My Light Diagram

Continuous monitoring of the mains voltage is required in many ap-plications such as manual volt-age stabilisers and motor pumps. An ana-logue voltmeter, though cheap, has many disadvantages as it has moving parts and is sensitive to vibrations. The solidstate voltmeter circuit described here indicates the mains voltage with a resolution that is comparable to that of a general-pur-pose analogue voltmeter. The status of the mains voltage is available in the form of an LED bar graph. Presets VR1 through VR16 are used to set the DC voltages corresponding to the 16 voltage levels over the 50-250V range as marked on LED1 through LED16, respectively, in the figure. The LED bar graph is multiplexed from the bottom to the top with the help of ICs CD4067B (16-channel multiplexer) and CD4029B (counter). The counter clocked by NE555 timer-based astable multivibrator generates 4-bit binary ad-dress for multiplexer-demultiplexer pair of CD4067B and CD4514B. Circuit diagram: Digital Mains Voltag...

author : Pafilis Ioannis - Aristotle University of Thessaloniki Department of Electronics and Telecommunications In the present article , we will describe the function of a digital stopwatch , 0 – 99 sec . The function of the stopwatch , relies in the use of 4 integrated circuits, which in this case belong to National Semiconductor ( http :// www . national . com ). It is obvious that other integrated circuits can be used to achieve the same result, however in this case we have used the following parts : Α. 1 x CD4060BM (14 stage ripple carry binary counter) B. 1 x CD4040BM (14 stage ripple carry binary counter) C. 1 x MC14518B (BCD counter) D. 2 x MC14511B (BCD to seven segment driver) E. 2 x 7 segment LED displays The circuit that has been used is shown in picture 1. Through the experimental part we will explain each of the parts function, but in order to have a notion of the basic idea, let just say, that this circuit besides the 5V...

Digital visitor counter is a reliable circuit that takes over the task of counting Number of Persons/ Visitors in the Room very Accurately. When somebody enters into the Room then the Counter is Incremented by one and when any one leaves the room then the Counter is Decremented by One. The total number of Persons inside the Room is displayed on the seven segment displays.The microcontroller do the above job it receives the signals from the sensors, and this signals operated under the control of software which is stored in ROM. Digital visitor counter Digital visitor counter

This Precision Amplifier With Digital Control circuit diagram is similar to the preceding circuit of the attenuator. Gain of up to 100 can be achieved in this configuration, which is useful for signal conditioning of low output of transducers in millivolt range. The gain selection resistors R3 to R6 can be selected by the user and can be anywhere from 1 kilo-ohm to 1 meg-ohm. Trimpots can be used for obtaining any value of gain required by the user. The resistor values shown in the circuit are for decade gains suitable for an autoranging DPM. Resistor R1 and capacitor C1 reduce ripple in the input and also snub transients. Zeners Z1 and Z2 limit the input to ±4.7V, while the input current is limited by resistor R1. Capacitors C2 and C3 are the power supply decoupling capacitors. . Circuit diagram : Precision Amplifier With Digital Control Circuit Diagram Op-amp IC1 is used to increase the input impedance so that very low inputs are not loaded on measurement. The user can terminate the...

Analogue signal Analogue meter display Analogue systems Analogue systems process analogue signals which can take any value within a range, for example the output from an   LDR   (light sensor) or a microphone. An audio amplifier is an example of an analogue system. The amplifier produces an output voltage which can be any value within the range of its power supply. An analogue meter can display any value within the range available on its scale. However, the precision of readings is limited by our ability to read them. For example the meter on the right shows 1.25V because the pointer is estimated to be half way between 1.2 and 1.3. The analogue meter can show any value between 1.2 and 1.3 but we are unable to read the scale more precisely than about half a division. All electronic circuits suffer from 'noise' which is unwanted signal mixed in with the desired signal, for example an audio amplifier may pick up some mains 'hum' (the 50Hz frequency of the UK m...

Doubler Digital Frequency circuit includes a simple and easy to understand. Digital Frequency Doubler circuit application contained in the system electronics such as audio-producing organ, or keyboard. The function of this series Digital Frequency Doubler for multiplying two input frequencies. The process of multiplying 2 on scales in an organ in principle is like this series Digital Frequency Doubler. Example of rising to a ringing tone DO RE then electronically technique in it is by multiplying the two frequency bands such as this series Digital Frequency Doubler. Digital Frequency Doubler.

