Activity for Carl
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Question | — |
Why do I need electrodes for ECG measurements? When recording an ECG signal, the raw signal is taken from the body and sent into an ECG amplifier to amplify the signal to a suitable range and remove common mode and other types of noise. Measuring the raw ECG signal is done by placing pre-gelled electrodes onto both wrists and one reference ele... (more) |
— | 11 months ago |
| Question | — |
What is a good PCB-layout? I am an electrical engineering student and I just finished designing an ECG-amplifier circuit. Here is the schematic: - Image alt text It is fairly simple. Initially, there is a 1st order highpass filter. Then, a differential amplification stage with AD620N in-amp followed by a Sallen-Key 2nd o... (more) |
— | about 1 year ago |
| Question | — |
What does it mean for a signal to have impedance? What does it mean for signals to have impedance? To me, impedance is kinda like an "extended resistance" that also includes phase shift $$Z = R + jX $$ It makes sense to me that components like capacitors ($ZC = \frac{1}{j\omega C}$) and inductors ($ZL = j\omega L$) have impedances because they... (more) |
— | about 1 year ago |
| Question | — |
Testing instrumentation amplifier with differential signal I am using the AD620 as instrumentation amplifier to amplify the body's ECG signal. An ECG is a differential signal (measured with two electrodes) and I want a differential gain of Gd=1000 . The datasheet has this formula: $Gd=1+\frac{49.4 \: \text{k}Ω}{RG}$ , so using two resistors of 27 Ω gi... (more) |
— | about 1 year ago |
| Question | — |
Duty cycle of buck-boost converter I have the following problem: - >Image alt text Using Wikipedia I find that during CCM we have the relation: - $$\frac{V{out}}{V{in}} = -\frac{D}{1-D} $$ Solving for \$D\$ and inserting values gives me $$D=\frac{20\text{V}}{20\text{V}-24\text{V}} = -5 $$ But this doesn't seem to mak... (more) |
— | about 2 years ago |
| Question | — |
Case temperature of MOSFET Homework problem > A MOSFET has a power dissipation of $P{d} = 10\text{W}$. The MOSFET is mounted on a heatsink. There is an isolation pad between the MOSFET case and the heatsink. We are given the thermal resistances: - > > Junction to case: $R{th,jc}= 1.7 \: \frac{°\text{C}}{\text{W}}$ > > I... (more) |
— | about 2 years ago |
| Answer | — |
A: How can we grow this community? I think this site needs to get an aesthetic make-over in order to make users coming back. This may be because I'm accustomed to StackExchange's appearance but to be honest, this site is ugly and unappealing visually. The only colour present other than white (which is about 95%) is blue. There ... (more) |
— | about 2 years ago |
| Question | — |
H(jω) does not exist for unstable systems, but we still use it when designing controllers - contradiction? According to Signal processing and linear systems by Lathi, the transfer function \$H(j\omega)\$ does not exist for systems with poles in the RHP: - Lathi This makes sense to me, since \$H(j\omega) = \frac{Y(j\omega)}{X(j\omega)} \$. However, since the system is unstable \$Y \$ is unbounded (an... (more) |
— | over 2 years ago |