Showing posts with label simple. Show all posts
Showing posts with label simple. Show all posts

Wednesday, November 19, 2014

Simple Sound to Light Converter Schematic Diagram

SimpleSimple Sound-to-Light Converter Schematic Diagram

Figure 1 shows a simple ambit for converting an audio arresting (such as one that comes from the apostle terminals of a CD player). The ambit basically consists of a buffer/amplifier date and three clarify circuits: a high-pass filter, a mid-pass filter, and a low-pass filter. The achievement of anniversary clarify ambit drives a light-emitting diode of altered color.

The ascribe arresting is fed to the absorber date through C1. The ethics of RF and RV1 should be called so that the absorber is able to drive the three filters absorbed to its output. The low-frequency, mid-frequency, and high-frequency apparatus of the ascribe arresting are alone accustomed to canyon through the low-pass clarify (bottom filter), the mid-pass clarify (middle filter), and the high-pass clarify (topmost filter), respectively, appropriately amid them from anniversary other.

Changes in the achievement of a clarify account its agnate achievement LED to about-face on and off. In effect, agriculture a connected audio arresting to the ascribe of this ambit causes the LEDs to dance.

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Monday, November 17, 2014

LM317 Simple Audio Amplifier

You most likely know that LM317 IC is applied as an practical provide regulator, but did you know it can be applied as an audio amplifier? This is a Low power Amplifier LM317 Simple Audio Amplifier Circuit a audio  designed with LM317 that offers a optimum probable 1W audio strength. 
LM317 Simple Audio Amplifier Circuit Diagrams :
LM317 Simple Audio Amplifier Circuits

Utilization a amazing heatsink for the LM317 IC and modify the 5K various resistor so that you have 4.5V on 10Ω resistor (or LM317 pin 2, Vout).
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Sunday, November 9, 2014

Simple Universal PIC Programmer

This simple programmer will accept any device thats supported by software (eg, IC-Prog 1.05 by Bonny Gijzen at www.ic-prog.com). The circuit is based in part on the ISP header described in the SILICON CHIP "PIC Testbed" project but also features an external programming voltage supply for laptops and for other situations where the voltage present on the RS232 port is insufficient. This is done using 3-terminal regulators REG1 & REG2. The PIC to be programmed can be mounted on a protoboard. This makes complex socket wiring to support multiple devices unnecessary. 16F84A, 12C509, 16C765 and other devices have all been used successfully with this device.

Circuit diagram:
Simple Universal PIC Programmer Circuit Diagram
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Thursday, November 6, 2014

Simple 12V to 220V 100W Transistor Inverter Diagram

This is a simple Simple 12V to 220V 100W Transistor Inverter Diagram. This circuit is an electronic circuit, and use very popular. Build this Simple 12V to 220V 100W Transistor Inverter Diagram and feel free.
Simple 12V to 220V 100W Transistor Inverter  Diagram
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Tuesday, November 4, 2014

Simple Current Monitor and Alarm

These circuits are intended for remote monitoring of the current consumption on the domestic mains line.

Fig

The circuit in Fig. I lights the signal lamp upon detecting a mains current consumption of more than 5 mA, and handles currents of several amperes with appropriate diodes fitted in the D, and D2 positions. Transistor Ti is switched on when the drop  across D,-D2 exceeds a certain level. Diodes from  the well-known I N400x series can be used for currents of up to I A, while lN540x types are rated for up to 3 A. Fuse F, should, of course, be dimensioned to suit the particular application.

A number of possible transistor types have been stated for use in the Ti position. Should you consider using a type not listed, be sure that it can cope with surges up to 700 V. As long as Ti does not con- duct, the gate of the triac is at mains potential via  C,, protective resistor R2 and diode Da, which  keeps C, charged. When Ti conducts, alternating current can flow through the capacitor, and the triac is triggered, so that Lai lights.
Fig
The circuit in Fig. 2 is a current triggered alarm. Rectifier bridge D4-D7 can only provide the coil voltage for Re, when the current through Di-D2 exceeds a certain level, because then series capacitor C, passes the alternating mains current. Capacitor C, may need to be dimensioned otherwise than shown to suit the sensitivity of the relay coil. This is readily effected by connecting capacitors in parallel until the coil voltage is high enough for the relay to operate reliably.

Finally, an important point: Many points in these circuits are at mains potential and therefore extremely dangerous to touch.


