Motor controller engineering test. continued

[shades2]

AC&DC Music Factory... :)

[DanFrederiksen]

@shades2 : )

[billhac]

hi dan, i looked at your circuit, it looks great, thanks for the video, i was wondering if you would share the C code with me so i can do some tests of my own, im just learning how to program the atmega 8 and i dont think i can design the code myself.

[DanFrederiksen]

@billhac this is ongoing code so I don't remember if it even compiles zev. dk/design/DCcr1/DCCR1.c

and it's for throttle control, like in the other video with the motor.

this might be the pulse code you see in this video but no guarantees: zev. dk/design/DCcr1/Pulse-Atmega8-­test.c

[billhac]

@DanFrederiksen thanks dan, how does that powerex dc converter you use handle the load, i see you only have one igbt in the circuit, have you tried it with more than one?

[DanFrederiksen]

@billhac I've tried with 3 and it should be able to handle many more.

the limiter is the driver, it might not like more than 6-8 typical TO247 IGBTs depennding on frequency

[billhac]

@DanFrederiksen what are your thoughts on paralling the powerx units, or just combining the 2 outputs for more current IE tieing the 15v and 5v together to maybe get 550 ma from the unit, right now i have a circuit that uses 2 lm339s to create the pwm and monitor temp and current so i dont need the 5v output but would like more avaliable current.

[billhac]

@billhac i also am working on learning code for the atmega 8, and i know once i have a working circuit i will need that 5v input.

[ehlers299]

Doesn't repeatedly turning devides on/off use more of the battery rather than steady power

[DanFrederiksen]

@ehlers299 there are some switching losses but it's relatively modest. the problem is that we have no technology that can deliver steady power efficiently. switchmode (in this case around 1000 times per second) can be nearly 100% efficient. it is possible to have a transistor turned half way on but the problem is that the way it limits the flow is with resistance meaning that at 50% on it wastes the other 50% of the energy. that's why we shift between full on and off and use timing instead

[ehlers299]

are you testing this for future automotive uses

[DanFrederiksen]

@ehlers299 I might soon make a prototype that will be tested by an electric motorcycle company yes. open source and simple so everyone can make their own or even start production. cost optimized

[DanFrederiksen]

: )