LEARNING

Power Supply negatif dari tegangan positif

2010-03-12T04:49:00.000-08:00

Op amps sangat berguna. Tapi salah satu kelemahan utama mereka adalah kebutuhan pasokan ganda. Ini serius membatasi aplikasi mereka dalam bidang di mana pasokan ganda tidak terjangkau atau tidak praktis. Sirkuit ini memecahkan masalah sampai batas tertentu. Ini memberikan tegangan negatif dari catu positif tunggal. Ini tegangan negatif bersama dengan pasokan positif dapat digunakan

switching Power Supply tunggal

2010-03-12T04:47:00.001-08:00

Salah satu fitur utama dari sirkuit diatur listrik yang disajikan adalah bahwa meskipun tetap tegangan regulator LM7805 digunakan di sirkuit, tegangan output adalah variabel. Hal ini dicapai dengan menghubungkan potensiometer antara terminal umum dari IC regulator dan tanah. Untuk setiap kenaikan 100-ohm nilai di-sirkuit perlawanan potensiometer VR1, kenaikan

Regulator penurun tegangan rendah linier

2010-03-12T04:46:00.001-08:00

Rangkaian adalah MOSFET berdasarkan regulator tegangan linier dengan penurunan tegangan terendah 60 mV pada 1 ampere. Setetes milivolt lebih sedikit mungkin dengan MOSFET lebih baik memiliki lebih rendah RDS (on) perlawanan. Rangkaian pada Gambar. 1 menggunakan 15V-0-15V sekunder dari transformator step down dan mempekerjakan sebuah MOSFET saluran-n IRF 540 untuk mendapatkan output 12V DC

Stabiliser tegangan listrik

2010-03-12T04:45:00.000-08:00

tegangan cut-out akan menghemat peralatan mahal Anda listrik dan elektronik dari efek yang merugikan dari tegangan listrik sangat tinggi dan sangat rendah. Sirkuit ini memiliki ulang otomatis dan menggunakan komponen yang mudah tersedia. Itu membuat penggunaan pembanding tersedia di dalam IC 555 timer. Pasokan disadap dari berbagai sudut sirkuit power supply untuk relay dan kontrol

Stabiliser tegangan pada power suara

2010-03-12T04:44:00.000-08:00

Variasi tegangan dan pemadaman listrik mempengaruhi berbagai alat tersebut seperti TV, VCR, sistem musik dan lemari es. Rangkaian sederhana akan melindungi peralatan mahal dari tinggi serta tegangan rendah dan tegangan surge (ketika kekuatan resume). Hal ini juga memberikan sebuah lagu merdu ketika daya listrik kembali. Ketika listrik tegangan normal, tegangan DC pada katoda dari dioda

Power suply tegangan tinggi

2010-03-12T04:42:00.001-08:00

Sebuah pasokan listrik tegangan tinggi adalah sumber yang sangat berguna yang dapat secara efektif digunakan dalam berbagai aplikasi seperti biasing gas discharge tabung dan detektor radiasi dll seperti power supply juga dapat digunakan untuk perlindungan atas kekayaan dengan listrik pengisian dari pagar. Berikut kebutuhan saat ini adalah urutan dari beberapa microamps. Dalam aplikasi tersebut

Charger Accu mobil sederhana

2010-03-12T04:41:00.000-08:00

Sirkuit ini sangat sederhana menggunakan transformator, dua dioda, kapasitor dan sebuah ammeter. Untuk mengisi baterai hanya menghubungkan + dan - terminal dari rangkaian ke terminal yang sesuai dari baterai. Bila daya baterai sudah tidak dikenakan biaya, pembacaan ammeter menunjukkan ampli 1-3. Setelah baterai terisi penuh ammeter membaca nol atau hampir nol, setelah baterai harus dikeluarkan

7 segment rolling display using PC

2010-03-12T04:39:00.001-08:00

It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some others as output lines. Some lines are open collector type which can be used as input lines.

PC based Frequency Meter

2010-03-12T04:38:00.000-08:00

Here is a simple technique for measuring frequencies over quite a wide frequency range and with acceptable accuracy limits using a PC. It follows the basic technique of measuring low frequencies, i.e. at low frequency, period is measured for a complete wave and frequency is calculated from the measured time-period. Cascaded binary counters are used for converting the high-frequency signals into

Simple Analog to Digital Converter

2010-03-12T04:36:00.001-08:00

Normally analogue-to-digital con-verter (ADC) needs interfacing through a microprocessor to convert analogue data into digital format. This requires hardware and necessary software, resulting in increased complexity and hence the total cost. The circuit of A-to-D converter shown here is configured around ADC 0808, avoiding the use of a microprocessor. The ADC 0808 is an 8-bit A-to-D converter,

Sawtooth wave generator

2010-03-12T04:34:00.000-08:00

Sawtooth wave generators using opamp are very common. But the disadvantage is that it requires a bipolar power supply. A sawtooth wave generator can be built using a simple 555 timer IC and a transistor as shown in the circuit diagram.The working of the circuit can be explained as follows: The part of the circuit consisting of the capacitor C, transistor,zener diode and the resistors form a

