Price: $ 0.65 per set of 2 pcs. (bought two sets for $ 0.3; using a $ 1 coupon)
Today there will be a small review dedicated toLED car bulbs with a base BA15S which are designed to replace P21W lamps as reversing lamps, at least as the Chinese seller says. I ask everyone who is interested in cat.
For those who want to know whether it is worth buying: I would not recommend it. The answer is why at the end of the article.
The order was placed on November 16, and delivered on 12January. 57 days on the road, Parcel without a track, a small orange envelope, inside of which lay two metallized antistatic bags in each of 2 bulbs. Light bulbs were purchased using a seller’s coupon of $ 1 from $ 1.01; 2 sets of 0.65 each = $ 1.3 - $ 1 (Coupon) = $ 0.3
The base corresponds to the declared, pins at the same height and strictly against each other, without offsets.
12 crystals are visible on the general board, which also corresponds to the description.
19mm in diameter (at the widest point, whichcorresponds to the COB matrix) in the photo it can be seen that the matrix is not all round, but there is a small cut on two sides, this is all the light bulbs that arrived, apparently a technological need.
22.3 (± 1) mm long
The declared lamp power is 3 watts, well, then connect the light bulb to the power supply and see
Here it turns out that the real powermore than two times lower (1.44 watts) and this is at a voltage of 14.4 volts, which, in principle, is a lot for a normal car, and at a voltage of 13.9 volts, the consumption current is about 0.8 A, which corresponds to generally 1, 12 watts, almost 3 times lower than stated.
Let's go back to the body of our light bulb, the head is in the form of COBthe matrix is soldered to the base in two places, decapitate, take the soldering iron and solder off, the head begins to dangle, then heat the positive contact, and separate the base (In general, this is the standard method of attaching LED assemblies to the base). After removing the COB, we see that the current is limited not by some circuitry there, but by the most advanced solution - a resistor!
Marking resistance of the resistor: 42 Ohms with a tolerance of 10% (the colors of the rings on the resistor are yellow, red, black, silver). According to the measurement results: 48.2 Ohms
And at the end of the review of the photo of how the lamps shine:
On the top photo is LED, on the bottom is ordinarycar lamp with a P21W filament, photos were taken with the same shutter speed, equally open aperture, the same lens on the same focus, from a tripod.
As can be seen from the photo, an ordinary lamp wins, both in brightness and in the area of lighting.
Comparisons of how these lamps shine in the taillights of a car will not,
firstly: it’s already clear from the photo on the table that ordinary lamps will shine brighter,
secondly: in my car almost all bulbs are baseless, and I just have nowhere to install them,
thirdly: they were bought just to use the coupon.
Also, the big question is the durability of these lamps, after 5 minutes of operation, the matrix has heated up to 70 degrees.
That's all, good luck to everyone and see you in new reviews.