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Saturday, November 1, 2014

Very Simple Audio Mixer Circuit

A very simple audio mixer can be designed using this circuit diagram electronic project. Audio mixing is normally performed by a mixer with virtual ground, in which the various input signals are applied through series resistors to virtual ground, that at the inverting input of operational amplifier. 

Very

The audio mixer is a little different and uses the principle of common ground, the input voltages are converted into alternating current which, when summed, is the AC component of the collector. In the case of a common base configuration, emitter impedance is small and works as a virtual ground that is making it impossible to crosstalk between different input signals. The output signal is taken from the collector of Q1. Amplification circuit is equal to R6 + Ri, where Ri is the input resistance (= one of the resistances RI ... R5). The T1s emitter circuit has been provided a power source consisting of T2 and T3.

Q1s base voltage is set by resistors R7 and R8. Ensure that the capacitor C1 of T1 to be effectively disconnected.
Number of entries can be modified, increased or decreased as desired.
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Sunday, October 26, 2014

IC 741 Simple High Pass Filter


This be Simple high pass Filter perform filter especial tall frequency can change only. By use IC 741 , be the integrated circuit op-amp very the circuit helps to are high frequency Filter model to be simple. By from the circuit will let 750 HZ frequencies s go up change more well , 60HZ frequencies are or lower. By friends can change the value RC for filter the frequency that can want which can see the detail has followed circuit picture yes.
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Friday, October 17, 2014

Simple OBD Vehicle Protection

Vehicle immobilisers are fitted as standard to modern cars and heavy goods vehicles. Anti-theft mechanisms have become more sophisticated but so have the methods employed by crooks. Nowadays once the thief has gained access to a vehicle they will most likely use an electronic deactivation tool which seeks to disable the immobiliser, once this has been accomplished a blank transponder key/card can be used to start the engine. In many cases communication with the immobiliser is made using the OBD-II diagnostic connector.

Although the OBD-II protocol itself does not support the immobiliser, the vehicle manufacturer is free to use the interface as neces-sary for communication, either the standard OBD-II signals or unused pins in the OBD-II connector (i.e. those undefined in the OBD-II standard). Using one of these pathways the immobiliser can usually be electronically disabled. 

OBD Vehicle Protection Circuit Diagram
This may be unsettling news for owners of expensive vehicles but when professional car-thieves call, armed with the latest OBD-II hacking equipment this simple low-cost low-tech solution may be all that you need. The idea is ver y simple: if all connections to the OBD-II connector are disconnected there is no possibility for any equipment, no matter how sophisticated to gain access via the vehicle’s wiring. 

The OBD-II connector is usually locate d underneath the dashboard on the passenger side; once its wiring loom has been identified a switch can be inserted in line with the wires. The switch should be hidden away some-where that is not obvious. In normal opera-tion you will be protected if the vehicle is run with the wires to the socket disconnected. Make sure however that you throw the switch reconnecting the socket before you next take the vehicle along to a garage for servicing or fault diagnosis. 

The diagram shows the ISO K and ISO L wires switched. To cover all bases it is wise for every wire to the socket is made switchable except the two earth connections on pins 4 and 5 and the supply voltage on pin 16. Almost ever y vehicle manufacturer has their own method of vehicle immobilisation, by disconnecting every wire it ensures that no communication is possible (even over the CAN bus). Now the innermost workings of your vehicle will be safe from prying eyes. When a hacker plugs in a deactivation tool it will power up as normal but probably report something like ‘protocol unrecognised’ when any communication with the OBD port is attempted.

Author : Florian Schäffer - Copyright: Elektor
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Thursday, October 16, 2014

Simple IC LM35 Temperature Sensor Characteristics

LM 35 temperature sensor IC is a IC chip production Natioanal Semiconductor which serves to determine the temperature of an object or space in the form of electric scale, or can also be defined as an electronic component that is used to change the temperature changes are accepted in the electrical wholesale changes. LM35 temperature sensor IC temperature change can change a change in voltage at the output. LM35 temperature sensor IC requires +5 volts DC source voltage and DC current consumption of 60 mA in operation. Physical form LM 35 temperature sensor is an IC chip with packaging that varies, in general packaging LM35 temperature sensor is packaged TO-92 as shown in the figure below.


