Previous in Forum: Diode with Half Arrow Symbol Means?   Next in Forum: 3 VDC to 1.5 VDC
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
3 comments
Rate Comments: Nested
Klevor007
Member

Join Date: Feb 2013
Posts: 5

Help on Finding Maximum Switch Speed

02/08/2013 6:49 PM

Trying to find a means to calculate speed decay time for amps in flyback capacitor circuit to get faster than L/R time constant.

H-bridge- mosfets W/ snubber and 2600uF Cap

8 coils in series, @ 11.40 Ohms each, Inductance 56567uH each. Voltage 0-74 varible at 5.5 amps each coil. coil capacitance varies from 4.5uF @ 10Hz to .13720 @ 1.8kHz.

If I do the L/R = t I get 4950 is that micro seconds? If so how do I figure that into switching time?

Also the coils are pulsing Perm. Magnets W/ 5000 Gauss, will this add to the flyback effect?
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
kvsridhar
Guru
India - Member - New Member

Join Date: Sep 2009
Location: Temporarily at Ashburn, VA
Posts: 2744
Good Answers: 164
#1

Re: Help on Finding Maximum Switch Speed

02/09/2013 7:18 AM

i have no clue about flyback capacitor or anything even remotely electronic. However, i use L/R my field of switchgear. As far as i know, with L in henries, and R in ohms, L/R is in seconds. Where does capacitance come in this? i have no idea. RC is a separate time constant.

Good luck, maybe someone will know the answer.

__________________
 Nothing worthwhile can ever be taught, it can only be learnt.
Register to Reply
olehwi
Power-User

Join Date: Jun 2010
Location: Canada
Posts: 139
Good Answers: 6
#2

Re: Help on Finding Maximum Switch Speed

02/09/2013 11:10 PM

You need to show a diagram . . .
Register to Reply
Winfield Hill
Power-User

Join Date: May 2010
Location: Cambridge, MA
Posts: 390
Good Answers: 82
#3

Re: Help on Finding Maximum Switch Speed

02/10/2013 9:04 AM

It's easy to go faster than the L/R time constant by overdriving the system. The topic was discussed at length in a July 2012 thread, Safe Way to the Reverse Polarity of a Electromagnet, where I posted circuits and waveforms. I'd be happy to answer any questions here for anyone who reads that thread. The O.P. of this thread, Klevor007, is in contact with me by email, and I'll be sending him some useful files.

__________________
 Thanks, Win
Register to Reply
Register to Reply
Have a Different Question?
3 comments
Copy to Clipboard

Users who posted comments:

kvsridhar (1); olehwi (1); Winfield Hill (1)

Previous in Forum: Diode with Half Arrow Symbol Means?   Next in Forum: 3 VDC to 1.5 VDC

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (129 right now)
Show Members
Advertisement