Rain Detector Using 555

Rain Detector Using 555 is a simple alarm that can be used to find out it was raining. In principle, Rain Detector Using 555 is an astable multivibrator which is prepared by IC555 with installed a sensor that can detect water. Astable multivibrator with the 555 is set in the audio frequency with a frequency of 1 KHz. The series of Using Rain Detector 555 can be disupplay with a voltage source that is free enough from 5-15 VDC. In the application circuit Rain Detector Using this 555 can be mounted motor, car or other object that we want to protect from rain.

Water sensors that are used in circuit 555 Rain Detector Using this we can make yourself degan a PCB that we make the path as shown in the image above or as disclosed from the image above is by using aluminum foil taped to a board or boards that are plastic insulator . The important principle of the sensor is to conduct electrical current very well when the surface is exposed to water even a little. Hopefully useful ...

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A serial to parallel converter using the AT89C2051

The example program included with the PG2051 evaluation kit is a basic serial to parallel converter written in 8051 assembler. This is probably a good example of the uses to which an AT89C2051 can be put - it would be hard to get a serial to parallel converter much simpler than the single 20 pin IC in this circuit. The program is meant to serve as a useful example of 8051 serial routines and other programming, whether or not you actually need a serial to parallel converter.

Source: http://airborn.com.au/serial/sertopar.html

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Car Wiper Control Using 555 PCB

Circuit In rainy seasons, it is very annoying that wiper of your car wiping instantly all the time. Have you ever think of speed control of the wiper?.There are wiper control modules available on the market but most of them are costly. So here is an automatic wiper control circuit which enables you to control your wiper sweep rates from 1 second to 10 second. 

The heart of this circuit is an astable multivibrator using 555 Ic. We actually change the duty cycle of the square wave to obtain different sweep rates to control the wiper. The output pin 3 of the IC remains high for a time period set by R2. During this time the wiper motor will sweep at rates. The power supply to this wiper control circuit should be 12V. fit the potentiometer R2 anywhere on the dashboard of your vehicle and control the sweep rates according to the intensity of the rain.

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Hi Fi Audio Amplifier using TDA1514

The TDA1514 Hi-Fi Audio Amplifier was available on voguish grouping Amplifier. Please read carefully and observe on circuit design images of TDA1514 Hi-Fi Audio Amplifier to know itemize in a row.

Hi-Fi Audio Amplifier using TDA1514

The TDA1514 integrated circuit is a ciao-fi power amplifier in lieu of treatment for instance a corporation obturate in broadcasting, box and added audio applications. The TDA 1514 racetrack is completely battlemented, moreover has a nonspeaking organize to can be real illusory for a episode afterward power-on with a delay dimension unchangeable by outside components. The device is wilful in favor of centrosymmetric power stores but an unsymmetric allot may well in addition be utilized. For photo amplifier assemblage use two go well together circuits.

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5V 2A Dc Converter Using LT3980

Using LT3980 manufactured by Linear Technology can be designed a very simple 5 volts dc converter circuit.

5V 2A Dc Converter Circuit Diagram

The LT3980 has an adjustable frequency from 100kHz to 2.4MHz and accepts input voltages up to 58V . The transient voltage of the LT3980 is around 80 volts . The maximum output current which can be delivered by the LT3980 monolithic buck switching regulator is around 2 Amps .

Main features of the LT3980 monolithic buck switching regulator are : wide input range from 3.6V to 58V , overvoltage lockout protects circuits through 80V transients , 2A Maximum Output Current , low ripple (<15mvp-p) burst mode, aadjustable switching frequency: 100khz to 2.4mhz ,low shutdown current: iq <1μa, thermal protection, soft-start capability 

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5V Power Supply Using LTM8021

This 5v power supply circuit is designed using the LTM8021 and will provide a maximum current up to 500mA. Almost all required parts are included in the LTM8021 package. This 5v power supply circuit based on the LTM8021 operate over a input voltage range between 3V and 36V .The LTM8021 supports an output voltage range of 0.8V to 5V, set by a single resistor. Only an output and bulk input capacitor are needed to finish the design.

5V Power Supply Circuit diagram

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Using TLC251Microphone preamplifier Wiring diagram Schematic

This is an IC Using TLC251Microphone preamplifier Circuit Diagram. A microphone preamplifier using: om CMOS op amp with its own battery, is small enough to be placed in a case of small microphone. The amplifier operates from a 1.5V battery cathode mercury low supply currents. This preamp will operate at very low power and maintain a reasonable frequency response as well. 