Simple variable frequency oscillator

2010-03-12T04:33:00.000-08:00

This is a very simple circuit utilising a 555 timer IC to generate square wave of frequency that can be adjusted by a potentiometer. With values given the frequency can be adjusted from a few Hz to several Khz. To get very low frequencies replace the 0.01uF capacitor with a higher value.The formula to calculate the frequency is given by:1/f = 0.69 * C * ( R1 + 2*R2) The duty cycle is given by:%

Discrete component motor direction controller

2010-03-12T04:31:00.000-08:00

This circuit can control a small DC motor, like the one in a tape recorder. When both the points A & B are "HIGH" Q1 and Q2 are in saturation. Hence the bases of Q3 to Q6 are grounded. Hence Q3,Q5 are OFF and Q4,Q6 are ON . The voltages at both the motor terminals is the same and hence the motor is OFF. Similarly when both A and B are "LOW" the motor is OFF. When A is HIGH and B is LOW, Q1

Super simple stepper motor controller

2010-03-12T04:30:00.000-08:00

The circuit shown above can be used to control a unipolar stepper motor which has FOUR coils (I've swiped it off an old fax machine). The above circuit can be for a motor current of up to about 500mA per winding with suitable heat sinks for the SL100. For higher currents power transistors like 2N3055 can be used as darlington pair along with SL100. The diodes are used to protect the

Discrete component motor direction controller

2010-03-12T04:28:00.000-08:00

Automatic Speed Controller for fans & Coolers

2010-03-12T04:25:00.000-08:00

During summer nights, the temperature is initially quite high. As time passes, the temperature starts dropping. Also, after a person falls asleep, the metabolic rate of one�s body decreases. Thus, initially the fan/cooler needs to be run at full speed. As time passes, one has to get up again and again to adjust the speed of the fan or the cooler.The device presented here makes the fan run at full

Alternating Flasher

2010-03-08T02:46:00.001-08:00

This circuit uses three easily available 555 timer ICs. All three work as astable multivibrators. The first 555 has an on period and off period equal to 1 sec. This IC controls the on/ off periods of the other 2 555s which are used to flash two bulbs through the relay contacts. The flashing occurs at a rate of 4 flashes per second. The diodes are used to protect the 555 ICs from peaks. The

Dancing Lights

2010-03-08T02:43:00.001-08:00

Here is a simple circuit which can be used for decoration purposes or as an indicator. Flashing or dancing speed of LEDs can be adjusted and various dancing patterns of lights can be formed. The circuit consists of two astable multivibrators. One multivibrator is formed by transistors T1 and T2 while the other astable multivibrator is formed by T3 and T4. Duty cycle of each multivibrator can be

Switch using a single Chip

2010-03-08T02:41:00.001-08:00

Using dual flip-flop IC CD4027 employ a 555 based monostable circuit to supply input clock pulses. The circuit described here obviates this requirement. One of the two flip-flops within IC CD4027 itself acts as square wave shaper

Christmas Star

2010-03-08T02:39:00.000-08:00

This circuit can be used to construct an attractive Christmas Star. When we switch on this circuit, the brightness of lamp L1 gradually increases. When it reaches the maximum brightness level, the brightness starts decreasing gradually. And when it reaches the minimum brightness level, it again increases automatically. This cycle repeats. The increase and decrease of brightness of bulb L1

Running Message Display

2010-03-08T02:36:00.001-08:00

Light emitting diodes are advan- tageous due to their smaller size, low current consumption and catchy colours they emit. Here is a running message display circuit wherein the letters formed by LED arrangement light up progressively. Once all

Automatic Room Lights

2010-03-08T02:34:00.000-08:00

An ordinary automatic room power control circuit has only one light sensor. So when a person enters the room it gets one pulse and the lights come on. When the person goes out it gets another pulse and the lights go off. But what happens when two persons enter the room, one after the other? It gets two pulses and the lights remain in off state. The circuit described here overcomes the

Emergency Light

2010-03-08T02:32:00.000-08:00

The circuit of automatic emergency light presented here has the following features: 1. When the mains supply (230V AC) is available, it charges a 12V battery up to 13.5V and then the battery is disconnected from the charging section. 2. When the battery discharges up to 10.2V, it is disconnected from the load and the charging process is resumed. 3. If the mains voltage is available and there is

Automatic Dual output Display

2010-03-08T02:30:00.000-08:00

This circuit lights up ten bulbs sequentially, first in one direc- tion and then in the opposite direction, thus presenting a nice visual effect. In this circuit, gates N1 and N2 form an oscillator. The output of this oscillator is used as a clock for BCD up/down counter CD4510 (IC2). Depending on the logic state at its pin 10, the counter counts up or down. During count up operation, pin 7 of

Pot plant water tester electronic

2010-03-07T21:02:00.000-08:00

This simple device checks if their is water in a pot plant. You stick the two probes(paperclips)into the pot plant and if the LED lights, it means there is water in the pot plant.You need to adjust the 47k potentiometer to set the level at which the LED goes on.