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  1. D

    Automatic DC supply selection?

    What is solution to that ? I sense its the Panel production coupled with load dump transient by utility causing excess V input to controller ? By the way thanks for jumping in on this thread, safety first. Regards, Dana.
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    Automatic DC supply selection?

    A pair of high current Schottky diodes simplest, one in each output lead then cathodes tied together, or a solution with even less loss : https://www.analog.com/media/en/technical-documentation/data-sheets/4357fd.pdf The above done for 48V solution, fine for your Voltage. Regards, Dana.
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    Design a short circuit protection for +15/-15 and +10/-10 DC power rails

    Also potential causes are switched L loads, or large output Cload when supply is turned off and Cload charge gets dumped back thru output of reg, and all the internal protection circuits no longer in effect. Here is design recommendations for the venerable LM317 adjustable, but principles apply...
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    Design a short circuit protection for +15/-15 and +10/-10 DC power rails

    In your schematic all those regulators have short circuit protection built in, but sevetral cases exceeding an amp. But you can have a case where reg load is excessive, and cause excess Pdiss. I did not check each datasheet to see if they have thermal shutdown as well. If you take the advice to...
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    Need a little help understanding the way my class AB power amplifier works.

    Read constantly, read about what you dont know, read diverse areas within the field..... Build / proto circuits, you are building up your AI memory and skills. Regards, Dana.
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    Is thisFoot Switch Relay useable with DC?

    Short answer is yes. But you need to config pin, to use as input, on STM32 with either a pullup or pulldown, and switch connected to pin to ground or pin to Vdd respectively. And debouce the switch in code. Also note if STM32 is running off 5V then pullup to Vdd as shown, for case SW1. or if...
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    Timer circuit

    Heat transfer directly proportional to flow rate if the flow rate creates eddies. But if its laminar flow all bets off. Where Laminar and Turbulent flow merge, ~ 2000. Here we see convective / conductive ratio essentially insensitive to flow rate : https://en.wikipedia.org/wiki/Nusselt_number...
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    Timer circuit

    Here is an example that is quite flexible, based on an arduino type part : https://www.electro-tech-online.com/articles/pulse-sequence-generator-smart-timer.938/ Use an Arduino Nano type board : Its like a 2 -3 board. Here is code project to program it with. Attached. Download mBlock and...
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    Timer circuit

    Why not base the timer on Temperature ? And sunlight level and or time of day ? Regards, Dana.
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    MF/HF marine radio

    Good chance radio is seeing high SWR out of spec, something has changed on antenna feed or driven element connections or cable short or.... Regards, Dana.
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    Low frequency adjustable but stable oscillator

    Error, post deleted.
  12. D

    Low frequency adjustable but stable oscillator

    Do synch motors experience slip, such that instantaneous RPM does not track line ?
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    Low frequency adjustable but stable oscillator

    Something like this. The low cost board, ~ $15, generates the sine and controls the LCD and reads out the pot for freq control. The LCD, Audio PA, Transformer are external of course. Audio chips that might do the job -...
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    Low frequency adjustable but stable oscillator

    What is power / current level needed for motor ? Regards, Dana.
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    beginner- Arduino Uno DC motor h-gate problems

    Just a recommendation but the ground buss normally used is blue on your proto board, the power buss red. Helps with reducing errors when using the breadboard. Also I do not see any capacitors on your protoboard, something like a 100 uF electrolytic in parallel with a .1 uF ceramic. Good chance...
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    Low frequency adjustable but stable oscillator

    Something like this : https://www.lisungroup.com/products/ac-and-dc-power-supply/ac-power-source.html Regards, Dana.
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    Help requested to identify common emitter, collector base bjt circuits

    When you use a transistor, bipolar, as a switch there is a rule of thumb. When transistor is on you want it to drop very little V between Collector and Emitter. This is called saturation, and there is a spec on Vcesat when it is on acting as a switch. To get Vcesat one has to drive the base...
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    Help requested to identify common emitter, collector base bjt circuits

    4.71 is a NPN transistor as switch, 4.72 is PNP. Both have load, LED and R, in the collector of their respective transistor. Both have a base resistor. Regards, Dana.
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    Testing Operational Amplifiers

    A quick and dirty way of gross test, use 2 9V batteries for supply, and drive input with a 1V 1 Khz sinewave, with and without 1V offset, and verify input and output are essentially identical for both cases. with and without offset. Then use Bertus analog.com link for more extensive testing...
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    Help requested to identify common emitter, collector base bjt circuits

    Dont get hung up on stuff like no resistor in base for Common Base, you can in fact have a CB circuit with an R in its base. Simple way is whats common leaves the other two terminals to function as input / output. So CB means Emitter and Collector are the the connections for in/out, each can...
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