Tehnik Service

This site has moved to a new address

2009-02-05T19:58:00.002+01:00

This site has moved to a new address: www.tehnikservice.net

New Design

2009-01-30T23:19:00.001+01:00

The web page of Tehnik Service will be moved to another server with a new design ,thank you for your undersending.

FM Transmitter with BC548

2009-01-25T20:37:00.003+01:00

Small Audio Amplifier

2009-01-21T23:38:00.005+01:00

Download eagle files: Small Audio Amplifier

Download eprom SANYO CLT 75KM

2009-01-20T00:12:00.004+01:00

Download eprom:
base.e2p
Hanset1.e2p
Hanset2.e2p

Download eprom SAMSUNG SPR915B

2009-01-20T00:05:00.004+01:00

Download eprom:
tel SAMSUNG SP-R915Bbase93C46.bin
tel SAMSUNG SP-R915HANSET93C46.bin

USB Led Light

2009-01-18T01:52:00.007+01:00

Service Manual SONY AVD-K700P

2009-01-17T14:38:00.001+01:00

Download Service Manual: SONY AVD-K700P

Power Supply regulater 1.5 - 30V by LM317

2009-01-04T18:55:00.003+01:00

AVR Controlled Dimmer Switch

2009-01-04T18:00:00.015+01:00

How does it work?

The triac TIC206D (BT136-600D) needs only a small current flowing through the gate to start conducting and turn a light on. This is the reason why they can be directly connected to the microprocessor, which can sink at least 10mA. Most digital circuits can sink much more current then they can source, that is why the whole dimmer works with -5 Volts. The resistors R1 to R8, limits the current to -5 mA. That it enough to get the triacs conducting in 3 out of the 4 quadrants. In the 4th quadrant the triacs need 10 mA to start conducting, but that is when the gate current is positive. That is another reason why we are using a negative voltage.

R9 in combination with C1, function as a low pass filter. They remove high frequencies caused by the fase cutting of the triacs. L1 prevents them from going back into the power grid where they spoil your radio reception.

Infrared receiver

The infrared receiver is build around standard highly integrated components. TSOP1736 is a receiver that responds best to signals transmitted on a carrier frequency of 36 kHZ like RC5 etc. Some other remote controls use different carrier frequencies, in that case use the appropiate ir receiver module.

Serial interface

The last part of the dimmer is the circuit around OK1 and OK2. These make sure that the serial interface is galvanically isolated from the power grid so that you can savely hook up your dimmer to your computer as long as it has a serial port. Through the serial port we can send or receive commands to or from the dimmer. Don't expect speeds to be much higher then 9600 baud, but this is more then sufficient.

Software (firmware)

The software for the dimmer is written in C and partly in assembler because of critical timing. To edit and recompile the firmware download both the integrated development environment (IDE) AVR Studio 4 and the GCC compiler and C-library WinAVR. First install WinAVR and then AVR Studio 4. Double click the Avrdimmer.aps file to open the project in AVR studio 4.

Source: http://domotica.homeip.net

Happy New 2009 Year

2009-01-01T21:00:00.001+01:00

We wish you and your family a Merry Christmas and a Happy New Year.

Car Battery Monitor

2008-12-24T22:55:00.004+01:00

The circuit is based on PIC16F819 18-pin microcontroller which has an analog-to-digital (A/D) input to monitor the battery voltage and outputs capable of driving LEDs directly, to keep the component count down.

There are seven LEDs in all, giving a good range of voltage indication. The topmost LED, LED1, comes on for voltages above 14V which will occur when the battery is fully charged. LED2 indicates for voltages between 13.5V and 14V while LED3 indicates between 13V and 13.5V. Normally, one of these LEDs will be on. LED4 covers 12.5V to 13V while LED5 covers 12V to 12.5V.

LED6 covers from 11.5V to 12V while LED7 comes on for voltages below 11.5V. These two LEDs are backed up by the piezo chime which beeps for voltages between 11.5V and 12V and becomes more insistent for voltages below. That might seem fairly conservative. After all, most cars will start with no troubles, even though the battery voltage might be a touch below 12V, won't they? Well, no. Some modern cars will happily crank the motor at voltages below 11V but their engine management will not let the motor start unless the voltage is above 11V. A standard 7805 3-terminal regulator is then used to provide a stable 5V to the microcontroller. The battery voltage is sensed via a voltage divider using 33kΩ and 100kΩ resistors. This brings the voltage down to within the 0-5V range for the A/D input of the PIC16F819. Port B (RB0 to RB7) of the microcontroller is then used to drive the various LEDs, with current limiting provided via the 330Ω resistor network. RB7, pin 13, drives a switching transistor for the piezo buzzer.