 Microphone preamplifier Circuit Diagram

The TLC251 is operating in low bias (operating at 1.5 V) draws a supply current of only 10 and has a year - frequency response of 3 dB 27 Hz to 4.8 kHz. With 8-pin grounded, which is designated as the polarization state high limit increases above 25 kHz. Supply current is only - 30 pA under these conditions.

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LED torch using MAX660

This is a simple LED torch schema based on IC MAX660 from MAXIM semiconductors. The MAX 660 is a CMOS type monolithic type voltage converter IC. The IC can easily drive three extra bright white LEDs.The LEDs are connected in parallel to the output pin 8 of the IC. The schema has good battery life. The switch S1 can be a push to ON switch.



Notes.

* Assemble the schema on a general purpose PCB.
* The IC must be mounted on a holder.
* The schema can be powered from two torch cells connected in series.
* The capacitors C1 and C2 must be Tantalum type.
* The diodes D1 to D3 must be of 1N4148.

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Melody Generator using IC UM66

Here is the simplest melody generator schema you can make using an IC.The UM66 series are CMOS IC’s designed for using in calling bell, phone and toys. It has a built in ROM programmed for playing music. The device has very low power consumption.Thanks for the CMOS technology.The melody will be available at pin3 of UM66 and here it is amplified by using Q1 to drive the speaker.Resistor R1 limits the base current of Q1 within the safe values.Capacitor C1 is meant for noise suppression.














Notes

* Power supply must be between 1.5V & 4.5V .Do not exceed 4.5 V.
* Speaker can be driven with external NPN transistor.
* Melody begins from the first note if power is reseted.
* Assemble the schema on a good quality common board.
* If transistor HE8050S is not available use any NPN transistor like BC548 or 2N2222.

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6W amplifier using TA7222AP

This is a good news for the car owners because this amp works with 12v.TDA7222AP is an excellent integrated audio amplifier which can deliver 5.8W to a 4 Ohms load





Notes.

* The schema can be assembled on a Vero board.
* Use 12V DC for powering the schema.
* The IC must be heatsinked.
* Speaker can be a 4 ohms one.
* For optimum performance input and output must be separately grounded.

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Build a Car Voltage Regulator Circuit Using LM317

The car cigarette lighter socket does not only light cigarettes, but can be utilized as an electrical channel for powering tools to work on the car such as laptops and other electronic devices. The following schema diagram shows a way of powering a two-way mobile radio using the LM317T voltage regulator.

The LM317T is an adjustable 3-terminal positive voltage regulator that efficiently provides a load current of 1.5 Amps over an output range of 1.2 V and 37 V. With reference to the schema, it can accept 14 volts without any hassle and the voltage can be controlled easily with the use of a potentiometer, a 3-terminal resister with sliding contact. The whole schema will contain the following components:

 Printed Circuit Board (PCB)
Resistor 1 (R1): 270 ohms
Resistor 2 (R2): 2K carbon potentiometer
Capacitor 1 (C1): 100nF
Capacitor 2 (C2): 1uF tantalum
LM317T Voltage Regulator
Heat Sink
DC Power Jacks
Green LED: Power
Red LED: Over Voltage
Zener Diode: over voltage LED switch

The zener diode switches on the over voltage LED if the voltage passing through is larger than the breakdown or preset voltage. The use of zener diode permits a constant amount of voltage and can be very beneficial for devices that inputs the same amount of voltage.

LM317T is cheaply available in the market and is very simple to integrate into several energy system to supply a maximum current or voltage.

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Power Pulse Using by LM350 and NE555

This is a Simple Power Pulse Using by LM350 and NE555 Circuit Diagram. This schema can use to drive lamp,power LED,DC motor etc. Adjust R5 for output amplitude.Adjust R1 for output power .

Power Pulse Circuit Diagram

The LM350 is adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 3A over a 1.2V to 33V output range.This schema requires 5-15V power supply.

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Magic Lights Circuit using Bi Colour LED

This is the magic lights schema which use bi-colour LED as the output to provide the light. The schema uses 14 bi-colour (red and green) LEDs having 3 terminals each. Various dancing colour patterns are generated utilizing this schema considering that each LED can create three various colours. The middle terminal (pin 2) of the LEDs will be the common cathode pin that is grounded. When a positive voltage is applied to pin one, it emits red light. Similarly, when positive voltage is applied to pin 3. it emits green light. And when positive voltage is simultaneously applied to its pins 1 and 3, it emits amber light.

The schema could be implemented for decorative lights. The IC1 (timer IC 555) is applied in astable mode of multivibrator to produce clock signal for IC2 and IC3 (CD4518) that are dual BCD counters.

