Power bridge modularity

Posted on September 3, 2014

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Njay – Funny how the power bridges have grown, they’ve got 4 boards now…

Njay's homebrew H-bridge power controller. You can see 3 boards: FET Driver board on the upper left, Microcontroller board on the bottom right, and MOSFET power board underneath them.

Njay’s homebrew H-bridge power controller, with the most recent heat sinks. You can see 3 boards: FET Driver board on the upper left, Microcontroller board on the bottom right, and MOSFET power board underneath them peeking at us on the top left (with the large capacitors, thick wires from the battery, and couple of 0.01 Ohm shunt resistors used for measuring the current). The 6 power MOSFETs are split 3 by 3 per half-bridge / heat sink, with 2 “N-channel” IRF3205 for Bottom switch and 1 “P-channel” IRF4905 for Top switch.

Modular FET driver board. It attaches to the power board via header pins.

Modular FET driver board. It attaches to the power board via header pins. Quite a few enhancements have been made here, because the gate driving current’s timing is of critical importance to how well the MOSFETs behave and how much power they dissipate.

You can browse all the schematics and code here, and download the entire project here.

Communications add-on board. This I2C insulator and debugger will be screwed on top of the heat sinks. It also provides temperature sensing of the heat sinks.

Communications add-on board. This I2C insulator and debugger will be screwed on top of the heat sinks. It also provides temperature sensing of the heat sinks and a connection for motor temperature sensors, all connected to the microcontroller’s ADC ports.

Njay – This is cool, because we can swap a board at any time and replace for example the driver circuit with a new one.

Vnevoa -Yes, that’s the way the Pros do it. Only after ironing out all the kinks and bugs they consolidate the design into a single final board. Anyway, we’re going to be burning some of those shortly… 🙂

(to be continued…)Lisbon_MMF_logos_Banner_big

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