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برق. قدرت. کنترل. الکترونیک. مخابرات. تاسیسات. - دیمر(تاریک ساز)dimmerیا dimer

برق. قدرت. کنترل. الکترونیک. مخابرات. تاسیسات.

دایره المعارف تاسیسات برق (اطلاعات عمومی برق)

dimmer درسته ولی برای اینکه موقع سرچ dimerهم جواب پیدا کنید این رو گذاشتم
من قصد دارم که این دیمر رو یه جورایی از راه دور کنترل کنم,ایده ای که تو ذهنم هست اینه که از یک موتور dc استفاده کنم ,آیا راهی جز این هم وجود داره؟
با تشکر

[تصویر: dimmer-switch-1.jpg]


و یا آیا میشه که با میکرو چیزی شبیه به دیمر درست کرد تا بتونم برق 220 ولت رو کنترل کرد؟


اولا برای کنترل این دیمر با موتور نمیتونی از موتور dc استفاده کنی! باید از سرو موتور استفاده کنی. البته با استپر موتور هم میشه...
ولی تنظیم اون با میکرو بدون این کار ایده ای به ذهن من نمیرسه

اما جواب نگرفتم,مطمئنم که میکرو کار میکنه.من سر از زمین کردن این مدار در نمیارم,من هر جا که نشون داده باید به زمین متصل بشه امدم به زمین آداپتورم وصل کردم آیا درسته؟
یک چیز دیگه: خروجی ترایاک رو به لامپ وصل کرده و طرف دیگه رو به 220 ولت آیا نباید لامپ رو به زمین هم وصل کرد؟

در مورد سوال دوم : نول رو زمین کرده واسه همین اون سمت ترایاک هم زمینه و سمته دیگه به لامپ وصله
خروجی ترانزیستور رو دیدی ؟ شکل موج مربعی (مدولاسیون موقعیت پالس یا پهنای پالس) باید باشه

Building a Simple Dimmer Circuit



In this example a potentiometer is controlling the firing point of the triac. Capacitor C4 is charged via resistors R3, R4, P1, and R5. After a certain time, dependant on the potentiometer, the charge contained in C4 is large enough for diac D to start conducting, so that a firing pulse is applied to the gate of the triac. Consequently the triac conducts and power is transferred to the lamp.


http://www.powerengineer.ir/uploads/posts/2010-04/1272045697_dimer.gif

The diacs, because of their symmetrical bidirectional switching characteristics, are widely used as triggering devices in triac phase control circuits em­ployed for lamp dimmer, heat control, universal motor speed control etc.

Although a triac may be fired into the conducting state by a simple resistive triggering circuit, but triggering devices are typically placed in series with the gates of SCRs and triacs as they give reliable and fast triggering. Diac is the most popular triggering device for the triac. This is illustrated in the following applications.

triac lamp dimmer circuit

triac lamp dimmer circuit

1. Triac Lamp Dimmer Circuit.

The circuit for a triac controlled by an R-C phase-shift network and a diac is given in figure. This circuit is an example of a simple lamp dimmer. The triac conduction angle is adjusted by adjusting the potentiometer R. The longer the triac conducts, the brighter the lamp will be. The diac acts like an open-circuit until the voltage across the capacitor exceeds its breakover or switching voltage (and the triac’s required gate trigger voltage).

Diac Heat Control Circuit

Diac Heat Control Circuit

2. Heat Control Circuit.

A typical diac-triac circuit used for smooth control of ac power to a heater is shown in figure. The capacitor C1 in series with choke L across the triac slows-up the voltage rise across the device during off-state. The resistor R4 across the diac ensures smooth control at all positions of potentiometer R2. The triac conduction angle is adjusted by adjusting the potentiometer R2. The longer the triac conducts, the larger the output will be from the heater. Thus a smooth control of the heat output from the heater is obtained.


Designer: Carlos Damian Lopez Herrero
E-mail:
Operating voltage: 220V AC 50 Hz
Published at www.epanorama.net: 06/2008
Copyright: Pictures Carlos Damian Lopez Herrero, text www.epanorama.net

NOTE: This circuit design is not tested by www.epanorama.net staff. The circuit design as submitted by the designer is believed to be correct, but there is no guarantee of the correctness of the circuit design. The contents of the articles below might be totally inaccurate, inappropriate, or misguided. There is no guarantee as to the suitability of said circuits and information for any purpose.

Warning: This circuit operates at potentially lethal 220V AC mains voltage. The circuit should be built and used only by people who know hot to safely work with such dangerous voltages and how to built the circuit so that it is safe to use.