Simple


From the picture above it can be seen that the temperature sensor IC LM35 basically have 3 pin that serves as a source of supply voltage of +5 volts DC, as a result of sensing the output pin in the form of a change in the DC voltage and Vout pin to Ground.

IC LM35 temperature sensor characteristics are:

  •     Temperature sensitivity, with linear scaling factor between voltage and temperature 10 mVolt / º C, so it can be calibrated directly in centigrade.
  •     Have the accuracy or the accuracy of the calibration is 0.5 º C at 25 º C.
  •     Has a maximum operating temperature range between -55 º C to +150 º C. Working at a voltage of 4 to 30 volts.
  •     Has current low at less than 60 mA.
  •     Have a low self-heating (low-heating) of less than 0.1 º C in still air.
  •     Has a low output impedance is 0.1 W for 1 mA load.
  •     have Nonlinearities only about ± ¼ º C.

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Saturday, October 4, 2014

Simple Preamp Mic using IC LM358

SimpleSimpleSimple 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
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Thursday, October 2, 2014

Simple Solid State Relay Circuit SSR

A well-known shortcoming of virtually all electronic components is their sensitivity to temperature changes.
Circuit functioning of this SSR circuit is as follows:

lt is true that triacs are not A too bad in this respect, but they do not like low temperatures: they just stop working! This is caused by the fact that triacs require a higher gate current at low temperature. Triacs are often triggered by opto-couplers which are not capable of supplying these higher currents. The circuit described, in contrast to normal .triac triggers, contains an amplifier which ensures sufficient gate current under all temperature conditions; The amplifier is formed by transistor  T1, which raises the signal from the opto-coupler to more than adequate level. The use of capacitor C2 as a dropping reactance ensures that the dissipation in the drive circuit is virtually nil; it also prevents the circuit presenting a dc load to the mains supply. The switch on current surge is limited to a safe value by resistor R3. As the drive circuit is supplied directly from the mains, the mains voltage must, of course, be reduced to an acceptable level. This voltage is therefore rectified by D1  and smoothed by C1. Zener diode D2 stabilizes the supply to the circuit to 15 V. As soon as transistor T1 conducts, capacitor C1 discharges via T1 and the triac gate, provides a gate current of about 40 mA. The discharge time, and consequently the trigger pulse, is not greater than 1 millisecond. RC network R4/C3 protects the triac against high voltage peaks.
Siemens application.  

The complete SSR or solid state relay circuit is shown below.


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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.  



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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



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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. 


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Wednesday, September 24, 2014

How to Make a Simple Solar Tracker Circuit Dual Axis

There are some hopes that the sun will become a main source of energy in the 21st century. By then, sources of oil will be almost exhausted and will only play a minor part in the supplying of energy. Interested to know how to make a simple solar tracker with dual axis? 
The present interest in solar energy is therefore not surprising. Some work has already been done with solar cells and solar panels. However, these only operate with optimum performance when positioned exactly at right- angles to the sun. Unfortunately, this situation is not usual in our latitudes unless the solar panels are rotated with respect to the sun. The efficiency of a solar panel system can be improved if the panels track the sun, and remain as long as possible at the most favorable angle of incidence.  The circuitry required is relatively simple. lt uses a window comparator which keeps the drive motor idle, as long as the two LDrs are subjected to the same illumination. Half the operating voltage is then applied to the non-inverting input of A1 and to the inverting input of A2. When the position of the sun changes, the illumination affecting LDRs R1 and 1 R2 is different, if they are at an angle to each other as shown in figure 2. In this case, the input voltage for the window comparator deviates from half the supply voltage, so that the output of the comparator provides information to the motor for clockwise or anticlockwise rotation.

Transistors T1 . . . T4 in a bridge circuit cater for reversing of I the motor. Diodes D1 . . . D4 serve I to suppress voltage peaks which can 1 be produced when the motor is switched. Preset potentiometers P1 and P2 are used for alignment. They are adjusted so that the motor is idle when the LDRs are subjected to the same illumination. if less light reaches LDR R2 than LDR R1 , the voltage at point A rises to more than half the supply voltage. The result is that the output of A1 goes high and transistors T1 and T4 conduct. The motor then   runs. if the illumination of the LDRs is then changed so that the voltage at point A drops to less than half the  supply voltage, output A2 goes high T and transistors T3 and T2 must conduct. The motor them rotates in the opposite direction. Small geared motors of the type used for models, with a suitable voltage and maximum operating current of 300 mA, are suitable for driving the solar panels. The use of this control circuit makes it possible to control the solar panel in one plane. Of course, in order to track the sun from sunrise to sun- down, two control circuits will be required: one for horizontal and one for vertical tracking.