The two counters of each one of these ICs have already been cascaded to acquire 8 outputs from each. The outputs from IC2 and IC3 are connected to IC4 through IC7 that are BCD to 7-segment latch/decoder/driver ICs. Therefore we acquire a complete of 14 segment outputs from each of the IC pairs composed of IC4 plus IC5 and IC6 plus IC7. While outputs from former pair are connected to pin No. 1 of all the 14 bi-colour LEDs through current limiting resistors, the ouputs of the latter pair are similarly connected to pin No.3 of all the bi-colour LEDs to acquire a magical dancing lights effect.

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Build a Simple Home Alarm Circuit Using 555 ICs

This is a Simple Home Alarm Circuit Using 555 ICs. This schema can be simplified by using a single 74C14 IC. This IC is also known by the following numbers: 40106, 40014, and 74HC14.  These are CMOS chips and are characterised by low current consumption, high input impedance and a supply voltage from 5v to 15v. (Do not substitute 7414 or  74LS14. They are TTL chips and operate on 4.5v to 5.5v and have low impedance inputs.)

 Simple Home Alarm Circuit Diagram

The 74C14 contains 6 Schmitt Trigger gates and 4 of these gates (Schmitt Inverters) are used in this schema.
The schema consists of a number of "building blocks" and the first consists of two transistors in a very clever "bootstrap" arrangement. The first transistor is turned on via the 3M3 and 47k. The second transistor is not turned on and the output is HIGH.

A small signal from the electret microphone will consist of positive and negative excursions and the negative excursion will turn the first transistor OFF. This will turn the second transistor ON and the left lead of the 100n will be pulled towards the 0v rail. The 100n is uncharged and the right lead will also be pulled towards the 0v rail and the input of the  74C14 will see a LOW. This will make the output HIGH and turn on the BC547 transistor.

When the second transistor turns ON, it also pulls the 2u2 down and this removes the "turn-on" voltage to the first transistor. The two transistors remain in this state for a few seconds while the 2u2 discharges and the voltage on the base of the first transistor rises. When this happens, the two transistors change state and the 2u2 charges. When the schema is waiting to detect audio, the 2u2 is charged via the 47k on the base of the first transistor and 47k collector resistor of the second transistor (plus the base-emitter voltage drop of the first transistor).

Simple Home Alarm Circuit Diagram A

 To exit the property, the EXIT button is pressed and this puts a HIGH on pin 1 of the IC so that any signal from the electret mic is not passed to the siren. The EXIT delay is determined by the value of the 100u and 2M2. Normally-open and normally-closed switches will also send a LOW to trigger the siren.

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Build A Voltage Inverter using IC NE 555

In many diagram we need to generate an internal adjustable voltage. This schema shows how it is possible to use a trusty old NE555 timer IC and a bit of external schemary to create a voltage inverter and doubler. The input voltage to be doubled is fed in at connector K1. To generate the stepped-up output at connector K2 the timer IC drives a two-stage inverting charge pump schema.

The NE555 is configured as an astable multivibrator and produces a rectangular wave at its output, with variable mark-space ratio and variable frequency. This results in timing capacitor C3 (see schema diagram) being alternately charged and discharged; the voltage at pin 2 (THR) of the NE555 swings between one-third of the supply voltage and two-thirds of the supply voltage.

Voltage Inverter Circuit Using IC NE555

The output of the NE555 is connected to two voltage inverters. The first inverter comprises C1, C2, D1 and D2. These components convert the rectangular wave signal into a nega-tive DC level at the upper pin of K2. The second inverter, comprising C4, C5, D3 and D4, is also driven from the output of IC1, but uses the negative output voltage present on diode D3 as its reference potential. The consequence is that at the lower pin of output connector K2 we obtain a negative volt-age double that on the upper pin.

Now let us look at the voltage feedback arrangement, which lets us adjust this doubled negative output voltage down to the level we want. The NE555 has a control voltage input on pin 5 (CV). Normally the voltage level on this pin is maintained at two-thirds of the supply voltage by internal schemary. The voltage provides a reference for one of the comparators inside the device. If the reference voltage on the CV pin is raised towards the supply voltage by an external schema, the timing capacitor C3 in the astable multivibrator will take longer to charge and to discharge. As a result the frequency of the rectangle wave output from IC1 will fall, and its mark-space ratio will also fall.

The source for the CV reference voltage in this schema is the base-emitter junction of PNP transistor T1. If the base volt-age of T1 is approximately 500 mV lower than its emitter voltage, T1 will start to conduct and thus pull the voltage on the CV pin towards the positive supply.

