signal for generating the actual end-impedance amplifiers and separates. The differential amplifier is a classic symmetrical with the current 5 mA per couple, which is about 2.5 mA each transistor. Equally, shifted the operating point voltage amplifier to approximately 13 mA. This modified driver will provide enough power for generating terminal transistor and is hard enough. At the end of this time is five pairs of end-type transistor 2SC5200 / 2SA1943. Current policy is converted into the number of transistors. It has a negative slope and replicates the characteristics of SOAR terminal transistors. Current protection for amplitude limitation limits the end-around transistors 7A. As has been mentioned on the thermal stabilization of the multiplier is used Ube, is formed by two NPN and PNP transistors.



The board also includes an amplifier circuit for the fan control. This circuit ensures that the fan speed control depending on temperature. At the temperature to 65 ° C, fan runs for about 30%, it greatly reduces noise. After exceeding this temperature, the fans start running at 100% and lights to signal overtemperature. fans again at reduced power switch at about 42 ° C. Thermal protection is associated with protection of the speakers at cooler temperatures exceeding 80 ° C, the speaker is disconnected. On board is a relay switch that allows stereo / bridge mode, the indikovám LED on the front panel. The amplifier also includes an auxiliary power source to the main board, formed by transistor stabilizer. Due to higher electric circuit protection circuit and fan control. There is also an indicator of an excited, solved by the presence of the indicator signal and clip detector.

Technical parameters:

Output power:                      2x 400W/4R, 2x230W/8R
Minimum holiday zázěž:         4R
Slew rate:                             45V/us
Bandwidth:                           8-150 000 Hz /-3dB
Maximum permissible voltage: +-75V
Filter Capacity:                    2 x 20G / 80V
Sensitivity DC protection:    + /-2V
Late connection:                  2 seconds
Fusing end amplifier:            4 8 A / F
Input sensitivity for maximum excitation: 1V



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Tuesday, October 28, 2014

Circuit flashing LED 4017

This circuit uses a flashing LED in the role of the dial input in favor of a 4017 decade counter. mainstream flashing LEDs (eg, DSE cat Z-4044) jiffy on with reference to 2Hz so the outputs Q0-Q9 resolve cycle through on to facilitate rate. For pattern, Q0 will bear on for partly a back up, followed by Q1, then Q2 and that up to Q8 then it will start by the side of Q0 again. Up to nine outputs can survive used. If you would like fewer outputs, link up an earlier output to MR, pin 15. If MR is not used, connect it to 0V.

Circuit

Uses in support of the circuit include sequencing another strings of Christmas illumination and that. The resistor from CP0 to ground can befall anywhere from almost 330O to about 10kO. drop standards self-control cause the LED to jiffy further brightly if with the aim of is necessary. With a 4.7kO resistor at the same time as given away, the device input CP0 (pin 14) will alternate flanked by about 2V and 7V. To drive heaps of up to 40W on up to 60V, join each one output to the gate of a 2N3055E before equivalent Mosfet (MTP3055E and so on), as publicized in place of Q0.

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600 Watt Mosfet Power Amplifier with PCB

Here is a circuit Power Amplifier with output power of more than 600 Watt speakers with impedance of 4 Ohm. Power Amplifier circuit with high power uses n-channel MOSFETs 6 in the output stage alone is giving about 400Watt power. And to make more than 600Watt need to use 12 N-Channel MOSFETs. One of the construction sequence to produce more output power of 900W using 12 IRFP460 MOSFET. Here is a Power Amplifier Circuit Diagram, and the Power Supply is suited for this amplifier. I also include a PCB Layout Design for the power amplifier and its power supply, you can see below.

600
600 Watt Mosfet Power Amplifier Circuit Diagram
PCB
PCB Layout Design 600 Watt Mosfet Power Amplifier

Power
Power Supply for 600 Watt Mosfet Power Amplifier
Power
Power suplly PCB Layout Design 600 Watt Mosfet Power Amplifier
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Monday, October 27, 2014

Protectors Circuit on SMPS power supply


The simplest example SMPS which still uses 3 transistors (C3807, A1015 and power transistors) classic problem that often occurs is: - Problem in the feedback circuit can cause the output voltage B + over so that it can endanger the aircraft as a whole. For example elco erupted, pcb burnt burnt by over-heated, horizontal transistor short.