General circuit operation

Solid-state light dimmers work by varying the "duty cycle" (on/off time) of the full AC voltage that is applied to the lights being controlled. For example, if the voltage is applied for only half of each AC cycle, the light bulb will appear to be much less bright than when it get the full AC voltage, because it get's less power to heat the filament. Solid-state dimmers use the brightness knob setting to determine at what point in each voltage cycle to switch the light on and off.

The exact time when the triac is triggered relative to the zero crossings of the AC power is used to determine the power level to the light bulb. When the the triac is triggered it keeps conducting until the current passing though it goes to zero (exactly at the next zero crossing if the load is purely resistive, like light bulb). By changing the phase at which you trigger the triac you change the duty cycle and therefore the brightness of the light.

Circuit diagram

Dimmer circuit diagram

The circuit contains a variable resistance that consists of R1 + PT1 in paralle with R2 + RV2. This variable resistance together with capacitors C1 and C2 form a delay from the mains zero crossing to the firing point of the diac. DIAC is a bidirectional trigger diode that conducts current only after its breakdown voltage (typically around 30V) has been exceeded momentarily. The larger the variable resistance feeding the capacitors, the longer it takes for the voltage across the capacitor to rise to the point where the DIAC fires turning on the triac TH1. The circuit is calibated in such way that first PT1 is turned to highest resistance values. The value of RV2 is turned in such position that the desired minumum brightness of the light bulb is reached. After this calibration the PT1 can be used to freely control the light bulb brightness at the desired control range form the maximum brightness to set minumum.

Capacitor C1 and inductor L1 make a simple radio frequency interference filter. Without it the circuit would generate quite much interference because firing of the triac in the middle of the AC phase causes fast rising current surges. The triac BT139 used in the circuit is rated for 16A continuous current when properly cooled with a large heat sink. The maximum current is less with less cooling. The components R4 and C4 for a RC nubber network that protects TRIAC from spurious triggering.

Component layout

Dimmer component layout

Built circuit



The dimmer

Neon glow lamps can also be used only for their U/I characteristic and not for producing light. These lamps are electrically very close to diacs: no current can flow through them since the voltage is lower than a trigger value (about 70 V for neon glow lamps and about 40 V for diacs). If the voltage is high enough to trigger the device a current can flow through it and the voltage drop is a little lower than the trigger voltage (about 50 V for neon glow lamps and about 30 V for diacs).

Diagram of the dimmer

In this circuit of a dimmer the diac is replaced with a neon glow lamp, but it works exactly in the same way than a classic one: an RC network delays the trigger pulses on the gate of the triac. The glow lamp rises the trigger voltage from about 40 V to about 70 V. Some adjustments to R and C values may be required to match specific glow lamps and triacs.

Picture of the dimmer


The stroboscope

A stroboscope is another application that requires a diac (or a neon glow lamp) for triggering the xenon tube: this circuit uses a neon glow lamp but it works in the same way as a classic diac one. The main voltage is rectified by a diode and charges two electrolytic high voltage capacitors (in parallel) that are used as an energy tank for the xenon lamp. A current also flows though a resistor and slowly charges a trigger capacitor: when the voltages reaches the trigger value of the glow lamp the SCR discharges this capacitor through a trigger transformer into the xenon lamp that flashes. Once the energy in the tank is over this cycle repeats; the frequency is adjusted by varying the resistance that charges the trigger capacitor.

Diagram of the stroboscope

The energy in the electrolytic capacitors can be lethal even when the circuit is switched off. Always discharge these capacitors before touching the circuit.

Picture of the stroboscope


An RF field monitor

This is the oddest application of a neon glow lamp, that is used as a electromagnetic field detector. In fact the trigger voltage of these lamps is a little bit lower in presence of a strong field.
A UJT transistor and a transformer (a common low power AC transformer) are used to produce a high voltage of about 200 Vac. This voltage is reduced by the trimmer to a value just below the trigger voltage of the lamp. In presence of a strong field the trigger voltage drops and the lamp lights.

Diagram of the RF monitor

To use this monitor just set the trimmer to 0 V, power the circuit on (when no field is present) and slowly turn the trimmer to rise the voltage until the glow lamp lights. Turn now the trimmer in the other direction and stop as soon as the lamp turns off: now the monitor is ready and a strong RF field will light the bulb. For testing you can try a cellular phone or a transmitter (some Watts of power are required) and the bulb will light in proximity of the antenna.
Connecting a small dipole to the lamps terminal dramatically increases its sensitivity.
Since this circuit is very simple is usually necessary to readjust often the trimmer to compensate the battery that is discharging itself.

Picture of the RF field monitor

Touch dimmer)ساخت دیمر با HT7700

 

                                               



Dimmer 220 volt circuit

اپتو ترایاك MOC 3041  داخل خودش Zero Crossing   داره.







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