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  1. F

    Supercapacitors anyone?

    Yes, it's worth a try. Although a quick Google did not find an n4007 Schottky diode. There is a 1n4007, but i don't think that is a Schottky. In any case, it's worth a try.
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    Supercapacitors anyone?

    pootler, No, your diagram is not correct. Sorry that my original diagram wasn't clear. I have revised it below. If you have any questions feel free to ask. Frank
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    Supercapacitors anyone?

    Actually, ratstar may have a point (gulp). That is, now that pootler's measurements show that the convertor is not shut off during cranking, maybe the problem is short dropouts and a small electrolytic capacitor might bridge the gaps. I would try bridging the 5v output with say a 1000uf cap and...
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    Supercapacitors anyone?

    Pootler, Yes, at .5amps the super caps should work well. At 1 amp draw the caps should keep the voltage above 4 volts for maybe 7 seconds. Further, you can put your caps on the output of the convertor and only 1 resistor and one diode is needed. I recommend that you use a Schottky diode for...
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    Supercapacitors anyone?

    Are you sure the accessaries are disconnected during cranking? Usually the battery voltage drops and it may just look like a disconnect. If it's not disconnecting it sounds like your adapter is not doing a good job. While cranking most batteries should not drop below 9v. I would think that a...
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    Replace IC 4049

    I wonder if the 4049 had proper bypass caps directly across its power pins. About 40 years ago I had a similar perplexing problem that drove me nuts for days. Out of desperation I added a 0.1uf bypass cap and the problem disappeared. As I recall I was using TTL logic chips, but I believe...
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    Replace IC 4049

    The 4049 should have a 12v swing, not 5v. Are you using cmos 4049 or TTL?
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    Replace IC 4049

    Yes, I understand the complementary logic. But the emitter current is nil after the gate is low so I don't see the transistor continuing to conduct leaving the mosfet gate floating between pulses, no? [edit:]True if the gate floats upward the transistor will clamp it low, but that doesn't sound...
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    Replace IC 4049

    I get an "attachment cannot be found" error when I try and view your attachment. I am assuming you are using colum's schematic. Anyway, measure the DC voltage across the 100 ohm gate resistors. It should be very close to zero. Any significant voltage (say >.5v) suggests there is current flow...
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    An intro

    I would start with a electronic project kit like the one below. One reason I like this kit is that it includes a basic voltmeter and ammeter, instruments that are necessary to understand circuits. Many kits don't have such instruments. If you are a total newbie to electronics this kit looks...
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    Connecting different panels in sizes and locations in parallel

    I don't have any significant knowledge of solar panels, but since no one has responded I'll try to help. I think the safest way to connect dissimilar solar panels in parallel it to add a blocking diode to each one. That way it's impossible for one panel to absorb the current from the other...
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    Diode help.

    I don't think you should try and power through the OBDII connector as you are likely going to backfeed into the car's entire 12v system. I am not an expert on car electrical systems so unless you have specific knowledge otherwise I would not do it. I suggest to backup the car battery directly...
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    CNC computer controlled Hotwire heat problems

    As already mentioned, checking the individual components would be a good first step. In most cases that can be done with a simple multimeter. Google can help you there. The semiconductor on the heatsink seems to show slight discoloration and that could be a sign of overheating. It looks like...
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    Replace IC 4049

    Does the circuit work as expected until the 4049 heats up and quits? How long does it work properly before it quits? You might try and isolate the 12v power to the IC's from the transformer power 'A'. You might be getting some big voltage fluctuations when the transformer draws power perhaps...
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    Help with something I cant find info on anywhere!

    Be very careful when modifying a riding toy. I did that once for my grandchildren and almost hurt them. As I recall, I augmented the battery voltage maybe by an additional 50%. It was a while ago so the exact details are fuzzy. Anyhow it worked great. Sure enough the car was faster and they...
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    How find the address of ptz camera

    The IP address is probably dynamically assigned by your router. In any case, log into your router and display the connected devices. Sometimes the name displayed for each connected IP address will be helpful to determine the actual applicable device. If that doesn't work, generally the cameras...
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    modified clothing dryer for low heat function?

    Keep in mind the light bulb or variac solution may not really solve the problem. If the temperature sensor doesn't reach the desired temperature it will not turn the heat off. So it just means it takes longer to reach the temperature sensor setting. Even if those solutions reduce the...
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    Converter output

    The RC filter I mentioned will be a lot more effective if you replace the 5 ohm resistor with a general purpose diode capable of handling 1 amp or more (e.g. 1n400x series). Also a larger capacitor than 2500uf might prove worthwhile depending on actual current draw of the USB charger and the...
  19. F

    Converter output

    I'm stunned why anyone would manufacture an RV converter that is not capable of charging the battery (or at-least a smooth 12v). Call me crazy, but why go through the trouble of a transfer switch, wiring, etc. when simply connecting an automatic battery charger to the batteries satisfies most RV...
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    Converter output

    Edit: Looking at the schematic I now see my confusion. I erased my above original text and will reply again when I get home.
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