Schematic Volt: digital

Showing posts with label digital. Show all posts

Tuesday, November 18, 2014

Digital Led Chaser circuit diagram

This particular circuit employs electronic digital circuits say for example a demultiplexer and also a binary table to build designs of "moving" led lights. This simple circuit is actually awesome while employed in the dark or light up an indicator of a few type, because it produces a awesome design which attracts the eyesight.

The primary component of the circuit is a demultiplexer 74ls138, we can be connected minimally important bits on the output on the counter, which will pick out one of many pins of the demultiplexer as being the output, lighting effects the led connected to the item. The counter can be wired only to be counted, plus a time clock beat is necessary to do that operate (the time clock circuit isnt involved, but almost any can do, if it is not very noisy)

One variation to apply is to connect the most major bit of that counter to a different a line leds, allowing and also disabling one of these so the design could observe 16 leds instead of the only 8 established these.

Wednesday, November 12, 2014

Digital Countdown Timer

The presented digital timer is built in addition to the before mentioned ultraviolet light box.
Indication is on 4 digits seven segment LED display.
The timer counting backwards from 99 minutes and 59 seconds to 00:00.
It is built with microcontroller PIC 16F84A and integrated circuit CD4511.
Supply for the ultraviolet LED diodes are terminated with the help of the electromagnetic relay 6Volti.
Set the countdown time is done with 2 command keys, and the timer starts with the tally.
Author:Petar Avramovski

Source: Magazine Emiter

Saturday, November 8, 2014

Digital Bike Tachometer SP

This digital SP tachometer for bikes uses 2 reed switches to urge the speed data of the bicycle. The reed switches are put in close to the rim of the wheel where permanent magnets pass by. The permanent magnets are connected to the wheelspokes and activate the reed switches everytime they pass by it. The speed is digitally displayed.

The tachometer circuit works in step with this principle; the pulses created by the reed contacts are counted inside an explicit time interval. The ensuing count is then displayed and represents the speed of the bike. 2 4026 ICs are used to count the pulses, decode the counter and management 2 7-segment LED show. RS flip-flops U3 and U4 perform as anti-bounce.Electronic bicycle SP tachometer circuit diagram

The pulses arrive at the counter’s input through gate U7. The measuring amount is set by monostable multivibrator U5/U6 and might be adjusted through potentiometer P1 so the tacho are often calibrated. The circuit U1/U2 resets the counters.

Since batteries are used to power the circuit, its not sensible to support the continual show of speed data. This circuit isnt continuously active. The circuit is activated solely once a button is pressed. a minimum of 3 permanent magnets should be put in on the wheel. The circuit are often calibrated with the assistance of another pre-calibrated tachometer.

Friday, October 31, 2014

Digital Isolation up to 100 Mbits Diagram Circuit

When it is necessary to send a digital signal between two electrically isolated circuits you would normally choose an optoisolator or some form of transformer coupling. Neither of these solutions is ideal; optocouplers run out of steam beyond about 10 MHz and transformers do not have a good low frequency (in the region of Hertz) response. The company NVE Corporation (www.nve.com) produces a range of coupler devices using an innovative ‘IsoLoop’ technology allowing data rates up to 110 Mbaud. The example shown here uses the IL715 type coupler providing four TTL or CMOS compatible channels with a data rate of 100 Mbit/s. Inputs and outputs are compatible with 3.3 V or 5 V systems. The maximum isolation voltage is 2.5 kV and the device can cope with input transients up to 20 kV/µs.

Circuit diagram:

The company produce many other configurations including bidirectional versions that would be suitable for RS485 interfacing. The IsoLoop coupler is based on relatively new GMR (GiantMagnetoResistive) technology. The input signal produces a current in a planar coil. This current generates a magnetic field that produces a change in resistance of the GMR material. This material is isolated from the planar coil by a thin film high voltage insulating layer. The change in resistance is amplified and fed to a comparator to produce a digital output signal. Differences in the ground potential of either the input or output stage will not produce any current flow in the planar coil and therefore no magnetic field changes to affect the GMR material. Altogether the circuit provides a good electrical isolation between input and output and also protects against input signal transients (EMV).
Author: Gregor Kleine - Copyright: Elektor July-August 200

Wednesday, October 22, 2014

TDA 7309 Digital Audio Processor Circuit

Digital Audio Processor TDA 7309 is a stereo audio processor with independent volume control of each channel was to get the audio quality of a good processor. Digital Audio Processor TDA 7309 is equipped with a loudness control is controlled externally. Digital Audio Processor TDA 7309 also has a soft mute feature stand-alone for each canals. Digital Audio Processor TDA 7309 is controlled via the I2C serial bus system with a microcontroller interface.