Making a dual axis solar tracker circuit mechanism:



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Simple Variable Voltage Current Power Supply Circuit Using a Single FET

  1. For many applications the requirements are not that stringent and a simple, discretely constructed regulator as described here will suffice.
  2. The current limiting components can then be left out.
  3. 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.
  4. The relation between input voltage, load resistance and regulated output voltage is shown in table 1.
  5. 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!
  6. The cost of high grade, regulated power supplies has dropped with the advent of modern lCs.

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Sunday, September 21, 2014

50 Watts Simple Audio Power Amplifier from OSU IEEE Student Group

This simple audio power amplifier was originally designed for a circuit board workshop, conducted by the OSU IEEE Student Group. At the workshop, 20 participants each constructed this amplifier, by etching and drilling the single sided circuit board, soldering all components, and attaching a pre-built heatsink assembly with the output transistors. Three workshops were held between 1995 to 1996. Though the design is simple, these amplifers have impressive preformance, with a frequency response to approx 40 kHz, very low noise, reasonably fast slew rate, and approx 50 watts (true "RMS" power) with the proper +/- 40 volt unregulated power supply.

Someday, Ill do some substantial testing to determine exactly what the power output is, and create some more detailed pages about how to build this amplifier.

schematic

Update: the input transistor are 2N5210, not 2N2510 as shown above

board

part

part

part

Transistor Color
2N5210 Blue
MPSA56 Pink
MPSA06 Yellow
2N3904 Green
2N3906 White

part
These color parts placement diagrams are also available in as postscript files in a ZIP archive.

This parts list is under construction... Im gathering part info for several lists, so pleast dont assume this list is totally correct or complete.

Qty Vendor Part # Description
1 Newark 58F508 Wakefield 421k Heatsink
2 Mouser 567-7-373-BA Low-Power TO-220 heatsink
3 Mouser 592-2N5210 Low Noise NPN, TO-92
1 Mouser 161-4215 Phono Jack, 90 deg PCB mount
1 Mouser 592-MPSA06 Medium Power NPN, TO-92
1 Mouser 592-MPSA56 Medium Power PNP, TO-92
1 Mouser 511-TIP29C Power NPN, TO-220
1 Mouser 511-TIP30C Power PNP, TO-220
1 Mouser 511-TIP33C High Power NPN, TO-218
1 Mouser 511-TIP34C High Power PNP, TO-218
2 ?? 2N3904 General Purpose NPN
1 ?? 2N3906 General Purpose PNP
2 Mouser 583-1N4742A 12V Zener Diode
5 Mouser 592-1N4148 Small Signal Diode
3 Mouser 583-1N4001 1A (slow) rectifier diode
6 Mouser 140-XLR16V100 16V 100uF Capacitor (radial)
1 Mouser 140-CD50N6-331K 330pF NPO Capacitor
1 Mouser 141-100N5-051J 51 pF NPO Capacitor
6 Mouser 140-PF2A104K 0.1uF Mylar film capacitor
2 Mouser 28PR002-0.3 3 Watt 0.3 Ohm Power resistor
1 Mouser 594-63P502 5K Top adjust cermet trim pot
2 Mouser 29SJ500-2.2K 2.2K 1/2 Watt Carbon Resistor
1/2 Injectorall PC18P 4x6 board
5

