一种改善荧光数码管低温显示性能的控制电路

随着发光科学的发展,显示器件的种类日益繁多。但是,当应用到野外工作的仪器上显示字符时,大多数器件的亮度在强烈日光下相形见绌。近年来LED半导体数码管亮度有很大提高,并制成光电组合件,但用在电池电源工作的野外小型化仪器中,耗电仍是一个很大的问题。荧光数码管兼有高亮度和低功耗两方面的优点,正好适用于这种工作环境。缺点是体积较大和抗震性能较差。

A CONTROL CIRCUIT FOR IMPROVING DISPLAY PERFORMANCE OF LOW VOLTAGE FLUORESCENT TUBES AT LOW TEMPERATURE

Low voltage fluorescent tubes have both high brightness and low power consumption. It is very suitable for miniaturized instruments in open field operations under strong sun light illumination. In some important applications, it is necessary to have a dark field shown on the display devices after turning on the power, in order to distinguish information "0" from the primitive state "0".However, at lower temperatures half bright will appear in the primitive state of fluorescent tubes. In this paper this problem is discussed. The designed grid control circuit is shown in Fig.3. The logic level output of TTL is increased by T1. 2CW5 move ground level to -10V in order to ensure reliable cut-off or saturation of T2 at variations of temperature. The grid potential difference between dark and bright state is increased by T2 so that the grid potential approximates to anode potential in order to ensure sufficient brightness Vbe of T3 equals just saturation voltage Vce of T2 to ensure cut-off of fluorescent tube in dark state.A display set has worked well under the temperature of -22℃~30℃. Power voltage -10V had been varied; the results of practical measurement is shown in Table 1.