Click to view larger.

Block Diagram of Digital Audio Processor TDA 7309 Feature-owned Digital Audio Processor TDA 7309 The input multiplexer with 3 stereo input Recording function on the output line Loudnes external ontrol Independent volume control Digital volume control with 1dB step Soft Mute All functions of the Digital Audio Processor TDA 7309 is programmed via the I2C serial bus system

Monday, October 20, 2014

Sooper Digital Volume Control

This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project.

Schematic

Parts:

Part	Total Qty.	Description
C1	1	0.1uf Ceramic Disc Capacitor
U1	1	DS1669 Digital Pot IC (See Notes)
S1, S2	2	Momentary Push Button Switch
MISC	1	Board, Wire, Socket For U1

Notes:

1. U1 is available from Dallas Semiconductor.

2. S1 turns the volume up, S2 turns it down.

3. The input signal should not fall below -0.2 volts.

4. Using a dual polariity power supply (+-5V works fine) will cure most clipping problems. You will have to check the data sheet for the correct pins to connect your voltages. Link

Thursday, October 2, 2014

Digital to Analogue Converter DAC Circuit

The circuit of a 9-bit Digital to Analog Convener (DAC) is shown. This system combines the concepts of multiple·switch COS/MOS lCs, a low-cost ladder network of discrete metal-oxide film resistors, a CA313O op-amp connected as a follower, and an inexpensive monolithic regulator in a simple single power-supply arrangement. An additional feature of the DAC is that it is readily interfaced with COS/MOS input logic, e.g. 10- volt logic levels are used in the circuit.

The circuit uses an R/2R voltage- ladder network, with the output potential obtained directly by terminating the ladder arms at either the positive or the negative power-supply terminal. Each CD4007A contains three "inverters", each "inverter" functioning as a single-pole double- throw switch to terminate an arm of the R/2R network at either the positive or negative power-supply terminal. The resistor ladder is an assembly of one per cent tolerance metal-oxide film resistors. The five arms requiring the highest accuracy are assembled with series and parallel combinations of 806,000 ohm resistors from the same manufacturing lot. A single 15-volt supply provides at positive bus for the CA313O follower amplifier and feeds the CA3085 voltage regulator. A "scale-adjust" function is provided by the regulator output control, set to a nominal 10- volt level in this system. The line voltage regulation (approximately 0.2%) permits a 9-bit accuracy to be maintained with variations of several volts in the supply. The flexibility afforded by the COS/MOS building blocks simplifies the design of DAC systems tailored to particular needs.

Thursday, August 21, 2014

Simple Analog to Digital Converter

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.

http://www.electronic-diagram-diagrams.com/computersimages/2.gif

The schema 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, having data lines D0-D7. It works on the principle of successive approximation. It has a total of eight analogue input channels, out of which any one can be selected using address lines A, B and C. Here, in this case, input channel IN0 is selected by grounding A, B and C address lines.Usually the control signals EOC (end of conversion), SC (start conversion), ALE (address latch enable) and OE (output enable) are interfaced by means of a microprocessor. However, the schema shown here is built to operate in its continuous mode without using any microprocessor. Therefore the input control signals ALE and OE, being active-high, are tied to Vcc (+5 volts). The input control signal SC, being active-low, initiates start of conversion at falling edge of the pulse, whereas the output signal EOC becomes high after completion of digitisation. This EOC output is coupled to SC input, where falling edge of EOC output acts as SC input to direct the ADC to start the conversion.
As the conversion starts, EOC signal goes high. At next clock pulse EOC output again goes low, and hence SC is enabled to start the next conversion. Thus, it provides continuous 8-bit digital output corresponding to instantaneous value of analogue input. The maximum level of analogue input voltage should be appropriately scaled down below positive reference (+5V) level.The ADC 0808 IC requires clock signal of typically 550 kHz, which can be easily derived from an astable multivibrator constructed using 7404 inverter gates. In order to visualise the digital output, the row of eight LEDs (LED1 through LED8) have been used, wherein each LED is connected to respective data lines D0 through D7. Since ADC works in the continuous mode, it displays digital output as soon as analogue input is applied. The decimal equivalent digital output value D for a given analogue input voltage Vin can be calculated from the relationship