Search found 831 matches

by Njay
Jun 24 2017 1:53pm
Forum: Battery Technology
Topic: LTC6811 Implementation Thread
Replies: 134
Views: 18210

Re: LTC6811 Implementation Thread

Just a potentially stupid question, but I'll risk anyways: Do those cells unbalance so much/often that you need to have an on-board balancer?
by Njay
Jun 21 2017 1:57pm
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4019
Views: 363953

Re: OpenSource firmware BMSBattery S/Kunteng KT controllers

I was looking at your map() and I have a great integer calculation coding tip for you :D When doing integer divides you should round the result to the nearest value. The integer division always drops the fractional part, which means for example that if both x and y are integer values and x / y = 1.9...
by Njay
Jun 12 2017 1:18pm
Forum: Motor Technology
Topic: DIY controller 48V/1000W with bluetooth Atmega328PB
Replies: 18
Views: 2593

Re: DIY controller 48V/1000W with bluetooth Atmega328PB

Very nice project, thumb's up :)
by Njay
Dec 12 2016 5:34pm
Forum: Motor Technology
Topic: How to determine the caps parallel to the DC-supply.
Replies: 12
Views: 1064

Re: How to determine the caps parallel to the DC-supply.

I use 2 x 330uF "low ESR" 105ºC electrolytics (can't remember the brand and the controllers are not with me) in a pair of 24V 250W controllers without any issues, and they don't warmup noticeably. Just for some reference.
by Njay
Dec 10 2016 8:48pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24280

Re: OSHW TO247 IGBT watercooled laminated half-bridge

When polypropylene caps are involved, it means much lower total capacitance at the power input than with electrolytics, and we may accidentally hit resonance territory (you don't need to be spot on to be affected!). Controllers in this power range made with electrolytics need to have lots of them be...
by Njay
Dec 10 2016 8:27am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24280

Re: OSHW TO247 IGBT watercooled laminated half-bridge

It's not the bridge's layout stray inductance, is the one from the battery - controller (the caps) loop (mainly wiring; depends on how long and far apart are the battery cables and such).
by Njay
Dec 09 2016 7:11pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24280

Re: OSHW TO247 IGBT watercooled laminated half-bridge

You want to stay away from the resonance frequency of the battery - controller(power input caps) parasitic inductance with the controller's power input caps.
by Njay
Dec 03 2016 3:08pm
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1820
Views: 224843

Re: Lebowski's motor controller IC, schematic & setup, new v

I guess you could implement a double pulse test in the chip, Lebowski. Here's a suggestion for a future release.
by Njay
Dec 02 2016 2:39pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 24280

Re: OSHW TO247 IGBT watercooled laminated half-bridge

What PWM frequency are you planning on using, Marcos?
by Njay
Nov 29 2016 11:47am
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1820
Views: 224843

Re: Lebowski's motor controller IC, schematic & setup, new v

You can also try an "old" patch Tomdb. Feed the uC's positive rail through a schotky diode and then a 100uF+ "decoupling" cap (keeping the uC's 100nF pin decoupling caps, of course). This prevents transient drops in the "global" supply rail from affecting the sub-circuit after the diode, where the "...
by Njay
Nov 26 2016 4:33pm
Forum: Motor Technology
Topic: DC Motor Controller Problems
Replies: 4
Views: 772

Re: DC Motor Controller Problems

Jeeez, I think you're right Terry, he seems to be doing asynchronous rectification, which definitely has the other FET heat up as hell.
by Njay
Nov 25 2016 3:09am
Forum: Motor Technology
Topic: DC Motor Controller Problems
Replies: 4
Views: 772

Re: DC Motor Controller Problems

First thing is Terry's point one.

