How to check if the BTA12 triac is good?

Hello, can you tell me if this triac is broken or not?

I wanted to check if the triac is good BTA12.

I connected to the bulb +12 V from the power supply, from the bulb to one Anode of the triac, and to the other negative anode. With the plus from the first Anode, I shorted to the gate - the bulb is on.

I did the opposite: I connected the plus to the bulb from the bulb to the second anode, I connected the minus to the first anode. And I shorted the gate + , the bulb does not light.

But when I gave a minus not to the first anode but to the gate, it lit up.

Please tell me if this triac is working or not?

Hello.
If your light bulb is not on all the time by connecting A1-A2 and in addition it reacts to the gate potential, it can be assumed that the triac is ok. However, it is easier to measure it with a meter, but you can also do it as you do. This is a strong triac and I don't think it will lose anything by such a measurement?
Regards.

And how to measure it?

What instrument do you have, analog or electronic? If the multimeter is on the range with the symbol of a diode (i.e. for measuring semiconductors) or an ohmmeter (which is not fully authoritative) there should be nothing between the Anodes.. neither A1 + A2- and vice versa, the measurement should also be the same, while Between one of the anodes and the gate should be something ie around 700mV or around 100 ohms? And here the variants are different depending on what is in the housing and what meter are you measuring? But there should be something :)

PS It is important that there is no obvious short-circuit, i.e. a transition with negligible resistance or a gap in each side. Triacs and thyristors most often fall into a short-circuit, i.e. anode - cathode or with a gate.

Scheme of thyristors and triacs serviceability meter.

aksakal wrote:

Scheme of thyristors and triacs serviceability meter.

just ask how many "do you have" thyristors to check, because if 1, 2 or 3, it's probably not much to take such a miracle?

I checked all the elements on the electronics board and in my opinion they are good, except for the triac because I am not sure about it. I tested it in a different way, connecting + 12V to one anode and to the bulb minus to the other anode, and from a separate 12V source I connected minus to the gate and plus to one of the anodes. Well, the light bulb is on, but when I disconnect the potential from the gate, the light bulb goes off and this is what I think is wrong, because the light bulb should be on all the time after giving an impulse to the gate.

Triac check scheme. When the button is pressed briefly, the LED (bulb) must light up. After releasing the button, the bulb should be on. The bulb will only go out when the power is disconnected. If not, the triac is faulty. Just don't be a dogmatist like some theoreticians on the forum. It is not mandatory to use an LED and a voltage of 5 V. You can use a voltage of 5-15V and a bulb for the appropriate voltage for power supply. When using the LED and the voltage more 5V increase the resistor denomination accordingly. I write so perfectly because the theoreticians on the forum have already tired their pedantry, as soon as you indicate which parameter of the element or regime with a tolerance of 0.5 percent - the discussion begins until the loss of voice. I also want to warn you that checking the triac or the thyristor with an electronic multimeter is usually not possible - you must not secure the necessary gate current.