Pulse Generator Flashcards Preview

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Flashcards in Pulse Generator Deck (9)
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1
Q

What is a monostable multivibrator (MMV)?

Other names?

What would be an example?

Draw the U vs. t graph for a MMV.

A

type of pulse generator

  • produces a single output pulse of defined length τ for every trigger pulse
  • also: one-shot, monoflop
  • ex: defibrillator
2
Q

What are the possible states of a pulse generator?

How can pulses of the same state even be more classified?

Draw the signal amplitude vs. time graph.

A

resting and active state (effected by signal pulse that exceeds the threshold level = trigger), since there is a forbidden state fast transitions occur and square pulses are generated

⇒ can be stable or unstable (after triggering spontaneous return to stable state)

3
Q

What does time constant τ indicate?

How can it be changed?

Draw a graph.

A

indicates the time until the voltage on the capacitor decreases to U0/e value (= active time of pulse)

  1. C discharges
  2. I decreases exponentially as it flows through R
  3. U decreases simultaneoulsy
  4. drop under U0/e ⇒ transition to stable state

⇒ dependend on τ = RC

4
Q

What is an astable multivibrator (AMV)?

Other names?

How is it constructed?

What would be an example?

Draw the U vs. t graph for an AMV.

A

type of pulse generator

  • produces a sequence of identical pulses
  • consists of 2 MMVs connected in a ring (trigger each other)
  • also: relaxation oscillator, free running multivibrator
  • ex: pacemaker
5
Q

Which parameters are restricted to AMVs, hence do not exist for MMVs?

Explain.

A
  • τ2: since there is a second MMV = time on stable, resting state of MMV1
  • TAMV: sum of τ1 and τ2 = time period
  • space factor: percentage of the time period occupied by pulse

⇒ pulse width and inactive time can be adjusted by individual RC elements

6
Q

What is the time of the resting and activated state of a pacemaker?

What is the usual voltage range?

A
  • resting state: 0.8 - 1s
  • active state: 0.05 - 2ms
  • voltage: 0.8 - 5V
7
Q

What is a bistable multivibrator (BMV)?

Other names?

Name some examples.

Draw the U vs. t graph for a BMV.

A

type of pulse generator

  • requires a trigger for the activation of either of the two stable states
  • also: flip-flop, biflop
  • ex:
    • ON/OFF switches
    • memory units (binaries: stable state 1/0)
    • frequency divider (# pulses = 1/2 # triggers)
    • binary counter array
8
Q

Draw the graph for the binary counter array.

A
9
Q

How did you calculate energy and charge of one pulse that would get through a tissue?

A

NOCH AUSSTEHEND