Then I would remove FETs leaving only 1 per leg and re-test (would be easier if you had 1 pull-down resistor per FET).
by Njay
Nov 23 2016 6:12am
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1820
Views: 224843

Re: Lebowski's motor controller IC, schematic & setup, new v

Here is the ringing on the 5v currently, the question now is, is it enhanced by my measurement setup or is it really there. You need to have a very short GND connection to the probe, such as when using the GND spring, if possible. The aligator lead is enough to pick up interferences. If I measure l...
by Njay
Mar 06 2016 12:34pm
Forum: Motor Technology
Topic: Technical approach docs of the LittleBox Google challenge
Replies: 1
Views: 286

Technical approach docs of the LittleBox Google challenge

The winner has been announced for the LittleBox Google competition ("An open competition to build a (much) smaller power inverter, with a $1,000,000 prize."). The target is not a motor inverter, but it's still interesting to take a look at the technical approach documents of the finalist teams: http...
by Njay
Jan 03 2016 8:04pm
Forum: Motor Technology
Topic: Arlo's power stage Leaf controller runs and drives page 103
Replies: 2595
Views: 245902

Re: Arlo's power stage.... New pics on page 78

Arlo1 wrote:(...) Today is a day I have been waiting for for a LONG time! Its going in the car :)
I now have confidence in the system. (...)
Hey Arlo, super! Congratulations 8)
Persistence always pays off.
by Njay
Jan 02 2016 9:32pm
Forum: Motor Technology
Topic: Arlo's power stage Leaf controller runs and drives page 103
Replies: 2595
Views: 245902

Re: Arlo's power stage.... New pics on page 78

ha, i think only the keenly interested like yourself are reading to that level of detail. it's a type-O, now that you show it. at least in that version posted to ivan's forumn. it should read VP15_UT which is stands for voltage positive 15V phase-U top. anyway, with the diode going form gate to the...
by Njay
Jan 02 2016 8:18am
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1820
Views: 224843

Re: Lebowski's motor controller IC, schematic and setup manu

Arlo1 wrote:Yes I use a 13.8v power supply for everything. Then from there the 5v and the 10v isolated supplies on the brain have their own liner regulators.
How about the grounds? If they move between the 5V and the 10V system you get a change in the sensor's output too.
by Njay
Jan 01 2016 8:33pm
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1820
Views: 224843

Re: Lebowski's motor controller IC, schematic and setup manu

The problem with most current sensors is they need a voltage applied to produce the 2.5v at neutral but the 2.5v can be off a bit depending on all the power supplies. I have a supply for 5v for the brain one for 10v for the sensors and then 2:1 divider resistors. And if any of those components are ...
by Njay
Aug 18 2015 8:55pm
Forum: Motor Technology
Topic: Arlo's power stage Leaf controller runs and drives page 103
Replies: 2595
Views: 245902

Re: Arlo's power stage.... New pics on page 78

Which 2 slopes? On the turn on it starts with a slow slope then a second faster slope. Blue trace as you asked for on the left side where is goes down. When it goes up its a off event that I need to address. Isn't the dual slope due to reverse recovery ? Isn't reverse recovery starting only when cu...
by Njay
Aug 15 2015 12:20pm
Forum: Motor Technology
Topic: Arlo's power stage Leaf controller runs and drives page 103
Replies: 2595
Views: 245902

Re: Arlo's power stage.... New pics on page 78

Which 2 slopes? On the turn on it starts with a slow slope then a second faster slope. That's caused by the total power loop inductance (the loop formed by the DC link caps and FETs). As the FET opens, current starts to circulate and it's the caps supplying it; but the inductance in the loop doesn'...
by Njay
Aug 15 2015 10:04am
Forum: Motor Technology
Topic: Arlo's power stage Leaf controller runs and drives page 103
Replies: 2595
Views: 245902

Re: Arlo's power stage.... New pics on page 78

The on looks fine. I am working on the off events its what needs attention if I make the off better I might then re-visit the on and see If I can speed it up. But for now its fine. yes I know, this is just data to try to estimate your layout's inductance. Here is a picture. The Blue trace Is E-C (D...