Tehnik Service » Circuit

Temperature controlled soldering gun with bar graph indication

TehnikService — Thu, 26 Jan 2012 18:52:00 +0000

This soldering station is designed to control the temperature of soldering gun Solomon SL-1 and other similar soldering devices with integrated thermocouple. DC voltage generated by thermocouple is amplified by operation amplifier CA3140.
The precise regulation and excellent small hysteresis of temperature is obtained by voltage stabiliser LM723M (military packaging). LM723M contains an embedded temperature stable reference voltage source with its own of constant current.
Visual indication of SET or READ temperature is realized by LM3914 and 10 LED bar graph display to represent of temperature range from 50 to 500 degree Celsius.
The electric circuit of soldering iron heater is optical insulated from control electronic circuit by CNY17 optocoupler.
However, this is an accurate device for regulation of your soldering iron and precise indication of the temperature.
I constructed it and I did it. Built it and you, do not wait.
8 years of continuous operation without a single malfunction of the device is sufficient confirmation of its quality.

The complete instruction, 3 PCB, schematic diagram et all you can find in EMITER 12/2004, follow the link: http://www.emiter.com.mk/poveke.php?napis_id=1582

Author: Primarius D-r Petar Avramovski, MD.

Simple Function Generator

TehnikService — Sun, 22 Jan 2012 22:19:38 +0000

Generator functions, or forms of waves, such oscillators are producing alternating voltages of different shape which correspond in appearance to a mathematical function.
They can be sine, rectangular, triangular, in the form of stairs, etc.. Applied in analog and digital electronics, the measurement and experimental techniques, for educational or professional purposes and as a laboratory device are always welcome in your electronics lab.
The text that follows we suggest a project for a very simple generator functions realized by IC CD4011.

No-electronics hobbyists (the readers of Emiter) who does not wish to have or who did not indicate a need for generating functions in his laboratory for electronics.
My old desire – to build the generator functions with Intersil integrated function generator ICL8038 – not true.
This specialized integrated circuit for that purpose, back in 1984, it was quite expensive and hard to find.
So I decided to build a function generator with conventional CMOS integrated circuit that is popular, cheap and easily available, the circuit CD4011. The device successfully and works well and I was benefited countless times in my elektronics practice.

Author: Primarius D-r Petar Avramovski MD,

-writer to magazine Emiter.
The complete article you can read on the pages of the Emiter 01/2012:
Follow the link: http://www.emiter.com.mk/poveke.php?napis_id=3910

LED candle for Christmas tree

TehnikService — Mon, 26 Dec 2011 19:28:51 +0000

The small electronics with a few transistors and a few passive components will revive a dozen of small LED sparks
deployed in the shape of the flame of the Christmas tree candle .
Failed attempt to blow off the flame, like a birthday cake, now become reality. Accumulated air in the children’s swollen cheeks
make magic explosive “puff” and when “flames” from the candle out gradually, children eyes shine with delight and curiosity:
How is that possible?
A small microphone which is placed at the bottom of the pcb under the led diodes,
it converts sound pressure into voltage and the serial transistor switch off.

Author: Primarius D-r Petar Avramovski, writer to magazine Emiter.
The complete article you can read on the pages of the Emiter 12/2011.

Folow the link: http://www.emiter.com.mk/poveke.php?napis_id=3891

VGA to VIDEO Composite converter

TehnikService — Mon, 19 Dec 2011 21:56:20 +0000

If you want to connect your PC to your house cinema, built VGA to VIDEO Converter.
The device is suitable for watching movies, performing video presentations and advertisements from a computer
that does not have video composite output signal.
Conversion is a stable, high resolution and high image quality in terms of brightness, contrast and saturation of colors.
Most sophisticated solution for converting VGA signal into composite video signal is application of the integrated circuit AD724.
Column is the product of electronic company Analog Devices, referred to as RGB to NTSC / PAL Encoder.
AD724 is basically an encoder that converts red (R), green (G) and blue (B) component of the signal
in their respective color signals corresponding to light (luminance) and color (chrominance) in accordance
with prescribed norms and NTSC/PAL standards.
The existing VGA to video converter in nothing behind commercial video cards posed a PC slot in personal computers
to provide an output video composite signal.
Given the fact that the cost of integrated circuit AD724 is only 6-7 dollars, then you win with quality / price ratio.

Author: Primarius D-r Petar Avramovski, writer to magazine Emiter.
The complete article you can read the pages of the Emiter 11/2011,

follow the link:
http://www.emiter.com.mk/poveke.php?napis_id=3863

Automotive Led Timing Strobe

TehnikService — Sat, 10 Dec 2011 20:15:47 +0000

Most older engines, and many newer ones, have timing marks in the form of a line marked on the rim of the vibration damper.
Some engines in front-wheel drive vehicles have timing marks on the flywheel. A pointer is attached to the timing cover.
When the mark is exactly under the pointer, the engine is ready to fire number one cylinder.
The spark will occur with the rotor pointing to the number one cap terminal.
The timing is generally set by using a strobe tamp, which is a light that is operated by high voltage surges from the spark plug wire.
The strobe lamp usually referred to simply as a timing light.

A useful timing strobe can be constructed using 9 high-brightness LEDs and a few common components: 2 monostable (CD4098), 1 double operation amplifier (CA3240E)
and 3 transistors.
Ignition pulses from the number 1 cylinder high-tension lead are used to trigger the circuit via a home-made inductive pickup.

