Browsing All Posts filed under »Design«

I know why the drivers heat up

September 16, 2014


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 […]

Power bridges ready. Or maybe not.

September 12, 2014


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 […]

Enough painting already!

September 7, 2014


We’re getting to the end of painting the Trike, so I’ve started reassembling it. The seat is going to get new upholstery, and I’m still thinking about paint details but not obsessively. 🙂 I’ve probably overdone it already with the hot-rod theme… 😀 Hey, it’s all in the name of fun any way! A safety […]

Paint job design

August 26, 2014


Vnevoa: Hey, Jo, do you remember this painting you did 2 years ago, at Manuel’s house? [She was 6 years old back then.] Jo: Yes, I do. Vnevoa: Do you like it? Would you still like to paint it like that? Jo: Yes. Hmmm…. I don’t know. No. Vnevoa: Cool. Let’s try colouring it again. […]

PCBs out to fabricate

August 22, 2014


Njay: The board has been sent to the producer. Don’t know how long it’s gonna take, but it should only be a few days if all goes well. This is what they’re going to look like if professionally produced… Vnevoa: Cool! 🙂 Can’t wait to build it and try it. Have you selected the other […]

First add-on PCB

August 21, 2014


Njay: Routing complete, ugh! Next I gotta print this and do an assembling mock-up, see if the components fit and all that. If everything goes well, I’ll have a pair of PCBs made and I’ll order the components. I’ll also see that the stuff is loaded into the git repository. Vnevoa: Jolly good show, partner!!! […]


August 20, 2014


Vnevoa: So, summing up today’s talk… Implementation objectives for the Maker Faire, by order of importance: 1 – measuring and limitation of instant current; 2 – reliable communication; 3 – measuring and communication of current + bridge temp + motor temp. Did I forget something? Njay: 0 – Verify the bridge behaviour with normal working […]

First Add-On board schematics, speed sensing, Faire

August 19, 2014


Njay: Ok, new revision with LEDs for the I²C on both sides of the insulator, with a port for the motor temp sensor and a second sensor for the bridge temp (there’s 2 heat sinks per bridge). At the moment not providing for the external speed sensor. Using a Hall or other type where we have […]

Open source repository, new add-on board

August 17, 2014


Vnevoa: My recently acquired mastery of Git has allowed me to split the GitHub repository into several branches. If you please: git clone -b MarkIV_RasPi_NJAY DiffTrike and put everything under /NJAY. There’s a README there so you can fill it with your inspirations and a “header.gplv3” that you can add to all your source files. […]

Main goals

August 16, 2014


Njay: MUST DO: 1 -Was it the RasPi or the bridges who reset? Yep, we better insulate them galvanically, although that ain’t simple. My opto scheme won’t do, it’s too slow and this protocol is too time-sensitive. To maintain a bi-directional protocol with a the clock line (like SPI or I²C) we need 3 lines […]