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On Sunday, July 24, 2022 at 12:26:29 PM UTC+10, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
If you hook up one end of an inductor to a positive power supply with a P=channel power MOSFET, and the same end to ground with an N-channel power MOSFET and alternately turn one and then other other on (but not both at the same time) the voltage at the other end of the inductor will be some fraction of the output voltage of the positive power supply determined by the mark-to-space ratio of drive wave forms - if both are on for 50% of the time it will be half.
This is independent of the direction of the current flow through the inductor.
Obviously the inductor must be able handle the current flowing through it (not burn out or saturate) and so must the MOSFET switches, and there\'s going to be a ripple element in the current which you may need to filter out.
Single chip microcontrollers can generate the switching waveforms - mostly you will need a driver chip to boost the output signal to the voltage and currents the MOSFET\'s need to switch fast enough to do the job - and most single chip micros come with an A/D converter that will let you monitor what\'s going on, and adapt the drive waveforms to create the effect you want.
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
On 24/7/22 12:26, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
A 4-quadrant motor driver can source or sink (regenerate) power in
either polarity.
The other thing to look for is a SMU (Source Measurement Unit), a piece
of lab equipment.
Clifford Heath
Any load has to get rid of incoming power. A linear circuit has to
dump it locally, into heat sinks. A switcher will push it uphill into
its power supply, which has to tolerate being back-driven.
søndag den 24. juli 2022 kl. 05.20.46 UTC+2 skrev bill....@ieee.org:
On Sunday, July 24, 2022 at 12:26:29 PM UTC+10, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
If you hook up one end of an inductor to a positive power supply with a P=channel power MOSFET, and the same end to ground with an N-channel power MOSFET and alternately turn one and then other other on (but not both at the same time) the voltage at the other end of the inductor will be some fraction of the output voltage of the positive power supply determined by the mark-to-space ratio of drive wave forms - if both are on for 50% of the time it will be half.
This is independent of the direction of the current flow through the inductor.
Obviously the inductor must be able handle the current flowing through it (not burn out or saturate) and so must the MOSFET switches, and there\'s going to be a ripple element in the current which you may need to filter out.
Single chip microcontrollers can generate the switching waveforms - mostly you will need a driver chip to boost the output signal to the voltage and currents the MOSFET\'s need to switch fast enough to do the job - and most single chip micros come with an A/D converter that will let you monitor what\'s going on, and adapt the drive waveforms to create the effect you want.
that just pumps the current into the input supply, so that must be able to source and sink
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
Scot
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
Scot
søndag den 24. juli 2022 kl. 05.20.46 UTC+2 skrev bill....@ieee.org:
On Sunday, July 24, 2022 at 12:26:29 PM UTC+10, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
If you hook up one end of an inductor to a positive power supply with a P=channel power MOSFET, and the same end to ground with an N-channel power MOSFET and alternately turn one and then other other on (but not both at the same time) the voltage at the other end of the inductor will be some fraction of the output voltage of the positive power supply determined by the mark-to-space ratio of drive wave forms - if both are on for 50% of the time it will be half.
This is independent of the direction of the current flow through the inductor.
Obviously the inductor must be able handle the current flowing through it (not burn out or saturate) and so must the MOSFET switches, and there\'s going to be a ripple element in the current which you may need to filter out.
Single chip microcontrollers can generate the switching waveforms - mostly you will need a driver chip to boost the output signal to the voltage and currents the MOSFET\'s need to switch fast enough to do the job - and most single chip micros come with an A/D converter that will let you monitor what\'s going on, and adapt the drive waveforms to create the effect you want..
that just pumps the current into the input supply, so that must be able to source and sink.
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
Scot
On 7/23/2022 10:26 PM, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
Scot
For modest powers the synchronous Cuk converter can operate
bidirectionally with few not many modifications:
https://www.researchgate.net/figure/Bidirectional-Cuk-converter-structure_fig1_236153344
The cap can be split and a transformer added to isolate it and avoid the
polarity inversion on the output if needed. The transformer doesn\'t need
to store energy so it doesn\'t need to be large
On Sunday, 31 July 2022 at 11:41:27 UTC-7, bitrex wrote:
On 7/23/2022 10:26 PM, Scot Bohnenstiehl wrote:
Not sure if there is quick answer but is there simple way to do bidirectional power supply (power supply plus DC load)? This application would be small, maybe no more than 10 W or 20 W DC load. This question came up recently and I can\'t seem to find my copy of Art of Electronics and I don\'t remember if such a topic is even covered.
Scot
For modest powers the synchronous Cuk converter can operate
bidirectionally with few not many modifications:
https://www.researchgate.net/figure/Bidirectional-Cuk-converter-structure_fig1_236153344
The cap can be split and a transformer added to isolate it and avoid the
polarity inversion on the output if needed. The transformer doesn\'t need
to store energy so it doesn\'t need to be large
Many switching power supply configurations can operate bidirectionally if required.
The Prius (and the other Toyota hybrids) has a buck/boost converter from the 200V battery to the variable voltage main bus (200-650V) to feed the motor drivers. It can transfer up to 30kW in the Prius.
In an AC powered supply the issue is that you also need a bidirectional AC to DC converter. It is not enough just to extract power from the load and provide it as DC - it needs to be converted to 50/60Hz AC and fed back to the power source.
kw