- Problem on feedback circuits may cause power regulator transistor is damaged due to over current transistor (eg, due to the 47k resistor transistor circuit on the secondary error detector value is delayed).
- If the input ac voltage drops can cause the power regulator transistor is damaged, due to over current transistor If the secondary there is a power transistor short can cause damage over current regulator.
- Protectors are designed to make the SMPS SMPS "reliable will not be damaged" if there are things that go wrong as mentioned above. 

SMPS Circuit

SMPS circuit using IC systems generally are designed with a surge protector, which include:
  • Over voltage protector (OVP)
  • Over current protector (OCP)
  • Over load protector
  • Short circuit protector
  • Over temperature protector
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Understanding Audio Amplifiers

Audio amplifiers are by the side of the very spirit of each at your house plays practice. to the same degree the quality and output power rations of at presents loudspeakers multiply, so puzzle out the stress of audio amps. It is fast to pick an amplifier known the obese come to of models and designs. I bidding explain more or less of the nearly everyone customary amplifier designs such so "tube amps", "linear amps", "division-AB" and "class-D" as well as "class-T amps" to help you understand some of the provisos commonly used by amplifier manufacturers. This conductor ought to and help you symbol not permitted which topology is ideal intended for your specific attention.

Simply set, the intent of an audio amplifier is to convert a low-power audio imply into a soaring-power audio signal. The high-power signal is huge an adequate amount to drive a loudspeaker amply loud. wearing order to solve to, an amp uses single before additional elements which are controlled by the low-power suggest to generate a large-power signal. These elements range from tubes, bipolar transistors to FET transistors.

Audio Power Amplifier
Tube amplifiers used to occur everyday a little decades before. A tube is able to control the current stream according to a control voltage which is connected to the tube. Unfortunately, tube amplifiers state a somewhat towering amount of distortion. Technically speaking, tube amplifiers motivation introduce elevated harmonics into the sign. However, this characteristic of tube amps still makes these standard. Many nation explain tube amps for instance having a kindhearted sound versus the cold sound of solid state amps.

an added drawback of tube amps, though, is the low power efficiency. The majority of power which tube amps consume is being degenerate as leg and lone a portion is being converted into audio power. additionally, tubes are quite expensive to get on to. like this tube amps experience mostly been replaced by solid-state amps which I motivation look on then.

Solid state amps reinstate the tube with semiconductor elements, typically bipolar transistors or else FETs. The most primitive type of solid-state amps is famous to the same degree category-A amps. modish class-A amps a transistor controls the current arise according to a lesser-level show. various amps avail yourself of a pointer machinery in order to underestimate the choral distortion. Class-A amps produce the lowest distortion and regularly furthermore the lowest amount of clatter of one amplifier architecture. If you need ultra-low distortion afterward you be supposed to take a closer look by panache-A models. The chief drawback is with the purpose of like to tube amps class A amps have very low efficiency. like a upshot these amps require corpulent heat up sinks to dissipate the shrunken energy and are typically rather bulky.

Class-AB amps pick up on the efficiency of class-A amps. They use a string of transistors to break up the large-level signals into two separate areas, every one of which can remain greater than before further efficiently. when such, style-AB amps are regularly less important than class-A amps. However, this topology adds selected non-linearity before distortion appearing in the region wherever the sign switches involving individuals areas. As such class-AB amps typically tolerate top distortion than class-A amps.

Class-D amps upgrade on the efficiency of rank-AB amps even advance by using a switching transistor which is constantly being switched on before inedible. thus this switching stage hardly dissipates a few power and along these lines the power efficiency of class-D amps commonly exceeds 90%. The switching transistor is being controlled by a pulse-width modulator. The switched overweight-level gesticulate has to happen lowpass filtered in the field of order to remove the switching signal and recover the audio signal. Due to non-linearities of the pulse-width modulator and the switching transistor itself, categorize-D amps by nature be inflicted with amongst the highest audio distortion of every audio amplifier.

