目前,恒温培养箱的温度控制电路,常见的是利用电子管栅极电压在某一数值时,呈现截止状态的原理,以水银电接点温度计控制电子管栅极电压的有无,从而使继电器工作线圈有电压吸合,无电压释放,控制电热丝加热与否,达到控制箱内温度的目的。以上电子控温器,常有两种接法,如图:图A电路的工作过程是:1、接通电源,2、电子管处于饱和导通状态;3、继电器线圈具有大于吸合电压而吸合;4、继电器常开触点接过电热丝加热; At present, the thermostatic incubator temperature control circuit, the common is the use of electron tube gate voltage at a certain value, showing off the principle of mercury electrothermal contact point to control the gate voltage of the tube, so that the work of the relay coil Voltage pull-in, no voltage release, heating wire heating control or not, to control the temperature inside the box. Above electronic temperature control, there are often two connections, as shown: Figure A circuit work process is: 1, connected to power, 2, the tube is saturated on state; 3, the relay coil has a pull-in voltage greater than the suction Together; 4, the relay normally open contact heating wire took over;