Ammar

118 reputation

bio	website
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	age	19
visits	member for	11 months
	seen	May 15 at 9:05
stats	profile views	12

I'm doing my Bachelor's degree in Electronics. Known for being lazy.

	118 reputation	bio	website		visits	member for	11 months
7 badges		location			seen	May 15 at 9:05

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Apr 15	accepted	Feedback for DC Motor Speed Control using PID
Apr 15	comment	Feedback for DC Motor Speed Control using PID Well I don't think I'm going to get any more answers and I've decided to go with an optical encoder. I appreciate your help on the matter!
Apr 13	comment	Feedback for DC Motor Speed Control using PID This is a great idea! I have a couple of questions though. Could I not do as Anindo Ghosh mentioned in a comment and use a frequency to voltage converter instead? Then I could invert the output voltage for negative feedback. On the other hand, if I use v to f conversion, I understand how the phase comparator would work but how would a XOR gate work? Logic chips are allowed and thank you for your help!
Apr 12	revised	Feedback for DC Motor Speed Control using PID deleted 16 characters in body
Apr 12	comment	Feedback for DC Motor Speed Control using PID @ChrisStratton : It doesn't matter if the range is limited since it's only meant to be a proof of concept. So basically I could use a multi-turn pot and connect it to a differentiator op-amp? This would also give me an output voltage proportional to the velocity right? Thanks for the idea!
Apr 12	comment	Feedback for DC Motor Speed Control using PID @DaveTweed : Sorry I seem to have misused the word. What I mean to say is, I can't use a tacho generator for this project because they're generally too expensive,unless there are more cost efficient options available. How would I go about using the back EMF? This is actually a project for my Control Systems course.
Apr 12	asked	Feedback for DC Motor Speed Control using PID
Nov 16	accepted	RC time constant in astable multivibrators
Nov 15	comment	RC time constant in astable multivibrators Thanks the link was very helpful. However I still don't understand why we use the time it takes to move halfway to its final value while charging. Is it just an arbitrary value we used for convenience? I feel like I'm missing something obvious..
Nov 14	awarded	Commentator
Nov 14	comment	RC time constant in astable multivibrators Thank your for replying. I'm still somewhat confused about this. If the values/formulas vary, then why is the same formula used with transistor based astable multivibrators? Is it just a coincidence? Also isn't the LS123 a monostable multivibrator?
Nov 14	asked	RC time constant in astable multivibrators
Nov 12	comment	Decoupling caps with PICs @Kaz - Thanks for the suggestion but I looked through the datasheet and wasn't able to find it. I might have missed it though.
Nov 12	accepted	Decoupling caps with PICs
Nov 11	comment	Decoupling caps with PICs @WoutervanOoijen - To be honest I was concerned about this. I was considering adding a dc jack along with the battery but it seemed odd for my project(digital thermometer). Do you have any suggestions?
Nov 11	comment	Decoupling caps with PICs Thank you! That makes sense but I have one more question. Why do we even need those caps at all considering that the source is pretty stable? Is it just a precaution?
Nov 11	asked	Decoupling caps with PICs
Nov 4	accepted	Bjt astable multivibrator questions
Nov 4	comment	Bjt astable multivibrator questions @OliGlaser - Well I got it working. I might decide to use a dual gang pot or something. I'm going to mark this as solved but I have one little question. These circuits are using common emitter configurations. You mainly use these for voltage gain or inverted output. The voltage gain is -VC/VB (ICRC / IB RB). So basically the voltage gain is really small and we're using the inverted output for switching right? Thank you for all the help!
Nov 3	comment	Bjt astable multivibrator questions Thank you for replying. I plan to use 10nF caps with high resistor values at the base. That's ok right? For my application it might make it a bit more confusing to calculate the frequencies but would using a single pot still be acceptable? (to get a range from around 30kHz to 45kHz or so)