1/2 inch 4-40 machine screw
5

4-40 nut
5

4-40 lockwasher
2

Shoulder Washer
2

Insulator, TO-218 size
1

Cable Clamp
2

Red Wire, 18 AWG
1

Yellow Wire, 18 AWG
1

Orange Wire, 22 AWG
2

Blue Wire, 18 AWG
1

Purple Wire, 22 AWG
2

Green Wire, 18 AWG
1

Black Wire, 18 AWG
1

Black Wire, 22 AWG
1

White Wire, 22 AWG
1

Gray Wire, 22 AWG
1

Resistor, 4.7 Ohm, 5%
2

Resistor, 47 Ohm, 5%
6

Resistor, 220 Ohm, 5%
1

Resistor, 330 Ohm, 5%
2

Resistor, 1k, 5%
2

Resistor, 1.1k, 5%
1

Resistor, 3k, 5%
1

Resistor, 6.8k, 5%
1

Resistor, 22k, 5%
1

Resistor, 47k, 5%
1

Resistor, 10k, 1%, metal film
1

Resistor, 47k, 1%, metal film




Note: The TIP33C and TIP34C have been discontinued and are generally not available anywhere. A wide range of power transistors will work, but they should be rated for at least 100V, 8A, and 80W power dissipation. Safe area operating curves and good thermal dissipation data are rarely available, so its a guessing game. The more expensive TO-3 package parts, such as the MJ15003 & MJ15004 will certainly be more than sufficient for replacing the TIP33C & TIP34C. The only really compelling reason to use the TIP33C & TIP34C are because they cost less and come in a TO-218 package, which requires only one mounting hole.

Wire

 Diode assembly: Gray 22 AWG (cathode)
 White 22 AWG (annode)
NPN Power Transistor: Red 18 AWG (collector)
 Orange 22 AWG (base)
 Yellow 18 AWG (emitter)
PNP Power Transistor: Green 18 AWG (collector)
 Violet 22 AWG (base)
 Blue 18 AWG (emitter)
Input Signal: No wires, PCB mount jack
Output Signal: Blue 18 AWG (from PC board)
 Black 18 AWG (from power supply)
PC Board Power: Red 18 AWG (to +35V on supply)
 Black 22 Awg (to ground on supply)
 Green 18 AWG (to -35V on supply)

Vendors

Mouser - 800-346-6873, 619-449-2222
Newark - 800-463-9275, 503-297-1984
Injectorall - 800-878-7227, 516-563-3388

Testing

If any of these tests fail, the amp is not constructed properly... the easiest and best way to find the problem is visual inspection.
  1. Turn variable resistor fully counterclockwise (max resistance)
  2. Connect to +/- 24 volt supply with 200mA current limit. No input and no output connected. Monitor current from power supply with a current meter.
  3. Apply power... if current is above about 25 mA, shut off immediately!
  4. Measure voltage across the 1k resistor connected to the input stage and Vcc. The DC voltage should be about 2 volt, or 2 mA of current through this resistor. Eg, if Vcc is at 24 volts, the side of this resistor connected to the 2N5210 transisor ought to be at about 22 volts.
  5. Measure the DC voltage on the output line. It should be appox zero volts. -0.2 volts is probably fine.
  6. Turn the variable resistor slowly until the amplifers current consumption is approx 50 mA. Turn slowly and be careful... if you turn too far you could damage the output transistors.
  7. Conect an oscilloscope to the output and apply a low amplitude 20 kHz square wave to the input. DO NOT connect any speakers during this test. This test should be done without the 330 pF capacitor installed. The amp should output a 20 kHz square wave with very little "ringing". It should not oscillate.
  8. Solder the 330 pF capacitor into the circuit.
  9. Shut off the power, connect audio input and a speaker. Make sure the volume is turned all the way down. Apply power... watch current meter again and shut off the power immediately if the current jumps to something much higher than 50 mA.
  10. Slowly turn up the volume and see if the amp works. DO NOT turn it up very much... the amplifier should not be operated with a supply less than +/- 30 volts. It should never be used for high volume output without a power supply rated for at least 2 amps of current (8 ohm load). After this initial test with +/- 24V at 200 mA (current limited) only a proper power supply should be used which can provide enough current.
 
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Tuesday, September 16, 2014

Simple Class B amplifier Opamp TL082


The circuit shown here is of a simple and easy Class-B audio amplifier based on opamp TL082, transistors TIP141 and TIP142. LM833 will be twin opamp with high slew rate and low distortion significantly designed for audio applications. This audio amplifier circuit will deliver 15 watt audio output into an 8 ohm speaker at +12/-12V DC twin supply.

Both opamps within the IC are used here. IC1a is wired as a buffer and capacitor C3 will the task of input DC decoupling. Ic1b is wired within the inverting mode and it provides negative feedback. Complementary power transistors TIP41 and TIP42 are wired within the class B push pull schematic and that they drives the loud speaker. Diode D1 provides 0.7V bias voltage for the push pull combine and capacitor C2 protects the 0.7V bias voltage across D1 from serious voltage swings at the IC1b’s output.

