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13

Buy a dimmer designed for LEDs. Your typical light dimmer puts out pulses of power; the brighter the setting the wider the pulses. This is OK for incandescent lamps as they draw lot of current and need a brief time to turn on and off. LED lamps draw about 1/10th as much current and turn on and off in millionths of a second, so the same narrow pulses that ...


9

This looks like a potentiometer with a built in on-off switch on the back. When you either push on the knob or turn it to the end of it's range does the resistance between A and B change from infinite to 0 ohms? If so, you have confirmed that it is a switch. The resistance between 1 and 3 should be fixed and between 1 & 2 (or between 2 & 3) vary ...


8

I am going to assume it's an incandescent bulb of the "artistic" type with interesting filament structure. If it's an LED or CFL bulb, the below comments do not apply. It's possible to connect a silicon diode in series with the bulb to permanently dim it. The behavior is not linear because the light bulb proportionally sucks more juice (technically ...


7

The three pin device is a triac. It turns on the power going out to the bulb for only a fraction of the full AC sine wave. This particular triac is discussed here. The little flat 2 lead device is an surface mount chip capacitor. The capacitor forms the capacitor half of an RC circuit that controls the when the triac turns on during the AC wave and thus ...


6

There are serial controlled dimmers such as these for various load wattages. There are also some wireless controlled dimmers (WiFi, BlueTooth etc) listed on the same page. For ballasted fluorescent lights, a different type of dimmer is needed: a Ballast Control Module. Similar, lower cost products are available on various auction sites, but caution is ...


6

The first link gives a simple schematic to follow as Matt says. The DF15005S is a bridge rectifier, which is basically 4 diodes connected together in order to create varying DC from an AC input, which can then be smoothed to pure DC using a capacitor/regulator. They are typically used with a step down/up transformer in DC power supplies. Here is one with ...


6

There are even simpler in-series circuits that can achieve the same: diac+triac (for bipolar waveforms) or just a bridge-rectifier+scr (thyristor) [this will only produce unipolar waveforms], or... if don't care about adjustment, just a diode! I'm honestly not sure what is that you don't understand. Reduce the problem to the simplest idea: a diode in series ...


6

Current draw is determined by the heater power you need. If you can reduce the heater watts, do that. I'll assume that you have already sized the heater. Both triacs and IGBTs have relatively high losses, and you can expect roughly 1W/A of losses for a triac. The IGBT may have a bit more, and the required bridge will have still more. Your best bet is to ...


6

Most dimmer switches are rated 500 watts max and a 10" tile saw might be 1500 watts. The nominal current consumption of the motor is already three times the maximum of the dimmmer switch. Worst is the starting current of the motor can spike even 10 folds of the nominal. This will instantly destroy the triac in your dimmer switch. Additional to this, motors ...


5

I'd start to debug by attempting to switch the load on and off a few times in the setup to ensure the TRIAC is firing, for example: void setup() { pinMode(AC_LOAD, OUTPUT); // Set the AC Load as output for (int i=0; i < 10; i++) { digitalWrite(AC_LOAD, HIGH); // triac firing delay(1000); digitalWrite(AC_LOAD, LOW); // ...


5

The trick is that you can leak a small amount of current through a lightbulb without turning it on. If you probe the light socket with a multimeter (CAUTION) you can observe this: http://www.newton.dep.anl.gov/askasci/eng99/eng99750.htm The control circuitry will require something like a miliwatt. There will be a capacitor-based rectifier in there; probably ...


5

You need to do two separate things: Measure the light level. This should be done with a light dependent resistor and an analog input of the PIC. Adjust the brightness of the display. The simplest way I can think of is to reduce the duty cycle, the fraction of the time that the LEDs are on. You are already be switching quickly between the separate digits, ...


5

The black device is an internally triggered triac which contains a an ordinary triac integrated with a diac trigger device. You could replace the internally triggered triac with a triac+diac, but that device generally can only be used in applications such as lamp dimmers. The part is similar (or identical, save for markings) to this one (Q2010LT 10A 200V ...


5

The main issue I see here is that the U1-U2 GND trace infringes on the isolation barrier in the design. I would shift the P1/P2/R1/R2 complex closer to U1/U2 -- this leaves room to reroute the ground trace to U1 between P2 and the edge of the board, then have it pop out between the pins at the bottom of P1/P2, so it doesn't compromise the isolation barrier ...


5

This looks like a mess waiting to catch fire or electrocute someone. You don't say where this is, but almost certainly some part of the AC line is tied to ground somewhere. That means you have a hidden conduction path from somewhere in the "AC Supply" block to the source of both FETs. The only way the concept is valid is if this "AC Supply" block is a ...