To solve the question of exalted audio distortion, newer switching amplifier designs incorporate response. The better indication is compared with the real McCoy low-level signal and errors are corrected. A well-recognized architecture which uses this type of pointer is known being "course group-T". Class-T amps before "t amps" do audio distortion which compares with the audio distortion of class-A amps while by the side of the same type offer the power efficiency of class-D amps. along these lines t amps can remain made tremendously undersized and still complete elevated audio fidelity.
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Sunday, October 26, 2014

220V AC Lamp Toggle Switch Circuit

Due to the low current drawing, the circuit can be supplied from 230Vac mains without a transformer. Supply voltage is reduced to 12Vdc by means of C1 reactance, a two diode rectifier cell D1 & D2 and Zener diode D3. IC1A, IC1B, R2, R3 and C3 form a reliable bounce-free toggle switch operated by P1. R4 and C4, wired to pin #6 of IC1B reset the circuit (lamp off) when power supply is applied. IC1C and IC1D wired in parallel act as a buffer, driving the Gate of the Triac through R5.



Circuit diagram:


220V AC Lamp Toggle Switch Circuit Diagram



Parts:

R1 = 470R
R2 = 10K
R3 = 100K
R4 = 100K
R5 = 1K
C1 = 330nF-400V
C2 = 100uF-25V
C3 = 100nF-63V
C4 = 10uF-25V
D1 = 1N4007
D2 = 1N4007
D3 = BZX79C12
D4 = TIC206M
IC1 = 4011 NAND Gate



Notes:
  • The circuit can be wired permanently to the mains supply as current drain is negligible.
  • Due to transformerless design there is no heat generation.
  • Low Gate-current Triacs are recommended.
  • Obviously, other appliances can be powered in place of a lamp, provided their power dissipation does not exceed about 400W @ 230V
  • 110-120Vac operation is easily obtained by simply changing C1 value to 680nF 250V. No further changes are necessary.
  • In some cases, e.g. when the controlled device is far from the toggle switch, a pilot LED could be necessary for monitoring purposes. If so, disconnect pin #10 of IC1C from pin #11 of IC1D and wire a LED and its 1K series current limiting resistor across pin #10 of IC1C and negative supply.
  • Warning! The circuit is connected to 230Vac mains, so some parts in the circuit board are subjected to lethal potential! Avoid touching the circuit when plugged in and enclose it in a plastic box.
  • P1 will SPST Pushbutton
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Saturday, October 25, 2014

Smart Trailing Socket Diagram Circuit

Mains sockets switched automatically by a Control Socket, Up to 1000W switched power

This circuit consists of a Trailing Socket (also called Extension or Distribution Socket) or similar device where two, three or more sockets (depending on the box dimensions and on constructors needs) will be powered only when a current flows in the Control Socket. For example: if an electric drill is connected to the Control Socket, the Switched Sockets will be powered each time the electric drill is running. In this case, a lamp could be connected to a Switched Socket and will illuminate when the drill is operating.

Another example: a desk lamp could be connected to the Control Socket and a PC, a Monitor and a Printer could be connected to the Switched Sockets and will be running after the lamp is switched on. Switching off the lamp, all the above mentioned appliances will be automatically switched off. A further application is the control of a High Fidelity chain, plugging the Power Amplifier in the Control Socket and - for example - CD Player, Tape Recorder, and Tuner in the Switched Sockets.

Usually, trailing sockets are placed to the rear of the appliances, often in places not easily reachable, so, even if the socket has a switch, it is much easier to switch on and off the High Fidelity chain from the main amplifier itself. The same consideration is valid for computer-monitor-printer chains etc. Nevertheless, in this case, the use of a table lamp plugged in the Control Socket is almost mandatory, as explained below. In fact, this very sensitive circuit works fine when appliances having full breaking switches like lamps, drills, most power amplifiers, old radios, old TV sets, fans, almost all electrical household appliances etc. are plugged in the Control Socket.

