The design of the magnetic lock (or electromagnetic lock) is the same as that of the electromagnet. It uses the principle of electromagnetism. When the current passes through the silicon steel sheet, the electromagnetic lock will produce a strong suction force and tightly attract the adsorption iron plate to achieve the effect of locking the door. . As long as the small current electromagnetic lock will generate a great magnetic force, the access control system that controls the electromagnetic lock power supply will be powered off after the correct identification personnel, and the electromagnetic lock will lose its suction to open the door.
Standard qualified magnetic locks generally provide 12V and 24V input voltages (the difference between single and double coils), which are selected and switched by jumpers. To judge the pros and cons of a magnetic lock, there are several ways:
1, look at the circuit board
The inferior magnetic lock can be judged from the circuit board. The inferior magnetic lock circuit board is rough and the layout is extremely simple. There is no varistor (that is, the surger is generally two), and there is only one set of voltage input.
2, measuring resistance
First remove the 12V and 24V switching jumpers of the magnetic lock (note: no power is required), generally there are 4 binding posts (jumpers), measure the red and black lines, and the resistance is about 50 ohms. good.
3. Measure the current value after power-on
It is better to measure the current value after the magnetic lock is passed through 12V voltage, which is consistent with the marked value. The magnetic lock of 280KG (600 lbs) is generally 400-450 mA. If it is less than 450 mA, it is not enough. If it is 24V, the marked value or actual value should be 200 mA.
4, insulation value
The standard qualified magnetic lock should have the insulation value of the lock body as infinite, and the specific value should be above 50 mega ohms; the specific test position is the steel cutting piece and the lock body output line (either one).
5, the verticality of the steel cutting piece
In principle, the steel cutting piece should be minimized by hand touch or stained. The standard of the perpendicularity and parallelism of the qualified magnetic lock steel cutting piece is better. The quality of the steel cutting plate should be checked by the presence or absence of oxidation marks on the steel cutting piece.
6, glue inspection
The colloid of the magnetic lock can not appear bubbles, should be flat and tidy, no cracks, and the angle is square.
7, cutting steel distance
The main concern is that the thickness of the steel cutting piece should be 0.35mm. Most of the current market uses 0.5mm steel cutting piece; the closer the steel cutting piece on the lock body is, the better the tightness is. Do not appear in the alignment.
8, no residual magnetism
Generally, the lock piece of the magnetic lock is made of pure iron, but most of the lock pieces are 99% pure iron, so it is necessary to have the function of demagnetizing, and has a protruding rubber pad for buffering function and anti-remaining device. The lock will reduce the pulling force of about 35 kg; if 99.9% pure iron is used, the residual magnetism can be basically eliminated without the anti-residual magnetic device, and the pulling force is sufficient.
9,4007 diode
Specifically, the locks that do not have the indicator light and the signal output are generally added to the positive and negative poles of the power supply of the lock. This treatment obviously reveals that the material of the lock is not closed, and some protection work done here to prevent positive and negative Extremely wrong or impact access control, etc.
10, the process of the lock body shell
The lock body shell is generally made of oxidized wire drawing or oxidized sandblasting, especially by oxidizing sandblasting, and fine sand is superior.
The wire drawing is neat, the banknote is evenly sprayed, and the cutting surface of the outer steel body is flat.
11, high and low pressure
At low pressure, the lock can still work, but the pulling force is reduced; when the pressure is high, the lock body will be hot. At this time, attention should be paid to the temperature rise. If the temperature rise exceeds 20 degrees, it is inferior. Generally, the temperature rise data can be obtained within one hour. .
12, acidity test
It is coated with a weak acid on the lock steel cutting piece. The good lock body will not oxidize after 45 minutes, and the difference usually oxidizes in 15 minutes. In addition, the lock body can be soaked in water, and it is inferior to black in 24 hours.
13, smoothness
Drop the small drops on the lock steel cutting piece to see if the flow is smooth, whether it is dragging the water, and the smoothness is excellent.
14, lock body plating
Pay attention to the plating quality of the corners of the lock body. Wrinkles and darkness are not applied to the lock body.
15, the output line
The two cores have no signal output electric lock, and the five cores have door position detection output.
At present, the suction strength of the electromagnetic lock is expressed in KG (kg), and the test method is static pressurization. The so-called static pressure is that the electromagnetic lock gradually increases the pulling force on the adsorption iron plate after the electromagnetic lock is energized. When the suction force of the electromagnetic lock is exceeded, the adsorption iron plate is pulled open instantaneously. The data of the pulling force is the pulling force value of the electromagnetic lock. Moreover, the force of the electromagnetic lock and the adsorption iron plate must be face-to-face and linearly pressurized, so that the suction force of the electromagnetic lock is the largest. The adsorbed iron plate may be temporarily magnetized due to the magnetic induction of the electromagnet for a long time.
Editor in charge: Xu Yuehua
Ce KN95 Face Mask
Kn95 Fold Flat 3D Mask,Kn95 5 Layers Face Mask,Kn95 Fold Flat Respirator,Kn95 Filters Cup Face Mask
Jiangmen anjian biotechnology co. LTD , https://www.anjianmask.com