Thursday, April 23, 2009

Gizmo Interface update.

As with any new item there is a testing and tweaking phase, then add a feature and do more testing and tweaking. The Gizmo Interface is coming along nicely. Variable regen is working on demand and the other basic functions work too.

Currently, while driving forward, I can press the activate regen button and vary the regen current with the throttle trigger. Unfortunately the controller only has a regen range of 50% of the max setting to the max setting. I wish it had a high and low setting so I could get a wider range of regen. I ran it with 250A max regen for a while but the low end was a little too agressive. I lowered the max to 200A which makes the low end more useable but I don't get the agressiveness I like at the high end.

I can also get regen if I pull the throttle while pulling on the brake. This is useful when doing a panic stop and you forget to hit the activate regen button.

I found a controller setting where the regen voltage can be changed. At first I thought this was an input voltage that the controller read to adjust the regen amount. In testing I discovered that this is the voltage in the armature (I think it is the difference in voltage but I'm not sure) at which point regen stops. I lowered this from 2.00V to 0.50V and now I get regen down to about 4mph. At these speeds the motor is spinning too slow to charge the batteries and it actually is a drain on the batteries. The batteries supply more current than generated at around 10mph but I'm trying to save the brake pads, not extend range. While I don't have a way to test it, regen probably comes out a wash as far as extending range goes. However, making the brake pads last an extra 500+ miles would be a great thing. As I expected, the motor doesn't get a chance to cool down during the coasting to a stop phase so it tends to warm up a bit. I'll probably add a blower to the motor to compensate for this. My 2 mile 400 foot elevation climb (most of this is in 1 mile) tends to heat things up quite a bit. I regularly see 250+A out of the battery. I'll have to check the armature current some time to see what it is.

The actual setting which controlls the regen amount is the Footbrake setting. I set this to come on at a voltage a little higher than the acceleration voltage and be at max just below the maximum voltage the throttle trigger sends out.

Next up: My new splash pannels. (Thanks goes to Fred in FL with Gizmo #30.)

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