This is because these devices have a switch that fully excludes the internal circuitry from the mains. Unfortunately, in modern devices like computers, monitors, CD players, recent radios and TV sets (usually powered by means of internal "switching" supplies), the power switch does not completely isolate the internal circuitry from the mains, as transient suppressors and other components remain on circuit. This causes a very small current to flow across the sensing circuitry, but sufficient to trigger the output Triac.

Therefore, the switched devices will remain always on, no matter if the control appliance is on or off. This could also happen when devices connected to the mains by means of plug-in power supply adapters are used as control appliances, due to their lack of a mains switch. In spite of this restriction, the circuit can be still useful, due to the high number and variety of devices allowing impeccable performance when they are plugged in the Control Socket.

Circuit diagram:
Smart Trailing Socket Circuit Diagram
Parts:

R1,R2_________100R 1/2W Resistors
C1____________100nF 630V Polyester Capacitor
D1 to D6_____1N5408 1000V 3A Diodes (See Notes)
D7__________TIC225M 600V 8A Sensitive Gate Triac (See Notes)
A commercial trailing socket to be modified or a self-made box with several sockets.

Circuit operation:

Six back-to-back power diodes are connected in series to the Control Socket. The current drawn by the device plugged into this socket when in the on state, flowing through the diode chain, causes a voltage drop of about 2V. This voltage, limited by R1, drives the Gate of the Triac D7 which, in turn, will switch the output sockets. C1 and R2 form a so called "Snubber network", helping to eliminate switching transients generated by inductive loads.

Notes:
  • The circuit is sufficiently small to be embedded into some types of commercial trailing sockets, or a box with a number of sockets can be made at will.
  • The diode types suggested in the Parts List for D1 to D6 will allow an appliance of up to about 500W power to be plugged in the Control Socket. Use BY550-800 diodes for up to 800 - 1000W.
  • For less demanding appliances, 1N4007 diodes will allow up to 200W power.
  • The Triac type suggested in the Parts List for D7 will allow a total power available to the Switched Sockets of more than 1000W. If you intend to drive loads of more than 500W total, please use a suitable heatsink.
  • Wanting to drive less powerful loads, you can use for D7 a TIC216M (up to 800 - 1000W) or a TIC206M (up to 500 - 600W).
  • Warning! The device is connected to 230Vac mains, so some parts in the circuit board are subjected to lethal potential! Avoid touching the circuit when the mains cord is plugged in!
Copyright: www.redcircuits.com
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Friday, October 24, 2014

FM Moulator with IC 555

FM Modulator circuit is a simple FM modulation circuit using IC 555, where the resulting modulated signal has a tenuous meeting depends on the signal frequency information. 

FM

FM

The resulting signal can be spelled out quite nice and stable so that the result will be more perfect. No winding or inductor in series modulator, so you do not need to bother to make a winding and calculate the value of the coil that you created it. With this circuit the desired value of frequency modulation can be obtained easily by calculating the frequency of IC 555 in general, which is determined by the resistor 6.8 K and 3.3 K and 0.1 UF capacitor. To obtain the other frequencies of your stay replace one or all three components.

Actually fm modulator ic 555 circuit is very simple though, but I think it reliable enough to handle a simple application purposes that do not require a big power or a very high frequency. But if you want more power you can add the RF amplifier circuit at the output of this circuit. Thus, the results of modulated signal can be amplified with the help of a series of supporters. In accordance with my experimental series modulators can work well at frequencies below the MHz range, because it is not IC IC 555 which is devoted to support of a very high frequency. You can use oscilltor transistor circuit, XTAL or others if you need a very high frequency.

The difference circuit with IC 555 on the multivibrator circuit in general is the use of pin 5, on the FM Modulator circuit is pin 5 of IC 555 is used as input information signal, which in turn will influence the shape of the output signal (modulated). But in applying this 5 pin multivibrator functions normally associated with 0.01 UF capacitor or left alone.
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Thursday, October 23, 2014

Control Relay Circuit with 9 Second

See figure below its Control Relay Circuit Schematics.



Control
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Ultra Fast Battery charger circuit

Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] which will be discussed in this article is Fast NiCad Battery Charger, called the Ultra Fast Charger Battery Charger NiCad because it can make filling fast NiCad Batteries Cell. A battery charger in Desai has a fast charging capabilities such as Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] on this article shall be equipped with some ability to protect the battery and charger circuit itself.

