In power supply design, safety is often the first, also in the switching power supply area. Grounding can protect the personal safety of users and ensure the regular operation of power equipment, so what is the appropriate grounding method in the switching power supply? What are the common grounding symbols? This article will introduce the grounding problem in the switching power supply.
The negative terminal can be grounded. The negative terminal of the switching power supply ground can play the dual role of accidental touch and protection.
In the switching power supply wiring, the basic principle is: according to the actual application, first distinguish the type of ground, and then choose a different grounding method; regardless of the grounding method, must comply with the “low resistance, low noise” principle. The following will introduce the actual wiring process of switching power supplies to consider the characteristics of various “ground” and grounding methods. Bucks line, due to the use of a large area of the ground, resulting in interference, is too large to carry heavy loads. The ground of the driver source should be as close as possible to the driven device to form a minimum loop to reduce oscillation and EMI problems.
Common grounding symbols for switching power supplies
- PE, PGND, FG: Protective ground or chassis
- BGND or DC-RETURN: Power supply (battery) return
- GND: Work ground
- DGND: Digital ground
- AGND: Analog ground
- LGND: Lightning protection ground
Grounding mode of LED power supply
Grounding methods are single-point grounding, multi-point grounding, and mixed grounding.
Single-point grounding divides into a series of single-point grounding and parallel single-point grounding.
Generally speaking, simple circuits use single-point grounding. Different functional modules use grounding areas between them. Low frequency (F10MHZ) circuits use multi-point grounding or multi-layer board (complete grounding layer).
LED power supply Connect the Negative Output to Earth Ground
If the switch power supply negative output connect to earth ground can play the dual role of miss touch and protection.
Generally speaking, if the closing coil can connect to the negative power supply. When grounded, the loop can effectively control the switch, trigger a trip, and effectively avoid short circuits. To eliminate external circuit faults, it can protect the equipment and ensure the stable and safe operation of the system.
In addition, if the negative pole of the switching power supply is grounded. When there is a surplus current, the current lets out directly. There will be no risk of electric shock, which has a perfect protective effect for experimenters and actual operators.
