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  1. AnalogKid

    12v relay with time delay and reverse polarity

    https://www.electronicspoint.com/threads/changeover-switch-relay.276138/ CDRIVE's output stage in post #24 was one possible solution for that question, and is perfect for this one. ak
  2. AnalogKid

    12v relay with time delay and reverse polarity

    Actually, the description in post #1 is perfectly clear. The relay reversing output part just went by in another thread in Circuit Help. One solution would be a CD4093 or CD40106 making two monostables (non retriggerable) in series, each one driving a SPDT relay. Note - this circuit needs...
  3. AnalogKid

    Switch to override "Clapper"

    Two things. First, there is a TRIAC switch for each outlet, and these usually switch a hi-side load to ground or neutral. So the identification of the hot and cold AC leads might be reversed. Second, without power to the electronics, what energizes the TRIACs for always-on operation? ak
  4. AnalogKid

    How to switch something as soon as power is applied

    Assuming this is a low power function such as a switch into a uC that then controls the engine, then: 1. Small reed relay across the switch with a capacitor in series with the coil. 2. Optocoupler across the switch with a resistor and capacitor in series with the LED. This is for when the...
  5. AnalogKid

    12v Fan Reduce speed in every minute interval using 555 timer.

    OTOOH, the OP has a total of 7 posts, 5 in this thread. If he is as new to forums as he is to electronics, he would need to read your mind in order to read Colin's. Double scarey. ak
  6. AnalogKid

    12v Fan Reduce speed in every minute interval using 555 timer.

    A side question - did you consider, for even one millisecond, including a link? ak
  7. AnalogKid

    Turning supercapacitors into batteries

    Years ago, Coleman (of all people) introduced a cordless screwdriver with supercaps in the handle instead of nicads. It didn't have as long a runtime as the standard Skil model, but it went from dead to full charge in 90 seconds. ak
  8. AnalogKid

    Turning supercapacitors into batteries

    No. How many? ak
  9. AnalogKid

    DA converter

    If that is your whole understanding, then you don't understand anything about electronics, let alone what has been explained. The specific case of converting an analog signal to a digital representation so it can be "processed" is a trivial fraction of the entire world of electronics. See my...
  10. AnalogKid

    Need someone to design and make a basic circuit (UK)

    Hold off on the panel meters; the tech description does not match the title. Hand holding is what this forum does. We get cranky when someone tries to get their homework done for free, but other than that a decent question gets a decent answer. Diodes and misc stuff will have to wait - I'm...
  11. AnalogKid

    Need someone to design and make a basic circuit (UK)

    http://www.ebay.com/itm/6-35V-to-1-35V-DC-DC-Buck-Boost-Charger-Power-Converter-Module-With-Aluminum-HG-/281746577986?hash=item4199679a42:g:ITgAAOSwjVVVoPRG Two of these look like a good starting point. From your point of view, they take anything in and make anything out. Under worst case...
  12. AnalogKid

    Electric arcs and spark gaps: Are they active or passive devices?

    Passive. An active device uses energy from one source to control energy from another source. Not necessarily amplify it, although it almost always is the case that a low energy control signal can activate a solid stage switch controlling a much higher energy level, and this could be considered...
  13. AnalogKid

    12v Fan Reduce speed in every minute interval using 555 timer.

    Really? We go through a few thousand a year and they're pretty much dumb as dishwater. ak
  14. AnalogKid

    Need someone to design and make a basic circuit (UK)

    Much better. What are the peak and average (if different) currents for the two sockets and the two lines to the housing. Also, are the sockets labeled correctly? You have the 24 V Socket connected to 12v+ Out. The most efficient way will have two independent regulators. The 24 Vin has a 12...
  15. AnalogKid

    synchronous binary counter question

    Th 4520 is a DUAL 4-bit binary counter. You string the two halves together by connecting the Q4 output of one half to the clock input of the other half to create a single 8-bit counter. Note that each 4520 on the schematic has two clocks, two Q1's, etc. From the text above the schematic...
  16. AnalogKid

    Need someone to design and make a basic circuit (UK)

    I tried to sketch the interconnects based on post #1 and got lost. Can you sketch what goes where? ak
  17. AnalogKid

    Help with a Design

    1. Yes. 2. Probably. Many people will not want to download and install this program just to read your output files, so post your schematics as either a PDF or as a graphics file (JPG, GIF, PNG, etc.). ak
  18. AnalogKid

    type of diode/protection

    A SPDT relay with a 6 Vdc coil. Power the coil off whichever source you want to power things when both sources are connected (we'll call it the primary). When the primary source is removed, the relay will drop out and whatever is connected to the NC contact will run things until the primary...
  19. AnalogKid

    12v Fan Reduce speed in every minute interval using 555 timer.

    To go from full speed to off in 1 minute you gradually reduce the energy available to the fan. There are two basic ways, analog and digital. Analog means a voltage regulator where either a control voltage is decreased slowly or the negative feedback that establishes the output value is changed...
  20. AnalogKid

    Disadvantage of several capacitors in parallel in a power supply?

    10,000 uF is awfully big for running a 5 V fan, but as long as the minimum voltage rating among the caps is greater than the peak voltage across them, no problem. And there is no problem with the caps being different values. ak
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