This is a Digital (VFD) With CA3207 and CA3208 Circuit Diagram. A vacuum fluorescent display (VFD) is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. This circuit uses the CA3207 sequence driver and CA3208 segment latch-driver in combination to drive display devices of up to 14 segments with up to 14 characters of display. The CA3207 selects the digit or character to be displayed in sequence, CA3208 turns on the required alphanumeric segments. Digital (VFD) With CA3207 and CA3208 Circuit Diagram

SW Converter for Digital AM Car Radio Circuit Diagram This circuit is purposely presented with many loose ends (not literally, of course) to stimulate experimenting with RF circuitry at a small outlay. Looking at the circuit diagram you may recognize a modified version of the SW Converter for AM Radios described elsewhere in this issue. The modifications were necessary to make the circuit compatible with a digital rather than analogue AM car radio. The main difference between digital AM radios and their all-analogue predecessors is that tuning is in 9 kHz (some-times 4.5 kHz steps) in compliance with the international frequency allocation for the band. Obviously, that particular step size, desirable as it may be on MW, is a stumbling block if you want to use a digital AM receiver in combination with a frequency step-up converter for SW, where chaos reigns and there is no fixed step size. The first attempt was to make the crystal oscillator variable by about 5 kHz each way.   SW Co...

This is 0-24VDC digital PIC power supply circuit. This variable power supply controlled with PIC microcontroller. There is LCD display in this circuit which will show the actual value of power supply output. This power supply use push on switch to adjust the output voltage and current value. Schematic Diagram: Component List : C1 = 2000uF per AMP, 40V (adjust capacity to power supply amps) C2,C3,C12,C15,C18,C21 = 0.1uF CER C4 = 0.01uF CER C5A,C5B,C5C,C5D = 0.01uF CER C6,C7 = 0.05uF CER C8 = Not used C9,C11,C19,C20 = 1uF CER C10 = 470uF 15V EL RADIAL C13 = 4.7µF 50V EL RADIAL C14 = 0.001uF CER C16,C17 = 22pF CER D1,D2,D4,D5 = 1N4148 D3 = 1N4004 Br1 = 1<10A BRIDGE RECTIFIER (adjust seize to power supply amps) DZ1 = 1N4751 30V ZENER IC1 = LM317KCS TO220 IC2 = LM337LZ TO92 IC3 = LT1491CN special HV opamp, do not substitute IC4 = PIC16F876A Q1 = 2N3906 Q2A to Q2D = TIP142TU 1 to 5 transistors (adjust quantity to power supply amps) Q3A to Q3D = 2N3904 (adjust quantity to power supply am...

A channel digital volume circuit on IC MAX5486 is shown here. MAX5486 40K digital volume / balance controller that pushbutton interface. The IC bias voltage that eliminated of an external circuitry for purpose and thereby by reduces external count. The IC has an LED indicator driver circuit be used for driving the indicator LEDs indicates level and balance level. The IC operated from or power and in pin TSSOP package. circuit on MAX5486 applied applications like personal audio systems, audio devices, home theatre systems, audio systems, audio systems etc. The right channel input is applied to the pin8 (high terminal (HR) of internal digital potentiometer of the IC) and left channel input is applied to the pin17 (high terminal (HL) of the second internal digital potentiometer of the IC). Low terminals (pin and 6) of potentiometers are shorted and connected to the mid bias voltage output (pin11) of the IC. at the buffered wiper terminal (pin10) of internal potentiometer and left channel...

The operation of the converter is based on the weighted adding and transferring of the analogue input levels and the digital output levels. It consists of comparators and resistors. In theory, the number of bits is unlimited, but each bit needs a comparator and several coupling resistors. The diagram shows a 4-bit version. The value of the resistors must meet the following criteria: R1:R2 = 1:2; R3:R4:R5 = 1:2:4; R6:R7:R8:R9 = 1:2:4:8. The linearity of the converter depends on the degree of precision of the value of the resistors with respect to the resolution of the converter, and on the accuracy of the threshold voltage of the comparators. This threshold level must be equal, or nearly so, to half the supply voltage. Moreover, the comparators must have as low an output resistance as possible and as high an input resistance with respect to the load resistors as feasible. Any deviation from these requirements affects the linearity of the converter adversely. Digital Converter to 4-Bit ...

General Description: The TDA7500 is an integrated circuit implementing a fully digital, integrated and advanced solution to perform the signal processing in front of the power amplifier and behind the AM/FM tuner or any other audio sources. The chip integrates two 43 MIPs DSP cores: one for stereo decoding noise blanking, weak signal processing and multipach detection and one for sound processing. Block Diagram:  

This Digital Electronic Lock Circuit Diagram shown below uses 4 common logic ICs to allow controlling a relay by entering a 4 digit number on a keypad. The first 4 outputs from the CD4017 decade counter (pins 3,2,4,7) are gated together with 4 digits from a keypad so that as the keys are depressed in the correct order, the counter will advance. As each correct key is pressed, a low level appears at the output of the dual NAND gate producing a high level at the output of the 8 input NAND at pin 13. Digital Electronic Lock Circuit Diagram The momentary high level from pin 13 activates a one shot circuit which applies an approximate 80 millisecond positive going pulse to the clock line (pin 14) of the decade counter which advances it one count on the rising edge. A second monostable, one shot circuit is used to generate an approximate 40 millisecond positive going pulse which is applied to the common point of the keypad so that the appropriate NAND gate will see two logic high levels whe...

