Predict this Toggle Circuits behavior - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th July 2006, 05:32 AM   #1
imix500 is offline imix500  United States
Proud Union Member
diyAudio Member
 
imix500's Avatar
 
Join Date: Mar 2004
Location: Nashville, TN
Default Predict this Toggle Circuits behavior

Hello all, so I needed a simple transistor based toggle/flip flop circuit to turn a momentary spst switch into a latching type. This circuit looks ok, but my question is will this circuit power up in the same state every time? If not, is there a way to modify it to do so? Thanks!
Attached Images
File Type: jpg toggle.jpg (24.3 KB, 632 views)
  Reply With Quote
Old 18th July 2006, 05:50 AM   #2
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Hi,

I don't see how this can toggle? Toggling normally involves saturating one half by for insyance pulsing its base so that the other side comes out of conduction, and vice versa. What you do here is momentary increasing the current in both halves. Tghe pushbutton should be between supply and one of the bases (with a series R of course).

The defined switch-on is normally done with something like a cap from supply to one base to delay that half so the other half switches on first.

Jan Didden
__________________
I won't make the tactical error to try to dislodge with rational arguments a conviction that is beyond reason - Daniel Dennett
Check out Linear Audio Vol 7!
  Reply With Quote
Old 18th July 2006, 06:28 AM   #3
diyAudio Member
 
sivan_and's Avatar
 
Join Date: Dec 2004
Location: B'lore/ Calicut India
Send a message via Yahoo to sivan_and


imix500 wrote:
Quote:
circuit to turn a momentary spst switch into a latching type
Is this what ur looking for ?
Attached Images
File Type: gif toggle.gif (3.5 KB, 563 views)
__________________
SivanandBalan
  Reply With Quote
Old 18th July 2006, 07:25 AM   #4
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
u need this.

Gajanan Phadte
Attached Images
File Type: jpg dethump reset.jpg (16.6 KB, 553 views)
  Reply With Quote
Old 18th July 2006, 12:35 PM   #5
cpemma is offline cpemma  United Kingdom
diyAudio Member
 
Join Date: Jul 2003
Location: S Yorkshire OK
Or with mosfet & PNP (starts with PNP off)
Attached Images
File Type: gif mosfet_toggle.gif (3.1 KB, 499 views)
  Reply With Quote
Old 18th July 2006, 03:30 PM   #6
imix500 is offline imix500  United States
Proud Union Member
diyAudio Member
 
imix500's Avatar
 
Join Date: Mar 2004
Location: Nashville, TN
Thanks guys. I was wondering about it charging both sides myself. The explanation provided with the circuit said that one capacitor will charge slightly faster than the other and switch first. Not sure if this is right though. Wouldn't be the first time I pulled a bad circuit off the web.
gmphadte, that looks more like what it should be. Any idea if it will power up with one side on every time?
cpemma, neat idea of using a mosfet. Will it toggle on/off?
Thanks!
  Reply With Quote
Old 18th July 2006, 03:51 PM   #7
Duo is offline Duo  Canada
diyAudio Member
 
Duo's Avatar
 
Join Date: Jun 2002
Location: Victoria, BC, Canada
Send a message via ICQ to Duo
The first curcuit posted will function quite well as a T-Latch (Toggle Latch).

I use it in a lot of my work because of its inherent simplicity.

If you get the values too out of place, it will become an astable multivibrator, which you don't want.

Either way, the circuit does work as stated.

If you want to get it to start in one state all the time, you have to add a little imbalance to it so that it will 'lean' over to that state a bit, but not enough to get stuck there.
__________________
-- Duo, W1ngs, VA7MON, and lesser known handles. --
-- http://www.w1ngselectronics.com -- My Work and Projects --
  Reply With Quote
Old 18th July 2006, 05:10 PM   #8
imix500 is offline imix500  United States
Proud Union Member
diyAudio Member
 
imix500's Avatar
 
Join Date: Mar 2004
Location: Nashville, TN
Hi Duo, that's good news since I already ordered parts to make up a few to try. I figured I would use the values as is with the only difference being that I'm using 2n2222 instead of the 2n3053.
So, how should one side be "biased" to come on first? Just increase one 2.7k to a higher value?
  Reply With Quote
Old 18th July 2006, 05:51 PM   #9
cpemma is offline cpemma  United Kingdom
diyAudio Member
 
Join Date: Jul 2003
Location: S Yorkshire OK
Quote:
Originally posted by imix500
cpemma, neat idea of using a mosfet. Will it toggle on/off?
Thanks!
Works in simulation, I'm waiting for a small mosfet to try it, 2N7000 also should be OK.

The problem with all toggles is catering for switch bounce, your first circuit may be sensitive.

A couple more circuits here.
  Reply With Quote
Old 18th July 2006, 06:24 PM   #10
imix500 is offline imix500  United States
Proud Union Member
diyAudio Member
 
imix500's Avatar
 
Join Date: Mar 2004
Location: Nashville, TN
Hi cpemma, those look like great designs. One constraint is that I will have to build 24 of these to accomadate 24 switches. Simpler is better both in time to build and space needed. However, if debouncing is going to be a problem I will have to go with a more complicated design. I will raid the parts bin and see if i can build your circuit.
Thanks!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
toggle switch with LED on tip for t-amp mod? gychang Class D 4 18th September 2006 05:54 AM
Research on tubes and circuits simple circuits Cazcotty Tubes / Valves 6 16th June 2006 12:50 PM
85 powersupply circuits 58 charge circuits gev Power Supplies 0 31st July 2005 11:27 AM
What do you predict the Mackie SRM350 will be like? rintincop2 Multi-Way 2 25th September 2004 07:46 AM
How to predict PSRR ? Kilentra Solid State 6 9th July 2004 07:31 PM


New To Site? Need Help?

All times are GMT. The time now is 04:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2