Activity for Olin Lathropâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #288415 | Initial revision | — | over 1 year ago |
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A: Variant of a Mosfet's Gate-Source protection If the TVS truly clamps the "+12V" line to 25 V, then the VGS of Q1 can't exceed 25 V. However, if you want to limit the gate voltage, limit the gate voltage. A Zener between gate and source guarantees that directly. You may still want the TVS to clamp the incoming power voltage for other reason... (more) |
— | over 1 year ago |
| Edit | Post #288391 | Initial revision | — | over 1 year ago |
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A: Why do I need electrodes for ECG measurements? The electrodes electrically connect to the skin in order to pick up tiny signals produced by the heart muscles. Electrically you're a bag of saltwater. Your skin (the bag) has a relatively high resistance. The innards (the salt water) has relatively low resistivity. To get good signal to nois... (more) |
— | over 1 year ago |
| Edit | Post #288390 | Initial revision | — | over 1 year ago |
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A: Synchronization of clock of satelite with devices here on the Earth First, the time dilation experienced by a satellite is tiny on a human scale. It takes sophisticated algorithms and lots of processing power to measure time differences between a spot on earth and various satellites. That's how GPS works. Early GPS receivers were rack-mounted boxes before integrat... (more) |
— | over 1 year ago |
| Edit | Post #288233 |
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— | over 1 year ago |
| Edit | Post #288233 |
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— | over 1 year ago |
| Edit | Post #288233 | Initial revision | — | over 1 year ago |
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A: Oscillator with non-rechargable battery There actually seem to be two different questions here. Can a primary (non-rechargable) battery be damaged by forcing reverse current thru it? Yes. Primary batteries are only intended to source power, not sink it. Forcing reverse current thru them, especially for significant lengths of time, ... (more) |
— | over 1 year ago |
| Edit | Post #288231 | Initial revision | — | over 1 year ago |
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A: Confusion in operation of analog computer The poteniometers (what you label as "variable resistors") are almost certainly just floating pots. If their ends were permanently connected to power and ground, then they'd be voltage sources, not pots. You might temporarily connect the top terminal to power, the bottom to ground, and measure the... (more) |
— | over 1 year ago |
| Comment | Post #288222 |
I don't know what other form you've seen pots in, but a rotating shaft is very common. In any case, you need to fix the question. (more) |
— | over 1 year ago |
| Comment | Post #288222 |
No, those are pots (potentiometers). You even label them yourself as <i>variable resistors</i>. Remember, this is an <i>analog</i> computer. Switches are digital. (more) |
— | over 1 year ago |
| Comment | Post #288222 |
I looked at your full image carefully, and the only rotary switch selects one of three frequency ranges for the built-in square wave generator. The silver-colored 10-turn knob above the rotary switch provides the fine adjustment. I see no rotary switch where <i>"set the rotary switch to multiply th... (more) |
— | over 1 year ago |
| Edit | Post #288192 | Initial revision | — | over 1 year ago |
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A: High Speed Digital Communication Bus Probing One of the first things you should do is provide a connection for the scope probe ground. If you think you'll be regularly looking at signals on this board, then one of those little loops or pins to clip a scope probe too would be useful. If it's a one-off problem, then just a thru-hole pad would b... (more) |
— | over 1 year ago |
| Edit | Post #288165 | Initial revision | — | over 1 year ago |
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A: SDR SDRAM PCB Timing Budget It would help to provide links in your question to the datasheets. Without the datasheets I can only give general advice. Look a the memory datasheet and see what the setup and hold time requirements are. There is always a window of time around a clock edge where the data must be held steady on ... (more) |
— | over 1 year ago |
| Comment | Post #288163 |
We need to see exactly what you connected to this chip. Show the schematic. It would also help to provide a link directly to the datasheet of the chip. (more) |
— | over 1 year ago |
| Edit | Post #288161 | Initial revision | — | over 1 year ago |
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A: How is it possible to perform a open circuit test on a induction motor? Your basic problem is that the motor needs some applied power to generate any EMF, but if you apply that power then its not an open circuit test. For a true induction motor you're probably stuck. You'll have to measure various parameters separately while the motor is being driven. By measuring t... (more) |
— | over 1 year ago |
| Comment | Post #288153 |
He probably used the same naming convention in his slides as in whatever book was assigned for the class. There are probably similar diagrams in the book, which should include better explanations for what the variables and axes mean.
