need fast help with triac

Hi, i created switch like there : . But its not working. I am using triac Bt138-800 instead of bt138-600. On load i am always getting around 80V, even there is signal or not.
Any suggestions? need fast help plz

Where dis you get that circuit?
It will always turn on for half a cycle irrespective if the state of the opto isolator.
Try removing R3.

now trying to remove R3.
Maybe some1 know normal working circuit, with bt138 and moc3061

same problem, only now voltage is 40V...

What load have you got on when you measure this?
Triacs do have some leakage and with no load to short it out you can get a voltage when it is supposed to be off.

I am using normal 230 VAC 60W lamp, its even turning on when there is signal

I am using normal 230 VAC 60W lamp, its even turning on when there is signal

I think you mean no signal.

Sounds like it is wired wrong or you have faulty components then. What is just as a test you remove the gate wire?

I found problem, but question is it safe. I did like was tolded, removed R3, still was the same problem, i connected capicator and resistor as shown there(beetwen load and hot) , there is now 0V at the load . i removed R1 ( i used 330 Ohms, 0.25W) , works fine ( turning on and ooff nicely) . Question is should i put R lover value, or it should be 0.5W , or it can be without resistor?
I am using Arduino Uno R3 to send signals to 2 shift registers (74HC595), shift registers turns on or off lumps. I am planning to use about 7 devices to turn on or off. To power shift registers i am using 5V, 2A charger.

R1 ( i used 330 Ohms, 0.25W)
Question is should i put R lower value, or it should be 0.5W , or it can be without resistor?

Datasheet of MOC3061 : Absolute maximum ratings for continuous forward current is 60mA. An average arduino pin can source around 40mA. WIth no resistor R1 in place you risk frying the output pin of your Arduino.

I would keep R1 but probably you need to tweak the value to get enough current to drive the MOC3061. In the datasheet typical values are given for each model (see Intelligent Power and Sensing Technologies | onsemi).
Full explanation is in the datasheet, the same one where you found the picture

Basic Applications
Typical circuit for use when hot line switching is required. In this circuit the “hot” side of the line is switched and the load connected to the cold or neutral side. The load may be connected to either the neutral or hot line. Rin is calculated so that I(FT) is equal to the rated I(FT) of the part, 15mA for the M0C3061 M, 10 mA for the M0C3062M, or 5mA for the M0C3063M.
The 39Ohm resistor and 0.01 pF capacitor are for snubbing of the triac and is often, but not always, necessary depending upon the particular triac and load used.

Be careful with the components you select, if you go with the snubber resistor/capacitor, be sure that the capacitor is rated for 300V !!! Also think about electrical safety, your PCB/breadboard/... will have hot areas. You may know it because you designed it, it may not be so obvious to anyone else handling the device.



thx for help. Resistor is 1W 39 Ohms, capacitor is rated for 630V. I am making it on pcb.