The Identification Method Of Micro Electromagnetic Lock

- May 09, 2019-

The miniature electromagnetic lock how to identifies the standard qualified electromagnetic lock,  Generally, it provides two input voltages (the difference between the single coil and the double coil) of 12V and 24V. They are selected and switched by jumpers. To judge the pros and cons of an electromagnetic lock, there are several ways:

1, look at the circuit board
The inferior electromagnetic lock can be judged from the circuit board. The inferior electromagnetic lock circuit board is rough printed and the layout is extremely simple. There is no varistor (that is, a surger, generally two), and only one set of voltage input.


2. Resistance Measurement

First, the switch jumpers of 12V and 24V of the electromagnetic lock are pulled out (note: no electricity is needed). Generally, there are four terminals (jumpers). The red and black lines are measured, and the resistance is about 50 ohms.


3. Measure the current value after power-on
It is better to measure the current value after passing the electromagnetic lock to 12V voltage, which is consistent with the marked value. The 280KG (600 lb) electromagnetic lock is generally 400-450 mA. If it is less than 450 mA, it will not be enough. If it is 24V, the marked value or actual value should be 200 mA.


4, insulation value
The standard qualified electromagnetic 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 electromagnetic lock steel cutting piece is better. The quality of the steel cutting plate is affected by the presence or absence of oxidation marks on the steel cutting piece.


6, glue inspection
The colloid of the electromagnetic 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, and most of the current market use 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 electromagnetic 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 magnetic 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 diodes 

Specifically refers to locks without indicator lights and signal output. This diode crystal is usually added to the positive and negative poles of the locks. This treatment clearly shows that the material of the locks is not up to standard, and some protective work is done here to prevent the wrong connection of the positive and negative poles or impact on the access control machine.


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 drawing is neat, the banknotes are 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 small water droplets on the steel plate of the lock body to observe whether the flow is smooth, whether the sludge is watery and smooth, the smoothness is better.


14. Lock body electroplating

Attention should be paid to the quality of electroplating at the edge and corner of the lock body. If wrinkles and darkness occur, the electroplating of the lock body can not pass.


15. Miniature Electromagnetic Lock Output Line

The two cores are non-signal output locks and the five cores are gate position detection outputs.