| 摘要 |
PURPOSE:To simplify the constitution of the titled circuit by using a both-end voltage of an impedance circuit for the driving voltage, in a comparison amplifying circuit for comparing a both-end voltage and a reference voltage of the impedance circuit connected in series to an output side. CONSTITUTION:An output current is passed through an impedance circuit 16 and supplied to a load, through a fly-back type constant current converter main circuit 2A from input terminals 1, 1'. A voltage proportional to this output current is generated in said impedance circuit 16, it is compared with a reference voltage 17 by a comparison amplifying circuit 5, and a constant-current control signal is obtained. This signal is fed back to said main circuit 2A through a photocoupler 6, and constant-current control is executed. In this case, a voltage generated across the impedance circuit 16 is utilized for a driving power source of said amplifying circuit 5. In this way, a voltage proportional to a stable DC constant-current can be received, and the circuit can be operated stably. |
