I would suggest a Pipe mounded in a drill press with Outer Diameter of your hole size. Then use mirror grinding grit (or sand) with water to do the actual...
I just got this official announcement from Parallax, so I thought I would pass it on. For those of you that like the Basic Stamp, Parallax is now offering a...
oh dear - I still don't think I understand this. Here is what I think I have read: For applications that need good position control and/or have low inductance...
A little late on this thread, but you could just de-tune a regular RF unit. I like the ones from Linx, Bruce at Rentron has 'em. All you would have to do is...
Good ideas. I will look into both the RFID idea, as well as the wireless mouse hacking. Thanks for the input! Scott ... running) ... components. ... sight....
3 intresting ideas have been presented to me recently that I would like to get feedback on and start a brainstorming session online. 1. Hedge trimming...
Hi Chuck, What an excellent digression/summation! Thanks! Kenneth once posted a method for doing a current-sense feedback hardware mod that allowed a direct...
Hi, David, ... [...] ... (Here's a digression on precision motion control that may be of interest.) Perhaps "the difference" is related to the application. In...
On Wed, 3 Nov 2004 06:52:09 -0800, "Larry Barello" <yahoo@...> ... I use sign-magnitude PWM on all my robots, but I do not ever pulse the enable pin. I...
Again, I repeat, and who said data sheets examples are optimal? DON'T USE THE ENABLE LINE!!! Think about it: with LAP the H-Bridge is ALWAYS connected to the...
Hi ... Any idea why? Did the standard PWM work properly at lower frequencies? That is what I've determined. Standard enable-pin driven PWM works fine at 120...
Many years ago, when starting out, this is precisely the behavior I saw in my robots. The solution, it turns out, is to not use the ENABLE line for PWM. Use...
In a legacy project I used 18200's with Clifton Precision motors and had an identical experience with different duty cycles between standard PWM and LAP that...
... [...] ... I don't think this is quite right. There *is* regenerative charging during the "dump the magnetic energy" period. If you are in a heavy...
Yes, a MOSFET gate driver is just what you need. They typically take a 5V logic-level input, and output a 12-15V (depending on supply voltage) gate drive...
Hi Ted, I've used sign-magnitude PWM on several robots, with a PWM freqency of 120 Hz. The SM works fine at that fq, but the LAP is pretty rough, and eats the...
David, I noticed this EXACT same issue with the L298N sign-mag...not getting motor motion until 50% duty. I am running at 20khz. I am using cheapie, ...
You could detect a brownout by having the raw solar cell voltage go through a resistor divider run that output into a comparator. The other leg of the ...
Hi Ok, I'm driving two Pittman 8712's with an L298N H-Bridge at 24 volts. With locked-antiphase PWM at 50% duty cycle, I get: 10 kHz = .066 A 15 kHz = .056 A ...
Thanks, Dave, that helps. I can't get the line follower down in that range. Well, I could turn two of our current light sensors into a line follower, that...
... It's pretty dang cheap - the most expensive thing will most likely be the batteries for the project. Some small, DC motors with direct-drive from the ...
I don't have the junkbots book here right now. I'm sorry, it's been months since I read it. I'm wondering if you had to buy components, how much do you think...
I have two 4W maxon 40mm F type motors, I am using these on a test robot platform for the magnetic compass sensor I am working on. I have a motor driver with...
Dave, the trade off comes in two flavors: Switching losses and current ripple. Current ripple is the ebb and flow of current from the voltage switching from...
Hi all, I am a high school student and have built a radio control lawnmower as a science project. I am using a Futaba R/C system and pwm to control 12V motors...
Not the most scientific method, but it is often very easy to write software to output a number of different frequencies. Just step through them observing the...
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Nov 2, 2004 2:04 am
We would like to remind you of this upcoming event. Monday Night Chat Date: Monday, November 1, 2004 Time: 7:00PM - 9:00PM PST (GMT-08:00) Monday Night Chat...
We would like to remind you of this upcoming event. Monday Night Chat Date: Monday, November 1, 2004 Time: 7:00PM - 9:00PM PST (GMT-08:00) Monday Night Chat...
