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    Sallen Key Low Pass Filter, bandpass filter

    This question has led, over the years, to thousands of ap notes and books on that very subject. Ideally one wants a single frequency (many applications) to pass thru a BPF type filter and all other freq content suppressed. Thats the classic "brick wall filter" so often pursued. But thats...
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    Help

    I get the following sim - Regards, Dana.
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    Triac problem

    Not supplying proper gate trigger ? Compare gate driving circuit to this : Regards, Dana.
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    help with RLC circuits

    The switch is in position a for a long time, so what is Va and Vcapacitor ?
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    Off the Shelf Logic Gates?

    The single gate logic referred to in post #3 is LV, typically 5V or lower. https://www.ti.com/pdfs/logic/littlelogicsg.pdf Load dump in automotive environments : https://www.allaboutcircuits.com/uploads/articles/protecting-and-powering-automotive-electronics-systems_compressed.pdf...
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    LM394 National Semiconductor 'supermatch' NPN pair

    The power is the ac line, so only matters where Rsense is and Vbase to the diff pair within its CM range. Regards, Dana.
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    LM394 National Semiconductor 'supermatch' NPN pair

    I think V of Rsense is not producing enough G when using a 1 mOhm Rsense (R6) to generate needed V to run the diff pair. When I hit 1 Ohm for Rsense I get a poor but distinctive somewhat linear relationship of Pload versus Rload. Here is same but running much high load current. The 1 Ohm...
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    LM394 National Semiconductor 'supermatch' NPN pair

    See if you can find sem in reliability handbook, NSC. Its a long shot, bitsavers one place to look for book, archive.org another. I found this - https://zeptobars.com/en/read/National-LM394CH-super-matched-bjt Regards, Dana.
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    DC Motor Control Using IR2104 Driver

    Do you have a schematic of your circuit ? Regards, Dana.
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    Where to add a potentiometer to vary input voltage?

    Answer here : https://www.electro-tech-online.com/threads/where-to-add-a-potentiometer-to-vary-input-voltage.165417/#post-1443313
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    Help

    I use these sensors in a web based system : https://www.olimex.com/Products/Components/Sensors/_resources/SNS-MQ-sensors.pdf Regards, Dana.
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    resistor confussion

    No. P = V x I = I^2 x R or R = P / ( I^2 ) So you are asking a .1W R to dissipate V x I = 5 x 2 = 10W....., thats a no no So R = .1 / 4 = .025 ohms, that the limit on a .1 W R if you drive 2 A thru it. Regards, Dana.
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    LED Photoelectric switch

    Do you want it to smoothly dim or switch on / off at a specific ambient light level ? LED color ? Google "dimmable led circuit battery 555 timer", lots of hits. Regards, Dana.
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    LED driver help

    The leds a series parallel combo ? The 24 all in series, depending on color, >> 24 Vdc : Constant current is prefered for leds in series, helps in brightness matching. LEDs can be run at less than their ratings and produce usable lkight, depends on application and goals for design. A 1 W...
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    Thyristor ТБ242-63-12-6-5

    https://cnrectifiers.en.made-in-china.com/product/RKjmuPXcniVM/China-Russian-Type-Fast-Thyristors-Stud-Version-Tb242-63.html https://www.vishay.com/docs/93701/vs-25ria.pdf Regards, Dana.
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    Thyristor ТБ242-63-12-6-5

    Its a : TB242-63-10 TB242-63-10 High-speed thyristor 63 Ampere, 1000 Volt, M10 So use digikey to screen part selection to aid in choice. Note you need to look at this parts specs, such as gate sensitivity and ratings, to help in the choice. Regards, Dana.
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    Relay Priority

    I added the min alarm on time to the code, and cleaned it up a little using subroutines. Regards, Dana.
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    Relay Priority

    Something like this ? mBlock takes the block construction (3'rd window over) and converts it to Arduino code, right hand window. A graphical way of programming. You drag from 2'ond window/column functional blocks and connect/config them in 3'rd window. Then hit upload and it uses Arduino...
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    Impact activated LEDs

    Just as an aside accelerometers have a fairly flat freq response at low freq, so maybe compare that with any mic solutions you decide to try. Obviously you dont want a hit intensity be a f(frequency), you just want it to be a f(force). Or you use a correction piece-wise linear table to...
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    Power supply for LED strand

    The 20V charger, thats controlled for charging a battery, so might have shutoff automatically or not even start up because it thinks battery pack (when used as a battery charger) is too low a V (in this case 12V) and no longer usable battery. How many strips do you have to run ? Is it 8W for...
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