3results about How to "Realize self-protection" patented technology

The utility model relates to the technical field of LED dimming, and provides a multi-gear high-precision LED constant-current dimming circuit, which comprises an LED lamp group, a dimming circuit, a booster circuit and an under-voltage protection circuit, and is characterized in that a plurality of adjusting resistors R2-R5 which are connected in series are arranged to be matched with a single-pole multi-throw dial switch SW1, so that the resistance value of the circuit on the series circuit can be flexibly adjusted, the current of the LED lamp group can be adjusted, and the dimming effect of the LED lamp group can be improved. Therefore, multi-gear high-precision adjustment is realized; a triode and an MOS tube are arranged to form switch control, the weak current control principle of the triode is utilized, a resistor R1 with the resistance value far larger than that of all resistors in a series adjusting module is arranged in a matched mode, when LED circuit dimming is carried out, the R1 with the large resistance value can neglect the influence of voltage drop of the triode Ibe on R3 / R4 / R5 on LED current precision, and meanwhile a loop of an LED lamp set can be thoroughly turned off when SW1 is turned off; a divider resistor is adopted to carry out real-time feedback detection on the output voltage of the booster circuit, and under-voltage self-detection and self-protection are achieved.

The application discloses a screw motor torque and rotating speed testing system, which comprises a screw motor torque and rotating speed testing device, a fracturing pump pry, a water tank and a PLC controller. The screw motor torque and rotating speed testing device comprises a testing unit, a power unit and a cooling system. The testing unit comprises a main shaft and a disc brake. The screw motor torque and rotating speed testing device further comprises a tension and pressure sensor and a rotating speed sensor. The tension and pressure sensor is used for monitoring the torque of the disc brake, and the rotating speed sensor is used for monitoring the rotating speed of the main shaft. The PLC controller is electrically connected with the rotating speed sensor, the tension and pressure sensor, the fracturing pump pry, the disc brake, the power unit and the cooling system respectively. The application can realize constant (dynamic) torque testing, rotating speed testing, torque setting, remote control and other functions, effectively solves the existing problems and improves the reliability and stability of the oil connection construction.

The invention relates to the technical field of high-voltage discharge, in particular to a high-voltage discharge system with a multi-protection function and a control method, high-voltage discharge multi-protection is realized through multi-circuit cooperation: a lighting switch circuit board converts 24V to 12V for a chip to work, and when VSample is higher than 10V, high voltage is cut off to prevent overvoltage of a xenon lamp; the peak absorption circuit board is driven to absorb reverse electromotive force to prevent breakdown by using an RCD network when the IGBT is turned off; the switching circuit generates SafeTrigger in real time, and the SafeTrigger is pulled down immediately to turn off the IGBT when the current exceeds 600A, the pulse exceeds 25ms and the like. The over-current protection circuit takes 8V as a threshold value, and is forcibly turned off to prevent the IGBT from being damaged when 600A; a pulse time length limiting circuit forcibly pulls down the SafeTrigger 25 ms later, and ultra-long pulses are completely eradicated; the time for limiting the turn-off of the IGBT is 15 microseconds, and the turn-off stability is ensured; when the over-temperature protection circuit is 70 DEG C, the signal is pulled down to close the drive; the constant current source feedback circuit amplifies and outputs as a current reference, maintains stable discharge, and improves the safety, reliability and service life of the system.