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  1. D

    Decade counter to Momentary relay?

    Doing a sim takes crazy values to get a "normal" button push delay, eg. 1 sec. Cant raise the R significantly, like to 1 Meg, because of putting transistor in sat. Dashed curve 100 uF, solid 1 milifarad. Relay modeled as 100 ohms, 10 mH. Could raise the R by using darlington, or move to...
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    Decade counter to Momentary relay?

    Web seems to discuss problems, causes, and solutions for this. I have seen it happen because of power source transient circuit response problems. Here of course we are talking about slow rise/fall time of a C based timing problem. Like users who like feeding slow C based Tr/Tf into CMOS and that...
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    Decade counter to Momentary relay?

    Your relay drive circuit should look like this : Transistor can be either Bipolar or MOSFET. Regards, Dana.
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    Decade counter to Momentary relay?

    The problem with the C approach is possible relay chatter when the cap decays and passes thru relay holding current minimum. And the button that advances the 4017 not being debounced. And you have power on issues / glitches that can occur. A simple approach use an Arduino Nano (~ $3) and mBlock...
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    I need some advice on the operation and programming of Infineon SLE78, Atmel ATA5577M1 microcontrollers/chips.

    Consult Microchip, they have a design consulting services program you can get a list of consulting companies providing services. Regards, Dana.
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    High Voltage Direct Current

    Nuclear fusion a nasty business, waste byproducts and half life's associated with radioactive decay materials. And a rich history already with polluted areas no longer discussed, Washington, Idaho..... Back to bicycles ? Humans versus volcanoes, lets not talk about Tetra Giga Biga tons of...
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    Need help to identify a MOSFET.

    What is the function of the mosfet being used for, the circuit it is in, what does it do ? Generally you look for similar - Vds breakdown, Idrain max, gate charge or capacitances, Rdson, package thermal R..... Regards, Dana.
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    Basic Announciator

    Is the numeric written to 7 seg display held when next display is updated ? What is the value of the numeric represent ? What generates its value ? This whole design cries out for a simple processor solution, like Arduino. And use block language on it, an example you can look at ...
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    LCD voltmeter for my power supply

    The protective diodes Kiwi recommended on yellow line should look like this (lower left) and for red (upper right) : You can omit the 100K to ground for yellow circuit if you are concerned about the small error it creates as a V divider on the yellow input. Leaving it in - Vyellow = (.99 X...
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    Need help in converting a 12VDC 16.5A PSU to +-17.5VDC 2A PSU

    https://usa.banggood.com/2-in-1-8W-3-24V-to-5V-6V-9V-10V-12V-15V-18V-24V-Boost-Buck-Dual-Voltage-Power-Supply-Module-for-ADC-DAC-LCD-OP-AMP-Speaker-p-1535929.html?cur_warehouse=CN&ID=510351&rmmds=search You possibly could change out one of the Rs to get 17.5 V..... Regards, Dana.
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    LCD voltmeter for my power supply

    Post a pic of backside connector and any labels on PCB next to connector pin. Regards, Dana.
  12. D

    design a limiter circuit

    Here is one of the clamps : Not sure yet how to do the other clamp.....:) Regards, Dana.
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    design a limiter circuit

    If you look at limitations : I would tackle the 2'ond item first. Than add the clamps, item 1 and 3. Break the design into parts and solve the parts sequentially so's to speak. Direct hint, you need to map one range into another on item 2. A way of doing that is : Hint let R3 = infinity...
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    Power Isolation

    Could be MOSFET gate drivers are supplying gate current via 5V supply ? How much current are you seeing ? Any scope screen captures of micro power rail ? Regards, Dana.
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    Can anyone help me please for this

    Capacitor klooks like it is bulkging, maybe shorted internally...... And obviously the resistor needs replacement. And the transistor checked. Regards, Dana.
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    Magnetic field and how it is dangerous

    https://ehs.psu.edu/sites/ehs/files/magnetic_field_safety_guide_v5_2017.doc#:~:text=Routine%20occupational%20exposures%20should%20not%20exceed%20600%20mT%20(6000%20G,8%20hr%20time%20weighted%20average.&text=A%20maximum%20ceiling%20(i.e.%20maximum,5%20T%20for%20the%20extremities...
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    Voltage Converter - Electric Heater Project

    Go to youtube and search "diy dc heater" and look for something suitable. https://www.youtube.com/results?search_query=diy+dc+heater Regards, Dana.
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    Hardware issues

    You might be experiencing triigered parasitic scr problem in CMOS : https://www.ti.com/lit/wp/scaa124/scaa124.pdf Regards, Dana.
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    Testing of currents

    A quick and dirty way is use a JFET like a J109, operate it as current source, and use a R to develop the V from the current. See this book, section starting on page 233 for current source application...
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    Decoding Chinese UART Protocol

    If you have a scope with UART decode capability you can typically look at the stream as ASCII or binary, and capture it for further examination. Typically data like that has a frame sequence of some sort that essentially allows receive end to complete the protocol. Regards, Dana.
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