Notes :

  • The audio amplifier circuit must be assembled on a good quality PCB.
  • Use a holder for mounting IC1.
  • Use a +12/-12V dual supply for powering the amplifier.
  • Potentiometer R2 can be used as a volume control.
  • Raising the power supply voltage will increase the output power. Anyway note the following points.
  • TIP42 and 41 can handle only up to 6A.
  • Maximum supply voltage IC1 can handle is +16/-16 V DC.
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Saturday, September 13, 2014

Simple 200W ATX PC Power Supply Wiring diagram Schematic

This is a 200W ATX PC Power Supply Circuit Diagram. Here I bring you wiring diagram of PCs power supply of DTK company. This power supply has ATX design and 200W performance. I was drawed diagram, when I repaired this power supply. 

 200W ATX PC Power Supply Circuit Diagram


200W

Circuit description

This power supply schema uses chip TL494. Similar schema is used in the most power supplies with output power about 200W. Device use push-pull transistor schema with regulation of output voltage.

Input part a standby supply

Line voltage goes through input filter schema (C1, R1, T1, C4, T5) to the bridge rectifier. When voltage is switched from 230V to 115V, then rectifier works like a doubler. Varistors Z1 and Z2 have overvoltage protect function on the line input. Thermistor NTCR1 limits input current until capacitors C5 and C6 are charged. R2 and R3 are only for discharge capacitors after disconnecting power supply. When power supply is connected to the line voltage, then at first are charged capacitors C5 and C6 together for about 300V. Then take a run secondary power supply controlled by transistor Q12 and on his output will be voltage. Behind the voltage regulator IC3 will be voltage 5V, which goes in to the motherboard and it is necessary for turn-on logic and for "Wake on something" functions. Next unstabilized voltage goes through diode D30 to the main control chip IC1 and control transistors Q3 and Q4. When main power supply is running, then this voltage goes from +12V output through diode D.

Stand-By mode

In stand-by mode is main power supply blocked by positive voltage on the PS-ON pin through resistor R23 from secondary power supply. Because of this voltage is opened transistor Q10, which opens Q1, which applies reference voltage +5V from pin 14 IO1 to pin 4 IO1. Switched schema is totally blocked. Tranzistors Q3 and Q4 are both opened and short-schema winding of auxiliary transformer T2. Due to short-schema is no voltage on the power schema. By voltage on pin 4 we can drive maximum pulse-width on the IO1 output. Zero voltage means the highest pulse-width. +5V means that pulse disappear.

Start of supply

Somebody pushes the power button on computer. Motherboard logic put to ground input pin PS-ON. Transistor Q10 closes and next Q1 closes. Capacitor C15 begins his charging through R15 and on the pin 4 IC1 begins decrease voltage to zero thanks to R17. Due to this voltage is maximum pulse-width continuosly increased and main power supply smoothly goes run.

Normal operation

In a normal operation is power supply controlled by IC1. When transistors Q1 and Q2 are closed, then Q3 and Q4 are opened. When we want to open one from power transistors (Q1, Q2), then we have to close his exciting transistor (Q3, Q4). Current goes via R46 and D14 and one winding T2. This current excite voltage on base of power transistor and due to positive feedback transistor goes quickly to saturation. When the impulse is finished, then both exciting transistors goes to open. Positive feedback dissapears and overshoot on the exciting winding quickly closes power transistor. After it is process repetead with second transistor. Transistors Q1 and Q2 alternately connects one end of primary winding to positive or negative voltage. Power branch goes from emitor of Q1 (collector Q2) through the third winding of exciting transformer T2. Next throug primary winding of main transformer T3 and capacitor C7 to the virtual center of supply voltage.

Output voltage regulation

Output voltages +5V and +12V are measured by R25 and R26 and their output goes to the IC1. Other voltages are not stabilised and they are justified by winding number and diode polarity. On the output is necessary reactance coil due to high frequency interference. This voltage is rated from voltage before coil, pulse-width and duration cycle. On the output behind the rectifier diodes is a common coil for all voltages. When we keep direction of windings and winding number corresponding to output voltages, then coil works like a transformer and we have compensation for irregular load of individual voltages. 