I can't tell whether these are supposed to be diagrams in a sin... (more) |
— | over 1 year ago |
| Comment | Post #288153 |
Where did you find these diagrams? There is probably some explanatory text around them. (more) |
— | over 1 year ago |
| Edit | Post #288135 | Initial revision | — | over 1 year ago |
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A: Over-voltage protection for device with photovoltaic cell source If you don't care about efficiency of the overall system, then a zener to limit the voltage will work. You are right in that a series resistor is not needed since the source is power-limited. One problem with a zener is finding one guaranteed to limit the voltage to the 5.5 V maximum while not ge... (more) |
— | over 1 year ago |
| Comment | Post #288130 |
Hi, Jason. It would be nice to get more of the EE.SE core contributors to do what I did, but it's difficult to convince people, let alone reach out to them. It would be unethical to leave messages on EE.SE asking people to come here. You can say what you want on your personal profile, but that onl... (more) |
— | over 1 year ago |
| Edit | Post #288117 |
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| Edit | Post #288117 |
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| Edit | Post #288117 |
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| Edit | Post #288117 |
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— | over 1 year ago |
| Edit | Post #288117 | Initial revision | — | over 1 year ago |
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A: Calculate values of externally excited DC generator/motor Your generator constant is 2 V per Webber-Hz, or 2 V/(Wb Hz) = 2 (V s)/Wb. You somehow got a value of 5. The rest of your calculations are probably off due to that. Added I didn't have much time when I wrote the above, but can delve into this more now. From your first measurement, we can s... (more) |
— | over 1 year ago |
| Edit | Post #288108 | Initial revision | — | over 1 year ago |
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A: Role of C2 (bypass capacitor) To properly answer this question, you need to show us a real circuit with a capacitor across the supply. There are various reasons a capacitor across a power supply might make sense. Protecting the supply from thermal noise created by a resistive load is way way down the list of likely explanatio... (more) |
— | over 1 year ago |
| Edit | Post #288094 | Initial revision | — | over 1 year ago |
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A: DC offset correction loop (DC servo loop). What's its advantage, compared to a high-pass RC filter? In addition to what Andy said, the DC servo method doesn't add impedance to the signal. Note that in your bottom circuit, the signal with the DC offset removed has an impedance of 1 MΩ at DC. In your case it doesn't matter since the signal is only going into an opamp input. In other cases ... (more) |
— | over 1 year ago |
| Edit | Post #288031 | Initial revision | — | over 1 year ago |
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A: How can I fix this 4-20 mA current loop to source current that matches current sink on its input? You are making this way too complicated. Go back to the basic problem definition, which is you want to get a digital reading of the current sunk by a current sink, with the valid range being 4-20 mA. It seems you chose the A/D you did because it is advertised to be able to directly read 4-20 mA c... (more) |
— | over 1 year ago |
| Comment | Post #288030 |
More popups when clicking on the links. No thanks. I probably don't need the datasheet if you just said what these parts are. Are they opamps, A/Ds, D/As, etc?
Also, how does your circuit fit into the larger block diagram? What exactly is driving PREG_N? Is that one of the current sinks you ar... (more) |
— | over 1 year ago |
| Comment | Post #288027 |
I really don't want to follow links in the first place. Any information pertinent to the question must be directly in the question. Posting a link to a datasheet is valid, but then it must go *directly to the datasheet*. There is no excuse.
No, I'm not gonna even read what a popup says. And, I... (more) |
— | over 1 year ago |
| Edit | Post #288029 | Initial revision | — | over 1 year ago |
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A: Is a current-dependent current source and a current mirror the same thing? It's not clear that the problem is. It seems you want to interface to this "digital air pressure regulator" via two 4-20 mA current loops. For reading the output, it should be as simple as a 24 V power supply with a resistor in series. A 250 Ω resistor, for example, will give you a 5 V sig... (more) |
— | over 1 year ago |
| Comment | Post #288027 |
It's a bit unclear which blocks are sending and receiving and how they are connected. I tried to follow the link to your chip, but got a page with popups instead of the datasheet. (more) |
— | over 1 year ago |
| Edit | Post #288011 |
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— | over 1 year ago |
| Edit | Post #288011 | Initial revision | — | over 1 year ago |
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A: What is a good PCB-layout? I have also designed and ordered a PCB It seems rather pointless to ask after you've already ordered the board. only uses THT-components That's just plain silly. This is the kind of thing that you might see from a clueless hobbyist, but is totally unacceptable from an electrical engineering... (more) |
— | over 1 year ago |
| Edit | Post #288006 | Initial revision | — | over 1 year ago |
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A: What is the role of master clock speed on DAC In protocol I2S we have 4 signal: 1.data 2.lrck/fck (frame synchronizer) 3.bck (bit clock) 4.mck/sck (master clock) Not really. IIS really only has 3 signals: bit data, bit clock, and left/right indication. Take a look at the actual IIS protocol from NXP. Some implementations do use a "master... (more) |
— | over 1 year ago |
| Edit | Post #287957 |
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— | over 1 year ago |