RING BELL ELECTRONIC CIRCUIT USING NE555 DIAGRAM

RING BELL ELECTRONIC CIRCUIT USING NE555 DIAGRAM

This circuit produces oscillating frequency around 1kHz, and able to be converted by changing the value of resistor R1. The speaker will produce a long beep sound with 1kHz frequency. Here is the schematic :

Parts list :

•     Resistor R1 : 10k ohm
•     Resistor R2 : 56k ohm
•     Capacitor C1-C2 : 0.01 uF
•     Polar capacitor C3 : 1 uF/15V
•     IC timer : NE 555
•     Speaker : 8 ohm 0.5 W
•     ON/OFF switch
•     5-15V Power supply

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Battery charger using LM350

This is very useful circuit for the vehicle owners.Because most of time they have to bring their heavy 12v battery hear and there.now you dont want to do that.because you can build your own 12v charger




Notes

Use a 20 to 30 V / 3A DC power supply for powering the circuit.
This circuit is not possible for charging GEL type batteries as it draw large amounts of current.

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Switching Power Supply Using the LMZ14202H

Using the LMZ14202H power switching controller, can be designed a very simple switching power supply circuit that can provide a fixed output voltage covering a wide range of voltages .

Switching Power Supply Circuit diagram

This power switching power supply electronic project will provide a fixed output voltage between 5 and 30 volt from an input voltage between 8 and 42 volt at a maximum output current of 2 ampere . This circuit project power supply require few external electronic parts and can be configured very easy . In the table bellow you can see components value that are required for different output voltage

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CMOS Toggle Flip Flop Using Laser Pointer

The circuit below is similar to the one above but can be used with a laser pointer to toggle the relay rather than a push button. The IR photo transistor Q1 (Radio Shack 276-145A) or similar is connected to the set input (pin 6). The photo transistor should be shielded from direct light so that the voltage at the set input (pin 6) is less than 1 volt under ambient conditions and moves to more than 10 volts when illuminated by the laser pointer or other light source.

CMOS Toggle Flip Flop Using Laser Pointer Circuit Diagram

The reset time is about a half second using a 4.7uF cap which prevents the circuit from toggling more than once during a half second interval. The 10K resistor and diode provide a faster discharge path for the 4.7uF cap so the circuit can be retoggled in less than 1 second. The 3K resistor in series with the photo transistor may need be adjusted for best performance. The relay shown is a solid state variety to be used with lights or other resistive loads at less than 3 amps. A mechanical relay can also be used as shown in circuit above.

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Li Ion Polymer Battery Charger Using LTC4098

Using the LTC4098 USB Power-Path controller you can design an high efficiency , full-featured Li-Ion Polymer battery charger using few external electronic components . This Li-Ion Polymer battery charger circuit can be used with many power distribution sources like: USB, wall adapter, automotive, Firewire or other high voltage DC/DC converters, and a Li-Ion/Polymer battery.

Li-Ion Polymer Battery Charger Circuit diagram

For automotive and other high voltage applications, the LTC4098 interface with a Linear Technology external switching regulator to provide a high efficiency high voltage power path. An overvoltage circuit protects the LTC4098 from high voltage damage on the USB/wall adaptor inputs with an N-channel FET and an resistor .

The voltage on the pin7 (Prog) pin always represents the actual charge current by using the following formula: IBAT =(VPROG/RPROG)x1030 The charge current is programmed using a single resistor from PROG to ground.The program resistor and the charge current are calculated using the following equations :RPROG =1030V/ICHG ; ICHG =1030V/RPROG . The charge voltage will be 4.2V with 0.5 accuracy . As you can see in the schematic circuit this charger is very simple an you need to apply just few easy equations to design a high efficiency Li-Ion Polymer charger .

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LED Driver using LNK454DG

A very simple high efficiency led driver circuit can be designed using LNK454DG controller designed by Power Integrations . This LNK454DG led driver is configured as non-isolated discontinuous flyback converter designed to drive LED strings at voltages of 2.5 V to 3.5 V with an output current of 366 mA The circuit meets both line surge and EMI requirements and the low component count allows board dimensions required for LED candelabra bulb replacement applications. LNK454DG led driver is very easy to be configured and require few external electronic parts.

LED Driver Schematic

Two differential pi (π) filter EMI stages are used with C1, R1, L1 and C2 forming one stage and C2, L2, R2 and C3 the second.The incoming AC is rectified by BR1 and filtered by C1, C2 and C3. The total effective input capacitance, the sum of C1, C2 and C3, was selected to assure correct zero crossing detection of the AC input by the LinkSwitch-PL device and to meet high power factor and low THD. Due to the limited input capacitance (to meet PF) RV1 and VR1 are used to limit component voltage stress during line surges.The LNK454DG device (U1) incorporates the power switching device, oscillator, output constant current control, start-up, and protection functions.

