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  1. Alec_t

    Touch activated circuits

    A voltage source with a series resistance of <100meg works fine as a trigger on pin 2, using the default 555 model in LTspice. But the model is an idealised one. I'm not familiar with Yenka and haven't a clue how accurate its models are.
  2. Alec_t

    Yamaha RX-V470 Fail To Power Up

    If there are any multi-way connectors to the circuit board give them a wiggle and make sure they are seated firmly. If the unit has been in storage for a long time a connection may have oxidised.
  3. Alec_t

    Need help building a push switch box with indicator light

    I'd call it a momentary-on switch. Here are some DPDT examples, listed as 'On-Mom'.
  4. Alec_t

    Touch activated circuits

    Can you post the schematic of your circuit, using the 'Upload a file' button?
  5. Alec_t

    Sensor choice for pond water depth

    Capacitive sensor?
  6. Alec_t

    Need help building a push switch box with indicator light

    If those are internal connections it sounds like the switch is effectively a single-pole type.
  7. Alec_t

    Touch activated circuits

    Depends on how the touch is sensed. As a potential difference, capacitance change or resistance change? Welcome to EP!
  8. Alec_t

    Need help building a push switch box with indicator light

    If you use a double-pole switch of appropriate rating you can use one pole to switch the main function and the other pole to switch an indicator light.
  9. Alec_t

    In search of a brain...

    The magnetic pull would be very weak when the arm is away from wall, so I don't see that working well. Better perhaps if the lever were held against the wall initially, by the maximum pull of a stationary magnet, and then pulled away by a spring when the magnet moved?
  10. Alec_t

    ESC and Motor using Variable Power supply

    Depends on the supply characteristics, also the ratings of those other things.
  11. Alec_t

    Flashing 12v To Constant

    That too would be illegal in Europe I believe. Is it legal in the US? Why would you want to do this? Sounds dangerous to me, since if you were stopped, waiting to turn into a side road, with no brake light showing you would be less visible to any motorist coming up behind you :eek:.
  12. Alec_t

    In search of a brain...

    Now that we know you need a holding force of 20N. that makes sense. A reed switch inside the enclosure could acivate the servo shown in your pic.
  13. Alec_t

    In search of a brain...

    I'm thinking string attached to tiny rare earth magnet one side of wall , soft iron magnet keeper on opposite side of wall, current pulse through coil around keeper to release. How much tension in the string before release?
  14. Alec_t

    Circuit Element for variable current control

    If your load is variable and not under your control then you can make a constant current flow through it OR you can apply a constant voltage across it. You can't do both at the same time.
  15. Alec_t

    Circuit Element for variable current control

    Now that we have more info about the load it does indeed seem that a voltage regulator may be better suited to this project.
  16. Alec_t

    7809 not outputting 9v

    You don't seem to have a ground (-V) connection to the IC?
  17. Alec_t

    Circuit Element for variable current control

    M1 is a MOSFET. R2 is a low value resistor in series with M1 and the Load (here 1Ω) and develops a voltage proportional to the load current (which is common to all three). This voltage is compared, by opamp U1, to an adjustable reference voltage which is tapped off by potentiometer U3 across a...
  18. Alec_t

    Circuit Element for variable current control

    Something like this maybe?
  19. Alec_t

    7809 not outputting 9v

    Welcome to EP! It's always advisable to read the datasheet for components you use. Here's how the IC should be wired.
  20. Alec_t

    Optimus CD-7200 Missing Lens

    You've nothing to lose by trying. Even a drop of clear superglue would naturally form a lens shape and might suffice.
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