Panel switch wiring

Monday, January 26, 2015

Low Cost Playback Amplifier For Cassette Deck

For some time now, there have been a number of tape cassette decks available at low prices from mail order businesses and electronics retailers. Such decks do not contain any electronics, of course. It is not easy to build a recording amplifier and the fairly complex magnetic biasing circuits, but a playback amplifier is not too difficult as the present one shows.

The stereo circuits in the diagram, in conjunction with a suitable deck, form a good-quality cassette player. The distortion and frequency range (up to 23 kHz) are up to good standards. Moreover, the circuit can be built on a small board for incorporation with the deck in a suitable enclosure. Both terminals of coupling capacitor C1 are at ground potential when the amplifier is switched on.

Cassette Deck Playback Amplifier Circuit Diagram:

Because of the symmetrical ±12 V supply lines, the capacitor will not be charged. If a single supply is used, the initial surge when the capacitor is being charged causes a loud click in the loudspeaker and, worse, magnetizes the tape. The playback head provides an audio signal at a level of 200–500 mV. The two amplifiers raise this to line level, not linearly, but in accordance with the RIAA equalization characteristic for tape recorders. Broadly speaking, this characteristic divides the frequency range into three bands:

Up to 50 Hz, corresponding to a time constant of 3.18 ms, the signal is highly and linearly amplified.
Between 50 Hz and 1.326 kHz, corresponding to a time constant of 120 µs, for normal tape, or 2.274 kHz, corresponding to a time constant of 70 µs, for chromium dioxide tape, the signal is amplified at a steadily decreasing rate.
Above 1.326 kHz or 2.274 kHz, as the case may be, the signal is slightly and linearly amplified. This characteristic is determined entirely by A1 (A1’). To make the amplifier suitable for use with chromium dioxide tape, add a double-pole switch (for stereo) to connect a 2.2 kΩ resistor in parallel with R3 (R3’). The output of A1 (A1’) is applied to a passive high-pass rumble filter, C3-R5 (C3’-R5’) with a very low cut-off frequency of 7 Hz. The components of this filter have exactly the same value as the input filter, C1-R1 (C1’-R1’). The second stage, A2 (A2’) amplifies the signal ´100, that is, to line level (1V r.m.s.).

Tuesday, January 6, 2015

Step Down DC Converter

This is a ADP1821 Step Down DC-to-DC Converter circuit.

This circuit uses ADP1821 that is synchronous pulse-width-modulated (PWM), step-down controller, inexpensive and versatile.

It can drive all N-channel power stage to regulate an output voltage as low as 0.6 V.

Friday, December 12, 2014

Electronic liquid detector circuit diagram

This electronic liquid detector circuit diagram is based on the ULN2429A monolithic bipolar integrated circuit designed for detecting the absence or presence of many different types of liquids. The ULN2429 electronic liquid detector circuit can be used in automotive , home or industrial applications .

Thursday, November 20, 2014

Doubler Digital Frequency

Doubler Digital Frequencycircuit 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.

Doubler Digital Frequency

Wednesday, November 19, 2014

ADC 0804 Microcontroler Interface Engineering

In ADC 0804 interface techniques with microcontrollers are pin-pin control must be controlled if we want to use the ADC with the microcontroller, there is value addition refferensi voltage to be supplied in 0804 ADC interface with a microcontroller, for example, we use the 0804 ADC (8 bit), if we give refferensi voltage 2.55 volts then we will get the increase of 1 bit to change 10 mVolt. Please note that the 0804 ADC pin on the leg that is form Vref Vref / 2, so to get a 10mV resolution is necessary for setting Vref / 2 equal to 1.275 V

The interface circuit microcontroller with ADC 0804

Mechanical interface microcontroller with ADC 0804

The steps in accessing data from the ADC 0804 by the microcontroller sebgai follows;

Enable ADC with signal 0 at the foot of Chip Select.