The integrated 725 V MOSFET provides extended voltage margin and ensures high reliability even during line surge events. The device is powered from the BYPASS pin via the decoupling capacitor C5.The rectified and filtered input voltage is applied to one end of the primary winding of T1.The other side of the transformer’s primary winding is driven by the integrated MOSFET in U1. The leakage inductance generated drain voltage spike is limited by an RCD clamp consisting of D1, R3, and C4.Diode D2 is used to protect the IC from negative ringing when the MOSFET is off due to the reflected output voltage exceeding the DC bus voltage, the result of minimal input capacitance to give high power factor.T1 transformer is an SNX R1568 coil from Santronics or some other equivalent .

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Tone Control Circuit Designed Using LM833

Using LM833 can be designed a very simple tone control circuit using few external components .For this Lm833 ton control circuit can be used almost any type of operational amplifier if it have high input impedance .The LM833 is a is a dual general purpose operational amplifier designed with particular emphasis on performance in audio systems.

Tone Control Circuit Diagram

The ton control from this circuit is based on this operational amplifier from National Semiconductor and two RC filters ( low pass and high pass ) .Using the formula presented bellow we can modify the frequency of the tone control circuit - the cut off frequency of RC filters (low pass and high pass )lm833 tone control formula For the tone control circuit presented in this schematic the frequencies are : fL = 32 Hz, fLB = 320 Hz and fH =11 kHz, fHB = 1.1 kHz.

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SP LED Flashlight Using Supercapacitor

Bored of joking with capacitors? Then its time for you to maneuver on to super-capacitors. These have huge storage capabilities. during this article you may conclude the way to build atiny low LED flashlight using supercapacitors.

The most disadvantage of capacitors is their giant voltage drop. For this project, a minimum voltage of two volts is needed to light-weight the LED. As a result, the “Joule Thief” style would be incorporated here. Using this, a AA battery is used to light-weight an LED until its fully discharged.
 during this case, a supercapacitor would be taking the place of the battery. Here an LED is employed to perform the operate of a diode. This ensures that theres sufficient voltage across the LED.

 the necessities of the project are listed below:
White LED
Super capacitor (10F, 2.7 V)
Transistor
Torus
1 k ohm resistor
Wires
Breadboard
The torus and therefore the transistor used here comes from an energy-saving lamp HS. Care ought to be taken whereas removing this from the lamp as a breakage may lead to the discharge of the mercury vapors. A lamp load along side a USB port is added to the circuit. This makes it compatible with a computer or a automotive radio.

A couple of precautions got to be taken whereas constructing the circuit. The USB port mustnt be supplied with excess power. The capacitor doesnt stand up to a high voltage and hence a zener diode is connected in parallel to handle the high voltage. The diode protects the capacitor when the voltage exceeds an explicit price.

 

 

 

http://streampowers.blogspot.com/2012/07/sp-led-flashlight-using-supercapacitor.html 

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Arrow LED Indicator using 74hc14 IC

This arrow led indicator electronic project can be used in some dark places to show the directions . You can use to indicate direction just an illuminated arrow or a flashing light , but is much nicer if the light moves in the correct direction.

This arrow led indicator is based on 74HC14 circuit and some LEDs which are used to show the way .
For this arrow led indicator we need six series of three LEDs arranged in the shape of arrows and are connected to the outputs . Each time the lit arrows move over by one column so it appears that the arrows run from right to left.

Arrow LED Indicator Circuit Diagram

If we want to change the speed of the moving light it’s need to change the value of C1 to C3 or R1 to R3 ( a lower value for this components decrease the time of moving lights). If we want a longer arrow we can mount in parallel with existing columns another columns .
For power supply we can use batteries or 6V regulated power supply .

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16 Channel LED Driver Using LT3754

The LT3754 16 channel LED driver with a step-up DC DC controller designed by Linear Technology is capable of driving up to 45V of LEDs. Each channel of the LT3754 led driver contains an accurate current sink with ±2.8% current matching.If are used high current Leds channels can be paralleled.

16 Channel LED Driver Circuit Diagram

 

 

The LT3754 16 channel LED driver circuit allows a PWM dimming range up to 3000:1 and an analog dimming range up to 25:1. Operating frequency of the LT3574 16 channel LED driver can be programmed from 100kHz up to 1MHz using just a simple resistor or an external clock .

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Dark Sensitive Power Switch Circuit Diagram Using LDR

Description

Circuit showing a Dark Sensitive Power Switch .Here we have used a ldr and a ordinary transistor for making this circuit
.Connect any 230 volt equipment at the load .You need a 9 volt power supply
Components Required

         Resistor

                     10 k , 680 R

          Transistor

                        BC 548

          Diode

                   IN 4007

         Relay

         LDR

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Simple Metal Detector Using 555 Timer

This metal detector electronic project schematic circuit is designed using a simple 555 timer integrated circuit . As you can see in the schematic circuit , this metal detector electronic project requires few external electronic parts . This circuit detects metal and also magnets.