A Simple electronic circuit project of digital to analog converter circuit, Figure A is an R/2R resistor ladder. Each switch that is closed increases the amount of current at. A simple channel A/D converter is shown in Fig. B. Digital To Analog Converter Circuit Diagram: The voltage reference (D2) is common to all channels, but-the value of the dropping resistor (R9) varies as the number of DACs installed in the system. IC15 is a DAC0808 A/D converter chip. ICI6A is an op amp to interface the output current from the D/A convert to an analog voltage output.

This is a simple Digital Cranial Electrotherapy Stimulator Circuit Project. Current generated flows through clips placed on the earlobes Output current adjustable from 80 to 600 micro Amperes. Owing to the recent launching in Europe of Cranial Electrotherapy Stimulation (CES) portable sets, we have been "Electronically Stimulated" in designing a similar circuit for the sake of hobbyists. CES is the most popular technique for electrically boosting brain power, and has long been prescribed by doctors, mainly in the USA, for therapeutic reasons, including the treatment of anxiety, depression, insomnia, and chemical dependency. CES units generate an adjustable current (80 to 600 microAmperes) that flows through clips placed on the earlobes.  The waveform of this device is a 400 milliseconds positive pulse followed by a negative one of the same duration, then a pause of 1.2 seconds. The main frequency is 0.5 Hz, i.e. a double pulse every 2 seconds. Some people report that this kin...

The circuit above above makes use of the CMOS 4017 decade counter IC. Each depression of a switch steps the output through 0– 9. By coupling the output via an AND gate to the next IC, a predefined code has to be input to create the output. Each PBS switch is de bounced by tw1o gates of a CMOS4001 quad 2-input NOR gate. This ensures a clean pulse to the input of each CMOS4017 counter. Only when the correct number of presses at PBS Awill allow PBS B to become active. This is similar for PBS C and PBS D. At IC4, PBS D must be pressed 7 times. Then PBS C is again pressed 7 times, stepping from output 1 to output 8. The AND gate formed around CMOS4081 then goes high, lighting the LED. The Reset switch can be pressed at any time. Power on resetis provided by the 100n capacitor near the reset switch. Below is a picture of one that I made about 15 years ago:   Unfortunately, this board was part of a much larger project containing multiple power supplies. One day whilst working on anot...

Digital Thermometer 0-100.0°C is a digital thermometer that operates in modetemperature measurement in Celsius (° C). Digital Thermometer 0-100.0 ° C in this article uses data processor in the form of a microcontroller AT89C4051. Temperature sensors used in Digital Thermometer 0-100.0 ° C. This temperature sensor LM35D. Digital Thermometer 0-100.0 ° C. It uses the temperature measurement data viewer in the form of 1 line LCD viewer. Digital Thermometer 0-100.0 ° C. It can display the temperature measurement data with a resolution of 0.1 ° C. Digital Thermometer Circuit Diagram Digital Thermometer 0-100.0 ° C. These temperature sensors make use of LM35D as temperature sensing. In Digital Thermometer 0-100.0 ° C. This temperature sensor measurement data this LM35D (Level Voltage) is then converted into 4-bit binary data using the ADC CA3162. Then the 4-bit data from ADC CA3162 which is a measurement of data if the temperature is in the AT89C4951 microcontroller so that it becomes an oper...

Now Build a Digital Stopwatch 0-60sec By using the same circuit of the Digital Stopwatch 0-99sec , we can add an AND gate, and transform the 0 – 99sec stopwatch to a 0 – 60sec stopwatch.We must find a way to control the RESET function of the BCD counter, which is responsible for the counting of the seconds. As we studied above, the circuit resets when we have 99 to 100, that is 1001 1001 à 0001 0000 0000. To make a transformation successfully we must force the pulse from 59 to 60 0011 1001 à 0100 0000 on the output of the BCD counter. By placing the AND gate, with its inputs on the Q1 and Q2 of the BCD counter of the decades, we make sure that when the gate closes, the RST input of the BCD counter will be set to logical “1”, which on its turn, will force the circuit to start over. The transformed circuit appears in picture 2.