This circuit can be added to voltage line that needs to be buffered, which allows all the voltage to be transferred over, while giving out a low impedance output so that a load can be powered. Any can be used; popular ones are the 2N and the 2N You can always use an other two 2Ns to get the base voltage on the top pair of transistors up to 12V. The line that you want buffered gets connected to the input and the load you want powered on gets connected to the output of the circuit. So the first thing is we decide how much voltage we’re going to supply this circuit. Nicolas D 1 6 After putting a CRO on the circuit and looking at the waveforms and DC operating points I made a number of modifications and increased the power supply to 14V which resulted in a power output of around mW.

Uploader: Shazil
Date Added: 15 November 2005
File Size: 47.35 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 2044
Price: Free* [*Free Regsitration Required]

For an NPN transistor to conduct the base voltage has to be above the emitter voltage. An emitter follower is circuit is a transistor circuit in which the voltage at the emitter follows the input voltage. What you have is a simple circuit, but I had to tilt my head and think about it to realize what it is actually doing.

Joataman Webpages

If Voh high-level output voltage from your 3. So bkffer is the first consideration. So for the output capacitor, we also calculate it according buffwr its 20Hz frequency response. Schematic looks fairly good to me also. This is creates a pretty good buffer effect on any voltage that needs to be buffered.


We will now get into the details of why the various components are needed for the circuit and how to choose the values for them.

Placing a finger on the 2N and 2N transistors showed the 2N was running cool whilst the 2N was getting very warm. If the input impedance of the device on the 5 Volt side is significantly higher than the 6. Therefore, the capacitor buffr the equivalent resistance of these 2 parallel resistors.

There are many options on the internet, some using a logic ic and some using 2 NPN transistors converter and inverterbut I never found an option using only a single transistor and 2 resistors.

Post as a guest Name. You can really choose any value from above V Bthe base voltage, to the maximum value that the transistor can handle on the collector. This means that any frequency at that range or lower will be filtered out to ground.

Now lastly we have to choose the value of the capacitors in this circuit. Could u suggest me some PNPs suitable for this job? The transistor circuit will be configured as an emitter follower another name is common collector circuit.

Home Questions Tags Users Unanswered. You should have get around Ok thanks for the response guys.

See this thread – Connecting 3v digital output to Arduino using bi-directional level shifting mosfet. If you visualized current flowing into the circuit, current can go either 1 of 3 ways. A low pass filter on the output converts the squarewave into a clean sinewave at the fundamental transmit frequency. On the other end of the spectrum, the transistor can swing down to near ground, about 0.

  18D1 D001 DRIVER

Consult the data sheets to buffed which works best.

Or current can flow through the transistor and flow through the R E resistor down to ground. The first part of this circuit from the capacitor and the resistor that it sees down to ground forms a high-pass filter, an RC high-pass filter.

Single transistor level up shifter – Electrical Engineering Stack Exchange

We’ll first show how to calculate the value of the capacitor at the 2n22222a. So, why wouldn’t such a converter work? I need a simple, single directionnal level shifter for 3. The value that we choose is integral so that we do not overheat and possibly destroy the transistor. To answer this, we look at the complete picture. Positioning the transistor at the midpoint of those voltages allows for the maximum swing of the AC signal from the buffrr to the floor.