Inverter/Yoonseo Design/H Bridge: Difference between revisions
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== What is an H Bridge == | |||
"An H bridge is an electronic circuit that enables a voltage to be applied across a load in either direction." See the [http://en.wikipedia.org/wiki/H_bridge H Bridge wikipedia page]. | |||
== Important Design Considerations == | == Important Design Considerations == | ||
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Avoid ground loop by having floating grounds (only on certain grounds -- need to clarify). | Avoid ground loop by having floating grounds (only on certain grounds -- need to clarify). | ||
=== What Switches to Use === | === What Switches to Use === | ||
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Operating Rds = Resistance from Drain to Source while Gate activated. Needs to be low for efficiency. | Operating Rds = Resistance from Drain to Source while Gate activated. Needs to be low for efficiency. | ||
Switching Rds = Resistance from Drain to Source needs to be | Switching Rds = Resistance from Drain to Source needs to be low during the switch (to avoid excessive thermal build up during the switch-on). | ||
See: [http://homepages.which.net/~paul.hills/SpeedControl/Mosfets.html MOSFETs and MOSFET drivers] | See: [http://homepages.which.net/~paul.hills/SpeedControl/Mosfets.html MOSFETs and MOSFET drivers] | ||
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=== What Resistors === | === What Resistors === | ||
Resistance gauged for maximum voltage and current that is acceptable by the MOSFET. Greater the power, the faster the switching speed, because the mosfet gate to source acts like a capacitor. Keep gate resistors close as possible to MOSFET gate. | |||
=== Position of Wires === | === Position of Wires === | ||
Keep signal wires from power wires. | Keep signal wires from power wires. | ||
Latest revision as of 22:06, 23 August 2012
What is an H Bridge
"An H bridge is an electronic circuit that enables a voltage to be applied across a load in either direction." See the H Bridge wikipedia page.
Important Design Considerations
General Concerns
Avoid ground loop by having floating grounds (only on certain grounds -- need to clarify).
What Switches to Use
Likely use MOSFET, NPN (off until switched). See MOSFET.
Considerations:
Operating Rds = Resistance from Drain to Source while Gate activated. Needs to be low for efficiency.
Switching Rds = Resistance from Drain to Source needs to be low during the switch (to avoid excessive thermal build up during the switch-on).
See: MOSFETs and MOSFET drivers
What Length of Wire
Important because high frequency of signal creates inductance via EMF. Make sure all wires leading to gates are the same length, and make the wires as short as possible to minimize the inductance.
What Resistors
Resistance gauged for maximum voltage and current that is acceptable by the MOSFET. Greater the power, the faster the switching speed, because the mosfet gate to source acts like a capacitor. Keep gate resistors close as possible to MOSFET gate.
Position of Wires
Keep signal wires from power wires.