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    Help me fix my subwoofer! Fuse keeps blowing - Tannoy TS12

    5'th picture own, middle of board, is that power R burnt ? The R right next to white molex power connector. Caps usually principle concern. Look for parts with bulging tops (the small electrolytics) : Any heat discoloration on any part or the PCB, thats a sign of localized failure or a...
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    Short pulse output

    The problem with simple cmos gate oscillators or 555 timer is accuracy of pulse width and T & V effects. If you dont care about fact electrolytic caps have wide tolerance range or variations (without pot trimming) of 50+ % then use those. Notice the tolerance column in this selector tool ...
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    Short pulse output

    Yes, use ATTINY85, and mBlock to program it. Here is solution : mBlock is free, use a Arduino Nano board 9$3) to program the ATINY85. mBlock takes your block configuration and generates Arduino code then using Nano as a programmer programs the ATTINY85 chip. Or just use the Arduino Nano...
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    Need help with microcontroller project

    4 bit from scratch controller : https://www.instructables.com/Simplest-4-Bit-TTL-CPU/ Or if you wanted to work with a basic structure on a chip (this is a small part of this chip ) : But assembler programming this is a challenge...
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    Can oscilloscopes measure circuits with different voltages at the same time?

    When you have two circuits that are not at the same potential best way to manage with an oscilloscope is to use differential probing : Regards, Dana.
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    Square wave signal restored by resistor

    Output circuit is an open drain circuit that discharged parasitic C so output decayed quickly and w/o pullup never could show a high level again without it ? Just a thought. Regards, Dana.
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    Need help with microcontroller project

    Do you want to build the actual controller itself or use a generic Micro ? Regards, Dana.
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    Automatic current/voltage regulator for LEDs

    If you go to TI, On Semi, ST Micro, .....many others they all have LED drivers and the accompanying datasheets and ap notes to support them. Also go to Digikey, and search, almost 7000 you can look at ...
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    Transistor amplifier circuit

    Actually you can reverse connect emitter and collector on transistors and get different results. For example on many this will allow one to achieve lower Vcesat on some devices, when operated as a switch. So we are al trying to look at this as a Darlington, but I would ask is there another...
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    Looking for a specific light-activated switch (12V DC)

    Detection of light could occur within mS of turn on. Driving a solenoid that can push handset up < 100 mS a little challenging, due to inertia and force required. You would need some experimentation. I can see a wall wart supply fine for application. Could be done with a ATTINY85 type solution...
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    AOCJY2 10 MHz OCXO time source

    Strictly for future reference, this is a single chip solution for 64 bits, could have been at least 128 bit counter if so desired. You drag and drop components (a "component" is an onchip resource) onto design canvas, wire up (with a wizard) to other components and out to pins, and provide some...
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    The LM317 Adjustable Voltage Power Supply kit

    https://www.aliexpress.us/item/3256801745127408.html?spm=a2g0o.productlist.0.0.6713602bRSjINL&algo_pvid=1914bc59-5a0d-477b-a90c-8ab579efe197&algo_exp_id=1914bc59-5a0d-477b-a90c-8ab579efe197-2&pdp_ext_f=%7B%22sku_id%22%3A%2212000018141641708%22%7D&pdp_npi=2%40dis%21USD%2111.03%2111.03%21%21%21%21%...
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    The LM317 Adjustable Voltage Power Supply kit

    What kit ? No links or docs or description.....
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    Logic GAtes

    Overkill for specific OP problem yes, informative for OP for future stuff possibly not. After all hard to beat a protoboard and a pile of parts in one chip for learning, testing out ideas....... Regards, Dana.
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    Logic GAtes

    A little more adventuress, use a chip with cut and paste resources internal to it. Here are 3 different solutions, all using chips internal resources, to do your problem. In this case its a codeless design, you just hit build button after you drag and drop onto canvas various resources and...
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    Logic GAtes

    Another way of doing this is with a simple micro and program it with block language Use a 8 PIN ATTINY85 to do the job. This of course is not basic logic elements so there is a small delay in processing the code. The program, mBlock, is free, it generates Arduino code from your block...
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    Help needed to build a Simple radio to generate a tone

    Is problem origin the actual UHF radio or ambient noise levels ? If latter you could do a simple tone burst over mic circuit and use a tone detector on other end. https://www.codrey.com/electronic-circuits/tiny-tone-decoder-module/ https://midians.com/signaling-encoders-and-decoders/...
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    Simple delay on

    We had a computer onboard. Used carefully characterized components in circuits. Used to have lab standards to measure against...
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    Simple delay on

    Would ballpark timing in the 100's of % be fine ? Thats what you get with 555 timers over T and V and Bulk cap tolerances. Datasheet very misleading as it shows its timing with a relatively small cap, .1 uF, not a bulk electolytic type cap whose intial tolerance can be in the 100's of %...
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    Simple delay on

    What is the accuracy you want for the timing, delays, events ? Room temperature application or wide environmental temperature operation ? Do you care about power up / down glitches ? Is the trigger source mechanical contacts, that would need debouncing to generate a clean valid trigger signal...
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