The design of the magnetic lock is the same as that of the electromagnet, which uses the principle of electromagnetism. When the current passes through the silicon steel sheet, the electromagnetic lock will generate a strong suction force and tightly absorb the adsorption iron plate to achieve the effect of locking the door. As long as a small current electromagnetic lock will generate a huge magnetic force, the access control system that controls the power supply of the electromagnetic lock will cut off the power after identifying the correct person, and the electromagnetic lock will open the door when it loses its suction.

Standard and qualified magnetic locks generally provide two input voltages of 12V and 24V (difference between single coil and double coil), which are selected and switched by jumpers. There are several ways to judge the quality of a magnetic lock:

1. Look at the circuit board

2. Measuring resistance

3. Measure the current value after power on

4. Insulation value

5. Verticality of cut steel sheet

6. Glue filling inspection

7. Distance between cut steel pieces

8. No residual magnetism

9. 4007 diode

10. Process treatment of the lock body shell

11. High and low pressure

12. Acidity test

13. Finish

14. Lock body electroplating

15. Output line

1. Look at the circuit board

Inferior magnetic locks can be judged from the circuit board. The printed circuit boards of inferior magnetic locks are rough and the layout is extremely simple. They do not use piezoresistors (that is, surge generators, usually two), and only have one set of voltage inputs.

2. Measuring resistance

First unplug the 12V and 24V switching jumpers of the magnetic lock (note: no need to power on), generally there are 4 terminals (jumpers), measure the red and black lines, and the resistance is about 50 ohms. good.

3. Measure the current value after power on

Measure the current value after connecting the magnetic lock to the 12V voltage, and it is better to match the marked value. 280KG (600 pounds) magnetic lock is generally better at 400-450 mA, if it is less than 450 mA, the pulling force is not enough; if the 24V voltage is applied, the marked value or actual value should be 200 mA.

4. Insulation value

The insulation value of the lock body of a standard-qualified magnetic lock should be infinite, and the specific value should be above 50 megohms; the specific test position is the steel piece and the output line of the lock body (any one).

5. Verticality of cut steel sheet

In principle, the cut steel piece should be touched or stained with hands as little as possible. The more standard the verticality and parallelism of the qualified magnetic lock cut steel piece, the better. The quality of the electroplating of the cut steel sheet depends on whether there are any oxidation marks on the cut steel sheet.

6. Glue filling inspection

There should be no air bubbles in the colloid of the magnetic lock, it should be flat and tidy, without cracks, and the angle should be square.

7. Distance between cut steel pieces

The main concern is that the thickness of the steel cuts should be 0.35mm. Most of the steel cuts on the market currently use 0.5mm steel cuts; the tighter the arrangement of the steel cuts on the lock body, the better. Pay attention to the There should be no glue seepage during the arrangement.

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 must have the function of removing residual magnetism, and it is equipped with a protruding rubber pad to play a buffer role, and there is an anti-residual magnet device. A high-quality lock will reduce the pulling force by about 35 kg; if a 99.9% pure iron product is used, the generation of residual magnetism can be basically eliminated without an anti-residual magnetic device, and the pulling force is sufficient.

9. 4007 diode

Specifically refers to locks without indicator lights and signal output. Generally, this diode crystal is added to the positive and negative poles of the lock's power supply. Pole connection error or impact access control machine, etc.

10. Process treatment of the lock body shell

The shell of the lock body is generally made of oxidized wire drawing or oxidized sandblasting, especially oxidized sandblasting and fine sand.

The wire drawing is neat, the banknote spraying is uniform, and the cutting surface of the steel body of the shell is smooth.

11. High and low pressure

At low pressure, the lock can still work, but the pulling force is reduced; at high pressure, the lock body will become 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

Apply weak acid to the steel cut piece of the lock body. The good lock body will oxidize after 45 minutes, while the poor lock body will generally oxidize within 15 minutes. In addition, you can soak the lock body in water, and those that turn black within 24 hours are inferior products.

13. Finish

Put small water droplets on the steel plate of the lock body, and observe whether the flow is smooth or muddy. If it is smooth, the smoothness is excellent.

14. Lock body electroplating

Pay attention to the quality of electroplating at the corners of the lock body. If there are wrinkles and darkening, the electroplating of the lock body is not qualified.

15. Output line

The two-core electric lock has no signal output, and the five-core one has door position detection output.

At present, the suction strength of the electromagnetic lock is expressed in KG, and the test method is static pressure. The so-called static pressure means that after the electromagnetic lock is energized, it gradually increases the pulling force on the adsorption iron plate. When the suction force of the electromagnetic lock is exceeded, the adsorption iron plate is pulled away instantly. The data of this pulling force is the pulling force value of the electromagnetic lock. Moreover, the force between the electromagnetic lock and the adsorption iron plate must be face-to-face and pressurized in a straight line, so that the suction force of the electromagnetic lock is the largest. The adsorption iron plate may be temporarily magnetized due to the long-term magnetic induction of the electromagnet.

Author:Written by Ms.Rebecca Fu from S4A INDUSTRIAL CO.,LIMITED