latching circuit

Discussion in 'General Electronics Chat' started by fred_uk, Jan 28, 2009.

  1. fred_uk

    Thread Starter Active Member

    Jan 3, 2009

    wonder if anyone can help

    i need to design and build a latching circuit, but it needs to be lower power consumption!!!

    I have a 6v battery and an digital input on another gadet

    The circuit needs to latch the input either high or low during alarm (which ever is the most effective re power consumption , or may be it wont make any differeance I don't know)

    The circuit will have an alarm input ( a reed switch, normally closed, going normally open on alarm and a reset input. When the alarm is triggered i need it to latch until the reset input is activated.

    But the power consumption is a massive issue for me as it needs to operate with as little power consumption as possible.

    Thanks for reading and for any advice...
  2. mik3

    Senior Member

    Feb 4, 2008
    Use a CMOS RS latch which consumes little power compared to TTL ones. Use the S input for the reed switch and the R input for the reset button or vice versa.
  3. Wendy


    Mar 24, 2008
    An SCR is also a latch, you can make it with transistors also. Depends on the application. I've use this configuration, it required a push button to break the current when the alarm was on for a manual reset.