In the feedback path NPN transistor T2 has the function of a voltage level shifter, being wired in common-base configuration. The threshold is set by the resistance of the feedback chain comprising resistor R3 and potentiometer P1. When the emitter voltage of transistor T2 is more than approximately 500 mV lower than its base voltage it will start to conduct. Its collector then acts as a current sink. Potentiometer P1 can be used to adjust the sensitivity of the negative feedback schema and hence the final output voltage level.Using T1 as a voltage reference means that the schema will adjust itself to compensate not only for changes in load at K2, but also for changes in the input supply voltage. If K2 is disconnected from the load the desired output voltage will be maintained, with the oscillation frequency falling to around 150 Hz.

A particular feature of this schema is the somewhat unconventional way that the NE555’s discharge pin (pin 7) is connected to its output (pin 3). To understand how this trick works we need to inspect the innards of the IC. Both pins are outputs, driven by internal transistors with bases both connected (via separate base resistors) to the emitter of a further transistor. The collectors of the output transistors are thus isolated from one another [1].

The external wiring connecting pins 3 and 7 together means that the two transistors are operating in parallel: this roughly doubles the current that can be switched to ground.The two oscilloscope traces show how the output voltage behaves under different circumstances. The left-hand figure shows the behaviour of the schema with an input voltage of 9 V and a resistive load of 470 Ω connected to the lower pin of output connector K2. The figure on the right shows the situation with an input voltage of 10 V and a load of 1 kΩ on the lower pin of output connector K2. The pulse width and frequency of the rectangle wave at the output of IC1 are automatically adjusted to compensate for the differing conditions by the feedback mechanism built around T1 and T2.

Because of the voltage drops across the Darlington out-put stage in the IC (2.5 V maximum) and the four diodes (700 mV each) the schema achieves an efficiency at full load (470 Ω between the output and ground) of approximately 50 %; at lower loads (1 kΩ) the efficiency is about 65 %. Link

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Burglar Alarm Using LDR and BC 548 Circuit diagram

Description

 Circuit showing a Burglar Alarm.Here we have used a ldr and a switching transistor for making this schema

.When the light coming towards the ldr during the period the ldr have low resistance so the buzzer will on.When the light going away the ldr during the period the ldr have high resistance so the transistor will off.Here you need a 12 volt power supply

Burglar Alarm Using LDR and BC 548 Circuit diagram

 

 Components Required

      Resistor

                   10 k(preset)

      Transistor


                   BC 548

       LDR


        Buzzer

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Simple MHz Oscillator using an ATtiny15

Most engineers will recognise the problem: Your schema needs a stable 1 or 2 MHz clock generator (in the author’s case it was for a Pong game using an old AY3-8500). A suitable crystal is not to hand so you cobble together an RC oscillator (there are plenty of diagram for such a design). Now it turns out that you don’t have exactly the right capacitor so a preset pot is add e d to allow some adjustment . Before you know it the clock schema is taking up more space on the board than you had hoped. 

Providing the application does not demand a precise clock source a tiny 8-pin microcontroller may offer a better solution to the problem. It needs no additional external components and an old ATtiny15 can be found quite cheaply. Another advantage of the solution is that clock frequency adjustment does not involve changing external components and is not subject to component tolerances. 

The microcontroller’s internal RC oscillator is already accurately calibrated to 1.6 MHz. With its inbuilt PLL, internal Timer 1 can achieve up to 25.6 MHz [2]. By configuring internal dividers the timer can output a frequency in range of roughly 50 kHz up to 12 MHz from an output pin. The difference between calculated and the actual output frequency increases at higher frequencies. A meaningful upper limit of about 2 MHz is a practical value and even at this frequency the deviation from the calculated value is about 15 %.

MHz Oscillator using an ATtiny15 Schematic

The schema diagram could hardly be simpler, aside from the power supply connections the output signal on pin 6 (PB1) is the only other connection necessary.The example program, written in Assembler is just 15 lines long! With a program this short comments are almost super fluous but are included for clarity. The code can be downloaded from the Elektor website [1]. 

The program only needs to initialise the timer which then runs independently of processor control to output the clock sign al . The processor can then be put into sleep mode to memory used up the remaining 99 % is free for use for other tasks if required. 

The OSCCAL register contains a calibration byte which allows some adjustment of the CPU clock. This gives a certain degree of fine tuning of the output frequency. A recommendation in the Atmel data sheet indicates that the CPU clock frequency should not be greater than 1.75 MHz otherwise timer operation cannot be guaranteed. 

The more recent ATtiny45 can be substituted for the ATtiny15. In this case the CK SEL fuses should be set to put the chip’s Timer 1 into ATtiny15- compatible mode [3]. After adjustment to the program it will now be possible to obtain a higher (or more exact) frequency from the timer, the ATtiny45’s PLL can operate up to 64 MHz.

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