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  1. Alec_t

    Stepping down speaker input to line level

    Are these powered and amplified speakers, or just naked speakers?
  2. Alec_t

    Electronics Design Process

    Research is definitely a first step. From working with Patents (a good source of technical information) I know that the vast majority of invented products/circuits are not totally novel but are developments of existing technology. Therefore, whatever you are designing, there is a high...
  3. Alec_t

    Low frequency

    If you have to ask that question, and given your assumption that a resistor will do the job, I would strongly advise you for safety reasons not to mess with 230V systems. Converting from 20MHz to 50Hz would not be trivial. What is the source of this 20MHz signal/power? Where did you see it? Some...
  4. Alec_t

    playing around with a current sink.

    Can you show where/how you are applying the 8V and where the 100 Ohm load is connected?
  5. Alec_t

    Hope I didn't make too big a mistake with my radio...

    Without a schematic it's anyone's guess as to how best to do the conversion. But is the conversion worthwhile? Most transistor radios have only a modest output level and are far from hi-fi.
  6. Alec_t

    Thermistor

    I agree it looks like a zero-Ohm jumper. The 'J1' marking on the board is a clue. Perhaps it was intended to act as a fuse?
  7. Alec_t

    Transistor LED circuit_LED not blinking

    The current through the capacitor is negligible compared to the transistor collector current, so significant LED current flows only when the associated transistor is switched on.
  8. Alec_t

    555 output to transformer failure

    Oops. Don't know why I saw an extra factor of 10 there. And I hadn't touched a drop :).
  9. Alec_t

    Component used to measure weight?

    There are safety implications here, so absolute reliability of the measurements would be essential. A mis-count could result in injury/death if the firer assumed the magazine was empty when in fact it wasn't.
  10. Alec_t

    555 output to transformer failure

    You are trying to step the voltage up by a factor of 4 x 10 = 400. For 2mA output, that reflects to a 800mA primary current. No way can a tiddly 9V battery with a 40 Ohm internal resistance provide 800mA :(.
  11. Alec_t

    Component used to measure weight?

    Welcome to EP! How do the objects arrive in the box? By conveyor, hand-delivered, ....? Roughly how big/heavy are the objects? Are all the objects the same weight? What measurement accuracy is needed? Couldn't you just use an off-the-shelf electronic scales?
  12. Alec_t

    RC Time Constant

    You forgot the '5'.
  13. Alec_t

    Bee venom collecting device

    U2a is an oscillator with a 1S on, 2S off output. U2b is a 1kHz oscillator which is gated (turned on/off) by the output of U2a. Here's a simulation result with U2a speeded up by a factor of 100 (10mS on, 20mS off) just for showing the gating action more clearly :-
  14. Alec_t

    voltage and current relationship for capacitor?

    Currrent I = dq/dt (rate of change of charge) and charge change dq = C*dV (where C is the capacitance and dV is the change in voltage on the capacitor). So if you know I and C you can calculate dV/dt.
  15. Alec_t

    how tolerant is USB?

    USB devices vary in tolerance. I have one mouse which works fine on 5m of cable, whereas another mouse doesn't.
  16. Alec_t

    Help with identifying resistor - yet again

    I know that.;). Analyse the band colour with Photoshop. R component dominates; G and B components are about equal and only half the R component. For orange, the G component would be markedly greater than the B component. R31 may not even come from the same manufacturer, so paint colours may vary.
  17. Alec_t

    Transistor LED circuit_LED not blinking

    Agree with Bob; that is NOT an oscillator circuit.
  18. Alec_t

    Need some documentation regarding Assembly Process??

    I note you are in India, but I expect that even if the standards you are considering exist they will vary from country to country. Are you interested only in Indian standards?
  19. Alec_t

    Bee venom collecting device

    Something like this? Output voltage is adjustable from 12V to ~34V. Output current of the 1kHz bursts is limited to <35mA.
  20. Alec_t

    Buck operation using IR2117 gate driver

    Oops. You're right.
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