Author: Primarius D-r Petar Avramovski, writer to magazine Emiter.
The complete article you can read the pages of the Emiter 11/2011

DIY PIC16F883 Development Board

TehnikService — Fri, 07 Oct 2011 21:29:34 +0000

Phil from jumperone.com he wanted to try to write software for Microchip PIC16F883 microcontroller and he couldn’t find simple development board for it. And so he decided to made own development board.

Source: jumperone

Table Lamp with LED

TehnikService — Fri, 30 Sep 2011 19:20:13 +0000

If you want to give life to the old table lamp, replace the orange “hot” light with a clean, “cold” and white, built the project with white LED diodes as the light source matrix.
The continuous change of the light source you can build the proposed electronic-switching regulator in pulse width modulation.
Associate surrounding red light only complements the decor of the “new” table lamp.

The idea to pretend my classic table lamp resulted from unwanted heat that gives the lamp as a heating filament and
unnatural orange hue in the spectrum of the generated light, which is different from the color temperature of light daily.
This was certainly the desire to revive the old lamp.
Besides the projected white light lamp is designed to give weaker and red light.

Purpose and why?
As the surrounding light at night to coordinate movement through space and light which will be used when working with photosensitive materials during photo-print PCB (developing good old celluloid tape, film). Red, why? White light on waking from sleep causes stress (not suitable for night), and photosensitive materials (Positiv 20) ??are not sensitive to the red part of the spectrum (no confusion with which the infrared-sensitive).
There is continuous light intensity regulation with NE555 from deep dark to bright light.
The power consumption of this cold light is only 4W.

Author: D-r Petar Avramovski
Source: http://www.emiter.com.mk/poveke.php?napis_id=3461

VU Meter 60db

TehnikService — Thu, 29 Sep 2011 15:21:23 +0000

If you want the dynamics of the music signals to visual representations of 20-segment LED indicator bargraf covering a dynamic range of 60dB, you are the right place.

Designed as an attractive desktop VU meter for home audio, has its own power supply, linear frequency range and excitement of the speaker directly.

Simplicity, low number of components, small size and adaptability to different amplifiers with different power and speaker impedance makes the device to be desirable and attractive visual indicator of each Hi-Fi enthusiast.

Most audio sources (radios, CD players, tape …) during the playback of your scores do not exceed dynamic range (dynamic range) the sound of 60dB.

These data determine the number of required LED indication light diodes for power to be measured.

Mon rational reading of 3dB of each individual LED diode and the target range of 60dB to specify the exact number, VU meters with 20 LED diodes.

Recall the front page of emitter no. 7-8 since 1996. command when it was released documentary of my electronics lab, where the right corner of the board, in part for AUDIO TEST, seen embedded VU meter with ten LED diodes. Prilozham nostalgic wanted to link to that number, but the website of my favorite magazine is still under construction (not included numbers from 1996) and therefore attach alternative link where you can view the built-in VU meter with 10 LED diodes.

I do not know if you remember the time when there was no integrated circuits, so painstakingly tried to make VU meter with a series of transistors, one for each LED diode indication, one transistor as a source of constant current and voltage divider. Imagine now had to prepare the AKP over 20 transistors, 60 resistors and 20 diodes LED. Fortunately, we now have integrated circuits. LM3915 is a “drug of choice.”

Author: Primarius D-r Petar Avramovski, writer to magazine Emiter.

The complete article you can read the pages of the Emiter 9/2011.

http://www.emiter.com.mk/poveke.php?napis_id=3782

Electronic protection for symmetrical power supply

TehnikService — Tue, 27 Sep 2011 21:33:37 +0000

The proposed solution for protecting, protects connected consumers with a complete shutdown of their power.

Growth failure, be it through positive or through negative part of power leads to complete exclusion from the power supply voltage of connected devices:

laboratory sources with symmetrical voltage power supplies, battery chargers, low frequencies amplifiers, stabilized or no stabilized voltage sources and so on.

This unit can work independently and as electric fuse with variable threshold setting or common goals, in addition to other sources of voltage.

So many types of protection, yet a number of blown power supplies, various electronic devices, speakers and NF-amps.

The protection is built mostly on the outskirts of the electronic device or amplifier, as over current as clipping indicator of protection,

as a quick fuse, thermal protection such as protection based on detection of one-pointed in the component signal and so on.
Starting from the logical fact that energy is “required” to destroy an electronic device, stabilized power supply, NF-amp or speaker,

it gives power to the device, effective protection would be that protection would have controlled the source of power as an energy source.

So, this would be a little different kind of care, protection incorporated in the power of electronic devices or NF-amplifier, rather than their output.

Of course, the best application of protection would be described as fast over current care one-way power sources, independently or as an addition on flow control with continuous change in the threshold circuit limitation.

author: Primarius D-r Petar Avramovski, writer to magazine Emiter.
source: http://www.emiter.com.mk/poveke.php?napis_id=2022

Analog Multiplexer with 74HC4051

TehnikService — Wed, 14 Sep 2011 16:25:57 +0000

Guys from Youritronics.com made a new project 74HC4051 Analog Multiplexer.

They have a job to measure the temperature of 32 thermistors (NTC) with microcontroller and later process the data.

With just four 74HC4051 they made multiplex 32 input channels to 4 outputs.