Controller failure after alarm trigger...

[Cornelius]

Ok I took all that on board.

The nets playing up so I had not loaded all the messages before I hit reply.

Its the nature of the damage that is curious.  A shorted fet!

Which fet out of the six did you replace?

Looking at the 'fet-side' viewing the backside of the fets with the legs towards you, the fifth...

[Cornelius]

What I was a bit surprised of, was the way the fets are connected thermically to the chassis... A steel-bar on the opposite side of the pcb, pressing the fets against the chassis, with a thermal rubber-mat between the fets and the chassis, and alot of thermal paste beneath that mat. the screws that held the steel-bar was not very tight, which I can understand, because tightening it could risk cracking the pcb...

It could be a bad thermal connection for the blown fet?

[Bikemad]

Which fet out of the six did you replace?

Looking at the 'fet-side' viewing the backside of the fets with the legs towards you, the fifth...

This one?

[Leslie]

Got your fith drain there, if the 55v fet holds up you got a bad draw.

Hey when the wheel lock goes on does the hub jolt?

[Leslie]

Which fet out of the six did you replace?

Looking at the 'fet-side' viewing the backside of the fets with the legs towards you, the fifth...

This one?

Hey Bikemad.

How does the anti theft system work?

Does it send PWM to all the phase wires to lock up or does the controller short the phase wires?

Or some other method?

[Bikemad]

Hey Bikemad.

How does the anti theft system work?

Does it send PWM to all the phase wires to lock up or does the controller short the phase wires?

Or some other method?

I only have the Magic Pie which is not wired to allow it to be used, so I don't know.

I assume it would have to apply current to at least one phase in order to lock it up solid, if it just shorted the phases together, it would only cause heavy drag while turning.

Alan
 

[Leslie]

I assume that the anti theft must engage the phase channel/s that is/are active via the sensor logic.

I cant see anything wrong with this topology unless the PWM was brutal.

The anti lock must work from the forward reverse Fets and that is what has gone here.

[Leslie]

What would happen if you bypassed all sensors and made them to be on and fed 10% throttle to the hub,

Would this work too?

I can think of a few ways that it may work.

Actually owning one would help.

[Cornelius]

Yes, Bikemad marked the right one.

When it locks up, the wheel rattle alot, but doesn't move far; the rim of the hub moves aprox. 0.5-1cm randomly back and forth...

I'm guessing full throttle at 50-100mS durations on single phases in random sequence; that would make this kind of racket... The noise doesn't sound healthy, so i'd imagine that an determined thief would blow the controller...

[Leslie]

Yes, Bikemad marked the right one.

When it locks up, the wheel rattle alot, but doesn't move far; the rim of the hub moves aprox. 0.5-1cm randomly back and forth...

I'm guessing full throttle at 50-100mS durations on single phases in random sequence; that would make this kind of racket... The noise doesn't sound healthy, so i'd imagine that an determined thief would blow the controller...

I had this feeling that when that jolt happens, it happens a little on my Ecrazyman sensorless controller, the wheel sometimes goes backwards to sync up and then hits forward, you get a doink.  I think thats been a reason for the lesser voltage version of Ecrazy controllers going out.  Almost similar behaviour.

Ive run it through my head 10 times.  I can see some awesome forces bouncing around between the output fet, and motor hammering at the barriers.

Most cases the MC fets should be able to take a good wooping. This seems to sort out any flaws in any switch real fast.

[Cornelius]

Just a Fyi:

I have ordered some new P140NF75 Mosfets to replace the P55NF80 one I use now. I haven't had any problems with the 55V, 80A Mosfet so far, but i'll feel better having the right Mosfets in place...

I managed to flush my 20A solar regulator with water here the other day, with the result of two blown IRFZ48 Mosfets This triggered the need to order some components, and I barely remembered the one in my GM controller...   

[Leslie]

There is no reason you cant use different FETS.  There is a similar version of FETS GM use with different qualities.


Interesting to know the 50v fet is holding up.

STP160N75F3

Type                 VDSS        RDS(on)          (max.)ID

STB160N75F3       75V         3.7 mOhm      120 A(1)
STP160N75F3       75V         4 mOhm         120 A(1)
STW160N75F3      75V         4 mOhm         120 A(1)
1. Current limited by package


Symbol                         Parameter                                      Value                                   Unit

 VDS                Drain-source voltage (VGS = 0)                    75 max                                   V
 VGS                Gate-source voltage                                  ± 20 max                                 V
 ID                   current (continuous) at TC = 25°C Drain        120 max                                 A


VGS(th)             Gate threshold voltage VDS= VGS,                250uA                               2 Min          4 V max


This package is good and it has a very low on resistance.

Where as P140NF75

75 V    .0075 ohm  120 A

Those still have the good on resistance but the STP160N75F3 has the resistance of half the GM FETS but rated at 75v.  Some resistance maybe safer for the fets though it would be interesting to learn more.

[Leslie]

:


I managed to flush my 20A solar regulator with water here the other day, with the result of two blown IRFZ48 Mosfets This triggered the need to order some components, and I barely remembered the one in my GM controller...  

Solar regulators.

I had been using this relay out of a dead controller for months.  Its nothing special but accurate enough.  Cant take bumps though, cost me near nothing and seems very reilable and electrically strong.  



It just switches the panels through to the big 5 watt resistor when the battery voltage reaches 14.8 and stays that wat until night and resets again.

I added another resistor where the yellow wire is cut.


Edit.

The relay can handle 20 amps electrically and has little resistance over the power contacts.  My one prolly requires 30ma or so to induce the latch so youre not using too much power to be concerned with.

If you wanted to use power in the daytime and have good acces to the panel during the day replace the big resistor with a standby voltage regulator that can handle more amps.

You can have this relay system for a backup power supply for if the switcher fails.  If it turns out more efficient then why not just use it.

[Cornelius]

Fets with lower resistance would mean not so much heat under load; might be a good idea in hotter countries where one has the controller locked inside a box... The rides i've had so far, has been in outside air temps of max 20deg C. Electrically, the 55V, 80A should hold up just fine on the 36V, 750W system; especially since each fet should only have to manage 1/3 of that power...

I do not know if the internal resistance does have a role to play in the GM controllers; it feels like the regen are a bit softer on my bike now, with that 55V, 80A fet, but that might just be me...

I've got 310W of solar panels and a batterybank with two Rolls S530 6V batteries in series (530Ah), connected together with a Steca PR2020 controller: http://www.stecasolar.com/index.php?Steca_PR_10_30_en
I'm using the solar power for lighting in my house, and to power my workshop in the basement where a 1000W inverter powers the powertools - and  charges my e-bike... (And for charging my lawnmnower, powered by a 36V, 2,7Ah battery (Bosch mower).)