Software

For the software, the design follows the basic template for a PIC microcontroller. Port A and its ADC (analog-to-digital converter) function are set up while port B functions as the output for the LEDs and buzzer. Once the set-up is complete, a reading will be taken at port RA2, the input for the A/D convertor. This reading is then compared with a series of values to determine the range of the voltage. This is similar to a series of "if" statements in Basic language. the voltage is found to be within a certain range, the relevant port B pin will be turned on. If the voltage is below 12V, the buzzer will be turned on for a brief period, to signal a low battery condition. As the voltage falls below 11.5V, the frequency of the beeps will increase, to signal increased urgency.

Where To Buy The Kit

This project is copyright to Futurlec. It is priced at $12.90 plus $4 for postage and packing. It can only be purchased from:
http://www.futurlec.com/

Source: Siliconchip

FM Transmitter Low Power

2008-12-21T00:57:00.008+01:00

The PCBs and/or a complete kit for this project can be purchased trough the Nuts & Volts Webstore.

From magazine: Nuts&Volts September 2008

Service Manual VESTEL DVD5500

2008-12-17T18:32:00.005+01:00

Download: Service Manual VESTEL DVD

Service Manual Monitor BELINEA 10 50 76

2008-12-17T01:41:00.003+01:00

Download: BELINEA_105076.PDF

7.2V Battery Replacement for Camcorders

2008-12-17T01:16:00.005+01:00

This circuit lets an external 12V SLA battery power a camcorder which normally has an inbuilt 7.2V battery. Such batteries can now be very difficult or expensive to obtain for earlier model camcorders.

In essence, the circuit is a standard LM317 adjustable regulator with resistors R1 & R2 set to provide 7.2V (depending on the accuracy of the 1.25V internal reference). If the resulting output voltage is low, it can be increased by reducing the 130 resistor and vice versa.

Service Manual Sony LCD TV KLV-S26A10

2008-12-13T10:59:00.003+01:00

Download:Service Manual Sony LCD TV KLV-S26A10

USB AVR Programmer STK500

2008-12-11T12:46:00.009+01:00

In this microcontroller project, Guido Socher design a state of the art USB programmer for the AVR microcontrollers from Atmel.

You can build it from scratch without the need of another programmer to load the initial firmware.The firmware is open source and programmed in C according to the AVR068 specification from Atmel.

Source: tuxgraphics

Audio Detector

2008-12-10T16:58:00.009+01:00

This circuit is for detecting any audio signal with justable noise offset. It could be used to generate a radio mute signal eg. from a PDA.

The circuit is consisting of:
- Input impedance
- Signal amplifier
- Rectifier
- Justable comparator (Noise offset).

Download: Schematic Source: KKelektronik-4u

AVR Digital Voltmeter

2008-12-10T11:50:00.006+01:00

This is a mini inexpensive AVR Digital Voltmeter Project with three digit display. It can be freely programmed, calibrated and even be programmed with a non linear formula. It's a display where you can define the relation between the measured value and the displayed number.

Download: Software, documents and future updates

Source: Tuxgraphics

Automatic white-LED garden light

2008-12-10T00:37:00.010+01:00

This white-LED driver circuit is ideal for use in a garden light. It automatically turns the LED on at night and runs from a single 1.2V nicad cell which is recharged by a solar cell during the day.

Diode D1 allows the solar cell to charge the battery during the day and prevents it from discharging back into the solar cell at night. Transistor Q1 controls the LED driver circuit. This transistor is normally on during the day (ie, when there is output from the solar cell) and so Q2 and the LED are off.

At night time, Q1 is off and this allows a simple blocking oscillator circuit based on T1, R2 and Q2 to operate. This circuit in turn drives LED1 via a 1W resistor which limits the peak current into the LED.

T1 is wound bifilar, with the two windings configured to produce a centre-tapped winding. Winding AB is the main primary winding and winding BC is the feedback winding. The number of turns and the core used are not critical. The prototype worked with a toroid scrounged from an old computer power supply, as well as with a small ferrite suppression bead and an Altronics L5110 core. The toroids were wound using 10 turns of 0.25mm wire, while the ferrite bead worked with just five turns of 0.25 mm wire through the hole (that's all that would fit)

Source: Silicon Chip

Service Manual DVD Player Quadro 707PS

2008-12-10T00:24:00.003+01:00

Download: Service Manual Quadro707PS

Download eprom TV Toshiba 14V2M

2008-12-10T00:14:00.003+01:00

Download: eprom TV Toshiba 14V2M

Download eprom TV Kopernikus 21T99

2008-12-10T00:08:00.003+01:00

Download: eprom TV Kopernikus 21T99

Download eprom TV Kopernikus 25T18

2008-12-10T00:04:00.002+01:00

Download: eprom Kopernikus 25T18