The Darlington Pair CIRCUIT
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You may remember the "Transistor as a Switch Circuit" which looked somewhat similar to this circuit. Howver, this circuit has two transistors. They are organised in such a way to amplify the base voltage. The amplification (GAIN) in voltage by a transistor is called HFE. The gain of the transistors used here is 282 (BC337 transistors). The total gain is 282x282 which is 79,524. This means the circuit is a lot more senstive and easier to tune. You may also remember a schematic diagram similar to this one. It was named the "Capacitor as a Timing Circuit". The effect of the Darlington Pair in this circuit is that the capacitor charges quicker, but it also discharges faster as well. |
The Challenge
Work out a track diagram for each circuit
Draw the schematic diagrams above and track diagrams in your exercise book.
Write down a list of materials needed.
Write out your method of construction step by step.
When done ask the learning leader to approve your work and then you can get the materials needed.
Once You Have the Circuits Finished
Record in a brief statement how the circuits work.
Are there any differences from the original circuit with a single transistor?
Use a multimeter to measure the voltage across the different components. Record your results.
Work out a track diagram for each circuit
Draw the schematic diagrams above and track diagrams in your exercise book.
Write down a list of materials needed.
Write out your method of construction step by step.
When done ask the learning leader to approve your work and then you can get the materials needed.
Once You Have the Circuits Finished
Record in a brief statement how the circuits work.
Are there any differences from the original circuit with a single transistor?
Use a multimeter to measure the voltage across the different components. Record your results.