(ET) E20 current draws update

Hi All,

I have the large mowing deck motors. I also have a PWM contolling the armature current and I switch in a power resistor (50 ohm) for field weakening when needed...kind of like a turbo switch. With no field weakening the drive motor was receiving full pack voltage on the armature and field. With field weakening the armature received full pack voltage and the field received approx. 7 to 8vdc (calculated). The no load battery pack voltage measured 38.0vdc at the start of the test. I did not measure the battery pack voltage sag with the different loads.

Here is probably the biggest selection of 14" blades with 3/8" center holes I have found...

http://www.oregonchain.com/OEP/oep_blades.htm

Tim

From: Tim

To: Elec-trak cosmos phy tufts edu

Sent: Tuesday, September 07, 2004 5:33 PM

Subject: (ET) E20 current draws

I measured the current draws of various areas of my stationary E20 for future reference with a digital clamp-on ammeter.

Mowing Deck only; suspended in air with original high-lift blades = 25.5 Amps.

Main Drive Motor, current of armature and full field, with transmission in neutral = 11.60 Amps.

Field current alone = 2.00 Amps, Armature alone = 9.60 Amps.

Main Drive Motor, current of armature and weakened field, with transmission in neutral = 17.00 Amps.

Field current alone = 0.60 Amps, Armature alone = 16.40 Amps.

Headlights = 4.00 Amps

Mowing Deck Lift Motor = 16.00 No Load. Max of 28.00 Amps to suspend deck level. 44.00 Amps just before stall.

Test conditions...Ambient = 70F. Battery charge = Full.

Tim