- on Power Supplies
- Published in issue 7/2006 on page 0
This circuit performs a similar function to the ‘sleep’ button on a radio alarm clock; pressing the button connects the battery supply to some external equipment or circuit (represented by RL) for a preset time period. The period can be extended by pressing the button again before ‘time out’. The circuit will avoid the situation where you forget to turn off some battery powered equipment and return to find the battery is flat.