Questions? Notify me of new posts via email. Once C1 fully discharges, its right plate will be pulled up to about 0.6V, which will turn on Q2. This is probably confusing. navigate to this website
This will apply the 12 V to the chip output and destroy it or, if there are protection diodes on the output, the current will flow through the protection diodes into But as the voltage from the top of the load (also the emitter) to ground begins to approach the base voltage - 0.6 V, the transistor starts to turn off again. All rights reserved. Report comment Reply Bil Herd says: September 18, 2015 at 8:44 am Heh, kinda why I go on about holes and mobility as well as electrons to get down to the
I always enjoy watching your videos, and this one made a subject that's hard for new commers easy to understand - I know this, because I just sent it to a jlbrian7 liked ASMP. Now we do the same dance the other way. How about 3V?
I don't understand why it matters whether the load is on the collector vs the emitter. Were there any drunk driving laws before the automobile? Microcontrollers FPGA Prototyping Boards Programmers all development Sensors Movement Biometrics Imaging Environment Capacitive all sensors Tools 3D Printing CNC Soldering Hand Tools Instruments all tools Miscellaneous All Kits Books Arts & Pnp Transistor Switch Circuit martynj 14 November 2012 at 2am Alright!
Different ways to implement a High Side Switch. Emitter will quickly swing up towards Vcc until the Base voltage is no longer more than a junction-drop between B and E. Oscillators are used in all sorts of circuits: from simply blinking an LED to the producing a clock signal to drive a microcontroller. https://forum.allaboutcircuits.com/threads/high-side-vs-low-side-driver-questions.26888/ Just flip everything.
At room temperatures and with modern silicon BJT's the quiescent current may be small enough to be ignored for most applications (see jcw's sample values above). Arduino High Side Switch It’s an incredibly popular circuit – the driving force behind countless robots that must be able to move both forward and backward. Controlling the PNP transistor with a low side NPN is a really good idea. The only way to avoid this would be to buffer all the data lines between the LCD & the uC.
If those answers do not fully address your question, please ask a new question. https://groups.google.com/d/topic/sydney-hackspace/aJ1tJqbl_xg Now, if the emitter is connected with zero resistance to Vcc and is thus at the voltage level of Vcc, then what is the voltage from the base to the emitter? Npn High Side Switch For minimal power drain and/or extended temperature range, a path is needed from Q1 collector to some +ve rail. Npn Low Side Switch I guess I thought it would be the same either way, but is an NPN transistor capable of switching much more current from near ground to ground than it is from
Rules Stick to questions on the theory, design and repair of electronic circuits. http://tuiconverter.com/high-side/high-side-low-side-gate-drivers.php For the current to flow the voltage between those two has to be positive. permalinkembedsavegive gold[–]doodle77 2 points3 points4 points 4 years ago(0 children)When your high side switch is ON, what is the voltage at its terminal connected to the load? GitHub YouTube Vimeo Facebook Instagram Google Plus Flickr Twitter RSS In 2003, CU student Nate Seidle blew a power supply in his dorm room and, in lieu of a way to High Side Switching Vs Low Side
Thanks guys! permalinkembedsaveparentgive gold[–]pmorBeginner 1 point2 points3 points 4 years ago(2 children)Thanks you !! No base current? http://tuiconverter.com/high-side/high-side-and-low-side-mosfet-drivers.php When the voltage at the base is greater than 0.6V (or whatever your transistor’s Vth might be), the transistor starts saturating and looks like a short circuit between collector and emitter.
Although not plainly obvious, this was still a case where there was an unavoidable common ground. High Side Switch Ic Typical questions "Trying to locate a replacement for a blown MOSFET" "Why doesn't my Op-Amp circuit work as expected?" "How do I calculate the bandwidth of an amplifier?" "How can I The switch has to be on the high side.
It varies with the collector current of the transistor. Not so fast. KVL is still satisfied. get redirected here A controller based load can even turn off its own power supply, though this is a little more complicated where the load needs time to shut down cleanly such as a
Which problem are you referring to? #7 Like Reply Aug 21, 2009 #8 Wendy Moderator Mar 24, 2008 20,964 2,701 The high side drivers, the fact that it isn't rail Mountain Time: (303) 284-0979 Chat With Us sparkfun.com Shop Learn Blog Support Shopping Cart 0 items log in register Shop Learn Blog Support Product Menu Education Forum Data Desktop Site All For an NPN what voltage do you need on the base emitter in order for the transistor be on ? Report comment Reply Ralph Doncaster says: September 18, 2015 at 4:56 am I was pleased to find cheap, small, and high current FETs like the ao3400.
Design Making something specific (e.g. In high-power switching arrangements, the N-channel MOSFETs are much better than their P-channel equivalents, so it makes sense. EDA Resources Teardown Videos EE Podcasts Datasheets Advanced Search Forum EDA Theory Elementary Electronic Questions [SOLVED] Questions about using npn transistor as a high side switch + Post New Thread When I/O is "0", no current flows into the base of the NPN transistor, which means it won't conduct, and hence no current flows into the base of the PNP transistor
Reply to Thread Search Forums Recent Posts Today's Posts 1Next > Aug 20, 2009 #1 alank2 Thread Starter Member Jul 14, 2009 26 0 Hi, I was trying to use an Report comment Reply Leave a Reply Cancel reply Enter your comment here... Is is a very small number (10-12 to 10-15), and Vt is ~0.025 V. Yes, my password is: Forgot your password?
To do this, the base voltage must exceed the collector voltage by ≈0.7V, and it must be current-limited. Can I leave the Amsterdam airport during my layover en route to Canada? To put that in perspective for us, the power being dissipated by the device is P=I2R, or .057 watts or 57 milliwatts. It is generally much easier to use a PNP for a high side driver.