1. First of all, exactly G4 and G9 refer to the pin types of different types of bulbs (light beads), G is a lamp holder that represents two or more pins, and this is used on the bulb to refer to the bulb. The type of the pin; the rear 4 or 9 or 5.3, 6.35, etc. refer to the distance between the center points of the pins. The standard method is to measure the inner distance and the outer distance of the two pins by the caliper and divide by 2 Yes, simply use a ruler to measure the amount of the center point of the two feet. The difference between 4mm and 9mm is very far, just know the amount.
2. For the current crystal lamps, most of them are G4 or G9. The difference between the two is very obvious. The most fundamental difference is that G4 can only do low voltage, because the distance of the pins is too close, so if your lamp is G4 Then, there must be a transformer in the ceiling of the lamp! And now the G9 only has to do high voltage, that is, if your lamp is G9, there will be no transformer on the lamp! This is a very good difference.
3. From the appearance of the G4, the two pins are very similar to the pins of the embroidery needle. Of course, the volume of the bulb is also small, and the two pins of the G9 are like oval ring pins, not like needles. Pins. Of course, the volume is also slightly larger.
4. For a luminaire produced by a regular manufacturer, according to the national standard, no matter which country's standard, it is necessary to affix a watt label, (or called a lamp head), the requirement is to stick to the customer when loading the bulb or replacing the bulb. The place that must be easily seen when it is usually attached to the lamp head. Of course, some manufacturers may not stick to each of the heads of the crystals, but at least they have to stick one. If you don't post one, then you buy the same as the three products. If there is a label, how many volts do you read above? G4 can only do low voltage, and generally do 12V, and for G9, because it is only high voltage, it should be written around 220V.
5. Also, if you buy a lamp with a light bulb at the time, then in addition to the distinction I said above, there should be a parameter mark on the light bulb, such as writing 12V 20W or writing 220V. 40W, etc., the word on a light bulb can't be seen clearly. You can look at the words of other light bulbs. If all of them are not printed, the quality of the light you buy is too unguaranteed. In fact, there are also JC bulbs for the G4 bulbs (referring to the capsule halogen bulbs).
6. Again, remind you to buy a replacement bulb, be careful that in addition to the model to be the same as the rated, the power of the bulb can not be greater than the rated power, such as the G4 bulb is equipped with a transformer, if the replacement bulb If it is larger than the rated one, the transformer can not withstand it, and it is easy to cause the transformer to burn.