Survey

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Switched-mode power supply wikipedia, lookup

Opto-isolator wikipedia, lookup

Current mirror wikipedia, lookup

Power electronics wikipedia, lookup

Schmitt trigger wikipedia, lookup

Resistive opto-isolator wikipedia, lookup

Surge protector wikipedia, lookup

Current source wikipedia, lookup

Integrating ADC wikipedia, lookup

Electrical ballast wikipedia, lookup

Immunity-aware programming wikipedia, lookup

Wien bridge oscillator wikipedia, lookup

Regenerative circuit wikipedia, lookup

Power MOSFET wikipedia, lookup

Operational amplifier wikipedia, lookup

Valve RF amplifier wikipedia, lookup

Josephson voltage standard wikipedia, lookup

Network analysis (electrical circuits) wikipedia, lookup

Standing wave ratio wikipedia, lookup

Radio transmitter design wikipedia, lookup

Index of electronics articles wikipedia, lookup

Valve audio amplifier technical specification wikipedia, lookup

Superheterodyne receiver wikipedia, lookup

Negative-feedback amplifier wikipedia, lookup

Analog-to-digital converter wikipedia, lookup

Analog television wikipedia, lookup

Oscilloscope history wikipedia, lookup

Transcript

NBE-E4120, Cellular Electrophysiology Exercise 1 Solving instructions 1. An example solution: Using trial and error method, we first select a 10M resistor to limit the currents. Current i divides into two branches, and iin should be ~50 pA. We assume that the current iin will be small compared to other currents -> i ≈ i2 Let’s try selecting a 100 M resistor to the other branch and then calculating the resistance for R. Kirchhoff: 4,5 − ∙ 10 − = 0 → ≈ 10 − − ∙ 100 = 0 i 10M iin 100M i2 R Rin 2. a) See exercise slides. b) The difference between the recorded voltage and the membrane voltage less than 1%: Combine with the voltage division equation: > 0,99 = + → ≈ 50 Ω c) Now we start considering signals that change over time. Therefore, we must apply impedances. Voltage division for the membrane potential and the measured potential (similar than in purely resistive circuit): = + 1 The impedance of a capacitive component: = The impedance of a resistive component: = The equation that describes the dampening of the signal amplitude as a function of 1 the angular frequency ω of the signal: =| |= √()2 1 √()2 +2 The dampening is given in dB: −3 = 20 log10 By combining two previous equations, the angular frequency that is dampened by 3 dB can be solved -> 99,8 1/s, which corresponds to 16 Hz. Does this have an influence on action potential recording? 3. Noninverting amplifier − = → = (1 + ) − = Inverting amplifier = → = − = 4. Familiarize yourself with the extra material of lecture 1 (especially chapter ‘Measuring biological signals’) and exercise task 2, where you can an example sketches of recording setups. What have you learned (based on task 2 and extra material) about e.g. input resistance of a measurement device or the effect of a micropipette on recording high frequency signals?