Diagram Guide

Showing posts with label a. Show all posts

Saturday, November 8, 2014

Making a Solar Energy with iPhone Battery Charger

For faster charging, a larger solar cell can be attached to the bag. Enough power can be generated to fully charge an iPhone in about 5.5 hours and an iPod Touch in 4 hours using a slightly larger solar cell with 6V at 250mAh. The charger will automatically switch to trickle charging when the cell reaches full charge. The charging current is limited to 100mA when charging using the mini USB port and the charging is limited to 280mA when charging using the barrel plug jack

Source : http://witcircuit.blogspot.com/2013/04/making-solar-energy-powered-iphone.html

Thursday, October 23, 2014

Class A headphone amplifier diagram

Class A headphone amplifier

Friday, October 17, 2014

Build a MHz Oscillator using an ATtiny15

Most engineers will recognise the problem: Your circuit 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 circuits 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 circuit 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 circuit 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.

Wednesday, October 15, 2014

Build a Rain and Water Alarm Circuit Diagram

This is the circuit diagram of Rain and Water Alarm circuit. This circuit generates alarm sound when its sensor is witted by water which make a short circuit (connection) between X and Y. A tone of about 1kHz which can be hear while detecting water, is provided by a stable multivariate from timer IC 555.

The sensor when witted by water completes the circuit and causes the 555 oscillate at about 1kHz. It has to placed generating an angle of about 30 – 45 degrees to the ground. This tends to make the rain water to flow over it towards the ground and prevents the alarm from going on because of the stored water on top of the sensor.

The metal implemented for making the sensor is required to be aluminum and not copper. This is simply because copper forms a blue oxide on its layer on prolonged exposure to moisture and needs to be cleaned on a regular basis.The aluminum foils may be secured to the wooden / plastic board via epoxy adhesive or small screws. The connection between X and Y from the sensor may be obtained by small crocodile clips or you could possibly use screws.

Build a Rain and Water Alarm Circuit Diagram

Saturday, September 13, 2014

Build a Precision Narrow Band Tone Switch Wiring diagram Schematic

How to Build a Precision Narrow Band Tone Switch Circuit Diagram. This is a simple Precision Narrow Band Tone Switch Circuit Diagram. This signal tracker and lock detector combine to make a precision tone switch. Filter R3/R4/C2 determines signal capture and tracking range, as well as settling time. Max. VCO frequency: R& Min. VCO frequency: + Pin 9 voltage affects both.

Precision Narrow Band Tone Switch Circuit Diagram

The minimum at pin 9 is 0 V and the maximum at pin 9 is VDD. In the lock detector, the PC (phase comparator) outputs are pulses whose width is proportional to the phase difference between the two PC inputs. At lock up, the two PC outputs are almost mirror images. The output of IC1A remains low and IC1B is high. This lights LED1. If the loop is unlocked, the LED will not light.

Build a High voltage Bucking Regulator Wiring diagram Schematic

This High voltage Bucking Regulator Circuit Diagram is basically tbe classic bucking regulator, except it uses a TMOS N-channel power FET for the chopper and creates its own supply for the gate control. Tht unique aspect of this schema is how it generates a separate supply for the gate schema, which must be greater than Vvv.

When power is applied, C2 charges, through D2, to +12 V. At this time, Q1 is off and the voltage at point A is just below zero. When the pulse-modulated signal is applied, the optoisolator transistors, Q2 and Q3, supply a signal to Q1 that turns it on. The voltage at point A then goes to Vvn. C2 back-biases D2, and the voltage at point B becomes 12 V above VnnÂ· After Q1 is turned on, current starts to flow through L1 into C1, increasing until Q1 turns off.

High voltage Bucking Regulator Circuit Diagram

The current still wants to flow through Ll, so the voltage at point A moves toward negative infinity, but is clamped by D1 to just below zero. Current flows less and less into C1, until Q1 turns on again. Q2 and Q3 drive Q1 `s gate between the voltages at point A and B, which is always a12 V swing, so Vcs max. is never exceeded. For proper operation, the 12-V supply has to be established before the pulse-width modulator signal is applied.

Sunday, September 7, 2014

Amplifier 24 Watts Class A

This is very good and low cost Amplifier for your medium indoor sound system. A 24 Watt Class A Amplifier made from discrete semiconductors, built and tested by Marc Klynhans from South Africa.

