How to build a bigger current source with a smaller one

Thread Starter

tpny

Joined May 6, 2012
220
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!
 

Thread Starter

tpny

Joined May 6, 2012
220
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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