Metal Detector with 555 Timer Circuit Daigram

When a magnet is brought close to the 10mH choke, the output frequency changes. This metal detector project can be powered from a power supply that can provide an output DC voltage between 6 an 12 volt . If a metal is closer to the L1 coil , will produce a change of output oscillation frequency, that will generate a sound in the 8 ohms speaker

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SW Receiver Using MK414

A Short Wave Receiver based on the MK484 (formerly ZN414) that includes the tropical bands and 49 metre bands.

SW Receiver Using MK414 Circuit Diagram

Notes:
The original data sheet for the MK414 states a maximum working frequency is around 4 MHz. SW transmissions are so powerful that this receiver will work well with signals up to about 6 or 7 MHz. The 10k resistor controls the operating voltage for the IC which is critical for good performance.

Coil Details:
The tuned circuit consists of a variable capacitor and fixed air spaced coil. For the coil, I wound between 10 and 20 turns of wire on an empty tube of around 1.5 inches diameter. The turns were spaced so that the overall length was around 3 inches. The variable capacitor tuned 0 - 300 pF but there is plenty of scope for experiment here. One final point, you will need an external antenna to receive broadcasts. I have an outside wire that is about 7 meters long and this was quite effective. The antenna can be connected at either end of the coil or via a series capacitor value between 10pF and 100pF.

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LED Emergency Light Circuit Using Boost Converter

The following circuit uses a very common voltage boost converter concept for making a group of white LEDs illuminate at relatively lower power supplies. Lets learn how to make this interesting and useful little LED boost emergency light circuit.


Yet again we take the help of the evergreen work horse, the IC555 for implementing the proposed actions. The figure shows a very simple circuit configuration where the IC 555 has been rigged as an astable multivibrator.
In an astable multivibrator design the various components are wired such that the output generates trains of pulses which are self sustaining and keeps coming as long as the circuit remains powered.

In the present configuration the output of the IC which is the pin #3 generates pulses at a frequency determined by the resistors R1 and R2 and also the capacitor C2.
R2 may be typically adjusted or made variable type for enabling dimming control of the LEDs. However here the value of R2 has been fixed for acquiring optimum brightness from the LEDs.

The pulses available at pin#3 of the IC is used for ddriving the transistor T1 which in turn switches in response to the positive pulses.

The switching of the transistor pulls the supply voltage through the inductor in a pulsed mode.
As we know when alternating or pulsed voltage is applied across an inductor it tries to oppose the current and in the process kick an equivalent high voltage for compensating the applied current force.
This action of the inductor is what constitutes the boost action, where the voltage is stepped to higher levels than the actual supply voltage.
The above functioning of the inductor has been exploited in this circuit also. L1 boosts the voltage in an attempt to restrict the applied AC, this high voltage generated across the coil during the non conducting phases of the transistor is fed across a series connected LEDs for illuminating them under lower current levels. This process helps to illuminate the LEDs at relatively lower power consumption.

L1 winding is not so critical, it is a matter of little experimentation, the number of turns, wire guage, the diameter of the core, all are directly involved and affect the boost levels, therefore must be optimized carefully.
In the prototype I had used 50 turns of 22 SWG over an ordinary ferrite rod, which is normally used in small MW radio receivers.

The LEDs used by me were 1 watt, 350 mA types, howver you may use different types if you want.

Parts List

R1 = 100K
R2 = 39K,
R3 = 100 Ohms,
C1 = 680pF,
C2 = 0.01uF
L1 = see text
IC = LM555
LEDs = as per preference.

PLEASE CONNECT A 10 OHM RESISTOR IN SERIES WITH THE LED CHAIN FOR SAFEGUARDING IT FROM HIGH BOOSTED VOLTAGE.

INCREASING THE VALUE OF R2 SHOULD INCREASE THE BRIGHTNESS OF THE LEDs AND VICE VERSA.

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Dew Sensitive Switch Circuit Using LM358

This is a simple design circuit that can be used to switch ON or OFF a device when the dew present in the surrounding atmosphere crosses a set value. This circuit uses a dew sensitive resistive element and a comparator based on LM 358 to perform the above said operation. This is the figure of the circuit.


In operation of the circuit, at normal condition the resistance of dew sensor element will be low and so the voltage drop across it. So the voltage at the non inverting pin of LM358 (IC1) will be less than the voltage at the inverting input of the LM358.So the output of the op amp will be low. This keeps the opto coupler (MCT2E) deactivated. When the dew increases the resistance of the element increases and so do the voltage across it. Now the voltage at the non inverting pin of LM358 (IC1) will be higher than the voltage at the inverting input of the LM358.So the output of the op amp will be switched to high. This in turn activates the opto coupler. The LED glows to indicate it. As a result we get an opto coupler activated and de activated according to the amount of dew in the atmosphere. The output pins of opto coupler pin (5&4) can be used to control the external device.

Diode D1, resistors R6&R3 and capacitor C1 is employed here to derive the power for the circuit directly from mains. The dew sensor is hard to find in market. But it can be easily obtained from a old VCR. Also the type no of the sensor is not so important here. Try with any thing you get. I used one from a old Hitachi VCR. LM 358 is a dual op amp. Here only one op amp inside it is used.

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