How to build a bigger current source with a smaller one

Discussion in 'General Electronics Chat' started by tpny, Sep 24, 2012.

  1. tpny

    Thread Starter Member

    May 6, 2012
    216
    0
    I have a current loop between 2 locations. Transmitter has power supply and transmits two current levels to the receiver - 10 and 20mA (10mA indicates idle and 20mA indicates signal). The receiver has no power supply. I want to put a battery (thinking 12 x 1.2 NiMH rechargables) on the receiver side. I want to use the idle 10mA to charge this battery. How can I do this? I'm thinking putting a big cap to consume the 10mA and when there's enough charge built up, release it to the battery. Then repeat this loop. I guess I also need to somehow maintain a sufficient charging voltage > 12V. Is this a good approach? How would I implement this? Thank you so much!
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,999
    745
    What does the receiver do, does it give out a voltage or change state?
     
  3. tpny

    Thread Starter Member

    May 6, 2012
    216
    0
    receiver only receives. During idle, transmitter sends 10mA to receiver and receiver uses that to charge battery. On some occassion not to frequent, transmitter sends 20mA to receiver and receiver then uses the power in the battery to turn on a solenoid relay for about 1 minute.
     
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