Feature owned by Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] 

  • Autoshut-off, is the ability of the charger to stop charging current to a NiCad battery if the capacity NiCad battery is fully charged.
  • Polarity Protection, with the existence of this capability so if there are mounting the battery on the charger upside yan can be known.
  • Constant output voltage
  • Output currents enough to fill some NiCad batteries at once in parallel.
  • Short Circuit Protection, with the existence of this protection circuit so if there is short-circuit caused by a battery and a charger circuit itself will not damage the other parts are not damaged.
  • Series Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad]


Image series above is a series of schematic drawings for Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad]. Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] can be used for 8 to 10 NiCad batteries at once with 12 volt output voltage and max current is 3.5 A. The main components in the circuit of Ultra Fast Battery Chager for Nickel-Cadmium battery cells [NiCad] is UC3843 and MC34181. UC3843 chip is a voltage regulator and M34181 is a JFET OpAmp with characteristic low offset voltage, input impedance is very high. MC34181 serves as a voltage comparator.
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800W Power Amplifier MOSFET

This Figure is a schematic power amplifier with power 800 Watt and driver and booster using MOSFET.
800W
Audio Power Amplifier with power output 800W
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Saturday, October 18, 2014

Multiplexer with CMOS IC 4556

In addition to the family of TTL ICs that support the function of a multiplexer is a family of CMOS ICs.

Despite the fact it is the family of TTL ICs that support more functions than the CMOS multiplexer. For the working principle of the multiplexer IC CMOS family is actually tantamount to a multiplexer circuit, or IC TTL logic gates. That should be all referring to the real multiplexer function, namely the determination of output lines which represent the number of input lines. The use of symbols is possible between TTL and CMOS IC has a different but actually run the same rules. For your reference if you are interested in using family of CMOS IC 4556 series in particular, I include also the truth table below:


INPUT
OUTPUT
E
A0
A1
O0
O1
O2
O3
L
L
L
L
H
H
H
L
H
L
H
L
H
H
L
L
H
H
H
L
H
L
H
H
H
H
H
L
H
X
X
H
H
H
H
L = LOW
H = HIGH
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Yamaha BC2 Schematic


Yamaha BC2 Schematic



Free download of Yamaha BC2 Schematic
Yamaha BC2 is simply something that you blow into to control the breath pressure input.
you want download Yamaha BC2 Schematic here
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Friday, October 17, 2014

LM386 Little Big Amplifier Circuit Diagram

The LM386, also known as JRC386 is one of the most used amplifiers integrated circuits, the reason is very simple, its versatility, low cost and consumption. An amplifier, as the name implies, amplifies, the signal increases in x times, depending on your configuration, in the case of the LM386 is an audio amplifier. It is very different from operational amplifiers as the LM741, these have different configuration requirements and use, since the LM386 audio amplifier is an innate, or whether it was designed to be an audio amplifier.

To get an idea of the grandeur of the LM386, the largest and best manufacturer of amplifiers, Marshall uses in their amplifiers miniature model MS-2 and MS-4 as output an integrated circuit manufactured by CCI NJM386.

 lm386


Features of LM386

The LM386 is a power amplifier designed for use in low power and low voltage applications. Its configuration is a Class AB amplifier, it consists of an IC 8 pin dual in line, DIP-8, with 3 basic types that are LM386N-1, LM386N-3 LM386N-4 and the most common of these is the LM386N -1. The gain is internally set at 20 times for technical reasons, but the addition of an external resistor or capacitor between pins 1 and 8 will increase the output gain up to 200 times.

The quiescent current is very low, consuming less than 30 mW with 5 Volt supply, making it ideal for circuits powered by batteries or batteries. Called IC power amplifier low voltage, he was considered the jewel for amateur projects where you need a good audio amplifier with the advantage of having fewer components, low power consumption and low voltage.
 

Its input resistance is 50k OHMs and the output impedance is 8 ohms and the LM386N-1 LM386N-3 and 32 ohms versions in LM386N-4 version. The consumption quiescent current is 4mA and if its distortion is very low, 0.2% (AV = 20, VS = 6V, RL = 8 [Ohm], PO = 125mW, f = 1 kHz).

