Browsing All Posts filed under »Controllers«

Integration Jam Session

September 21, 2014

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Njay got the burned bridge rebuilt, tested, and “burned-in” for an hour at 10Amps, so we got together again to finish integrating the system. This time with the 500 kbps I²C bus between the RasPi and the Power Bridges, so that the link is loud and clear. Njay was afraid that such high speeds would […]

Tuning out the glitches

September 20, 2014

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WE ARE AT THE FAIRE RIGHT NOW! 🙂 JOIN US! Meanwhile we’ll keep posting the story behind the project… Me and NJay finally got together for a hacking jam session to find out what the heck is going wrong with the I²C comms bus between the RasPi and the Power Bridges. This is where his […]

Vroom vroom

September 19, 2014

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ATTENTION: THE Lisbon Mini Maker Faire 2014 OPENS TO THE PUBLIC TOMORROW, SATURDAY. GET YOURSELF REGISTERED ONLINE AS A VISITOR SO YOU DON’T HAVE TO WAIT IN LINE AT THE VENUE. IT’S FREE OF CHARGE, BUT YOU HAVE TO REGISTER FIRST. And now, back to our soap opera. 🙂 The time has come to finally […]

Communications test, system bring-up

September 18, 2014

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So, the hardware was finished and basically tested. Time to go for the software and get all this stuff to actually do something together. 🙂 I had to spend some time updating my motor “device driver” module to be compatible with Njay’s new power bridges. I took my “latest and greatest” version (which had been […]

New wiring, power test

September 17, 2014

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Vnevoa: Due to the new I²C communications bus scheme, I had to make new cables to connect the Raspberry Pi controller to Njay’s power bridge controllers. This cable is a simple “Y” shaped common bus made from CAT-5 network cable. The network cable is cool for the job because it’s already got 4 twisted pairs […]

I know why the drivers heat up

September 16, 2014

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Njay: I think I know what warms up more in the drivers. It must be the transistors that pull the N-FET up (to turn on), Q3 and Q8 in the schematics. When it’s ON, pumping current into the capacitor that is the MOSFET gate, is dissipates a lot of heat because it is being fed […]

Bridge supports crafted

September 15, 2014

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Njay got me not just the bridges but also some kind of ultralight plastic material plank to use as support for them. This mechanical support is of critical importance for the survival of the bridge circuits, because the only mechanical attachment between the bridges and their big heavy heat sinks are the electrical pins of […]

Power bridge status point & To-do list

September 14, 2014

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Njay: Status point, so that we both know where things stand. Both bridges have only 1 N-MOSFET connected, via a 100Ohm resistor. This is the configuration that tested the longest time, so I’m sticking with it. The gate resistor on the disconnected FET is removed (there is a pull-down that keeps the FET off). However […]

Christmas time!!!

September 13, 2014

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NJay: Look what I brought you… Vnevoa: YESS!! 🙂 My turn to play with them!! 😀 And as soon as I got home I tried them out for size on the chassis… (to be continued…)

Power bridges ready. Or maybe not.

September 12, 2014

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Njay: Hi, something happened. No, I didn’t burn the bridges. 🙂 But I goofed up again. Before handing them over to you I wanted to make a specific measurement now that I’ve got a 4 channel oscilloscope: to see the Vgs & Vds voltage wave forms in 2 parallel FETs. It’s a tough one to […]