intermittent cutoff

[erdurbin]

Well, I have a Watts up meter and watch my voltage anyway. Hopefully I will never have to go back to SLA!

[pdonahue]

   (R4 is already at zero)

...humm. Hold up a minute... to retain factory settings how about cutting the R4 trace and adding a 1.5k or even a 1.8 pot since decreasing cutoff is the more likely direction? This way you can experiment/adjust the setting with a voltmeter for whatever pack you use, excluding SLA/AGM of course. A two position external switch for zero resistance and 1.5k to replace R4 would be great as well. Never know when you might need those SLA/AGM's to go back into service.

Putting a resistance across R4 will increase the voltage.  But, your idea would work if you just replace R11 with a pot instead of R4 (more of a wire than a resistor really).  In fact, with pots replacing R4 and R11 it would be possible to go up or down.

Pete

Okay, my error... I was not doing the math, only the concept of using pots or multiple resistors and switches. So then with the right set of resistors and switches you would have controller with cut-off voltages for all battery types. Right?

Correct

[David Merrill]

Ok so I changed it like pete said, the r11, 1201 ohm resistor with a bigger (lot bigger in size in fact) 1.6k resistor and... it WORKs like a charm. no cutoff, on slope or against the wind... real cool. Thank you everyone for your help.
 

The note on the first photo says to make R4 larger or R75 smaller. The note is missing on the enlarged photo. So djimme has changed the reference voltage to a comparator, and by mistake completely defeated the LVC by making R11 larger. My additional evidence is that R4 is desoldered from the second Photo and marked with a red arrow - telling me that R4 is the one to increase by around 50%.

That is how I am reading this anyway. On one side of R4 is the reference voltage; maybe even 31.2V. It does not need to be 31.2V but it sets a ratio of 31.2/38-40V full battery charged.

I believe that when I get into my new controllers tomorrow I will set my Cyclon SLAs to 25V cutoff, from the unsatisfactory 31.2V by putting a 10K pot there across the removed R4 and adjusting the reference. Then I will solder a similar resistor in place. I will change that if need be when I upgrade to different batteries.


Thanks for all your help.


P.S. R4 is a solder bridge - a 0 Ohm resistor.

R11 is the 1.1K Resistor so I will replace that with 1.5K and test it out.

[David Merrill]

I fixed it and tested it. Crazy thing though, my fork broke - while I was standing still at a STOP sign - thank God.

Be careful to remove the rubber on the heat sink screws because if you round one, you have to drill it out.


Regards,

David Merrill.


P.S. Afterthought; light as that 1/4 watt resistor is, I should put a dab of hotglue on it so that there is no strain on the pads.

[hasadam]

Guys,
Is this formula....3.1*(R73+R4+R11)/R11 also valid for the 48V controller?

Thanks

[Bikemad]

As this thread relates to the earlier basic GM controllers, which are completely different to the new magic controllers, it is unlikely to apply to your controller.

Alan
 

[hasadam]

To be honest I don't know, if I got the old controllers or the new: I have bought 2 48V controllers in November 2009.

Thanks for Alan's prompt reply & support.
I will measure the battery voltage at the controller 48V inlet under load today to see the cut off voltage, if there is any.
I still have doubts that this is due to too low voltage...
I tested 2 controllers with the same result: Power Cut off when I want to start to throttle with impulse-type pushes 3-4 times per second.
But when I very very carefully & slowly rotate the throttle just below the cut off point, I can accelerate step by step.
When I reach a certain speed by this way, I can directly go to full stroke on the throttle & the motor goes to high speed.

Now I want to be very sure before I open the casing of the Controller & start soldering.

[Bikemad]

To be honest I don't know, if I got the old controllers or the new: I have bought 2 48V controllers in November 2009.

The old standard controllers looked like this:


The old regen controllers looked like this:


And the "magic" cruise controllers now look like this:


Alan