A well-known Italian shoe machine manufacturing company needs to use hydraulic cylinders for its front upper machine, middle and back upper gluing, back upper nailing and other equipment. The hydraulic solenoid valve that drives the cylinder has a large power. The rated working current of a conventional DC24V hydraulic solenoid valve is about 0.8-1.5A, and the maximum output current of the controller PLC is 0.5A, so a power amplifier needs to be installed between the PLC output point and the solenoid valve coil. The old products of this manufacturer use intermediate relays as power expansion devices. Since the solenoid valve coil is an inductive load, according to the characteristic that the inductive current cannot change suddenly, the solenoid valve will store energy and cannot release it at the moment the relay is turned off, so the relay contacts will generate a high-voltage arc at the moment of disconnection. The high-voltage arc will damage the alloy (usually silver-plated) contacts of the relay. When the contact damage accumulates to a certain extent, it will cause contact adhesion, poor contact and other faults, thereby affecting the normal operation of the equipment. As an actuator of electromagnetic propulsion machinery, relays inevitably have mechanical fatigue, so the intermediate relay must have a very important parameter: "reliable contact times". The nominal value of most intermediate relay manufacturers is 100,000 times, which can often reach 1 million times in actual use. After our statistics and observations, taking the company's back-end nailing machine as an example: the solenoid valve that performs nailing has an action frequency of about 10 seconds. Calculated based on the machine working 8 hours a day, the reliable life of the intermediate relay is: 34.7 days. The actual observation and statistical data is about half a year. Therefore, the company often replaces the intermediate relay for customers free of charge during the warranty period, which increases the company's after-sales maintenance costs and seriously affects the company's brand phenomenon.
However, our DC amplifier board does not have the above defects. The freewheeling diode is integrated inside the board. After cutting off the coil current, the freewheeling diode will reversely connect the coil until all the energy inside the coil is released. The power output element of the amplifier board is a high-power MOSFE field effect tube, which has no mechanical fatigue, so there is no limit on the number of lifespans. The reliable service life is more than 5 years.
Replacing the company's equipment will basically prevent the occurrence of failures that damage the power amplifier components during the warranty period. Our products have been highly recognized by the company.