Design&Research Of The Energy Saver IC For AC Contactor

AC contactors are massively used in industry and agriculture as low-voltage electric appliances. The usage amount can be hundreds of millions in the whole country, which consumes large amount of energy. Therefore, in order to ease the energy shortage and build an energy-saving society, the designing of an AC contactor energy-saving chip with intellectual property rights will be quite significant.The thesis proposes an operating mode of "Strong magnetic to close, weak magnetic to close" according to the working principle "AC close, AC hold" of AC contactors, and furthermore designs one kind of AC contact energy-saving chip called ZDLX-1H. The energy saver based on this chip makes the AC contactors operate in DC mode, which not only saves energy, but also markedly reduces the noise and temperature rising. And the energy saver is easy to be installed or transformed into the existing traditional AC contactors for its small size. In addition, the chip ZDLX-1H also comes with the function of high or low voltage alarm and temperature alarm, so that to improve the safety and reliability of the energy saver.The main work and innovations include:(1) Pulse Width Modulation (PWM):When the AC contactor work rightlly (when it sves energy), the pulse width of the chip can be automatically adjusted according to the supply voltage. When the supply voltage is too high or too low, the output pulse width will reduce or increase according to the supply, which can ensure that the whole current of the system keeps an appropriate value, so energy-saving rate remains a stable value.(2) Low voltage off:When the supply voltage is lower than132V, which is beyond the working limit, the energy saver will output zero to release the AC contactor.(3) Undervoltage Alarm:When the supply voltage is lower than185V, the energy saver will alarm.(4) Overvoltage Alarm:When the supply voltage is higher than242V, the energy saver will alarm. The testing result shows that it does not work rightly, so it has been redesigned.(5) Over temperature Alarm:When the energy-saver detects that the temperature of the coil is over125℃, the energy will give a alarm signal, meanwhile when the temperature falls down to85℃, the energy saver will cancel the alarm.(The operating temperature data comes from the newest tapeout in April2014. The test data in the fifth chapter comes from the former edition in November2013.So the target of temperature in the thesis is based on the newest version.)(6)The chip ZDLX-1H is implemented based on the CSMC0.5um. The testing result show that the static current is300uA and the consumption is only1.5mW.The energy saver together with the ac contactor CJ20-100work rightly and the energy-saving ratio is90%.The whole system passed the EMC result which was mentioned in the GB8871-2001.