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  1. hevans1944

    Signal generator using 555 timer

    I think you have it right, Harald. My "go to" probe, that I usually use on the bench for design or troubleshooting, is a switchable 1X/10X probe. I only use the 1X probe when I need the maximum sensitivity of the 'scope to observe very small signals. Some of these switch-selected...
  2. hevans1944

    Erasing PIC16C54C

    Actually, 3 flavors, if you have a really high volume application and mature (bullet-proof) code. There is a masked ROM version available, but it is obviously not for the faint of heart. Still, if your market volume is measured in the millions of units, there could be considerable savings, not...
  3. hevans1944

    Signal generator using 555 timer

    The usual 1:1 probes do not have (or need) compensation, so don't go looking for an adjustment that isn't there. Check the results pages of this Google search for more information. If you did purchase 10X (1:10) or 100X (1:100) probes, these DO have (and require) compensation. A decent...
  4. hevans1944

    Triac replacement

    With a little bit of ingenuity and a diode bridge rectifier, you can use a MOSFET to serve in lieu of an SCR or TRIAC. Connect the n-channel MOSFET drain to the positive terminal of the bridge rectifier, connect the source to negative terminal. Connect the AC bridge input in series with your...
  5. hevans1944

    Need help with LED sign I found on the road

    Hey, it's the 21st Century! Why don't you have a calling plan with unlimited, free, long-distance calling like just about everyone else does? Not to worry, though. The number (303) 440-0746 visible in your photo has been disconnected. The company, Data Display Corporation, Boulder, Colorado...
  6. hevans1944

    And the Relay is Called ...

    The relay is called (by Micromatic) an INTERVAL ON time delay relay. Their description of its operation: Read more about it on this Macromatic webpage. Interestingly, the Macromatic relay that matches your specifications is not available from distributors. Contact the factory for information...
  7. hevans1944

    Oscillator

    Why don't you post links to the web pages where you found 200 kHz oscillators with (1) 2 legs and (2) 4 legs. A part number and name of manufacturer would also help us to recommend something for you. How do you propose to use a 200 kHz oscillator to determine water depth?
  8. hevans1944

    Thermistor for a drinks machine

    @kellys_eye provided a link to a large selection of "bare" thermistors. Your problem is to select one that works for your application and then mount it in the stainless steel tube you showed in your photos, replacing the (apparently) defective one in the photographs. Sure, but you need to know...
  9. hevans1944

    Thermistor for a drinks machine

    You assume too much. Since the resistance decreases with increasing temperature, this is a negative temperature coefficient thermistor. It does not "switch" anything, much less the current of the heater element. There are also positive temperature coefficient thermistors. Omega Engineering is...
  10. hevans1944

    Parallel help

    Yep, that's what I did when I was vaping. But I noticed when I started vaping that there is a sub-culture of vapers who want to DIY the whole vaping rig... except maybe for the glass atomizer. I could sort of understand the allure of winding your own coils... some vapers really push the limit on...
  11. hevans1944

    The new types of IOT

    Oh, is it a variation of Read The Fine Directions Sir?
  12. hevans1944

    Parallel help

    The purpose of the coils is to create surface area for heating the liquid, as well as increasing the effective resistance in a given volume. You do not want adjacent turns to short together! Stainless steel wire, IIRC, is used with a temperature-controlled box mod and runs at a higher...
  13. hevans1944

    Parallel help

    Ah! Sounds like a coil for a vaping rig. About the right resistance and size. If the two coils are interlocking, I would expect that to yield a resistance substantially less than two of them connected in parallel at their ends, so less than 0.1 ohms, not 0.2 ohms, and definitely not 0.4 ohms. If...
  14. hevans1944

    Alternative Energy Charge Bank

    To date, I'm not a fanboy of renewable energy... too expensive, too unreliable, not enough power available for all my toys. I "need" roughly ten kilowatts available 24/7/365. More would be better for "special projects". Still, it would be nice to occasionally disconnect from the grid and...
  15. hevans1944

    Parallel help

    Is this another woo-woo science project? Supercoils indeed.
  16. hevans1944

    The new types of IOT

    Well, maybe so... but I didn't find any mood ring interface to the Grindr app... and they did sell a 60% stake in the company to "a Chinese gaming company, Beijing Kunlun Tech, for $93 million" in January 2016 (according to Wikipedia), so perhaps an Asian entrepreneur there will add a mood ring...
  17. hevans1944

    Alternative Energy Charge Bank

    This looks like it might actually work, assuming the Sun shines and the Wind blows.
  18. hevans1944

    to make a ultrasound speaker

    You should look at this Google result first. You may be able to build your own "ion tweeter" or "plasma tweeter" that could be more effective than a piezoelectric transducer. If you can do that, throwing together an ultrasonic oscillator/amplifier is a "piece of cake" as us electronic project...
  19. hevans1944

    MOSFET equivalent

    Yeah, maybe you can get "lucky" with one of their "lucky bags" of assorted MOSFETs and IGBTs.
  20. hevans1944

    Oscillator

    Three legs is kinematically stable. Two legs and four legs are not. Find a crystal oscillator package with Power, Ground, and Output "legs" of suitable frequency for "depth measurement" (whatever you mean by that). We could provide more help if you would actually tell us what you want to DO...
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