Search found 31 matches
- Tue Jan 20, 2004 4:06 pm
- Forum: General Discussion
- Topic: Permanent magnet motors...
- Replies: 10
- Views: 6814
Re: Permanent magnet motors...
The "stronger" magnets will cause the magnetic flux (phi) to change. This will cause a different torque to be seen given a specific armature current. The equation for this is; t=k*(phi)*Ia where t is torque Ia is armature current and k is the motor armature constant k=Na*p/(pi*a) where p i...
- Fri Jan 16, 2004 6:36 pm
- Forum: Computer Programming
- Topic: pic c compilers
- Replies: 3
- Views: 5119
Re: pic c compilers
Thanks for the links, I never thought of using piclist to find out about C... it's great!
- Thu Jan 15, 2004 6:43 pm
- Forum: Computer Programming
- Topic: pic c compilers
- Replies: 3
- Views: 5119
pic c compilers
I am looking for a c compiler for pics than handles the 14-bit parts. Most specifically I need to program 16f872's and 16f77's. My most important need is a good math library. By this I mean one that has sin, cos, tan, arcsin, arctan, arcos... which compute in radians, not the 0-255 range of the BS2 ...
- Thu Jan 15, 2004 6:27 pm
- Forum: Robotics
- Topic: How PWM works?
- Replies: 21
- Views: 16200
Re: How PWM works?
Sunil, the physics is perhaps less important than the concept and idea. By varying the duty cycle, the time averaged amplitude is changed. Regardless of what is on the other end, if an o-scope is connected to a wire and a square wave is seen on the screen with a duty cycle of 50% with 5 V pk-pk, the...
- Mon Jan 05, 2004 8:46 pm
- Forum: Robotics
- Topic: DC Motor speed control help
- Replies: 8
- Views: 9132
Re: DC Motor speed control help
'Al' is correct, if your motor is going to be driving a load, then the feedback can (should) be fed into a controller which then varies the duty cycle in order to maintain a constant speed. However, if you are just concerned with driving a motor at a constant speed with no load or a very light load ...
- Sat Jan 03, 2004 8:33 pm
- Forum: General Discussion
- Topic: Schematic CAD program?
- Replies: 10
- Views: 7115
Re: Schematic CAD program?
There was a free version of 2-D Turbocad that may still be available on their web site. As far as schematic drawings, try the Orcad student version. http://www.orcad.com/downloads/demo/default.asp I use this software all the time not only for drawing schematics, but also flow charts and everything e...
- Sat Jan 03, 2004 8:07 pm
- Forum: Robotics
- Topic: DC Motor speed control help
- Replies: 8
- Views: 9132
Re: DC Motor speed control help
Do you want to use feedback control (closed loop system) or keep it as an open-loop system (no sensor feedback)? Assuming a closed loop system, there are two ways to go about this problem, the hard way and the "hard" way. The hard way would be to derive transfer functions for the dynamics ...
- Tue Nov 26, 2002 12:42 pm
- Forum: General Discussion
- Topic: Microphones
- Replies: 9
- Views: 9498
Re: Microphones
1 to 10 uf is a little to heavy. Without considering filtering, the capacitor is only blocking out the DC, so a small ceremic capacitor will work fine. In fact, feeding the signal through a .01 uf capcitor and pulling the side of the capacitor not connected to the microphone to ground with a 100k re...
- Tue Sep 03, 2002 8:15 am
- Forum: General Discussion
- Topic: defective crystal
- Replies: 3
- Views: 4058
defective crystal
What are the chances that a crystal oscillator would be defective?
- Mon Sep 02, 2002 6:23 pm
- Forum: General Discussion
- Topic: implementing finite state machines with PICs
- Replies: 3
- Views: 4379
Re: implementing finite state machines with PICs
I've reasoned it out. For applications where asynchronous aspects are required at low frequencies, the PIC will work fine. However, at high frequencies, this aspect may be better implemented on a traditional FSM. Additionally, the flow chart created for the FSM can be almost exactly implemented into...
- Mon Sep 02, 2002 6:11 pm
- Forum: Robotics
- Topic: Just currious...
- Replies: 20
- Views: 15811
Re: Just currious...
Try this link, http://www.frc.ri.cmu.edu/~hpm/project.archive/robot.papers/1999/SciAm.scan.html I read the article a couple of years ago. Moravec derives the speed computers must run at to compare to a human, very interesting. One of his books is basically devoted to this, Robot Mere Machine to Tran...
- Sun Aug 18, 2002 7:11 pm
- Forum: General Discussion
- Topic: Parabolic Microphone
- Replies: 13
- Views: 9473
Re: Parabolic Microphone
Edmund Scientific sells parabolic reflectors, here is a link to my first search under "parabolic". http://www.scientificsonline.com/Products/Search.cfm?SearchQuery_Required=Please+enter+a+search+query&query=parabolic+ <p>Satellite dishes should still be parabolic, or fairly close to it...
- Sun Aug 11, 2002 7:14 pm
- Forum: General Discussion
- Topic: implementing finite state machines with PICs
- Replies: 3
- Views: 4379
implementing finite state machines with PICs
Does anybody have any general tips or experience doing this, or ideas for directly going from a Moore or Mealy machine diagram or flowchart to a programming flowchart? <p>Douglas
- Sun Aug 11, 2002 6:58 pm
- Forum: General Discussion
- Topic: dusk switch adjustable sensitivity...
- Replies: 8
- Views: 6125
Re: dusk switch adjustable sensitivity...
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">code:</font><hr><pre> <pre><p>+12 0---/\/\---o---/\/\---0 GND CdS | Var. Res. | | --------- \ / \ / Schmitt trigger inverter +12 0----\ /----0 GND \_/ (_) | | |_________/\/\______ |b NPN __|__ +12 o_____/ \___|-----...
- Sun Aug 11, 2002 11:00 am
- Forum: General Discussion
- Topic: Need some basic stamp II help
- Replies: 2
- Views: 3663
Re: Need some basic stamp II help
All you really need is the BSII pinout. I have THE BSII carrier board, and it really isn't anything more than a protoboard with the programming port on it. So to build a carrier board, connect;<p>pin 1 of BSII to pin 2 of serial port (TX) pin 2 of BSII to pin 3 of serial port (RX) pin 3 of BSII to p...