The Godfather talking
You may crack software. How about me?
Sonsivri
 
*
Welcome, Guest. Please login or register.
Did you miss your activation email?
March 29, 2024, 11:28:20 11:28


Login with username, password and session length


Pages: [1]
Print
Author Topic: [RQD]help with Pololu Pushbutton Power Switch LV  (Read 3481 times)
0 Members and 1 Guest are viewing this topic.
Wizpic
Global Moderator
Hero Member
*****
Offline Offline

Posts: 1195

Thank You
-Given: 539
-Receive: 408



« on: August 30, 2015, 10:32:03 22:32 »

I'm working on my milliohm meter and want to add an single push button for on then control it with auto off from the arduino  but the trouble is it runs off a3v battery (2x1.5v batteries)and then a step up converter to 5v and came across the Pololu Pushbutton Power Switch LV which works with 2.5v to 5.1v input, I can buy the mosfet used (FDS4465) but not sure how they do the latching circuit has can't find the rest of the schematic of that part (latching) anybody got any ideas about how they do it, I think it's just a transistor to hold the gate on then turn off the transistor off to turn circuit off or is the a better way with low current draw
Logged

When you think, "I can't do anymore. I need a break," that is the time to challenge yourself to keep going another five minutes. Those who persevere for even an extra five minutes will win in life..
bbarney
Moderator
Hero Member
*****
Offline Offline

Posts: 2430

Thank You
-Given: 405
-Receive: 545


Uhm? where did pickit put my mute button


« Reply #1 on: August 30, 2015, 11:15:43 23:15 »

http://www.eevblog.com/2012/03/30/eevblog-262-worlds-simplest-soft-latching-power-switch-circuit/

and  here http://www.eevblog.com/forum/projects/an-improvement-on-the-soft-latching-power-switch/
« Last Edit: August 30, 2015, 11:17:55 23:17 by bbarney » Logged

Ever wonder why Kamikaze pilot's wore helmet's ?
CocaCola
Senior Member
****
Offline Offline

Posts: 482

Thank You
-Given: 169
-Receive: 232



« Reply #2 on: August 31, 2015, 12:25:51 00:25 »

http://www.faqs.org/patents/app/20090237065

Or you can go to the real patent website and do a search for patent number 7,781,920

http://patft.uspto.gov/netahtml/PTO/search-bool.html

Click on the [images] button after you search to see the schematics...
Logged
Wizpic
Global Moderator
Hero Member
*****
Offline Offline

Posts: 1195

Thank You
-Given: 539
-Receive: 408



« Reply #3 on: August 31, 2015, 07:16:28 07:16 »

Barney I did see the first one but reading and playing with it on another project I found it was not good a bit hit n miss,did not see the second one looks good  but I want to be able to turn it off by the arduino will look more in detail at it may be I can add it.
Coca great find did not think about doing a patent search normally you don't find so much detail
Logged

When you think, "I can't do anymore. I need a break," that is the time to challenge yourself to keep going another five minutes. Those who persevere for even an extra five minutes will win in life..
Parmin
Hero Member
*****
Offline Offline

Posts: 582

Thank You
-Given: 494
-Receive: 133


Very Wise (and grouchy) Old Man


« Reply #4 on: August 31, 2015, 11:54:51 23:54 »

I am sure there are some SR-Latch made in SOT23 package.  that would definitely simplify the switching.

NC7SZ373
Logged

If I have said something that offends you, please let me know, so I can say it again later.
Parmin
Hero Member
*****
Offline Offline

Posts: 582

Thank You
-Given: 494
-Receive: 133


Very Wise (and grouchy) Old Man


« Reply #5 on: September 02, 2015, 01:10:24 01:10 »

Here is the schematic I use for the switching.
Logged

If I have said something that offends you, please let me know, so I can say it again later.
an007_rld
Junior Member
**
Offline Offline

Posts: 52

Thank You
-Given: 33
-Receive: 52


« Reply #6 on: September 02, 2015, 03:58:15 03:58 »

... personally I like this one (very reliable): http://todbot.com/blog/2010/01/02/momentary-button-as-onoff-toggle-using-555/
-an
Logged
Avalynn
Newbie
*
Offline Offline

Posts: 10

Thank You
-Given: 15
-Receive: 27


« Reply #7 on: September 03, 2015, 03:05:18 15:05 »

@Parmin for an SR latch like that would you require some method of debouching the switch since you are pulsing the clock?
If so would a simple RC sufficient for that purpose?
Logged
Parmin
Hero Member
*****
Offline Offline

Posts: 582

Thank You
-Given: 494
-Receive: 133


Very Wise (and grouchy) Old Man


« Reply #8 on: September 03, 2015, 11:04:12 23:04 »

@Parmin for an SR latch like that would you require some method of debouching the switch since you are pulsing the clock?
If so would a simple RC sufficient for that purpose?

Yes
Logged

If I have said something that offends you, please let me know, so I can say it again later.
Pages: [1]
Print
Jump to:  


DISCLAIMER
WE DONT HOST ANY ILLEGAL FILES ON THE SERVER
USE CONTACT US TO REPORT ILLEGAL FILES
ADMINISTRATORS CANNOT BE HELD RESPONSIBLE FOR USERS POSTS AND LINKS

... Copyright © 2003-2999 Sonsivri.to ...
Powered by SMF 1.1.18 | SMF © 2006-2009, Simple Machines LLC | HarzeM Dilber MC