Activity for TonyStewartâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #292090 |
It ought to be a continuous test for PE gnd like an RCD at these power levels for car & human safety.
Ground is just 0V in theory a local reference point regardless if it is floating like earth. (more) |
— | 4 months ago |
| Edit | Post #292192 | Initial revision | — | 4 months ago |
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A: Circuit for earth conductor presence detection Fault Codes (Page 38) Tesla gnd fault codes PE ground is mandatory to be functional and is tested. Typical standards expect < 25 Ohms for residential zones. RCD's and similar testers use as test resistor to force an unbalance current using well-balanced common mode latching relay.... (more) |
— | 4 months ago |
| Edit | Post #292188 |
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— | 4 months ago |
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— | 4 months ago |
| Edit | Post #292188 | Initial revision | — | 4 months ago |
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A: Are LDOs more efficient than switching regulators in very low currents? One common solution for some 3 LDO's is to use a Buck regulator followed by a very low dropout PFET linear regulator combined into one part. IC's with very low V logic-level FETs (Vt=0.65) are used in a 1.2V supply. Low noise is preferred for Vref and Va on ADCs used by some uC's. The voltage rati... (more) |
— | 4 months ago |
| Edit | Post #292187 |
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| Edit | Post #292187 |
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| Edit | Post #292187 |
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| Edit | Post #292187 |
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— | 4 months ago |
| Edit | Post #292187 | Initial revision | — | 4 months ago |
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A: Purpose of resistance between SENSE/FORCE line of power supply This looks like the block diagram was done by a technical writer, not the designer. It is someone's conceptual misunderstanding of a linear servo with feedback relays and optional FET drivers with error amplifiers (and R5) between Vo and Sense (not accurate). It has no power supply. Some old H... (more) |
— | 4 months ago |
| Edit | Post #291315 | Initial revision | — | 7 months ago |
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A: Control logic for mosfet in piezoelectric energy harvesting circuit Every real part has resistance including your piezo current source. Every switch resistance is a loss in energy (I^2 R t)=E and includes diode and transistor switches. What you need, I think, is to incorporate MPT theory into your block diagram and use a goal of matched impedances to achieve it. ... (more) |
— | 7 months ago |
| Comment | Post #290874 |
FR-4 and soldermask will slowly absorb moisture under pressure. https://www.nextpcb.com/blog/waterproof-pcb--nextpcb (more) |
— | 9 months ago |
| Comment | Post #290595 |
When I did Hipot testing, I modified the tester with a string of resistors to current limit and prevent destructive failures yet trigger insulation failures in the 100uA test. When I tested 5 MVA transformers to 200kV, I used an AM radio and LeCroy scope to measure partial discharge (PD) events befo... (more) |
— | 10 months ago |
| Comment | Post #290595 |
"When should a transformer core be potted?"
>When being attacked by environmental stress from all sides.
"Should it be potted at all? "
> It is not mandatory. Consider if Dk affected the frequency applied or the thermal temperature from insulation. This may not be in your case, but just ... (more) |
— | 10 months ago |
| Edit | Post #290722 |
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— | 10 months ago |
| Edit | Post #290722 |
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— | 10 months ago |
| Edit | Post #290722 |
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— | 10 months ago |
| Edit | Post #290722 |
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— | 10 months ago |
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— | 10 months ago |
| Edit | Post #290722 |
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— | 10 months ago |
| Edit | Post #290722 | Initial revision | — | 10 months ago |
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A: estimation of pogo pin resistance I agree with Olin that unknown contact area is the biggest variable. I think the scientific way is to test and verify each contact using a 4 pin kelvin bridge. The sum of 2 pins carrying constant current can be measured as voltage by 2 adjacent pins on pads sufficiently large. It probably wo... (more) |
— | 10 months ago |
| Edit | Post #290720 |
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— | 10 months ago |
| Comment | Post #290720 |
My assumptions were based on analyzing the photo of the transparent substrate that the membrane switches were bonded to without any conductive traces. Yet on the same side below them was the carbon printed traces connecting the domed membranes beneath the clear substrate. It is true that membrane sw... (more) |
— | 10 months ago |
| Edit | Post #290720 | Initial revision | — | 10 months ago |
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A: What type of button is this on a remote control It is interesting to see how they deposited these carbon electrodes over solder mask and copper traces both under the button foil switches and membrane switches alike which offer more tactile feel. Both offer capacitance changes to non-conductive switches. The membrane switches are mounted on their... (more) |
— | 10 months ago |
| Comment | Post #290448 |
Can you measure or compute the L & C values? https://www.ti.com/seclit/ml/slup376/slup376.pdf (more) |
— | 11 months ago |
| Edit | Post #290424 |
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— | 12 months ago |
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— | 12 months ago |
| Edit | Post #290424 |
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— | 12 months ago |
| Edit | Post #290424 | Initial revision | — | 12 months ago |
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A: Can I make an AC inductor (reactor) rated 75mH 40A from a 3-phase induction motor? The 70.9/40.8 A rating for L.R. is rated only for ; Locked rotor time 19s (cold) 11s (hot) I doubt this meets your requirements unless you modify from a forced air cooling motor to a pumped liquid cooling system. I'd contact a local oil-filled transformer supplier and get an autotransformer. ... (more) |
— | 12 months ago |
| Comment | Post #290354 |
Charge pumps suffer from high very impedance output impedance leakage issues and are not worth the effort.
Murata package is my best recommendation.
https://www.digikey.ca/en/products/detail/murata-power-solutions-inc/NMV0512DC/5799183 (more) |
— | 12 months ago |
| Edit | Post #290423 | Initial revision | — | 12 months ago |
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A: CAN BUS monitoring with a LED You'll need a differential comparator, something like what was suggested in here. Imagealttext But I'd look for a proper Canbus Rx and extract that to convert to single ended one shot to pulse for activity. (more) |
— | 12 months ago |
| Edit | Post #290341 | Initial revision | — | 12 months ago |
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A: Ceramic capacitor "memory" effect? I have never seen this slow drift in ceramic caps, yet I have seen fast memory effect drift in S&H designs using high Dk ceramic capacitors in the 70's. So I have learnt that all ceramic caps have memory effects (except low Dk C0G/NP0's). The capacitance also changes with DC voltage, so Ic= VdC/dt +... (more) |
— | 12 months ago |
| Edit | Post #290339 |
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— | 12 months ago |
| Edit | Post #290339 | Initial revision | — | 12 months ago |
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A: What fabrication process is being used for jellybean parts As of the early 2020s, common technology nodes for SSI (Small-Scale Integration) and MSI (Medium-Scale Integration) ICs include nodes such as 180nm, 130nm, 90nm, 65nm, 45nm, and 28nm. Each technology node represents a specific level of lithographic resolution that costs billions to create. Migrating... (more) |
— | 12 months ago |
| Edit | Post #289916 |
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— | about 1 year ago |
| Edit | Post #289916 |
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— | about 1 year ago |
| Edit | Post #289916 | Initial revision | — | about 1 year ago |
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A: Driving LED with NPN transistor from I/O pin If you choose suitable ultrabright LEDs , there is no need to use 40 mA. I have over 10 thousand LEDs all over 16,000 mcd at 20 mA which is painfully bright for close indicator but works well 100 m away. They are also all matched brightness and Vf within 10%, but I ordered these special for a high ... (more) |
— | about 1 year ago |
| Edit | Post #289915 | Initial revision | — | about 1 year ago |