Marcs website may be found at: http://mrcshobbies.blogspot.com

Monday, September 1, 2014

Build a 1 2 36V 5A Adjustable Power Supply with LM317

Build a 1.2-36V 5A Adjustable Power Supply schema diagram with LM317. This schema is a simple power supply schema. 1.2 - 36V adjustable bench power supply with 5A of output current. Max input voltage is 37V and output is adjustable via potentiometer between 1.2 up to 36 volts. TIP147 PNP darlington transistor boosts the current of LM317 from 100mA to 5A. LM317 is the most useful and inexpensive adjustable regulator and for this schema you can also use LM317 L that can give 100mA, thats enough for transistor bias.

1.2-36V 5A Adjustable Power Supply Circuit Diagram

D1 and D2 are protection diodes because when you turn the schema off the output capacitors are discharging and can damage the transistor or regulator. 100nf capacitors are in parallel with electrolytic capacitors to remove high frequency noise because large value electrolytic have large ESR and ESL and cant remove high frequency noise.

Friday, August 29, 2014

Triac Light Switch as a dimers

The series of light switches this time slightly different from the voltage of work. The series of light switches can work directly on the AC power network. Light switches are using the main component of TRIAC and LDR. The circuit is very simple and the components were sold in the market.

If you want a light reception sensitivity of this circuit can be arranged then the 3.3 MOhm resistor can be replaced with a variable resistor. For more details can be seen from the following series of images.

Circuit Diagram

With Triac Light Switch series is as dimers, but dimers control performed by the reception of light around the LDR. The lower the intensity cayaha received LDR then bright lights. For installation LDR need to be considered so as not exposed to light from the lamp directly.

Tuesday, August 26, 2014

Build a Pulse Generator using Basic Operational Amplifier

How to build a pulse generator schema using operational amplifier, very basic, it is the schema stable multi vibrator or square wave oscillator. It uses a dual operational amplifier IC, one in 1458. The output frequency set by the value of R1 and C1. The calculation is Frequency = 1 / (2R1.C1.ln3)

The capacitor C1 1uF to change capacitance value by the frequency of 8 Hz, = 0.1uF 50Hz, 700Hz = 0.01uF, 0.001uF = 6kHz. In place of 1458 4558 may be used, LF353, etc.

Pulse Generator using Basic Operational Amplifier Circuit Diagram

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Saturday, August 23, 2014

Build a Bang Bang Controllers Circuits Wiring diagram

Bang-Bang Controllers Circuits Diagram Just one chip, the PWR-DRV1 from Power Integrations, builds a `bang-bang` controller that switches 275 mA and runs off the rectified 115-Vac mains. An on-chip zener diode powers the chip from high voltage through a dropping resistor.

Bang-Bang Controllers Circuits Diagram

Thursday, August 21, 2014

Build a Variable Bandpass Audio Filter Wiring diagram Schematic

Build a Variable Bandpass Audio Filter Circuit Diagram. This Variable Bandpass Audio Filter Circuit Diagram is a variable audio bandpass filter that has a low cutoff variable from about 25 Hz to 700 Hz and a high cutoff variable from 2.5 kHz to over 20 kHz. Roll off is 12 dB/octave on both high and low ends. R2-a-b and R6-a-b are ganged potentiometers for setting lower and upper cutoff frequencies, respectively.

Variable Bandpass Audio Filter Circuit Diagram

Tuesday, August 19, 2014

Build a Low Cost Line Receiver Wiring diagram Schematic

Build a Low Cost Line Receiver Circuit Diagram. This is a simple low cost line receiver schema diagram. This timer makes an excellent line receiver for control applications involving relatively slow electromechanical devices. It can work without special drivers over single, unshielded lines.

Build a Low Cost Line Receiver Circuit Diagram

Sunday, August 17, 2014

Build a Simple Single Chip Dc Supply Wiring diagram Schematic

How to Build a Simple Single-Chip Dc Supply Circuit Diagram. This Simple Single-Chip Dc Supply Circuit Diagram Direct derivation of 5 to 24 Vdc from ac mains, without a transformer is possible with this schema. Note that a direct mains connection to the dc output exists. Suitable safety precautionary must be taken.

Simple Single-Chip Dc Supply Circuit Diagram