| 摘要 |
PURPOSE:To supply a constant current by reducing output fluctuation by selecting a current source circuit, which have mutually reverse characteristics of output fluctuation for change of temperature of use, among many current source circuits, and using them in combination. CONSTITUTION:In a current power source circuit shown in Fig. 1, the ratio of the base-emitter voltage of a transistor TRQ and a current limiting resistance R2 corresponds to a current flowing through a load resistance R1, and the forward voltage varies with temperature, so that the load current decreases according to a rise in ambient temperature. In a circuit in Fig. 2, on the other hand, the base-emitter voltages of two TRs vary with temperature and as temperature of use rises, a current flowing through a load resistance R5 increase. In the circuit of the invented device, however, a current flowing through a load resistance 11 is the sum of load currents shown in Fig. (a) and (b) and nearly constant against fluctuations of temperature of use.
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