PWM current multiplication effect

[fechter]

If you want to monitor motor heating and efficiency, an ammeter between the motor and controller would probably be the easiest thing. It would also give you some interesting data. If the controller goes discontinuous, the motor amps will drop, and you'd see this in the meter.

My current mode throttle circuit could easily be modified to measure the motor current with a brushed motor. This would automatically compensate for any current multiplication going on in the controller and give you a pure torque control. It could also limit the current to a safe level that would prevent overheating no matter how steep the hill. You could still stall though.

I built a similar thing for the regen current limiter on my Zappy. When in regen, the torque was almost perfectly constant over a very wide speed range.

 

[safe]

My current mode throttle circuit could easily be modified to measure the motor current with a brushed motor. This would automatically compensate for any current multiplication going on in the controller and give you a pure torque control. It could also limit the current to a safe level that would prevent overheating no matter how steep the hill. You could still stall though.

This would work for "Boost Control" too right?

That's the preferred way to deal with this issue. It's better to just incorporate the "effect" into the normal limits so that it's the controller that prevents a problem rather than having to gear your bike so high that it avoids it that way.

An unrelated issue:

While I'm still able to write this post, my Big Screen TV seems to have lost it's ability to hold it's blue color horizontal adjustment. (happened this morning) I bought the thing in 2002 and it's been running a lot since I've been using it for both my computer and my TV. What do you think the chances are that it's something that can be fixed?

Since I've actually gotten "burn in" already on this TV (from the computer) I'm not that crazy about keeping it alive, but it was still a $1500 TV five years ago. These days you can get the plasma screens for about a thousand.

So now I'm running on a TV that has a failing screen and an old Windows 98 computer... looks like I'll have to spend some money again...

Back onto an older TV and a regular computer screen for now. I'm "functional" again. (much crisper picture with a computer monitor)

 

[xyster]

While I'm still able to write this post, my Big Screen TV seems to have lost it's ability to hold it's blue color horizontal adjustment. (happened this morning) I bought the thing in 2002 and it's been running a lot since I've been using it for both my computer and my TV. What do you think the chances are that it's something that can be fixed?

Oh fun.... Is it a rear projection with CRT tubes? If so, good luck fixing it. In the process of moving recently, our early 90's big screen took a whack and went out of alignment. I've tried everything, but haven't been able to fix it. I even removed the tubes and tried draining the CRT coolant, cleaning the insides, replacing the coolant and realigning everything from scratch. Didn't help at all. All three colors are wildly out of alignment. Aligning two in one plane invariably screws up any other proper alignment. It's like trying to solve Rubik's Cube without a book of patterns available. CRT's suck! 15 years old, this TV isn't worth the money it'd take to pay a pro to try his or her hand. Next TV is going to be LCD. Thank you for giving me this venting opportunity. Ahhhh....I feel much better now!

 

[safe]

CRT's suck! 15 years old, this TV isn't worth the money it'd take to pay a pro to try his or her hand. Next TV is going to be LCD. Thank you for giving me this venting opportunity. Ahhhh....I feel much better now!

At least you got 15 years out of it. Mine lasted 5 years, that's 82 cents a day. Here in Missouri the lightning is so intense that even with the surge protectors there's a constant attack on your system even when it's off because it's still "on" when it's "off". You have to disconnect the plug completely to prevent the surges (hard to do it all the time). Seems also that the surge protectors lose their "tightness" over time so once a large storm hits your area everything is potentially going to go bad unless you constantly replace them. We had a "direct hit" of lightning last year and several of my electrical appliances developed problems afterwards. (those that were not protected) At the time I'm pretty sure my tv and surge protector were unplugged.

Anyway... in 2002 a 42" 720p CRT cost $1500 and an LCD cost $4000. These days an LCD can be had for $1000. So compared to the $4000 I "COULD" have spent I'm still doing okay.

 

[Lowell]

Screw the TV, just download torrents for whatever you want to watch. We sold ours a while back, and I haven't missed it one bit. The extra space is now occupied by a soldering station and various more useful electronics.

 

[fechter]

CRT's make fun target practice. I shot one with a reloaded .38 wadcutter and the bullet bounced off the screen without breaking it. I thought I had missed at first (unlikely), but on close examination, I could see the lead streak where it hit. Amazing.

The next shot I used a .44 mag. It makes a cool sucking sound when the vacuum breaks.

 

[xyster]

next shot I used a .44 mag. It makes a cool sucking sound when the vacuum breaks.

 

[TylerDurden]

>>>

 

[fechter]

You just need to ask yourself one question:
DO YOU FEEL LUCKY?