alternating pressure

Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE ( pressure relieving support surfaces)-trial

气垫床垫与气垫床罩预防压力性溃疡的随机、对照试验：PRESSURE（减压支持表面）试验

The temperature regulator tube plate and steel tube beam work in the frequent change of temperature for a long time, their high alternating pressure make the tube plate's weld crack and tube beam leak.

减温器管板和钢管束长期工作在频繁变化的温度中，交变压力很大，造成管板焊缝处经常开裂，管束泄漏。

Three-phase alternating frequency modulation control signal produced by 8051 CPU is magnified to control the switch of the silicon controlled rectifier in inverse main bridge circuit, thereby constant pressure speed-adjusting is realized.

由8051CPU产生三相交流调频控制信号，经放大来控制逆变主桥路中可控硅晶闸管的通断，从而实现恒压调速。