Stop supply current going to zero
Stop supply current going to zero
(OP)
Hello,
i am trying to stop the current into a 3W SMPS ever going below 40mA.
(i posted before but now have a new design)
It goes to zero when the smps fails or when there is a transient input voltage step (momentarily). -or during start-up
Here is the circuit (smps represented by resistor)
[IMG]http://i44.tinypic.com/2n0da1.jpg[/IMG]
here is the LTSpice simulation file
http ://rapidsh are.com/fi les/252509 861/___339 46__cap_r_ zener_trxi ent_catche r__window_ 2.asc.html
Please does any reader know any simpler (less component) solution?
For transient voltage detection, i use an npn + cap feeding a window comparator which switches a load on for the duration of a monostable's period. -keeping the input current above 40mA.
-the CLC resonance of the input EMC filter makes the supply current go to zero for a short while when a supply voltage transient occurs.
i am trying to stop the current into a 3W SMPS ever going below 40mA.
(i posted before but now have a new design)
It goes to zero when the smps fails or when there is a transient input voltage step (momentarily). -or during start-up
Here is the circuit (smps represented by resistor)
[IMG]http://i44.tinypic.com/2n0da1.jpg[/IMG]
here is the LTSpice simulation file
http
Please does any reader know any simpler (less component) solution?
For transient voltage detection, i use an npn + cap feeding a window comparator which switches a load on for the duration of a monostable's period. -keeping the input current above 40mA.
-the CLC resonance of the input EMC filter makes the supply current go to zero for a short while when a supply voltage transient occurs.





RE: Stop supply current going to zero
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RE: Stop supply current going to zero