Give commands from conversion by providing a low pulse to the foot of the ADC Write narrow

Wait for the ADC issued a signal 0 from his leg INT

Give a moment of time delay for data from the ADC is correct

Give the read command by giving the signal 0 at the foot of ADC Read

Give a moment of time delay Now data from the ADC is ready for use and if the microcontroller.

Tuesday, November 18, 2014

Powerful Bat Detector device

Powerful Bat Detector device Circuit Diagram

The Powerful Bat Detector is a abundance analysis blazon device. Abundance analysis blazon detectors acquiesce you to apprehend accelerated complete by digitally ascent the abundance bottomward into the animal audition range. For instance, a western pipistrelle bat emits accelerated complete in the ambit of 53 to 91 kHz. If you bisect that abundance by 16, the new abundance ambit is 3.3 to 5.7 kHz, calmly aural our audition range. Because the analysis is done digitally, all amplitude advice is lost. Accelerated sources candy by the detector catechumen to sounds like geiger-counter clicks and chirps.

The basal ambit of the Simple Bat Detector is apparent in the schematic diagram to the right. It is about composed of 3 chip circuits, or ICs. The arresting from an accelerated transducer is fed to IC-1, an LM386 audio amplifier, which is configured to accommodate a arresting accretion of 200. The arresting is accompanying to IC-2, a added LM386, by a .05 uf capacitor. IC-2 is configured to accommodate an added accretion of 20, for a absolute arrangement accretion of 4,000. The achievement of IC-2 is absolute accompanying to the ascribe of IC-3, a 7 date CMOS agenda affiliate circuit. The ascribe date of the affiliate acts as a aught bridge detector, triggering on the abrogating alteration of the arresting from IC-2. The bisect by 16 achievement is affiliated to a potentiometer, which serves as an audio akin control. A aerial impedance bowl earphone is affiliated to the achievement of the akin control. The 10K akin ascendancy is a baby printed ambit pot that is set and forgotten. The detector ambit is powered by a nine volt battery. ( The numbers abutting to the IC nodes accredit to the pin numbers of the ICs. Note the added pins listed at the basal of the schematic that charge to be angry to ground. )

A above advantage of a abundance analysis detector is that it is a advanced bandage accessory ... that agency it will let you apprehend all apparent bat sounds after the charge to tune the detector to any accurate frequency. Heterodyne detectors, which action accelerated complete in the analog domain, alone catechumen a baby ambit of frequencies at any accustomed time - you charge baddest which frequencies to accept to. If you tune up about 60 kHz to accept for a pipistrelle, you may not apprehend the big amber bats aerial nearby. The abundance analysis detector works in the agenda domain, converting the abounding spectrum of complete that the transducer is able to detect. So you get to accept to all of the accelerated sounds about you, after missing annihilation due to adverse affability choices. I feel this no-knobs-needed appropriate of the abundance analysis detector makes it a abundant best for the accidental bat observer, and student.

Monday, November 17, 2014

Multiplexer Circuit With Logic Gate

Multiplexer circuit with a logic gate is a multiplexer circuit that utilizes a combination of logic gates.

Where the above example can be seen that the circuit has 2 bit selector and 4 input lines. You can make a circuit with more input channels by increasing the number of bits of the selector. And also you can use a combination of gates based on your own design with reference to the previous multiplexer truth table you should specify. So by making a truth table in advance you can easily create a series of logic gates.

The working principle of the multiplexer circuit above is:

1. Value of bit 00 from the selector will choose the path of the first input as the output
2. Value of bit 01 of the selector will choose the path of the second input as output
3. Value of bit 10 of the selector selects the third input lines as output
4. Value of bit 11 of the selector will choose the four input channels as output
5. As long as there is no change in the bit selector logic condition of the output logic state also will not be amended.
6. If the line selector is connected with a series of counter-up the output to be obtained will represent the input lines in sequence.
7. So it can be concluded that the usefulness of the implementation of a multiplexer function is to satisfy the principle of a simple data distribution. Thus, with multiplexers is possible to transmit data remotely using only one connection.