Emitter followers/common collectors using a NPN BJT can take the voltage of a weak signal and apply it to load with a loss of 0.6V. In doing so, the transistor provides the current needed to hold the voltage across the load that the signal is giving other than losing approx. 0.6V.
- 013 555 timer astable mode basics
- 014 NPN BJT switch improved 555 timer output NE555
- 016 NPN BJT current source – Zener – Trimpot – LDR Light Dependent Resistor
- 017 PNP BJT current source set with zener diode
YouTube video covering NPN emitter follower/common collector circuits
Assortment of commonly used integrated circuits (IC). I made a lot of videos with them.
Diagram used in this video added below.
White version of the oscilloscope that I use in many of my recent videos.
One of my favorite portable power banks, this one has a better display than my version.
Why various signals need a voltage follower:
- Trimpot voltage divider output can easily set a variable fraction of the supply voltage, but it can not provide much power.
- Light dependent resistor voltage divider output can provide a very widely variable voltage, but not much power.
- Zener diode circuit fragment output provides a relatively stable fixed voltage that is lower than the supply, but it is tricky getting enough current to hold the zener voltage and power a load.
Really easy to use USB multimeter tester used in a number of my videos.