# Peak current control of capacitive half-bridges with synchronous rectifier

**URL:** <https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428>\
**Category:** PLECS\
**Tags:** control, current, peak, capacitive, half-bridges\
**Created:** [May 6, 2018, 7:30am UTC](https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428 "2018-05-06T07:30:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Dirac](https://avatars.discourse-cdn.com/v4/letter/d/cc9497/32.png) [@Dirac](https://forum.plexim.com/u/Dirac)\
**Post date:** [May 6, 2018, 7:30am UTC](https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428/1 "2018-05-06T07:30:14Z")

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Hello everybody,

I am developing a capacitive half-bridge with synchronous rectifier(see picture with Plecs), which should always deliver 14.2V and 7A as rated current.  
The input voltage range is 36V to 60V and the rated voltage is 48V. The simulaion without regulation works, that is, when I simulate with the nominal values (48V and 2 ohms), the rated current is 7A and the output voltage is also 14.2. I also get these values with the control (peak current control). But if I change the load, the output current is no longer 7 A.

Has anyone an idea what I can do to get always 14.2V and 7A when I change the load

thank you in advance

Dirac

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**Author:** ![Kris\_Eberle](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/kris_eberle/32/6_2.png) [@Kris\_Eberle](https://forum.plexim.com/u/Kris_Eberle)\
**Post date:** [May 6, 2018, 2:32pm UTC](https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428/2 "2018-05-06T14:32:32Z")

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Please provide a model.

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<div class="post-metadata">

**Author:** ![Dirac](https://avatars.discourse-cdn.com/v4/letter/d/cc9497/32.png) [@Dirac](https://forum.plexim.com/u/Dirac)\
**Post date:** [May 6, 2018, 4:01pm UTC](https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428/3 "2018-05-06T16:01:36Z")

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Hello,

attached is the circuit

Thanks

[Peak\_current\_control\_of\_capacitive\_half-bridges\_with\_synchronous rectifier.plecs](https://forum.plexim.com/uploads/short-url/uVdAdD15ltxIItmb6fpK9Bp0Qj6.plecs) (37.3 KB)

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**Author:** ![Oliver\_Schwartz](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/oliver_schwartz/32/6_2.png) [@Oliver\_Schwartz](https://forum.plexim.com/u/Oliver_Schwartz)\
**Post date:** [May 11, 2018, 4:32pm UTC](https://forum.plexim.com/t/peak-current-control-of-capacitive-half-bridges-with-synchronous-rectifier/428/4 "2018-05-11T16:32:17Z")

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\> Has anyone an idea what I can do to get always 14.2V and 7A when I change the load

Sorry, I’m afraid you cannot achieve that. Hint: Ohm’s law. You will only get 14.2V and 7A with a load of 14.2/7 Ohm. And no, “Peak current control” does not mean constant output current but limited peak current.