Pin


Pin out LM386

Pin 1: Gain
Pin 2: Input -
Pin 3: Input +
Pin 4: Earth
Pin 5: Vout (Output)
Pin 6: Vs (Power)
Pin 7: Bypass
Pin 8: Gain

Pins 1 and 8 are control gain. When not connected (NC), the amplifier gain is 20 times. Adding a 10uF capacitor between them passes to gain 200 times. Intermediate values ​​and a resistor will vary the gain as described in the datasheet, we will see below.

Pin 2 is the negative input ( GND ) will usually land or - .

Pin 3 is the positive input that is the input signal to be amplified . A 10K ohm pot before the pin that adjusts the level of the input signal, ie , a volume control .

Pin 4 ( GND - Ground) and Pin 6 ( VCC + Vs ) are the power inputs for amplification , an electrolytic capacitor of at least 100uF between them near the IC prevents unwanted oscillations .

The pin 5 is the output of the amplifier. The electrolytic capacitor 250uF filter the DC component and the remaining AC vam to the speaker . A 0.05uF capacitor and a resistor of 10 Ohm pin 5 to ground is used to prevent high frequency oscillations .

Pin 7 is called bypass ( bypass ) , but the data sheet does not provide any additional detail about him or their use . But technically serves to reduce the noise ( humming ) input and also decrease the distortion
inter- modulation. It isolates the input stage high-gain power supply noise . A 100nF capacitor of 10uF can be used to this pin.

Below is a table with the main characteristics of the types of LM386

Chip Name Min Max Voltage Power Voltage Minimum Output Power

LM386N-1 4 Volts 12 Volts 250 mW 325 mW
3 LM386N-4 Volts 12 Volts 500 mW 700 mW
LM386N-4 5 Volts 18 Volts 700 mW 1,000 mW

Typical circuit LM386 amplifier with gain of 20 times

Typical


Under an amplifier circuit using the LM386 with a gain of 20 times, requires a minimum of external components, this makes it compact and simple.

Typical circuit LM386 amplifier with gain of 50 times


Typical

This is the LM386 scheme for a gain of 50 times, addition of the capacitor between pin 1 and 8 is used 1K2 ohm resistor for limiting the gain. Another change is the placement of a capacitor to ground on pin 7 which is the ByPass to avoid instabilities in the circuit, it should be done whenever the gain is more than 20 times.

Typical LM386 amplifier circuit with a gain of 200 times

Typical


Varying the gain of the LM386

To make the LM386 amplifier is more versatile, both pins 1 and 8 are used for gain control. With pins 1 and 8 open, without any component and the gain of 20 times or 26 dB. But if a capacitor is placed between pin 1-8, the internal configuration is ignored, and the gain will go up to 200 times or 46 dB. If we place a resistor in series with the capacitor, the gain can be adjusted to any value of 20x and 200x.

We see that the LM386 is an integrated amplifier ideal for amateur and professional circuit assemblies. Here is an IC that should not miss on the bench, and along with the 555 makes a perfect pair of multipurpose components.

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Simple Shadow Detector Alarm

This is also known as Sun up alarm, in this circuit you can set the LDR’s sensitivity by 100k potentiometer, you can set it with any lamp around your room (tube light, bulb, LED etc) by varrying the 100k potentiometer. We can also control the buzzer time by 1M potentiometer 
 
You can Enhance this project and set the sensitivity of the LDR with a lazer light and keep it on the way of any door circuit at one side and lazer at other side of the door and a then you can make this project to buzz as soon as some one enters in a room 


I personally set this project in my room with sensitivity of tube light and whenever i came in and turn my room’s tube light on

sourced by: rookieelectronics

Parts Required:
  1. 100k & 1M potentiometers 
  2. 10k, 1Mx(3), 47k
  3. 0.1mF, 0.01mF & 10mF
  4. LDR
  5. BC337 transistor
  6. Beeper/Buzzer
  7. 9v Battery Supply
   Circuit Diagram:
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