5

The proposed replacement is 25x more sensitive with regard to trigger current in the relevant quadrants. Current rating is probably okay. Voltage rating is similar (and not very generous for 220V mains). The big problem is that one is a triac and the other is an SCR, so no the proposed part is not a suitable replacement!


5

This seems to be the only relevant part of the pictures you posted: It seems to show that the LED connections are independent of the switch connections. To decrease LED brightness, you decrease the current thru the LED. Since you didn't actually post or link to any real specs for this switch, we don't know whether there is a bare LED inside, what its ...


5

Light dimmers are not meant to be used with inductive loads like motors. You will destroy it pretty quickly. You can buy dimmer/speed controllers that are meant for use with motors. The tile saw is almost certainly a series-wound motor which will work just fine with a triac speed controller.


4

Well, a light bulb is a purely resistive device and if you think a series 2 kohms would fit the bill for reducing its brightness to the right level then it's worth considering using a capacitor instead. To get the same reduction in current you'll probably need between 2 kohms and 3 kohms and the capacitor value would be: - C = \$\dfrac{1}{2\pi f \cdot 2500}\...


4

The input of a line-powered SMPS is usually designed for AC (sinusoidal) voltages of a certain frequency. There are some with a specification of a DC input, and except for compact fluorescent lamps (CFLs), I know of exactly zero with a specification for an AC input with chopped-off edges (phase-angle control as offered by a dimmer). There are reasons... Two ...


4

Most typical SMPS (switch mode power supply) should be totally fine with under voltage or chopped up input. When the input voltage or current is below what is required they simply shuts down or fail to start One of the big design wins with a SMPS is that there is very little relationship between input voltage and waveform, and out voltage and waveform. So ...


4

The lowest-cost solution would consist of the following: a mains AC phase detector (a zero-cross-detector) an opto-triac (without a zero-crossing circuit!) such as the MOC302x a triac or a pair of SCRs to be driven by the optocoupler Safety, safety, safety, since you're working with relatively dangerous voltage levels! How does it work? A triac will ...


4

Lamp dimmers change the brightness of light bulbs by delaying the turn-on of the output till later on the AC cycle as shown below. This scheme works pretty good for resistive loads like incandescent light bulbs. It does not work very well with the cheap transformers found in the AC transformer type wall warts. If the transformer ends up being able to pass ...


4

I very much suspect that your dimmer is intended for use with incandescent bulbs, and it's not turning off completely. This is not a problem with regular bulbs, as you've found out. However, your LED bulbs have a power supply circuit which is able to operate on the small amount of power being passed by the dimmer, and this creates your problem. You have ...


4

It sounds like the old dimmer switch is the problem. In the OFF position it is still leaking a small amount of current. The old fashioned bulbs are so inefficient that that small amount is not enough to light them. The new bulbs are very efficient so the small amount of leakage is lighting them up. By placing a single old fashioned bulb shunts the current ...


4

In general for dimming a lamp following is applicable. Make the amount of power going into the lamp variable Prevent as much as possible the loss of power in the controller In many domestic dimmers using mains this is done with a triac or IGBT controller. The triac controller makes that an adjustable part of the incomming mains voltage is transfered to ...


4

Line voltage is 240 volt and output voltage goes till 328 volt. Is this normal working of triac BT139 or I am doing something wrong? If the RMS voltage is (say) 1 volt then the peak voltage will be 1.4142 volts. If the RMS voltage is 230 volts then the peak voltage will be 1.4142 x 230 volts = 325 volts and the peak-to-peak voltage will be 650 volts. ...


4

Your TRIAC does turn off correctly. Remember, it's turning off automatically as soon the current through it is zero. Not as soon the voltage over it is zero. What you have there is a slightly inductive load which introduces a phase-shift between voltage and current. It's all okay. Those spikes will become a bit smaller as soon you put more load on the 12V ...


3

Forget about the interrupt routine for a few moments. Did you check if you actually see the zero crossings on your input pin? You might want to write a sketch that toggles the pin13 LED every 50 or 60 or zerocrossings. You should see a visible 1Hz blink. I can't test the sketch (but it compiles without errors), but I think it should look a bit like this: ...


3

If you do not SHOW the exact circuit and connections that YOU are using then ALL questions of this sort are pointless. This is the circuit diagram accessed via the page you referenced. Please add YOUR connections to it and post as part of your question. Arduino ground MUST be connected to MOC3021 ground. NB!!! - The following highlights a defect in the ...


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