Static eliminators need to have three capabilities
1. Static elimination speed
It should have the ability to quickly eliminate static electricity. This ability depends on the way high voltage is applied. Its measurement index is the time required for the voltage on the charging plate of the static detector to drop from 1000V to 100V.
2. Ion balance
Ion balance is a measure of how much static electricity the static eliminator can eliminate and how long it can stay at the lowest value. The closer the static voltage is to 0V, the better the balance of the static eliminator.
3. Maintenance of static elimination ability
The capacity of the static eliminator (discharge speed and ion balance) gradually weakens with the increase in use time. The main factor of the weakening is the accumulation on the electrode ** and the wear of the needle tip. When using the static eliminator, not only should be considered Speed, the change of static elimination ability over time should also be considered.
The applied voltage type static eliminator is composed of grounding device, high voltage current and electrode probe. Its static elimination ability depends on the application method. The common application methods are as follows:
1. AC mode (AC mode)
This method applies positive high voltage to the discharge probe during the positive half cycle to generate positive ions, and applies negative high voltage to generate negative ions during the negative half cycle. It can neutralize charged objects with positive and negative polarities and has an excellent ion balance. This method It is a traditional and mass-applied way, and the price is low.
2. DC method (direct current method)
This method generates positive and negative ions on different electrodes by continuously providing positive and negative high voltages at the same time, thereby quickly eliminating static electricity.
3. Pulse DC method
This method is for positive and negative separation respectively? The electrode probe, alternately applies DC positive and negative high voltage to produce gapped positive and negative ion output. This method generates a large number of ions, so the elimination of static electricity is faster, and it has a good ion balance ability.
4. Pulse AC method
This method is to alternately apply positive and negative DC high voltage to the same electrode probe. It combines the advantages of AC, DC and pulsed DC methods. Compared with the AC method, the number of ions generated is larger, so the electrostatic elimination speed is faster. At the same time, it has a good ion balance.
Control method of DC static eliminator:
In order to obtain the high stability and symmetry of the DC high voltage, it is common to have feedback and comparison self-balancing methods, and also to achieve the best ion balance state by adjusting the symmetry of the positive and negative high voltages.
At present, some manufacturers use single-chip microcomputer technology for centralized group control research and development of DC static eliminators, and monitor the operating conditions of two or three hundred static eliminators through computers at the same time, making a beneficial contribution to improving the management efficiency of static eliminators on the production line.