transistor as power switch - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 25th May 2012, 02:55 AM   #1
diyAudio Member
 
Join Date: May 2012
Default transistor as power switch

Hi all .....

how to use a transistor switching circuit if the load is a positive voltage of the IC ...
I want to add the switching circuit on the microcontroller to control the IC so that the IC can be used for specific conditions ..
I'm avoiding using the relay because I will be using a lot of relay if I want to control more than 10 IC for different conditions ..

anyone can share the circuit?!?!?
  Reply With Quote
Old 25th May 2012, 07:50 AM   #2
RJM1 is offline RJM1  United States
diyAudio Member
 
Join Date: Jan 2010
Location: Titusville, Fl.
Use a PNP transistor to switch the positive voltage on by grounding the base through a resistor, to turn it off remove the ground from the base or connect it to the positive supply. (See examples)
Attached Images
File Type: jpg switch-on.JPG (52.7 KB, 99 views)
File Type: jpg switch-off.JPG (53.1 KB, 98 views)
  Reply With Quote
Old 25th May 2012, 08:41 AM   #3
diyAudio Member
 
Join Date: May 2012
thanks for sharing ..
if the base is connected to the microcontroller logic (0 volt or 5 volt), can VEE more than volts?!?! because I will switch 12 volts ..
  Reply With Quote
Old 25th May 2012, 11:39 AM   #4
diyAudio Member
 
Join Date: May 2012
Quote:
Originally Posted by herryawan View Post
thanks for sharing ..
if the base is connected to the microcontroller logic (0 volt or 5 volt), can VEE more than volts?!?! because I will switch 12 volts ..
revision:
if the base is connected to the microcontroller logic (0 volt or 5 volt), can VEE more than 5 volts?!?! because I will switch 12 volts
  Reply With Quote
Old 25th May 2012, 11:46 AM   #5
RJM1 is offline RJM1  United States
diyAudio Member
 
Join Date: Jan 2010
Location: Titusville, Fl.
Yes the 2n3906 can take up to 40V and 200ma, or use a bigger transistor if you need more voltage or current.But the base current has to shut off to turn the transistor off, If you are trying to switch 12V and your control voltage is 0 to 5 V you would need to add a 8.2V zener diode in series with R2 to get Q1 to turn off.

Last edited by RJM1; 25th May 2012 at 11:52 AM.
  Reply With Quote
Old 25th May 2012, 01:11 PM   #6
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Make sure the switching transistor is saturated while ON.
Do this by getting the base current high enough to ensure that Ic/Ib <10.
If Ic is very variable then Ib must be chosen for the highest Ic and you must then check that the transistor is still able to operate properly when Ic is low, i.e. when Ic/Ib approaches 2
__________________
regards Andrew T.
  Reply With Quote
Old 25th May 2012, 03:17 PM   #7
diyAudio Member
 
Join Date: May 2012
thank you for the solution, it works ..

Do you have a paper for this?!
to be added to my final project report ..

This results from my simulation ..
is there any correction of my simulation?
Attached Images
File Type: png off.png (14.2 KB, 56 views)
File Type: png on.png (14.6 KB, 54 views)
  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
Capacitor Across Power Switch to Control Switch On Noise? DreadPirate Analog Line Level 20 21st April 2013 02:58 PM
Transistor switch audio mute TheFixer Solid State 23 11th September 2012 02:51 PM
Transistor as a Switch, is this correct? silentblackhat Solid State 13 19th May 2009 12:05 AM
Heater switch transistor ianl Tubes / Valves 4 23rd March 2006 01:11 PM
Using a momentary switch for main power switch? FullThrottleRic Parts 9 25th June 2002 08:23 PM


New To Site? Need Help?

All times are GMT. The time now is 09:45 AM.


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