| 摘要 |
<p>PURPOSE: To obtain a long delay time without use of a large capacitance capacitor by providing a charge current supply means to supply a current intermittent at a duty ratio in response to the delay time to a capacitor. CONSTITUTION: A charge current supply circuit 2 is made up of an oscillator 4 outputting a pulse signal with a duty ratio in response to a delay time to be obtained, a constant current circuit 5 supplying a constant current to a capacitor C1 and a transistor(TR) Q2 . Then the TR Q2 is conductive/ nonconductive in response to a pulse signal supplied from the oscillator 4 to control supply of a current to a capacitor C1 of the circuit 5. The oscillator 4 oscillates a pulse signal whose high level period is longer as a delay time is longer and whose low level period is shorter. The output pulse signal is fed to a base of the TR Q2 , which is conductive when the pulse signal is at a high level to stop the circuit 5 and nonconductive when the pulse signal is at a low level to activate the circuit 5.</p> |