In a common practise are voltage deviations to 10% from rated value. From the internal 5V reference regulator (pin 14 IC1) goes reference voltage through the voltage divider R24/R19 to inverting input(pin 2) of error amplifier. From the output of power supply comes voltage through divider R25,R26/R20,R21 to the non inverting input (pin 1). Feedback C1, R18 provides stability of regulator. Voltage from error amplifier is compared to the ramp voltage across capacitor C11. When the output voltage is decreased, then voltage on the error amplifier is too decreased. Exciting pulse is longer, power transistors Q1 and Q2 are longer opened, width of pulse before output coil is grater and output power is increased. The second error amplifier is blocked by voltage on the pin 15 IC1.

PowerGood

Mainboard needs "PowerGood" signal. When all output voltages goes to stable, then PowerGood signal goes to +5V (logical one). PowerGood signal is usually connected to the RESET signal.

+3.3V Voltage regulation

Look at schema connected to output voltage +3.3V. This schema makes additional voltage stabilisation due to loss of voltage on cables. There are one auxiliary wire from connector for measure 3.3V voltage on motherboard.

Overvoltage schema

This schema is composed from Q5, Q6 and many discrete components. Circuit guards all of output voltages and when the some limit is exceeded, power supply is stopped.
For example when I by mistake short-schema -5V with +5V, then positive voltage goes across D10, R28, D9 to the base Q6. This transistor is now opened and opens Q5. +5V from pin 14 IC1 comes across diode D11 to the pin 4 IC1 and power supply is blocked. Beyond that goes voltage again to base Q6. Power supply is still blocked, until he is disconnected from power line input. 

ATX Power Connector

Pin Signal Color 1 Color 2 Pin Signal Color 1 Color 2
1 3.3V orange violet 11 3.3V orange violet
2 3.3V orange violet 12 -12V blue blue
3 GND black black 13 GND black black
4 5V red red 14 PS_ON green grey
5 GND black black 15 GND black black
6 5V red red 16 GND black black
7 GND black black 17 GND black black
8 PW_OK grey orange 18 -5V white white
9 5V_SB violet brown 19 5V red red
10 12V yellow yellow 20 5V red red

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Friday, September 12, 2014

Simple Small Portable Alarm Circuit

The system of using this schema is positioning a little magnet close to the stalk switch SW1 while being connected to the hand or garments of the individual holding the sack with the use of a tiny cable. Since the schema is tiny, it can be put in a tiny plastic box. The magnetic field will definitely loose its contact with the splint change the moment the bag is snatched instantly. The schema will definitely start oscillating if SW1 starts and will certainly produce a loud alarm sound from the loudspeaker. Alternatively, the unit can be placed in a pocket while the cable is linked to the bag, to develop a reverse approach of connection.

The high efficiency oscillator is made up by electrical wiring a corresponding transistor-pair that will definitely drive a small 8 Ohm loudspeaker directly. A very compact assembly is the result of 3 V electric battery quantity B1 and reasonable count of parts made use of.

Any kind of loudspeaker can be made use of yet the measurement is directed by the box where it will be positioned. Considering that the standby current being drawn is less than 20 uA, it is not required to include an ON/OFF switch. A existing of around ONE HUNDRED mA is consumed by the schema when the alarm system is sounding. To make the schema a lot more appealing, a 3.5 mm mono jack can be made use of as substitute for the switch while a 3.55 mm mono jack plug with its interior leads shorted can be made use of in place of the magnet. The tiny cable will certainly be connected to the jack plug. The voltage used to provide this schema should not go over 4.5 V since the transistor Q2 could acquire ruined. To be on the risk-free side, it is suggested to utilize a 3 V supply with two AA cells wired in series.

The personal alerts are one of the fastest growing portions in the self protection sector today because they are exceptionally loud as well as beneficial to hold. It could be available in the kind of essential chains, rich torches, levered hook, or hand band. It is utilized for scaring off an attacker by unexpected them with high pitch alarm that may attract attention of others in the spot. The opening of a window or doorway may give a signaling procedure utilizing this gadget which can be done by putting the box on the frame as well as the magnetic field on the transferable part. In this way, the splint switch as well as the magnetic field will definitely be extremely close when the window or doorway is closed.
  • BC547 isNPN tiny signal transistors produced for basic application changing and boosting due to its reasonable voltage, low current as well as 3 different gain options
  • BC327 is a PNP basic purpose transistor in a TO-92 bundle, made use of for basic purpose changing and amp applications which is suitable for AF driver periods and inexpensive power outcome stages of audio amps due to its attributes of high current at FIVE HUNDRED mA maximum and inexpensive voltage at 45 V optimum
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