| 摘要 |
PURPOSE:To apply current limit to a feeding circuit independently by providing a current limit element not conductive till a feeding current exceeds a prescribed value and showing a constant voltage characteristic to the input side. CONSTITUTION:Zener diodes 81, 82 are connected in back-to-back (2-way) to the input side of a 1st mutual conductance amplifier 10 and Zener diodes 81', 82' are connected in back-to-back (2-way) to the input side of a 2nd mutual conductance amplifier 20. Till a feeding current exceeds a prescribed value, the Zener diodes 81, 82 and 81', 81' are not conductive and when the feeding current exceeds a prescribed value, the Zener diodes 81, 82 and 81', 81' show a constant voltage characteristic, then the flowing of the feeding current of a prescribed value or over to the feeding circuit is prevented. Thus, the feeding current is limited with simple constitution without new provision of a current detection circuit and a comparison discrimination circuit. |
